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1
Brand, Mariette Rieks. "Pollination ecosystem services to onion hybrid seed crops in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86238.
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Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Insect pollination contributes in various degrees toward the production of a variety of agricultural crops that ensure diversity and nutritional value in the human diet. Although managed honeybees (Apis mellifera L.) are still the most economically valuable pollinators of monoculture crops cultivated globally, wild pollinator communities can contribute substantially toward crop pollination through pollination ecosystem services sourced from neighbouring natural habitats. Pollination ecosystem services are thus valuable and can motivate for the protection of natural ecosystems hosting diverse insect pollinator communities. F1 onion hybrid seed production is entirely dependent on high insect pollinator activity to ensure cross pollination, seed set and profitable seed yields. Data was collected on 18 onion hybrid seed crops grown in the semi‐arid Klein Karoo and southern Karoo regions of the Western Cape, South Africa. These two main production regions are located within the Succulent Karoo biome, recognized as a global biodiversity hotspot of especially high plant diversity. It is also habitat to the indigenous Cape honeybee (Apis mellifera capensis Esch.). Sites selected varied in the percentages of available natural habitat and managed honeybee hives stocking density. Diverse anthophile assemblages were sampled with pan traps within all the onion fields, regardless of the percentage of available natural habitat near the crop. Crop management practices significantly affected the diversity of anthophile species caught within onion fields, although less than 20% of this diversity was observed actually visiting onion flowers. The honeybee (managed and wild) was by far the most important pollinator because of its high visitation frequency and regular substantial onion pollen loads carried on their bodies. Honeybee visitation significantly increased onion hybrid seed yield, while anthophile diversity and non‐Apis visitation had no effect on seed yield. Neither managed hive density, nor percentage natural habitat were important in determining honeybee visitation or seed yield. Total annual rainfall was the only significant factor determining honeybee visitation. Secondary factors caused by rainfall variability, such as wild flower abundance or soil moisture, may have significantly affected honeybee visitation. In addition, the positive correlation between honeybee visitation and the diversity of hand‐sampled insects from onion flowers; indicate that either or both onion varietal attractiveness and/or pollinator population size may have had significant effects on overall insect visitation. Honeybees showed marked discrimination between hybrid onion parental lines and preferred to forage on one or the other during single foraging trips. Hybrid onion parents differed significantly in nectar characteristics and onion flower scent which would encourage selective foraging through floral constancy. Interspecies interactions were insignificant in causing increased honeybee pollination because of the scarcity of non‐Apis visitors. Most farming practices are subjected to favourable environmental conditions for successful production. However, and especially in the South African context, the dependence of onion hybrid seed crops on insect pollination for successful yields, increase its reliance on natural ecosystem dynamics that may deliver abundant wild honeybee pollinators, or attract them away from the crops. Nevertheless, this dependence can be mitigated effectively by the use of managed honeybee colonies to supplement wild honeybee workers on the flowers.
AFRIKAANSE OPSOMMING: Insek bestuiwing dra in verskillende grade by tot die produksie van landbou gewasse wat variteit en voedingswaarde in die mens se dieet verseker. Al is die heuningby (Apis mellifera L.) steeds die waardevolste ekonomiese bestuiwer van verboude enkelgewasse, kan wilde bestuiwers wesenlik bydra tot gewasbestuiwing deur middel van ekosisteem dienste afkomstig van natuurlike habitatte. Bestuiwing ekosisteem dienste is daarom waardevol en kan dus die bewaring van natuurlike ekosisteme, wat diverse gemeenskappe huisves, regverdig. F1 basterui saadproduksie is totaal afhanklik van hoë insek‐bestuiwer aktiwiteit om kruisbestuiwing, saadvorming en winsgewende saadopbrengste te verseker. Data is ingesamel op 18 basterui saad aanplantings in die half‐droë Klein Karoo en suid‐Karoo streke van die Weskaap, Suid‐Afrika. Hierdie twee hoof produksie streke is geleë binne die Sukkulente Karoo bioom wat erken word as ʼn globale biodiversiteits “hotspot” met hoë plant diversiteit. Dit is ook die habitat van die inheemse Kaapse heuningby (Apis mellifera capensis Esch.). Aanplantings is gekies om verskillende grade van beskikbare natuurlike habitat en bestuurde heuningby korf digthede te verteenwoordig. Diverse versamelings blom‐besoekers is versamel met water‐wippe in al die aanplantings, ongeag die persentasie natuurlike habitat beskikbaar by elke aanplanting. Gewas bestuurspraktyke het die diversiteit van blombesoekers betekenisvol beïnvloed. Tog is minder as 20% van hierdie diversiteit as aktiewe besoekers op die uiekoppe waargeneem. Heuningbye (bestuur of wild) was oorwegend die belangrikste bestuiwers as gevolg van hoë besoek frekwensies en wesenlike ladings uiestuifmeel op hulle liggame. Heuningby besoeke het saadopbrengs betekenisvol verhoog, maar blom‐besoeker diversiteit en nie‐Apis besoeke het geen effek op saadopbrengs gehad nie. Bestuurde korf digtheid en persentasie natuurlike habitat was nie belangrik in die bepaling van heuningby besoeke of basterui saadopbrengste nie. Totale jaarlikse reënval was die enigste betekenisvolle faktor wat heuningby besoeke bepaal het. Sekondêre faktore wat versoorsaak word deur reënval veranderlikheid, soos veldblom volopheid of grondvog, kon betekenisvolle effekte op die aantal heuningby besoeke gehad het. Bykomend, dui die positiewe korrelasie tussen heuningby besoeke en die diversiteit van hand‐versamelde insekte vanaf die uiekoppe op die moontlike betekenisvolle effek van elk of beide basterui variteit aantreklikheid en/of bestuiwer populasie grote op algehele insek besoeke. Heuningbye het noemenswaardige diskriminasie getoon tussen die basterui ouerlyne en het verkies om op een of die ander te wei tydens enkele weidingstogte. Basterui ouerlyne het betekenisvol verskil in nektar eienskappe en blomgeur wat die selektiewe weiding van heuningbye, toegepas deur blomkonstantheid, sal aanmoedig. Tussen‐spesie interaksies was onbetekenisvol in die verhoging van heuningby bestuiwing omdat nie‐Apis besoekers baie skaars was. Meeste boerdery praktyke is onderhewig aan gunstige omgewings toestande vir suksesvolle produksie. Maar, en veral in die Suid‐Afrikaanse konteks, omdat basterui saad aanplantings afhanklik is van insek bestuiwing vir suksesvolle opbrengste, word daar meer staat gemaak op natuurlike ekosisteem dinamika wat volop wilde heuningby bestuiwers kan voorsien, of selfs bestuiwers van die aanplanting kan weg lok. Nietemin, hierdie afhanklikheid kan effektief verlaag word deur die gebruik van bestuurde heuningby kolonies om die aantal wilde heuningby werkers op die blomme aan te vul.
2
Sheldon, Bonita Joy. "Heavy metal uptake and accumulation in agricultural crops in urban areas of the Western Cape." Thesis, Cape Peninsula University of Technology, 2005. http://hdl.handle.net/20.500.11838/2006.
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Thesis (MTech (Physical Sciences))--Cape Peninsula University of Technology, 2005.A research study into heavy metals in the Cape Town area, found significant amounts of potentially toxic metals such as lead, cadmium, chromium and iron leaching into the underground aquifer. A further additional study conducted on a community garden in Khayelitsha, showed that vegetable crops have the tendency to accumulate certain heavy metals if they are present in soil and water resources. This study was centered around the Philippi Horticultural Area, which is a large significant farming area within the Cape Metropolitan Region. The significance of the study lies in the fact that at least 50% of the local farmers' produce is sold directly to street traders, residents, local supermarket-chains and restaurants. The remainder of the produce is sold at the Epping Market. The purpose of this study was to investigate heavy metal accumulation in various vegetable crop species taken from some of the local farms in the Phillipi Farming area with the objective to: • investigate heavy metal accumulation in various vegetable crop species taken from some local farms in the Phillipi Farming area. • determine the concentrations of heavy metals present in water and soil resource since these will be the primary source of heavy metals to the vegetables. • determine the soil pH and soil organic matter as these two factors would determine the bie-availability ofthe heavy metals. • identify those crops that pose a definite health risk by means of comparing the determined results to the allowed limits.
3
Rentel, Monique. "Morphology and taxonomy of tortricid moth pests attacking fruit crops in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/79825.
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Thesis (MScAgric)--Stellenbosch University, 2013.ENGLISH ABSTRACT: Cydia pomonella (codling moth), Thaumatotibia leucotreta (False codling moth), Thaumatotibia batrachopa (Macadamia nut borer), Grapholita molesta (Oriental fruit moth), Cryptophlebia peltastica (Litchi moth), Epichoristodes acerbella (Pear leafroller/Carnation worm) and Lozotaenia capensana (Apple leafroller) are the most economically important tortricids affecting various crops in South Africa. The correct identification of these species, especially of the larval stage, is of great importance in pest management. Using available literature, augmented by additional morphological studies, an interactive identification key (Lucid key) for larval and adult stages of the seven species was developed. The colour and markings of the head, characteristics of the prothoracic and anal shields, the position of the prespiracular setae (L-group) relative to the spiracle on the prothoracic segment, the position of the spiracle on the eighth abdominal segment and L-group on the ninth abdominal segment, as well as the presence or absence of the anal comb are key characteristics for larval identification. For adult identification, wing pattern and genitalia are the most important features. However, the use of genitalia for moth identification might be difficult for the lay user, as the dissection and mounting of these structures requires certain skills and specialized equipment. Thus, genitalia have not been included in the Lucid Key. Differences in the morphological characteristics of most pupae were so minute that this stage was also not included in the Lucid key. However, the pupae of E. acerbella and L. capensana are easily distinguished from those of the other species by the presence of acremaster. This study also included the first morphological description of the pupa of L. capensana, which can be distinguished from that of E. acerbella by various features of the cremaster, antennae, spiracle shape, number of setae on abdominal segments A5-7, the size of spines on A3-7, and the presence/absence of spines on A9. A previous study by Timm (2005) indicated that geographically isolated populations of T. leucotreta tend to be genetically distinct. This raised the question of whether speciation/subspeciation has occurred or is occurring. Male moth genitalia are thought to evolve rapidly and are often the only features that can reliably distinguish similar species. Hence, variation in the shape of the valvae of T. leucotreta was used to determine whether divergence has occurred between populations of T. leucotreta. Elliptical Fourier analysis was used to analyze the valvar variation in three different populations. Although some variation in valvar shape was detected among mean population values for certain traits, no clear pattern emerged. Principle component analysis also showed no distinct clustering of valvae shape among populations, providing no evidence for divergence in male genitalia and therefore no morphological evidence of incipient speciation.
AFRIKAANSE OPSOMMING: Cydia pomonella (Kodlingmot), Thaumatotibia leucotreta (Valskodlingmot), T. batrachopa (Makadamianeutboorder), Grapholita molesta (Oosterse vrugtemot), Cryptophlebia peltastica (Lietsjiemot), Epichoristodes acerbella (Peerbladroller/Angelierrusper) en Lozotaenia capensana (Appelbladroller) is die mees ekonomies belangrike tortrisiede van die vrugtebedryf in Suid-Afrika. Die juiste identifikasie van hierdie spesies, veral van hulle larwale stadium, is van groot belang by plaagbestuur. Deur gebruik te maak van beskikbare literatuur, aangevul deur bykomstige morfologiese studies, is ‗n interaktiewe uitkenningssleutel (―Lucid key‖) vir die larwale en volwasse stadia van die sewe spesies ontwikkel. Die kleur en tekening van die kop, kenmerke van die prothorakale en anale skild, die ligging van die prespirakulêre setae (L-groep) relatief tot die spiraculum op die prothorakale segment, die ligging van die spirakulum op die agste abdominale segment en L-groep op die negende abdominale segment, asook die aan- of afwesigheid van die anale kam is sleutel kenmerke vir larwale uitkenning. Vir die volwassenes is die vlerktekening en genitalia die mees belangrike kenmerke. Die gebruik van die genitalia vir motuitkenning kan egter vir die leek gebruiker moeilik wees omdat die disseksie en montering van hierdie strukture bepaalde vaardighede en gespesialiseerde toerusting vereis. Vir die rede is die genitalia nie in die Lucid-sleutel ingesluit nie. Verskille in die morfologiese kenmerke van meeste papies is klein en die stadium is gevolglik ook nie in die sleutel ingesluit nie. Die papies van E. acerbella en L. capensana kan egter maklik van die ander spesies onderskei word deur die aanwesigheid van ‗n cremaster. Hierdie studie sluit ook die eerste morfologiese beskrywing van die papie van L. capensana in, wat van dié van E. acerbella onderskei kan word deur gebruik te maak van kenmerke van die cremaster, antennae, spirakulêre vorm, aantal setae op abdominale segmente A5-7, die grootte van stekels op A3-7, en die aan- of afwesigheid van stekels op A9. ‗n Vroeëre studie (Timm 2005) het aangedui dat geografies geïsoleerde bevolkings van T. leucotreta neig om geneties verskillend te wees. Dit het die vraag laat ontstaan of spesiasie/subspesiasie moontlik plaasgevind het of steeds plaasvind. Manlike mot genitalië word geag om vinnig te ontwikkel en is dikwels die enigste kenmerke wat betroubaar tussen soortgelyke spesies kan onderskei. Dus is die variasie in die vorm van die valvae van T. leucotreta gebruik om te bepaal of divergensie wel tussen bevolkings van T. leucotreta plaasgevind het. Elliptiese Fourier ontleding is gebruik om die valvae se variasie by drie verskillende bevolkings te ontleed. Alhoewel enkele variasie in die vorm van die valvae bespeur is by die gemiddelde bevolkingswaardes vir bepaalde eienskappe, kon geen duidelike patroon bespeur word nie. Hoofkomponentontleding het ook geen duidelike groepering van valvae se vorm tussen bevolkings getoon nie, wat geen bewys lewer van divergensie in die manlike genitalia en dus geen morfologiese bewys van beginnende spesiasie.
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Manamathela, Sibongile Amelia. "The water footprint of selected crops within the Olifants/Doorn Catchment, South Africa." University of the Western Cape, 2014. http://hdl.handle.net/11394/4751.
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>Magister Scientiae - MScRapidly increasing global population is adding more pressure to the agricultural sector to produce more food to meet growing demands. However the sector is already faced with a challenge to reduce freshwater utilisation as this sector is currently using approximately 70% of global water freshwater resources. In South Africa, the agriculture sector utilizes approximately 62% of freshwater resources and contributes directly about5% to the Gross Domestic Product. South Africa is a water scarce country receiving less than 500mm/year of precipitation in most parts of the country, and consequently approximately 90% of the crops are grown under irrigation. Studies have evaluated irrigation practices and crop water use in the country. However information is lacking on the full impact of South African horticultural products on freshwater resources. The water footprint concept can be used to indicate the total and source (blue/green) of water used to produce the crops. Information about water footprint (WF) can be used for identifying opportunities to reduce the water consumption associated with production of vegetables and fruits at the field to farm- gate levels, including the more effective use of rainfall (green water) as opposed to water abstracted from rivers and groundwater (Blue water). It can also be used to understand water related risks associated with the production of crops and facilitate water allocation and management at catchment/water management scale. While the potential value of water footprint information is well recognized there is still inadequate knowledge on how best to determine the water footprints of various crops within a local context. The aim of this study was to determine the water footprint and the crop water productivity of navel oranges, pink lady apples and potatoes produced with the Olifant/Doorn water management area in South Africa.The water footprint of the navel oranges, pink lady apples and potatoes assessed following the water footprint network method was 125 litres/ kg, 108 litres/kg and 65 litres/ kg respectively. The study concluded that water footprint studies should be carried out on the whole catchment instead of one farm in order to assess the sustainability of the process.
5
Morgan, John (John Idwal). "Evaluating the returns to research on a project level : cover crops in the South African wine industry." Thesis, Stellenbosch : Stellenbosch University, 1999. http://hdl.handle.net/10019.1/51261.
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Thesis (MScAgric)--Stellenbosch University, 1999.ENGLISH ABSTRACT: The purpose of the study is to determine the rate of return to cover crop research in the wine industry. The method followed will prove an invaluable contribution toward the need to determine a suitable approach for evaluation studies. The importance behind such a study is the development of appropriate ex ante evaluation approaches, which will assist in the allocation of public research resources in both a social and economical manner. The wine industry is currently enjoying healthy international demand, but will need to remain competitive to reap the full benefit of international exposure. The need therefore exists for a continuation of research at the institutional level, in order to maintain the progressive nature of research knowledge that was available in the past. The evaluation of ex post and ex ante research will assist in maintaining government funding for research and help with campaigning for private investment of research in the wine industry. The use of two evaluation approaches was used for the analysis. Firstly, the production function approach achieved a rate of return of 44 percent, using weather and research expenditure as a means to explain the variations in wine grape yield. Secondly, a cost benefit approach was devised in order to make a direct comparison between the cost and benefits related to the cover crop research. The rate of return achieved for this mode of analysis is 37 percent, using trial plot data as a source of information on potential benefits. In addition to this the cost benefit approach was used to show the difference in rate of return that is achievable between two growing regions. The variable that exists between the two regions, is the higher rate of irrigation in one of the regions. The high rate of return achieved for the investment, provides suitable motivation for the increase in state funding for research in the wine industry, and provides valuable information for the enticement of support by private investors. The two methods used in the study will both draw a certain amount of criticism, largely as a result of the lack of available data. The empirical nature of the approaches is however simple and applicable down to the project level.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie is om die opbrengs op navorsing oor dekgewasse in die Suid- Afrikaanse wynbedryf te bepaal. Hierbenewens het die studie dit ook ten doel om gepaste metodieke vir die evaluering van navorsingsprojekte daar te stel. In hierdie opsig maak hierdie studie ' n bydrae tot besluitneming oor die allokering van openbare fondse vir landbounavorsing op 'n ekonomies en sosiale optimale wyse. Die Suid- Afrikaanse wynbedryf beleef tans ' n bloeifase, hoofsaaklik as gevolg van sterk internasionale vraag na sy produkte, maar salop sy internasionale mededingendheid moet let indien die volle voordele hiervan benut kan word. Daarom is dit noodsaaklik dat die bedryf op tegnologiese gebied moet kan meeding, en dus dat navorsingsbesteding nie onoordeelkundig ingekort word rue. Inligting oor die opbrengs op navorsingsbesteding is dus noodsaaklik om die volgehoue betrokkenheid van die staat te kan regverdig, hetsy as finansier of as katalisator vir privaatsektor betrokkenheid. In hierdie studie is die opbrengs op navorsing gemeet deur beide die bekende produksiefunksie benadering sowel as deur koste-voordeel ontleding. In die eerste geval is 'n opbrengskoers van 44% gemeet, en in die tweede geval is dit 37%. By die kostevoordeel ontleding is ook 'n verdere onderskeid gemaak tussen twee wynbou-streke om die invloed van meer besproeiing te bepaal. Ten spyte van dataprobleme, veral wat betref die koste van navorsing, kan beweer word dat die inligting so verkry van nut sal wees vir besluitnemers by die toekenning van skaars navorsingsfondse, asook by bedinging om privaatsektor fondse.
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Maali, Safiah Hasan. "Biomass production, yield and quality response of spring wheat to soil tillage, crop rotation and nitrogen fertilisation in the Swartland wheat producing area of South Africa." Thesis, Stellenbosch : University of Stellenbosch, 2003. http://hdl.handle.net/10019.1/949.
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Thesis (PhD(Agric) (Agronomy))--University of Stellenbosch, 2003.108 leaves printed on single pages, preliminary pages i-vi and numbered pages 1-1 to 1-5 to 9-1 to 9-3. Includes bibliography, list of abbreviations and 22 figures in color. Digitized at 300 dpi grayscale and 300 dpi 24-bit Color to pdf format (OCR), using an HP Scanjet 8250 Scanner.
ENGLISH ABSTRACT: A long term experiment was conducted at the Langgewens Experimental Farm, near Malmesbury in the Western Cape province of the Republic of South Africa. The effect of soil tillage, crop rotation and nitrogen fertiliser rates on mineral-N levels in the soil, nitrogen levels in plants, wheat growth and yield components, grain yield as well as quality parameters of spring wheat were determined. Although the tillage treatments tested were initiated in 1976, present crop rotations and nitrogen application rates were only applied since 1990. Most of the data that are discussed however was recorded during the 1997 to 2001 period. The trial was designed as a randomised complete block with a split-plot arrangement and four replicates. Main plots were tillage methods namely conventional tillage (CT), tine tillage (TT), minimum tillage (MT) and no tillage (NT). Crop rotations used were continuous wheat (WW) and wheatl lupin/wheat/canola (WLWC). Both soil and crop data were recorded. The results of this study showed the differences in total mineral-N content of the soil. N-contents of wheat, wheat growth and yield components as well as wheat quality parameters were found between tillage treatments, crop rotations used as well as N- fertiliser rates applied. Response however, varied largely between years due to annual variation in especially total precipitation and distribution of rainfall. The inclusion of a legume crop (lupin) and canola in the rotation with wheat was found to have only a small effect probably due to the fact that lupins were grown once in a four year cycle only. Application of different nitrogen rates did increase the mineral-N in the soil, but the effect did not last very long in most years due to either N-leaching or plant uptake. To ensure sufficient mineral-N levels, late application of N-fertiliser will therefore be needed. Minimum tillage or reduced tillage performs better than conventional tillage in low rainfall years. In general these tillage systems should be combined with crop rotation to ensure that yields are comparable to that obtained with conventional tillage.
AFRIKAANSE OPSOMMING: Die ontwikkeling, graanopbrengs en bakkwaliteit van koring (Tritium aestivum L.) in reaksie teenoor gewasratasie, metode van grondbewerking en N-bemestingspeil is in 'n lang tennyn sllldie op Langgewens Proefplaas, naby Malmesbury in die Weskaap provinsie van die Republiek van Suid-Afrika, bepaal. Hoewel die verskillende grand bewcrkingsmetodes sedert 1976, en gewasrotasies en slikstofpeile sedert 1990 toegepas is, is daar in hierdie studie gekonsentreer op data wal gcdurcnde die periode 1997-2001 ingesamel is. Die eksperiment is as 'n randomiseerde blok ontwerp met vier bewerkingsmetodes nl. konvcnsionele bewerking (CT), tand bewerking (TT). minimum bewerking (MT) en geen bewerking (NT), twee gewasratasies nl. monokuhuur koring (WW) en koring/lupienelkoringiCanola (WLWC) en drie N-peie (60 kg N ha- ', 100 kg N ha- 1 , 140 kg N ha- I uitgevoer. Aile stikstof is in die vorm van kalksteen-ammoniumnitraat toegedien. Die reaksie van beide grondfaktore soos die minerale N inhoud en gewaskomponente 5005 biomassa produksie, opbrengs en kwaliteit teenoor bogenoemde faktore het '0 goeie korrelasie getoon met die heersende klimaatstoestande. Lae reenval jare (gebiede) sal volgens hierdie stlldie die grootste voordeel verkry met minder intensiewe grand bewerkingstelsels. terwyl 'n frekwensie van meer as een peulgewas per siklus van 4 jaar nodig sal wees om grondvrllgbaarhcidsvlakke betekenisvol te verhoog. Stelsels van rninder intensiewe grondbewerking is ook tot 'n grater mate deur gewaswisseling bevoordeel as konvensionele melOdes van grondbewerking. Hocwel minerale-N vlakke in grond deur verskillende N-peile be'lnvloed is, was die efTektiwiteit van toedienings laag en het verdeelde tocdienings groat voordele ingehou.
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Mbizana, Nandipha. "Identifying appropriate paths for establishing sustainable irrigated crop based farming business on smallholder irrigation schemes: a case of Ncora Irrigation Scheme." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1016205.
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The study examined the impact of small scale irrigation technology in crop production under Ncora areas of Cofimvaba. To achieve the objective of the study, data were collected from 212 farmers engaged in various crop enterprises under the Ncora. The farmers were randomly selected. Descriptive Statistics, DEA model, linear regression model and gross margin analysis were used to analyse the results obtained from the survey. The descriptive results showed that Ncora farmers are small-scale farmers cultivating small hectare of land and using simple farm tools, mainly using furrow irrigation. Furthermore, they produce more than one crop enterprises. The gross margin Analysis shows that Ncora cultivation is profitable. The most profitable crop was found to be maize than potatoes. Farm production function revealed that land, labour and purchased inputs had a positive relationship with the output of the enterprises. SPSS was used to run data for linear regression model (OLS). It was suggested that extension services and private organizations assist farmers especially the emerging ones via provision of training, processing and storage facilities. Furthermore, continuous monitoring of soil and water quality as well as ground water table was recommended, in order to ensure sustainability of Ncora irrigation in the area.
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Lewu, Muinat Nike. "Studies on the nutritional value of seven accessions of cocoyam growing in South Africa." Thesis, University of Fort Hare, 2010. http://hdl.handle.net/10353/d1001054.
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Cocoyam [Colocasia esculenta (L.) Schott] is widely cultivated as a staple food in the tropical and subtropical regions of the world. The crop, however, remains unpopular and not well known outside KwaZulu-Natal Province of South Africa where it is cultivated mainly for subsistence. The aims of the study were to collect local landraces (accessions) of the crop from where it is found growing within the country for various studies and also to document its nutritional values as well as the safety/toxicity of the crop. The study was carried out using various methods. These included a comparative assessment of the proximate, mineral and antinutrient compositions of cooked and uncooked tubers of a typical commercially available cocoyam and potato found in South African markets. These investigations were repeated for the tubers and leaves of available landraces (seven accessions) of C. esculenta found growing in the farmers’ fields in KwaZulu-Natal Province. Also, an in vivo toxicological study on cooked accessions of the local landraces was conducted to determine possible toxicity effects after consumption using albino rats as a model. The results revealed that commercially available cocoyam and potato tubers have very close nutritional components. Analysis of the proximate composition of seven accessions (UFCe1- UFCe7) of cooked and uncooked tubers of cocoyam indicated that UFCe7 was better in ash, crude protein, crude fibre and crude lipid contents but with higher moisture which could make it more vulnerable to microbial attack. No tubers of the seven accessions appeared to be ii outstandingly better than the others based on their mineral compositions. However, in terms of antinutritional factors, UFCe1, UFCe3 and UFCe7 had the least amounts of oxalate, tannins and phytate in their cooked states. It was discovered however, that the leaves of the accessions of this vegetable contain substantial amount of minerals, and therefore, can contribute significantly to the nutrient requirements of humans and could be recommended as a cheap source of nutrients in South Africa. None of the accessions was outstandingly better than the others in terms of their mineral contents and anti-nutritional factors. Moreover, the current study has shown that boiling the leaves of cocoyam prior to consumption is an effective way of reducing the antinutrient contents of the leaves of the plant thereby making it safe for consumption. The findings also revealed that cooking C. esculenta leaves may increase the levels of protein, fibre and lipid contents while cooking may also decrease the mineral, carbohydrate and caloric contents of the leaves of the accessions. The leafy vegetable may, therefore, be recommended as a cheap source of plant protein. Cooking improved the nutritive value as a result of the reduction in antinutrient levels, thereby improving the food quality in all the tuber and leaf samples used for this study. At the same time, cooked samples also suffered loss of some nutrients with respect to the proximate and mineral compositions. However, supplementation from other food sources that are rich in these nutrients is necessary when these crops are cooked for consumption. Any of the cocoyam accessions may be recommended for consumption for improved protein and mineral nutrients while tubers of accession UFCe7 have also shown good promise in terms of protein and fibre content availability. The results of the in vivo study, using the liver and kidney functional endpoints of weanling albino rats (Rattus norvegicus) maintained on different accessions of cooked cocoyam-based iii diets (UFCe1-UFCe7) for 28 days, revealed that all the accessions produced selective alterations on the hepatorenal indices of weanling rats. The highest alterations were produced by UFCe4 while the least was from UFCe2. These alterations may have consequential effects on the normal functioning of the liver and kidney of the animals. The UFCe2 exhibited the least toxicity risk among the accessions of C. esculenta growing in KwaZulu-Natal Province of South Africa.
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Chitsa, Gilbert. "Analysis of entrepreneurial behaviour of smallholder irrigation farmers: empirical evidence from Qamata Irrigation scheme." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1019769.
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Albeit much effort having been put to review the performance trend of smallholder irrigation farmers in South Africa. However, there seems to be a paucity of information regarding the level of entrepreneurship on these farmers. Most research works on smallholder irrigation farmers have mainly focused on livelihoods trajectory providing a review on how the welfare of the rural poor has been transformed after the introduction of irrigation schemes. With most research evidence indicating a high degree of underperformance on most smallholder irrigation schemes, this research attempted to investigate the level of entrepreneurship among the small holder irrigation farmers. In order to achieve the main research objective, a sample of 110 farmers drawn from Qamata irrigation scheme was interviewed and each farmer’s performance on the nine components of entrepreneurship was assessed. The aspects assessed to determine the farmer’s entrepreneurial behaviour were: planning ability, risk taking, achievement motivation, leadership ability, Cosmo politeness, decision making, and innovativeness and farming knowledge. Basing on previous studies which indicated entrepreneurial behaviour to be influenced by several factors the study also analysed the determinants of entrepreneurship among the irrigation farmers and a binary logistic regression model was used to establish the connection between various independent variables and the farmers’ entrepreneurial performance given as a total score of the nine components. Though the findings of the study revealed a prevalently low level of entrepreneurship among the smallholder irrigation farmers on Qamata irrigation scheme, a high proportion of the respondent farmers (65.5% and 60.5%) showed to have a high degree of achievement motivation and decision making ability, respectively. The observed trend thus reflected that smallholder farmers have a potential to become entrepreneurs and are willing to succeed. The binary model results revealed that the prevailing land tenure system will be a strong determinant of the farmer’s level of entrepreneurship. Equally, levels of training in farming, motive for farming and information seeking tendency also proved to have a significant influence on the degree of farmer entrepreneurship. Based on the results of this study recommendations have thus been drawn on the need for policies and practices aimed at promoting entrepreneurship and not dependency among farmers. Key focus areas identified include: the need to revise the current land ii tenure system on irrigation schemes, intensify on entrepreneurship training for both farmers and extension officers and regular on-farm training on new technologies.
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Mzuyanda, Christian. "Assessing the impact of primary agricultural co-operative membership on smallholder farm performance (crops) in Mnquma Local Municipality of the Eastern Cape Province." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1021285.
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Mdoda, Lelethu. "Farmers’ awareness of climate change and variability and it’s effects on agricultural productivity: (the case of King Sabata Dalindyebo Municipalty in Eastern Cape)." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1021294.
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Climate is an important factor of agricultural productivity and many rural dwellers in developing countries depend on agriculture and are highly affected by climate change and variability. The world is currently experiencing climatic changes and variability conditions which results in high temperatures, low rainfall patterns, shortage of water and drought persistence. Climate change and variability is affecting weather patterns and shifting seasons which results in serious repercussions on smallholder farmers. Smallholder farmers are extremely vulnerable to climate change and variability because their farming and production systems are climate sensitive and are not rebound to climate stresses. These adverse effects in developing countries arise from different climate change and variability-related causes, notable extreme weather events, food security, increased health risks in agriculture from vector home diseases, and temperature-related morbidity in environments. The study was carried in King Sabata Dalindyebo Municipality in the Eastern Cape Province in South Africa. This study examines farmers’ awareness of climate change and variability and its effects on agricultural productivity in King Sabata Dalindyebo municipality using a Descriptive Statistics, Binary and Ricardian Model fitted to data from a cross-sectional survey of 200 farmers in King Sabata Dalindyebo Municipality. Both primary and secondary data was used. This research study estimates the effects of climate change and variability on King Sabata Dalindyebo agricultural productivity using a continental dimension of Ricardian analysis. Results revealed that local farmers were aware of climate change and variability and perceived changes in average temperatures and rainfall. The changes in average temperatures and rainfall had adverse effects on crop and livestock production. However, farmers’ awareness of climate change is not to an extent that they presume adaptation to climate change as a necessity and crucial. The results show that climate change and variability affects farm income and there is a non-linear relationship existing between climatic variables (temperature and precipitation) and farm income which depicts U-shaped. The study results indicated that climate change and variability affect agricultural productivity and have an effect on agricultural productivity in King Sabata Dalindyebo Municipality. In view of the research findings, several policy proposals are suggested. The study findings suggest that climate change and variability must be taken seriously and monitored. Policy makers and government officials must support farmers with information distribution,education, market access, well trained extension agents, credit and information about mitigation strategies to climate change and variability which includes institutional and technological methods, particularly smallholder farmers.
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Mditshwa, Sithembele. "Estimating maize grain yield from crop growth stages using remote sensing and GIS in the Free State Province, South Africa." Thesis, University of Fort Hare, 2017. http://hdl.handle.net/10353/6016.
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Early yield prediction of a maize crop is important for planning and policy decisions. Many countries, including South Africa use the conventional techniques of data collection for maize crop monitoring and yield estimation which are based on ground-based visits and reports. These methods are subjective, very costly and time consuming. Empirical models have been developed using weather data. These are also associated with a number of problems due to the limited spatial distribution of weather stations. Efforts are being made to improve the accuracy and timeliness of yield prediction methods. With the launching of satellites, satellite data are being used for maize crop monitoring and yield prediction. Many studies have revealed that there is a correlation between remotely sensed data (vegetation indices) and crop yields. The satellite based approaches are less expensive, save time, data acquisition covers large areas and can be used to estimate maize grain yields before harvest. This study applied Landsat 8 satellite based vegetation indices, Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI) and Moisture Stress Index (MSI) to predict maize crop yield. These vegetation indices were derived at different growth stages. The investigation was carried out in the Kopanong Local Municipality of the Free State Province, South Africa. Ground-based data (actual harvested maize yields) was collected from Department of Agriculture, Forestry and Fisheries (DAFF). Satellite images were acquired from Geoterra Image (Pty) Ltd and weather data was from the South African Weather Service (SAWS). Multilinear regression approaches were used to relate yields to the remotely sensed indices and meteorological data was used during the development of yield estimation models. The results showed that there are significant correlations between remotely sensed vegetation indices and maize grain yield; up to 63 percent maize yield was predicted from vegetation indices. The study also revealed that NDVI and SAVI are better yield predictors at reproductive growth stages of maize and MSI is a better index to estimate maize yield at both vegetative and reproductive growth stages. The results obtained in this study indicated that maize grain yields can be estimated using satellite indices at different maize growth stages.
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Gerber, Audrey I. (Audrey Inga). "Effect of pruning on economic biomass production of Protea cv. Carnival." Thesis, Stellenbosch : Stellenbosch University, 1994. http://hdl.handle.net/10019.1/58407.
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Thesis (MScAgric)--Stellenbosch University, 1994.Some digitised pages may appear illegible due to the condition of the Microfiche
ENGLISH ABSTRACT: Many Proreaceae species indigenous to South Africa have potential as cutflower crops. Commercial production of proteas for expurt, mainly to Europe, must emphasise quality of flowers and time of production. Good export quality flowers have stems longer than 50cm and unblemished flowers. Cut-flower proteas are in greater demand and command better prices during the European winter (September to May, Southern hemisphere), when competition from flowers grown in Europe is less. Both quality and time of harvest can be manipulated by pruning techniques. Protea cv. Carnival (a natural hybrid, possibly between P. neriifolia and P. compacta) produces flowers in late summer, from February through to May. Picking flowers or pruning shoots of Proteo cv. Carnival entails removing the terminal portion of shoots with heading cuts to leave on the plant short stumps, known as bearers. Lateral shoots arising from axillary buds on bearers elongate by successive growth flushes until flowers are initiated terminally. The characteristics of the shoot determine whether or not flower initiation will take place, and will affect the quality of the resulting flower. Plants were pruned to produce bearers of different length and diameter. The characteristics of shoots arising from different bearers were recordea. Thick bearers of length 20-25cm produced the most shoots, and the longest shoots. Plants producing flowers biennially, rather than ann'Jally, produced thicker bearers, which, in turn, lead to production of better quality shoots arising from the bearers in the following season. Changing the time of pruning changed both the flowering cycle and the biomass allocation of Prorea cv. Carnival. Plants of Profea cv. Carnival were pruned on six different dates in 1991. Pruning in March, April or May, 1991, resulted in an annual flowering cycle. Less than 40% of the fresh mass produced in 1993 was reproductive, of which approximately 5% had stems long enough for export. The 1994 annual harvest was of s:milar size and quality as the 1993 annual harvest. Pruning in July, August or September, 1991, resulted in a biennial cycle of flowering. No flowers were produced in 1992, and a large crop was harvested in 1993. In 1993 lip to 70% of the fresh mass produced was reproductive, of which approximately 80% had stems long enough for export. Plants were pruned shortly after flowering in 1993, and the biennial cycle was replaced by an alternate flowering cycle, with a large crop being followed by a smaller crop. The large harvest in 1993 was significantly earlier than normal, but the small crop produced in 1994 was later. The harvest in 1994 from plants with an alternate flowering cycle was similar in size to the 1994 harvest from plants floweting annually, but flower stems were longer.
AFRIKAANSE OPSOMMING: Heelwat inheemse Proteaceae spesies besit die vereiste eienskappe om as snyblomr.-le verhanctci te wod. Indien proteas kommersieel verbou sou word vir uitvoer moet die klem val op gehalte van blomme en die tyd van produksie. Goeie gehalte uitvoer blomme moet steellengte van langer as 50cm en perfek gevormde blomme besit. Daar is 'n groter aanvraag na kommersieel verboude proteas gedurende die Europese winter (September tot Mei, suidelike halfrond) en beter pryse word derhalwe ook dan verkry. Beide gehalte en die oes periode kan gemanipuleer word deur snoeitegnieke. Wanneer blomme gepluk word of lote gesnoei word van Profea cv. Carnival (waarskynlik 'n kruising tussen P. compacta x P. neriifolia) word die terminale gedeelte van die loot teruggesny. Die oorblywende gedeelte bestaan uit kort stompe wat bekend staan as draers. Laterale lote afkomstig van okselknoppe op draers verleng totdat 'n blom terminaal ontwikkel. Die eienskappe van die loot bepaal of 'n blom inisieer sal word of nie, en sal ook die gehalte van die gevormde blom beinvloed. Protea plante was gesnoei om draers van verkillende lengtes en deursnee te produseer. Die eienkappe van lote afkomstig van die verskillende tipe draers was gemeet. Dik ..draers van lengte 20-25cm het die meeste asook die langste lote geproduseer. Plante wat twee-jaarliks, in teenstelling met jaarliks, geblom het, het dikker draers geproduseer en ook gelei tot produksie van beter gehalte lote in die opeenvolgende seisoen. Die verandering in die tyd van snoei het beide die blom siklus en die biomassa verspreiding beinvloed. Plante van Protea cv. Carnival was up 6 verskillende datums in 1991 gesnoei. Snoei in Maart, April of Mei, 1991, het 'n jaarlikse blom siklus veroorsaak. Minder as 40% van die vars massa geproduseer in 1993 was reproduktief, waarvan 5% steellengte lank genoeg vir uitvoer gehad hel. Die 1994 jaarlikse oes was van dieselfde grootte en gehalte as die van 1993. Snoei in Julie, Augustus of September, 1991, het egter 'n twee-jaarlikse blom siklus veroorsaak. Geen blomme was in 1992 geproduseer nie, maar die oes in 1993 was heelwat groter as die jaarlikse oeste. In 1993 was to 70% van die vars massa geproduseer, reproduktief, waarvan 80% steellengte lank genoeg vir uitvoer gehad het. Die twee-jaarlikse blom siklus het 'n vroeer oes in 1993 veroorsaak, maar 'n later oes in 1994. Die twee-jaarlikse oes in 1994 was van dieseifde grootte as die jaarlikse oes in 1994, maar die blomstele was langer.
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Cox, J. R., and J. L. Stroehlein. "Climatic and Edaphic Conditions at Lehmann Lovegrass Sites in Southeastern Arizona and the Republic of South Africa." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/201077.
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Fourie, J. C. "The evaluation and management of different grasses and legumes as potential cover crops in the vineyards of South Africa." Thesis, Link to online version, 2007. http://hdl.handle.net/10019/387.
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Cheteni, Priviledge. "Barriers and incentives to potential adoption of biofuel crops by smallholder farmers in selected areas in the Chris Hani and O.R. Tambo district municipalities, South Africa." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1020182.
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Since the launch of the Biofuels Industrial Strategy in 2007 by the South African government, only a few smallholder farmers have adopted biofuels for production. The government hopes to stimulate economic development and alleviate poverty by targeting areas that were previously neglected for agriculture by the apartheid government. However, there still appears to be a lack of a clear and comprehensive policy framework for the development of a South African biofuel industry, because the proposed initiatives have not been implemented to date. There are also concerns among stakeholders that government policy is taking too long to formulate, compounding existing uncertainty in the industry. This study therefore aims to identify barriers and incentives that influence the potential adoption of biofuel crops in selected areas in the Eastern Cape Province, South Africa. The study utilised a semi-structured questionnaire to record responses from 129 smallholder farmers that were identified through a snowballing sampling technique. Descriptive statistical analysis and a Heckman two-step model were applied to analyse the data. Analysis was done using SPSS 21 and EViews 8. Results obtained showed that the variables: arable land, incentives offered, challenges faced, labour source and farm experience were statistical significant at 5 or 10 percent p value to awareness of farmers to biofuel crops. Adoption of biofuel crops was statistically related to gender, qualification, membership to association and household size. The study recommends that the Biofuels Industrial Strategy Policy be revisited in order to have a mechanism of including smallholder farmers that it aims to empower with employment and improvement in their livelihoods. The government can help smallholder farmers by addressing the challenges they face in improving their output. Furthermore, it recommends that a national study on barriers and incentives that influence the adoption of biofuel crops be carried out in order to identify other factors that may hinder the Biofuels Strategy Policy aims in empowering the disadvantaged farmers.
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Ramoroka, Mokgadi Mizen. "Grain yield, gravimetric moisture content, dry matter accumulation and chlorophyll production in maize-legume intercrop under minimum and conventional tillage systems." Thesis, University of Limpopo (Turfloop Campus), 2008. http://hdl.handle.net/10386/639.
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Thesis (M.Sc. (Agriculture)) --University of Limpopo, 2008Maize is a dominant crop in smallholder farming systems in the Limpopo province of South Africa, generally cultivated as intercrop with grain legumes. The major constraint in this cropping system is inadequate soil moisture during the growing season, which also limits nutrient availability to the component crops. The minimum tillage system has been reported to improve soil moisture availability on farmers’ fields but this has not yet been verified in an intercropping system in the province. The objective of this study was to quantify grain yield and chlorophyll production of intercropped maize, and to assess seasonal moisture availability under minimum tillage (MT) and conventional tillage (CT) systems. Dryland field experiments were conducted at two locations in the province namely, farmer’s field at Dalmada in 2002/2003 and 2003/2004 growing seasons and at the University of Limpopo Experimental farm at Syferkuil during the 2003/2004. The experimental design was a randomized complete block in split plot arrangement at all locations and seasons. Tillage systems consisting of conventional tillage and minimum tillage were the main plot treatments, whereas five different cropping systems namely, sole maize, and maize intercrop with cowpea (variety, Bechuana White), cowpea (variety, Agripers), Lablab bean (variety, Rongai) and Velvet bean were assigned as sub-plot treatments. Maize grain yield in 2002/2003 at Dalmada was significantly lower (357 kg/ha) under CT relative to 755kg/ha under MT. In 2003/2004 at Dalmada, grain yields under the two systems were similar, where as at Syferkuil, 15% higher grain yield results was obtained under MT. Minimum tillage systems resulted in higher number of maize cobs per plant at Dalmada in both growing seasons and weight per cob was higher under MT at both locations and seasons. At Dalmada, significantly higher soil moisture was recorded under the MT relative to the CT depending on depth and sampling dates. Chlorophyll content of the youngest fully expanded leaves of maize was generally higher under MT than CT, but this was observed only at the later stages of plant growth. The results also showed that the rate of senescence (reduced chlorophyll content in older leaves) was higher in maize plants grown under CT relative to those under MT. The minimum tillage system has shown the potential of being a superior system for dryland maize production, but further research involving additional locations is required to ascertain this fact.
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Müller, Francuois L. "Native legume species from the Northern Cape province of South Africa and their potential use as forage crops." University of Western Cape, 2021. http://hdl.handle.net/11394/7932.
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Philosophiae Doctor - PhDThe lack of bioclimatically suitable forage species for livestock production in the water-limited agro-ecological areas of South Africa has resulted in significant feed shortages within these areas during the ongoing drought experienced within the country. This, in turn, has resulted in significant livestock mortalities leading to financial difficulties for the farmers and farming communities within these areas. Thus, many of the water-limited agro-ecological areas in South Africa have been declared disaster areas. These cyclic long-term droughts, as well as more common short-term droughts are expected to increase in frequency, duration and intensity under the predicted future bioclimatic conditions. Although there has been significant investment into the development of improved, better-adapted forage crops for these bioclimatically marginal agro-ecosystems, these efforts, to date, have largely been unsuccessful. Therefore, in this study, we propose to identify and evaluate species that are native to the water-limited South African agro-ecosystems and that can potentially be implemented in alternative fodder flow programs within these water-limited agro-ecological areas.
2022
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Malahlela, Nkele Dorcus. "Socio-economic contribution of community food gardens to the livelihoods of rural households in Lepelle-Nkumpi local municipality of Limpopo province, South Africa." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1021330.
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Community food gardens are regarded as a means through which rural households can improve their livelihoods. This study explores the contribution of community food gardens (CFG) to livelihoods in the Lepelle-Nkumpi local municipality in the Limpopo province. The objectives of this study are, firstly to explore the reason behind CFG participation and the reasons behind the participating possibility. Secondly, the study seeks to identify the socio-economic factors influencing the participation of households in CFG and lastly to determine the influence of CFG and other socio-economic variables on household food security status (HFSS). Descriptive statistical analysis was used to describe the socio-economic characteristics and the reasons behind CFG participation and the reasons behind the participating possibility. The binary logistic regression model was used to analyse the determinants of household participation in community food gardens as well as the contribution of CFG to HFSS on Statistical Package for Social Science (SPSS) software version 21. Through a structured questionnaire, data was collected from a sample of 180 households which was obtained using multistage sampling. Descriptive results on the characteristics of sampled households revealed that there are high levels of food security in the area with 70% being food secure of which around 42.2% are CFG participants and 30% are food insecure. Furthermore the descriptive statistical analysis indicated that participation of households in CFG is mainly to obtain a source of food among the CFG participants and to generate income amongst the non-participants. On the basis of descriptive analysis, this study concludes that source of food and income generation respectively are the main reasons behind CFG participation and the possibilities of becoming a participant. Therefore the study accepts the research hypothesis stating that “There are social and economic reasons behind household participation and the possibilities of participating in CFG”. Binary results for the determinants of CFG participation revealed that socio-economic variables such as household size, farm income, household monthly income, land size, household perception, marital status, agricultural training and homestead gardening significantly influence household decisions to participate in CFG. This is an implication that socio-economic variables tested in this study are significantly influential to the household decision to participate in CFG, leading to the acceptance of the first hypothesis which states that “Socioeconomic factors determine the community food garden ownership or participation”. The results of the contribution made by CFG to HFSS showed that socioeconomic variables such as gender, age, household size, farm income, educational level, household monthly income, marital status, information access, formal employment status and CFG involvement significantly affect household food security status in the study area. The result indicates a positive contribution to HFSS and implies that socio-economic variables tested in this study have a significant influence on HFSS, leading to the acceptance of the second hypothesis which states that “Community food gardens have a positive effect on food security status of household in Lepelle-Nkumpi Local Municipality Limpopo province.” Therefore it is relevant to concluded that in the area of Lepelle-Nkumpi local municipality, social economic factors plays a vital role in the participation of households in CFG as well as improving the state household food security status.
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Lindeque, Michelle Irene. "Diversity of root nodule bacteria associated with Phaseolus coccineus and Phaseolus vulgaris species in South Africa." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-02162007-170945.
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Mupambwa, Hupenyu Allan. "Winter rotational cover crops effects on soil strength, aggregate stability and water conservation of a hardsetting cambisol in Eastern Cape Province, South Africa." Thesis, University of Fort Hare, 2012. http://hdl.handle.net/10353/453.
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Winter rotational cover crops (WRCC) are often used to boost soil fertility and plant nutrition. However, selection and use of WRCC for soil physical improvement is usually overlooked. The objective of this study was to determine the effects of WRCC on soil strength, aggregate stability and water conservation of a hardsetting soil. The soil physical properties were determined after four rotations of growing monocultures of vetch (Vicia dasycarpa cv. Max), lupin (Lupinus angustifolius cv. Tanjil) and oats (Avena sativa cv. Sederberg) and after two rotations of growing bicultures of oats (Avena sativa cv. Pallinup) and vetch (Vicia dasycarpa cv. Max) across two soil layers, 0 to 15 cm and 15 to 30 cm. The individual WRCC and a weedy fallow constituted the treatments in the monoculture study whilst in the biculture study the various combinations of WRCC namely; 90% oat plus 10% vetch (O90V10); 70% oat plus 30% vetch (O70V30) and 50% oat plus 50% vetch (O50V50) and a weedy fallow constituted the treatments. After four rotations with cover crop monocultures, oats significantly (P ≤ 0.05) reduced penetration resistance (PR) whilst vetch increased PR in both soil layers compared to the weedy fallow control. The effect of the biculture treatments was only experienced within the 15 to 30 cm depth. The treatments O50V50 and O70V30 increased the PR compared to the control. The WRCC in monoculture significantly increased the soil aggregate stability relative to the control in both soil layers. Vetch, lupin and oats resulted in a 41.7%; 20.4% and 15.7% increase in MWD in the 0 to 15 cm soil layer and 47.2%; 44.2% and 39.7% in the 15 to 30 cm depth, respectively. An increase in aggregate stability was associated with increased macro-aggregation. Under the biculture, WRCC slightly increased, non- significantly, the aggregate stability. Both hot water and dilute acid extractable polysaccharides showed no significant correlation with aggregate stability in the two studies. Oats monoculture resulted in a significant difference (P ≤ 0.05) on cumulative infiltration compared to the control. However, after 2 h vetch and lupin showed no significant difference from the control on cumulative infiltration. Oats resulted in a 7.8% increase in final infiltration rate (FIR) whilst vetch and lupin reduced FIR by 9% and 16.7% respectively, compared to the control. Bicultures of oats and vetch significantly (P ≤ 0.05) increased cumulative infiltration compared to the weedy fallow control. A similar significant increase in FIR was also observed under bicultures. The treatments O50V50; O90V10 and O70V30 resulted in a 163.3%; 113.3% and 105.4% increase in FIR respectively, compared to the control. Cover crop monocultures significantly (P ≤ 0.05) increased plant available water (PAW) compared to the weedy fallow, with vetch, oats and lupin resulting in a 28.3%; 22% and 23.9% increase respectively, in PAW. However, no significant differences were observed on PAW after two rotations with bicultures. Compared with winter weedy fallow, WRCC improved most of the soil physical properties under study, with the most suitable results expected under bicultures compared to monocultures. Under CA, selection of WRCC like oats, vetch and lupin, one should therefore take into consideration their effects on soil physical properties as a selection criterion and not biomass and fertility alone.
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Njaimwe, Arnold Ngare. "Tillage and crop rotation impacts on soil, quality parameters and maize yield in Zanyokwe Irrigation Scheme, South Africa." Thesis, University of Fort Hare, 2010. http://hdl.handle.net/10353/460.
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Intensive tillage and monoculture cropping practices reduce soil C accumulation hence increasing soil vulnerability to chemical, physical and biological degradation. This study focussed on enhancing biomass production of wheat and oat winter cover crops as a means of increasing C sequestration in the low organic C soils of the central part of Eastern Cape Province. The specific objectives were (i) to evaluate the short-term effects of no till and cereal-fallow based crop rotations on; soil organic matter related parameters, pH and electrical conductivity, (ii) soil bulk density, water retention and aggregate stability, (iii) soil microbial biomass C and N, mineralizable N, soil respiration, and dehydrogenase enzyme activity, (iv) grain yield, soil nutrient concentration (N, P and K) and their uptake by maize, and (v) to identify soil parameters with high sensitivity to tillage under maize-fallow-maize, maize-wheat-maize and maize-oat-maize rotational cover cropping practices. The experiment was laid out as a split-plot arrangement in a randomized complete block design with 4 replicates. Tillage treatments (CT and NT) were applied on the main plots which measured 8 × 18 m while crop rotation treatments were applied in the subplots which measured 8 × 6 m. The rotation treatments were maize-fallow-maize (MFM), maize-wheat-maize (MWM) and maize-oat-maize (MOM). Weed control in NT plots involved preplant application of glyphosate to control mainly the grass weeds while post emergence weed management was done using Atrazine (485 atrazine and 15 g l-1 triazines). Initial weed control in CT plots was achieved through ploughing to a depth of 20 cm followed by disking while post emergence weed iii management was done by hand hoeing. Soil parameters measured were; (i) particulate organic matter (POM), soil organic carbon (SOC), total nitrogen (TN), pH and electrical conductivity (EC), (ii) soil bulk density (b), moisture at field capacity (FC), aggregate mean weight diameter (MWD) determined by fast wetting (FW), slow wetting (SW), mechanical breakdown by shaking (MB) and the stability index (SI), (iii) soil microbial biomass C (MBC) and N (MBN), mineralizable N (MN), soil respiration (SR), and dehydrogenase enzyme activity (DHEA). No-till increased POM and TN compared to CT in Lenye and Burnshill, respectively. The MWM and the MOM rotations increased TN relative to the MFM rotation in Lenye. The MWM and MOM rotations enhanced SOC relative to MFM in all sampled soil depths at Burnshill and similar observations were made under MOM rotation in the 5-20 cm depth in Lenye. The MWM and MOM rotations tended to depress soil pH relative to the MFM rotation in both sampled soil depths in Lenye while NT reduced soil pH relative to CT on the surface soil layer in Burnshill. Soil EC and pH varied with depth across tillage practices but both parameters remained within the ideal range for successful crop production over the study period. Soil stability index (SI) and aggregate MWD determined by FW, SW and MB were higher in Lenye compared to Burnshill. The MOM rotation enhanced the SI relative to MFM and MWM rotations at both sites. Scanning electron microscope (SEM) showed that more organic C was incorporated into the soil under NT and MOM rotation compared to CT and MFM rotation which had few organic coatings on the soil particles. Microbial properties varied with plant biomass input as influenced by tillage and type of rotational cover crop at both sites. Like in other past studies, NT showed higher levels of MBC, MBN, NM and SR at the soil surface layer compared to CT in Burnshill. No till increased MN iv relative to CT in both sampled soil depths in Lenye and resulted in higher DHEA compared to CT in Burnshill. The MOM rotation increased MBC, MBN, MN relative to MFM rotation especially within surface soil layer. Similar observations were made with respect to MN and SR in both sampled soil layers at Lenye. By contrast, the DHEA was higher under the MFM relative to the MWM and MOM rotations in Lenye but similar under the MFM and MOM rotations in Burnshill. Maize grain yield was not affected by both tillage and crop rotations but varied with cropping season. Comparable grain yields observed under the two tillage practices with similar fertilizer application rates indicated the advantage of NT over CT in saving on labour costs in maize production without compromising yields. High plant biomass retention under NT relative to CT contributed to high soil N and P levels under the former compared to the latter tillage practice especially on soil surface layer at both study sites. Principal component analysis (PCA) revealed that soil chemical and biological parameters closely linked to organic matter, namely SOC, MN, MBC and MBN showed the highest sensitivity to tillage and crop rotation treatments. Soil aggregate MWD determined by SW and b were the physical parameters which were highly altered by agronomic management practice. The MWM and MOM rotations were clustered together and clearly separated from the MFM rotation and this observed trend only applied to the 0-5 and 5-20 cm depths in Lenye site only. No till, MWM and MOM rotations enhanced POM, SOC and TN relative to CT and MFM rotation suggesting these practices have greater potential to improve soil chemical properties compared to intensive tillage and maize monoculture based production practices. Reduced soil b under MOM rotation and improved SI under NT compared to MFM and CT, respectively v indicate that these practices have the potential to improve degraded soils. Although not significantly different, NT values for MBC, MBN, MN, SR and DHEA were higher compared to CT indicating the potential of the practice to improve soil biotic activity relative to conventional tillage practices. No till enhanced surface soil nitrate N and extractable P compared to CT at both sites revealing the long-term potential of NT in improving the supply of these essential plant nutrients compared to CT. Principal component analysis showed that SOC, MN, K, P, MBC, MBN, soil aggregate MWD determined by SW and b were the most sensitive parameters to tillage and crop rotations. Therefore, these parameters could constitute the minimum data set for assessments of the impact of selected CA practices on soil quality attributes.
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Finiza, Tabisa Nomava. "Assessing farmers’ aspirations and goals to expand irrigation crop production from homestead gardens to irrigation plots in Mhlontlo Local Municipality." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1016173.
Full textAbstract:
Most land is still state owned and is granted to users through traditional authorities. Even though the government has undertaken some programmes to reduce rural poverty and has initiated land reform programmes, improved service delivery and formed new water rights legislation in rural areas, the problem of low crop production still persists among South African farmers. The study was undertaken to identify different farmers’ aspirations and goals for expanding their crop production from homestead gardening to irrigation plots in Mhlontlo Local Municipality, in the Eastern Cape of South Africa. The central problem is that smallholder farmers are not expanding their scale of crop production even though they have access to natural capital which includes land and water. The broad objective of the study was to determine the aspirations and goals of farmers to expand irrigation crop production from homestead gardens to irrigation plots. The specific objectives of the study were to assess factors that addressed smallholder farmers’ aspirations and goals to expand crop production, to identify challenges that smallholder farmers encountered in expanding from homestead gardens to irrigation plots and to determine the current state of homestead gardens and irrigation plots. A list of 20 goals were identified from the field survey with 54 homestead food gardeners and 50 smallholder irrigation farmers in the different villages of the Mhlontlo Local Municipality. Random sampling was used to select the farmers who were asked to score the identified farm enterprise goals in terms of their relative importance. The goals were categorised into five factors using Gasson goal ranking methods which ranked goals on the basis of intrinsic, expressive, instrumental, and social criteria. The next step was to determine the standard deviations and means of the ranked goals. Descriptive statistics was then used to profile the farmers according to such factors as age, gender, years of farm experience, types of plot, the availability of water and land for crop production, the income farmers generate from the sale of crops produced and these are cross-tabulated with their goal rankings. The Logit model was used to estimate the probability that farmers would belong to a particular goal ranking and performance category. The logit model was also used to identify the factors that influence the expansion of the cropped area. The results revealed that maize production and land size where significant at 1%. Age and type of irrigation used were also positively significant at 1%. The results also revealed that the adoption of agricultural technology by smallholder irrigation farmers and homestead food gardens contributed to better quality produce.
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Itumeleng, Mathlo. "Risk preferences of smallholder irrigation farmers in the former Ciskei homelands of the Eastern Cape Province, South Africa." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1016206.
Full textAbstract:
Although several studies have investigated on commercial farmers’ risk preferences, there is still lack of information on the risk attitudes and risk preferences of smallholder farmers in South Africa. Risks associated with the adoption of new agricultural technology need to be explored in order to address the transition from homestead food gardening to smallholder irrigated farming. This study seeks to understand risk perception of smallholder irrigation farmers by linking constraints to commercialisation, adoption of new agricultural technologies and risk preferences of smallholder farmers in the former Ciskei Homelands of the Eastern Cape. A total of 101 respondents were surveyed, consisting of 38 smallholder farmers and 63 homestead food gardeners in the Eastern Cape. Questionnaires were used to record household activities, socio-economic and institutional data as well as household demographics through personal interviews. The probit results indicated that older farmers are less risk averse thus more willing to take risk. The risk analysis indicates that farmers who are employed elsewhere are more willing to take risk as income is playing a major role in risk preferences. The results also prove that factors such as tenure system and years in farming have a major influence on farmers’ decision to take risk and adopt new agricultural technology. According to the multi-logit model the major factors influencing technology adoption and risk taking are household size, water rate and type of irrigation system used by the farmers. This study provides useful practical insights for policy makers, farm advisers and researchers in the design of effective and efficient policies, programmes and projects which can affect the adoption of technology, increase smallholder farmers capacity to manage risk and drive growth in the food market.
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Tabalaza, Nomthetho. "The impact climate change on rural households in Binfield village." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/20626.
Full textAbstract:
Climate change poses a major environmental challenge, due to its adverse effects on human settlement patterns and food security. The global phenomenon upsets seasonal shifts, leading to changes in planting dates and weather patterns. This unpredictability has severe and adverse effects on farmers and rural communities, as variable environmental factors govern activities related to daily sustenance and food availability. The kind of rapid and intense climate change that South African rural spaces are experiencing now, increase the likelihood of extreme weather events such as droughts, heat waves and floods. There are growing concerns that the rural poor will be unable to adapt. Rural livelihoods are therefore facing overwhelming and extensive environmental threats, while rural dwellers are finding it difficult to adapt and cope. As a result, climate change can thus be described as one of the most complex and dangerous environmental problems challenging rural livelihoods today. The aim of this study was to explore the impact of climate change on rural poverty at Binfield village in the Eastern Cape and to identify the livelihood activities practiced. Furthermore, the research was conducted to ascertain how rural livelihood activities are affected by climate change and identify and assess the effectiveness of adaption strategies employed by the households. The research also aimed to explore and establish further adaptation strategies. This study made use of a qualitative research method. Babooa (2008) argues that qualitative research is concerned with stories and accounts including subjective understandings, feelings, opinions and beliefs. The study used both primary and secondary data for data. The researcher adopted interviews and field observation for primary data whilst secondary data was sourced from journals, articles and internet sources. O‘ Leary (2004) describes the interview as a method of collecting data where the interviewer asks the Interviewee open-ended questions. The questions were based on the key areas of interest. Qualitative research methods are aimed at understanding the rich, complex characteristic nature of human phenomena. Qualitative methods are concerned with understanding human behaviour from the participant‘s own frame of reference.
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Isaac, Gura. "Crop rotation and crop residue management effects under no till on the soil quality of two ecotopes in the Eastern Cape, South Africa." Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/2934.
Full textAbstract:
The degradation of soil quality due to undesirable farming practices has reached alarming scales in the Eastern Cape and this has had negative repercussions on soil productivity and the environment in general. There is growing evidence that conservation agriculture (CA) practices involving minimal mechanical disturbance, maintaining permanent surface cover and embracing diverse crop rotations increase soil organic carbon (SOC) and therefore has potential to mitigate soil quality deterioration. A study was carried out at two sites located in two ecotopes to investigate the effects of crop residue retention and crop rotations in a no till system on overall soil quality using the Soil Management Assessment Framework (SMAF) as the soil quality assessment tool. The CA study trials were laid out in 2012 at two different locations, one at the Phandulwazi Agricultural High school within the Phandulwazi Jozini ecotope and the other one at University of Fort Hare Research Farm within the Alice Jozini ecotope. The experiment was laid out as a split-split plot arrangement in a randomized complete block design with three replicates. Tillage treatments were applied on the main plots while crop rotation treatments were applied as subplots. Crop residue retention treatments were applied as sub-sub plots. The rotational treatments were maize-fallow-maize (MFM), maize-fallow-soybean (MFS), maize-wheat-maize (MWM) and maize-wheat-soybean (MWS). The initial assessment of the overall soil quality of the two ecotopes using the SMAF soil quality index (SQI) revealed that the soils at the Alice site were functioning at 80% while the soils at the Phandulwazi site were functioning at 79 percent of their optimum capacity. The slight difference in the soil quality of the two ecotopes could be attributed to their different soil organic C contents where the Alice Jozini ecotope had significantly higher soil organic C contents than the Phandulwazi Jozini ecotope. After 3 years of continuous treatment application, crop residue retention significantly improved most of the measured soil quality parameters. Generally across the sites, more soil organic C, microbial biomass C (MBC), ß-glucosidase (BG) activity, mineral N, extractable P and K, Cu, Zn, Mn, Fe, and macro-aggregates were recorded in treatments where crop residues were retained. Crop rotations alone did not have a significant impact on most of the measured soil quality indicators. The crop rotations influenced significantly the availability of mineral N across the two sites, highlighting the importance of using a legume in rotations on available N for the subsequent crops. Most of the measured soil attributes were not significantly influenced after 3 years of continuously applying combined treatment of CA components. Mineral N (NO3 + NH4), K, Zn and Fe were significantly impacted on by the interactions of CA components at the Phandulwazi site, while N, Cu, Zn and Mn were significantly increased at the Alice site. Low response of SOC to combined CA treatments in the short-term prompted the need to examine treatment effects on individual soil carbon fractions. The interaction of crop rotation and residue management techniques were significant on the fine particulate organic matter – C fractions and microbially respired C. These soil C fractions were more sensitive to short-term treatments of combined CA components than SOC and MBC, therefore they can be used as short-term indicators of CA effects on SOM. Soil organic carbon, MBC, extractable P and K, soil pH, EC, b, AGS (aggregate stability) and BG activity were measured and the Soil Management Assessment Framework (SMAF) used to calculate soil quality index (SQI) values for each treatment. The combination of the crop rotations with crop residue retention showed the potential to significantly improve SQI values in the long term. The highest soil quality improvement at both sites was achieved by the maize-wheat-soybean (MWS) rotation with crop residue retention.
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Gouws, Marijke. "The refuge concept in insect resistance management :|bits history and future application in South Africa / M. Gouws." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9168.
Full textAbstract:
Genetically modified (GM) crops developed for insect control express cry genes from the bacterium Bacillus thuringiensis (Bt). These genes produce target specific insecticidal proteins that protect the plant against insect pest attacks throughout the growing season. The largest threat to the continued success of these insecticidal GM crops is the potential development of target pest resistance. Models and theories suggested several possible strategies to delay the development of resistance. Of these strategies the high-dose/refuge strategy was selected as the optimal insect resistance management (IRM) option and is currently implemented throughout the world. The high-dose/refuge strategy comprises planting Bt maize plants that produce high doses of the toxin and non-Bt plants (refugia) in close proximity to one another. The theory behind this strategy is that the high dose of toxin kills nearly all the individuals of the target pest while the refuge area sustains susceptible pest individuals that survive on the crop and mate with survivors on the Bt crop. Recent reports of resistance development to Bt crops has raised questions about the refuge concept. In the cases where resistance has developed it was largely ascribed to non- compliance to the prescribed refuge requirements or non-functionality of the refuge approach. The Bt crops used throughout the world were developed in North America against the insect pests that occur there. Since there are differences in the lifecycles and behaviour of insect species targeted by Bt crops the refuge areas also needs to be specified for different target pests. For example, the currently used IRM strategies do not differentiate between polyphagous and monophagous pests and also do not take into account differences that exist in biology and behaviour of different pest species. These IRM strategies have also been developed mainly with large scale commercial farming systems in mind and do not take into account farming systems in developing countries. Current IRM strategies need to be revised and adapted for use by small-scale African farmers.Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.
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Puta, Usanda. "Effects of genetically modified maize (MON810) and its residues on the functional diversity of microorganisms in two South African soils." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/419.
Full textAbstract:
Genetically modified (GM) crops are commercially cultivated worldwide but there are concerns on their possible negative impacts on soil biodiversity. A glasshouse study was conducted to determine effects of Bt maize residues on soil microbial diversity. Residues of Bt maize (PAN 6Q-308B) and non-Bt maize (PAN 6Q-121) were incorporated into the soil and corresponding maize seeds planted. The treatments were replicated three times. Fertilizer and water application were similar for both treatments. Rhizosphere and bulk soil was destructively sampled from each treatment and analyzed for microbial community level physiological profiles using Biolog plates with 31 different carbon substrates. Absorbance in the Biolog plates was recorded after 72 h of incubation at 20oC. Arbuscular mycorrhizal fungi spore counts were also determined. Field studies were conducted at the University of Free State and University of Fort Hare Research Farms to determine the effects of growing Bt maize on soil microbial diversity. One Bt maize cultivar (PAN6Q-308B) and non-Bt maize (PAN6Q-121) were grown in a paired experiment at University of Free State farm, while two Bt maize (DKC61-25B and PAN6Q-321B) and their near-isogenic non-Bt maize lines (DKC61-24 and PAN6777) were grown in a randomized complete block design with three replicates. Fertilization, weed control and water application, were similar for both Bt maize cultivars and their non-Bt maize counterparts. Rhizosphere soil samples were collected by uprooting whole plants and collecting the soil attached to the roots. The samples were analysed for microbial diversity and for arbuscular mycorrhizae fungal spore counts. Principal component analysis showed that soil microbial diversity was affected more by sampling time whereas genetic modification had minimal effects. Presence of residues also increased the diversity of microorganisms. Mycorrhizal fungal spores were not affected by the presence of Bt maize residues. Growing Bt maize had no effect on the soil microbial diversity in the rhizosphere.
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Muzangwa, Lindah. "Cover crop biomass production and effects on weeds and soil fertility in a maize-based conservation agriculture system." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/484.
Full textAbstract:
Low cover crop biomass production is a major obstacle to the success of conservation agriculture currently promoted as panacea to the inherent problem of soil erosion and loss of soil productivity in the Eastern Cape (EC). Therefore, this study evaluated cover crop management strategies for optimizing biomass production for better soil cover, soil nitrogen (N) and phosphorus (P) fertility, weed control and maize yields. The strategies tested are cover crop bicultures, selection of an adapted lupin cultivar and seeding rate, and the feasibility of rain fed winter cover cropping. The cover crop experiments were carried in rotation with summer maize between the winter of 2009 and summer of 2010/2011. Biculture trial was carried out by seeding oat (Avena sativa) and vetch (Vicia dasycarpa) at three mixture ratios and as sole crops under irrigation. On a separate irrigated trial, two lupin cultivars (Lupinus angustifolius var Mandelup & Qualinock) were seeded to a range of seeding rate, 40 to 220 kg ha-1. To study the feasibility of rain fed winter cover cropping, oat, vetch, rye (Lolium multiflorum), barley (Hordeum vulgare), radish (Raphanus sativa) and triticale (Triticale secale) were relayed into a maize crop in February, March and April of 2010. The irrigated trials were followed with SC701 maize cultivar, whilst the rain fed trial was followed with DKC61-25 maize cultivar. Bicultures gave higher cover crop biomass than sole vetch, increasing with an increase in the oat component of the mixture. Increased N and P uptake was observed with bicultures compared to sole oat, however, the levels were comparable to sole vetch. Sole vetch increased soil inorganic N and P at maize planting, whilst the slow decomposition by sole oat residue resulted in mineral lock up. Bicultured cover crop residues had intermediate decomposition rates and resulted in optimum levels of inorganic N and P for prolonged periods compared to sole crops. Weed suppression by the bicultures was comparable to sole cover crops. Biculturing technology significantly (P<0.05) increased maize grain yield compared to sole oat and the yields were comparable to those from sole vetch. For lupins, 206 kg ha-1 seeding rate gave the optimum biomass yield. Weed dry weights in both cover crop and maize crop decreased with an increase in lupin biomass. Comparable soil total N and inorganic P values at maize planting, were observed from plots planted to 120, 180 and 220 kg ha-1. Maize grain yield increased with an increase in lupin seeding rate. The study on rain fed winter cover cropping had most cover crop species’ biomass decreasing with each delay in planting except for radish, which increased. Vetch produced the highest amounts of biomass from February and March planting whilst radish had the highest biomass in April planting. The two species resulted in the greatest N improvement compared to the other species. Regardless of the grazing, the grass specie residues managed to persist to the next cropping season and the residue remaining were comparable to that of radish and vetch. Late-planted cover crops had the greatest residue remaining than early-planted, as a result, April planted cover crops provided better weed suppression than March and April planted. Vetch provided the highest maize grain yield (4005 kg ha-1) whilst all other species tested had comparable grain yields. The results suggested that bicultures could be grown to give sufficient biomass for both weed suppression and soil fertility improvement. Furthermore, increasing lupin plant densities improve its function as a cover crop with respect to weed suppression, soil fertility improvement and maize yields. The study also showed that for dry land systems, February and March planted vetch and April planted radish can provide the greatest biomass and maize yield improvement.
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Netnou-Nkoana, Noluthando. "Aspects of intellectual property protection in relation to seed crops, floriculture and medicinal plants that may impact on policy and legislative developments in South Africa." Thesis, University of Pretoria, 2016. http://hdl.handle.net/2263/60129.
Full textAbstract:
The Plant Breeder’s Right (PBR), also known as Plant Variety Protection (PVP), is a form of
intellectual property afforded to breeders of newly bred plant varieties. In South Africa,
intellectual protection of new plant varieties is afforded through the Plant Breeders’ Rights Act,
1976 (Act No. 15 of 1976) as amended in 1996.The writer has been Registrar: Plant Breeders’ Rights since November 2007. Over the years the writer has interacted with several stakeholders with interest in plant breeders’ rights, including breeders, farmers, patent attorneys, growers, plant breeders’ rights administrators from other countries and civil society organisations. Although South Africa has had Plant Breeders’ Rights legislation since 1976, it has been observed that this piece of legislation is relatively unknown and often misunderstood even by the users of the system. In engagements with various stakeholders, it has been established that there are conflicting views amongst the stakeholders on pertinent issues related to the plant breeders’ rights system. There are views, among others, include: that the plant breeders’ rights system is only relevant and benefits breeders from big multinational companies such as Monsanto and farmers can never benefit in such a system; that the Plant Breeders’ Rights Act is synonymous with genetically modified organisms; that indigenous plants are neglected, and that the system only promotes protection of foreign varieties. The most contentious issue is however around the impact of plant breeders’ rights on the tradition of farmers to save, sell and exchange seed.
Very little is documented on the South Africa plant breeders’ rights system, more so from the administrator’s perspective. This study explored some aspects of the plant breeders’ rights system that may need policy interventions and legislation amendments, such as matters around the plant breeders’ rights system in relation to farmers’ rights, possible dual protection of Genetically Modified varieties in terms of the Plant Breeders’ Rights Act 1976 and the Patents Act 1978, as well as the participation of indigenous ornamental crops in the plant breeders’ rights system.
On the issue of the farmers’ rights: results of this work show that the current provision in the Plant Breeders’ Rights Act deals with Farmers’ Rights in a narrow sense, i.e. with the rights of farmers to save seed. It was established that this provision is inadequate for both the breeders and the farmers. A survey was also conducted among smallholder farmers from four provinces, namely Eastern Cape, Free State, Limpopo, and Western Cape. The interesting finding was that although there is so much debate around the impact of the plant breeders’ rights system on farmers’ rights, the majority of the farmers from this study group have never heard of the Plant Breeders’ Rights Act. There are farmers who are continuing with the practice of seed saving; however some farmers have indicated that they do not save seed they believe that this practice lowers yield. Those who do save seed mostly save their traditional seed, i.e. locally adapted seed lacking formal crop improvement as opposed to modern commercial seed. Some farmers have indicated that they do develop varieties through their own selections and believe that their varieties could qualify for protection in terms of the Plant Breeders’ Rights Act. It is evident that both government and the civil society organisations need to do more to educate smallholder farmers about laws and policies that impact their livelihood. Based on this study, a proposal was made to have the farmers’ privilege provisions in the current Plant Breeders’ Right Act amended to allow the Minister responsible for Agriculture to prescribe among others: the crops in which this provision will apply; the category or categories of farmers that would benefit; the circumstances under which royalties should be paid. This proposal was welcomed by most stakeholders and has since been incorporated in the draft Plant Breeders’ Rights Bill. It is envisaged that specific details around these factors will be included in the Regulations to the Act after extensive consultations with all relevant stakeholders.
There is a gap in policy and legislation with regard to the recognition of Farmers’ Rights as envisaged in the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA). As such there are calls from some stakeholders including the civil society organisations that legislation on plant breeders’ rights must address these gaps and/or an alternative sui generis (of its own kind) system should be explored as the International Union for the Protection of New Plant Varieties (UPOV) system is not tailored for developing © University of Pretoria vii countries. In South Africa, legislation dealing with some aspects pertaining to Farmers’ Rights is spread over different government departments, e.g. Department of Agriculture, Forestry & Fisheries dealing with intellectual property protection only in as far as plant breeders’ rights; Department of Trade & Industry being custodians of intellectual property laws in South Africa and administrators of, among others the Patents Act; Department of Environmental Affairs dealing with Access and Benefit Sharing matters; Department of Science and Technology dealing with Indigenous Knowledge Systems and intellectual property protection emanating from publicly funded research institutions. More discussions are needed on South Africa becoming a member of the ITPGRFA as these will pave the way for further discussions and policy interventions addressing Farmers’ Rights in a broad sense.
As far as the Genetically Modified Organisms are concerned, South Africa has approved only three Genetically Modified (GM) crops for commercialization in terms of the GMO Act, 1997, namely cotton, maize, and soybean. This is contrary to some statements made by members of the public that much more crops, including pumpkin, potato, banana and tomato are genetically modified. In terms of intellectual property protection, of the total number of GM varieties protected by plant breeders’ rights per crop: 60% of varieties are GM for cotton, 61% for yellow maize, 34% for white maize and 63% for soybean. Currently there are no GM events used in these crops protected in terms of the Patents Act 1978, which effectively means that there is currently no dual protection for these crops. Dual protection is however one of the most hotly debated issues because of the impact it might have on the rights of farmers to save seed. It has been argued that in South Africa dual protection is possible. Scrutiny of the Plant Breeders’ Rights Act 1976, the Patents Act 1978 and the draft National Policy on Intellectual Property shows that all are silent on the issue of dual protection of plant varieties. The Departments of Agriculture, Forestry & Fisheries together with the Department of Trade and Industry need to initiate discussions around dual protection as well the use of Technology Agreements, between technology holders and technology users, in protecting GM varieties and the impact thereof for all role players in the value-chain in order to come up with the country position in this regard.
This study showed that ornamental plants attract the highest number of plant breeders’ rights applications. Of the applications received between 2000 and 2010 about 20% are of varieties developed from indigenous plants. Of plant breeders’ rights in ornamental plants, 84% are owned by foreign entities. Of the 16% owned by local entities, 12% are privately owned and 4% are owned by public research institutions. Some of the challenges facing this industry include the fact that there is inadequate turnover to allow for breeding programs and research initiatives; this is exacerbated by plant breeder’s rights infringements which lead to further revenue losses. Other challenges the industry face include high labor costs and lack of market information. The national Department of Agriculture, Forestry and Fisheries together with the other relevant departments, e.g. the Department of Labour and the Department of Trade and Industry need to engage more with the floricultural industry stakeholders to discuss the challenges facing the industry and come up with policies that would be conducive for the further development of the industry in order for South Africa to benefit from its unique biodiversity. Literature study has also established that breeders are keen on developing varieties of medicinal plants that are uniform and stable. This would call for domestic legislation on intellectual property protection that is aligned with legislation on Biodiversity and Access and Benefit-Sharing.
This study highlights the importance of engaging stakeholders from both the formal and informal sector and brings attention to gaps in our policies and legislation. This study has already made a major contribution in the draft Plant Breeders’ Rights Bill through the inclusion of the revised provision on farmers’ privilege. This revision is aimed at ensuring that the legitimate interests of the breeder are protected whilst the rights of the farmers are recognized. It is hoped that this study will make a positive contribution to future policy developments and will lay a foundation for future studies pertaining to the plant breeders’ rights system and its impact in the agricultural sector.
Thesis (PhD)--University of Pretoria, 2016.
Department of Agriculture, Forestry & Fisheries
Paraclinical Sciences
PhD
Unrestricted
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Mngqawa, Pamella. "Preliminary investigation of the natural contamination of agricultural crops with selected mycotoxins in northern rural South Africa (Limpopo and Mpumalanga Provinces)." Thesis, University of Western Cape, 2013. http://hdl.handle.net/11394/3456.
Full textAbstract:
>Magister Scientiae - MScSubsistence farmers may contribute significantly to food production, food security, and employment in South Africa. However poor storage practices and contamination with mycotoxins, particularly fumonisins and aflatoxins impacts adversely on production, food safety and food security. Mycotoxins are toxic natural food-borne compounds which frequently contaminate agricultural produce worldwide. They are hazardous to humans and animals and result in significant production losses for farmers. This study focused on former Bantustans in Northern South Africa, namely Vhembe District Municipality (Limpopo) and Gert Sibande District Municipality (Mpumalanga). The aim was to assess mycological and mycotoxin contamination of crops grown by subsistence farmers. A semi-structured questionnaire was administered to randomly thirty-nine households. Data on demographics, storage practices and production during period of 2011 and 2012 cropping seasons were collected. One hundred and fifteen (115) crop samples (maize, beans and peanuts) were collected for analysis. Standard mycological methods and validated mycotoxin analysis methods (HPLC and LC- MS/MS) were used. It was found that maize was the staple food in both provinces, with a significant difference (p = 0.0184) in its production between the two districts; Vhembe produced 0.6 tonnes compared to 2.4 tonnes in Gert Sibande. The majority of the farmers for storage used traditional open wooden cribs (15/20) and steel tanks (5/20) while VDM farmers used sealed store houses 5/19 and 15/19 used polystyrene sacks. Aflatoxin occurrence was low with <1% of GSDM samples contaminated compared to 11% of VDM samples. No significant difference (p > 0.05) was observed in the aflatoxin contamination in VDM samples between the year 2011 and 2012. Samples from VDM households had higher Aspergillus fungal infection (maximum incidence 69%) compared to GSDM (27%) over both seasons. The most frequently isolated Fusarium species in VDM samples was F. verticillioides (92%; 93%), and F. subglutinans (97%; 80%) in GSDM samples over seasons 2011 and 2012, respectively. Highest levels of fumonisins (FB1+ FB2) ranged between 1010 μg/kg and 12168 μg/kg with less than 30% extremely contaminated above the regulated limit in 91% of samples from Limpopo over both seasons (2011 and 2012). Fumonisin levels between the two seasons in VDM showed no significant difference (p>0.05). Only three (less than 5%) from 68% GSDM contaminated maize samples were above the FB1 and FB2 limit. In 2011, there were two highly contaminated maize samples (1762 μg/kg and 4598 μg/kg) with the other samples less than 600 μg/kg, whereas in season two (2012) all samples were below 200 μg/kg, except one highly contaminated sample (26115 μg/kg). None of the beans and peanuts from Mpumalanga was contaminated with mycotoxins above the recommended limit, but from Limpopo 1/5 peanuts was found contaminated with aflatoxin G1 (41 μg/kg). Natural occurrence and contamination of both fumonisin and aflatoxin in stored home-grown maize from VDM was significantly (p < 0.0001) higher than GSDM over both seasons. In general, Limpopo farmers’ experience lower harvests and greater mycotoxin contamination of agricultural produce. This may be attributed in part to poor storage practices and environmental and climatic conditions in that agro-ecological zone.
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Kambanje, Ardinesh. "Productivity and profitability of different maize varieties and cropping systems used in the smallholder sector of the Eastern Cape Province of South Africa : implication on food security." Thesis, University of Fort Hare, 2018. http://hdl.handle.net/10353/6237.
Full textAbstract:
Low maize yields in the midst of abundant arable land, favourable climatic conditions, input and financial support programs, plagues smallholder maize farming in Eastern Cape Province. These scenarios have led the province to be a net importer of maize. In essence, low production may signify a mis-match between maize varieties being promoted amongst smallholder farmers and their farming system. Thus, the main objective of the study was to investigate the productivity and profitability of different maize varieties and cropping system under smallholder agriculture in selected villages of the Eastern Cape Province of South Africa as well as, the implications posed on the household food security. The study sought to assess: (i) the productivity of different maize varieties and cropping systems, (ii) the effect of GM maize adoption on food security among smallholder farmers, (iii) the profitability of GM, conventional hybrids and OPV maize varieties produced by farmers under different agro-ecological conditions and (iv) the impact of different maize varieties and cropping systems on food security in the smallholder agriculture. A cross sectional quantitative-based survey study was carried out to obtain information from a total of 650 small holder farmers. The study was conducted in three local municipalities in Oliver Reginald (OR) Tambo District Municipality of the Eastern Cape Province of South Africa. Descriptive statistics, partial factor productivity, gross margin analysis, household food insecurity access score (HFIAS), ordinal logistic and linear regression were the analytical techniques used in establishing correlations among variables. Results obtained from the survey indicated that under mono-cropping system, Genetically Modified (GM) maize variety was highly productive with an average yield of 1.9 t/ha whilst, improved OPV maize variety was productive (with an average yield of 1.6 t/ha) under mixed cropping system. Furthermore, GM maize (GM = -R418.10), and landrace (GM = -R1 140.29) maize varieties had negative gross margins whilst, conventional hybrids (GM = R5 181.21) and improved OPV (GM = R1 457.41) were profitable. There was a significant and negative correlation between use of GM maize variety and reduction of household food insecurity. GM maize varieties, improved OPV, white maize, white as well as yellow GM maize varieties had a significant impact in reducing household food insecurity; whilst using more than one variety of maize (landraces and GMO) positively influenced household food insecurity. In light of these research findings, it is recommended that, there is need to address household food security by growing improved OPVs under a mixed cropping system and GM maize under monocropping system.
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Masekoameng, Mosima. "Indigenous knowledge systems in food gathering and production in selected rural communities in Sekhukhune District of the Limpopo Province." Thesis, University of Limpopo, 2007. http://hdl.handle.net/10386/1836.
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Hanyani, Charles Tawanda. "Effect of full and semi-scavenging rearing systems on crop contents and the quality of meat from village chickens during spring season of Eastern Cape, South Africa." Thesis, University of Fort Hare, 2012. http://hdl.handle.net/10353/440.
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The objective of this study was to compare the nutrient status of full scavenging and semi-scavenging village chicken production systems. The semi-scavenging chickens were given broiler finisher mash between 14-24 weeks of age, whilst the full scavenging relied on natural foraging. The study also sought to compare the quality of meat from chickens from the two systems. After slaughtering the chickens, the crop contents were physically separated and analysed for chemical composition. Meat pH and colour were measured on the breast muscle of individual carcasses and a consumer sensory evaluation was also done on the breast muscle. The mean crop content weights per day were significantly higher in full scavenging chickens (±16.7g/day biomass) than in semi-scavenging chickens (±9.14g/day). Dry matter, calcium, and phosphorus levels were higher in the crop contents of the full than in the semi-scavenging chickens but crude protein, crude fibre and metabolisable energy were higher in the latter system. Semi-scavenging (1.3 ± 0.05kg) carcasses were heavier (P<0.05) than full scavenging ones (1.0 ± 0.06kg). The ultimate pH (24h) (pHu) of meat from full scavenging chickens (6.0 ± 0.03) was higher (P<0.05) than that of meat from the semi-scavenging chickens (5.7 ± 0.04). Meat from the full scavenging chickens had higher L* values (60 ± 1.2) than meat from the semi-scavenging chickens (47 ± 0.8). The a* value of meat of full scavenging chickens was significantly (P<0.05) less (4 ± 0.4) than that of meat from semi-scavenging chickens (15 ± 1.3). There was a significant positive (0.60) correlation between pHu and L* of meat from village chickens across rearing systems. The semi-scavenging system meat had better sensory attributes than the meat from the full scavenging system. Female consumers scored the typical flavour of village chicken meat across rearing systems higher (P< 0.05) than male consumers. The Shona consumers scored the meat higher (P< 0.05) than the Xhosa, Zulu, Ndebele and other tribes for initial juiciness, first bite impression and muscle fibre and tenderness of the chicken across rearing systems. Consumers scored of the meat from the semi-scavenging system higher (P<0.05) on initial juiciness (4.3 ± 0.20), first bite impression (4.2 ± 0.197), muscle fibre tenderness (4.5 ± 0.217) than meat from the full scavenging chickens. There were positive correlations (0.46) between aroma intensity and overall flavour intensity across both rearing systems. The semi-scavenging system produced better carcass characteristics, lighter (L*) meat and more consumer acceptable meat than full scavenging chickens. Therefore the full scavenging rearing system had better nutrient composition in its scavenging feed resource base, although the semi-scavenging systems produced chickens with better carcass, meat pH, colour and sensory characteristics than the full scavenging chickens.
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Murungu, Farayi Solomon. "Evaluation and management of cover crop species and their effects on weed dynamics, soil fertility and maize (Zea mays L.) productivity under irrigation in the Eastern Cape Province, South Africa." Thesis, University of Fort Hare, 2010. http://hdl.handle.net/10353/335.
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The current interest in conservation agriculture (CA) technologies is a result of the need to reduce excessive land degradation in most crop producing areas as well as to enhance sustainable food production. Cover crops that are usually grown under CA to provide soil cover, may offer secondary benefits, depending on the farming system. The concept of growing cover crops is a relatively new phenomenon to smallholder farmers. Production of large biomass yields and weed suppression from cover crops were major challenges affecting success and uptake of CA technologies by smallholder irrigation farmers. Coupled with this, low soil fertility limit maize productivity and reduce water use efficiency on smallholder irrigation schemes in what is largely a water strained agro-ecology in South Africa. While cover cropping can increase maize productivity, benefits of different types of mulch are not well understood, leading to challenges in selecting the most appropriate cover crop species to grow in the Eastern Cape Province (EC) of South Africa (SA) which has a warm temperate climate. With respect to any new technology, smallholder farmers are more interested in the economic benefits. Cover crops have been defined as leguminous or non-leguminous plants used for ground cover in various temporal and special configurations used in crop or animal production systems. The purpose of these cover crops is to improve on or more of the following: soil erosion, availability and cycling of N, P, K, Ca and other nutrients, soil moisture and water infiltration, and weed or pest control (Eilitta et al., 2004).. Improvement of animal or human diet may be additional goals. This definition accommodates diverse systems which may include intercrop and sole-cropping systems. In the Eastern Cape Province of South Africa, a government initiative has promoted the growing of winter cover crops in smallholder irrigation schemes (Allwood, 2006). In other parts of Africa, legume food crops have been simultaneously grown with cereal staples to improve both soil cover and human diet (Eilitta et al., 2004). Winter experiments were undertaken in 2007 and 2008 to evaluate biomass accumulation, C and N uptake, weed suppression and response to fertilization. Winter cover crops planted included; oats (Avena sativa), grazing vetch (Vicia dasycarpa), faba bean (Vicia faba), forage peas (Pisum sativum) and lupin (Lupinus angustifolius). After cover crops were terminated, the effects of residues on weeds, fertility, moisture conservation and maize productivity were undertaken in the 2007/08 and 2008/09 summer seasons. Field studies were also done in the 2007/08 and 2008/09 summer seasons to investigate effects of strip intercropping patterns (3:2; 4:2; and 6:2 patterns) of maize (cv. PAN 6479) with mucuna (Mucuna pruriens) or sunnhemp (Crotalaria juncea) on maize productivity and summer cover crop biomass production. In a separate experiment effects of relay intercropping sunnhemp, mucuna and sorghum (Sorghum bicolor) on biomass accumulation and maize productivity were investigated. Decomposition, N and P release from both winter cover crops and summer cover crops were also assessed in laboratory incubation experiments. Oats, grazing vetch and forage peas cover crops produced mean dry mass of 13873 kg/ha, 8945.5 kg/ha and 11073 kg/ha, respectively, while lupin had the lowest dry mass of 1226 kg/ha over the two seasons. Oats responded to fertilization while, there was little or no response from the other winter cover crops. Oats and grazing vetch also reduced weed density by 90 % and 80 % respectively while lupin only reduced weed density by 23 % in relation to the control plots. Nitrogen uptake was 254 kg N/ha for oats while it was 346 kg N /ha for grazing vetch. In the subsequent summer season, grazing vetch and forage pea residues significantly (P < 0.01) improved soil inorganic N. Oat and grazing vetch residues significantly (P < 0.05) reduced weed dry masss and weed species diversity compared to plots with lupin residues and the control. Lack of maize fertilization tended to reduce maize yields but not for maize grown on grazing vetch residues. From an economic perspective, grazing vetch resulted in the highest returns. Decomposition of winter cover crops was much faster for grazing vetch followed by forage peas and lastly oats. Oats had 40 % ash free dry mass remaining after 124 days while grazing vetch and forage peas had 7 % and 16 % respectively. Maximum net mineralized N and P were greater for grazing vetch (84.8 mg N/kg; 3.6 mg P/kg) compared to forage peas (66.3 mg N/kg; 2.7 mg P/ha) and oats (13.7 mg N/kg; 2.8 mg P/kg). In the strip intercropping trials, sunnhemp achieved the highest biomass yield of 4576 kg/ha in the 3:2 pattern while mucuna achieved 1897 kg/ha for the same strip pattern. The 3:2 strip intercropping pattern slightly depressed yields, however, yield reduction was more pronounced in the first season where water stress was experienced. Growing maize on previous cover crop strips failed to increase maize productivity probably due to weed growth during the fallow reducing mineral N in these strips. Decomposition was faster in sunnhemp leaves and mucuna compared to sunnhemp stems. Sunnhemp stems had about 65 % of ash free dry mass remaining after the end of the experiment at 132 days while just over 10 % of mucuna and sunnhemp leaves still remained. Mucuna mineralized 60 mg N/kg and 3.2 mg P/kg and sunnhemp mineralized 45 mg N/kg and 3.5 mg P/kg. Relay intercropping did not significantly (P > 0.05) affect maize biomass and grain yield. Sorghum experienced the largest drop in biomass when relay-intercropped with maize. Mucuna resulted in the highest N uptake (271 kg N/ha) in sole cropping while sorghum had the lowest (88 kg N/ha). Grazing vetch results in high biomass yields with minimal fertilizer application in a warm-temperate climate. Grazing vetch mulch is also the most cost effective mulch for better early weed control, improving soil mineral N status, water conservation and ultimately enhanced maize productivity in smallholder irrigation maize-based systems. The 3:2 pattern maximizes summer cover crop biomass yields compared to the 6:2 and 4:2 patterns. However, the 3:2 pattern may slightly depress yields in a water stressed environment. Relay intercropping mucuna, sunnhemp and sorghum into a maize crop at 42 days after maize sowing has no effect on maize productivity while cover crop biomass yields are low. Having a long winter fallow period after maize harvesting, a common practice in the study area, reduces the positive impact of legume cover crops on soil mineral N. Results suggest that winter cover crops may result in weed control, soil fertility and maize yield improvement benefits while a long fallow period may cancel-out these benefits for summer cover crops. Grazing vetch is a cost effective cover crop that produces high maize yields with minimal fertilizer input. Maize growing on oat mulch requires more fertilizer application than crops growing on grazing vetch mulch. Conservation agriculture systems in which summer cover crops are grown alongside the maize crop with a long winter fallow period do not produce the intended CA benefits.
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Beukes, Natasha. "An investigation into the synergistic association between the major Clostridium cellulovorans cellulosomal endoglucanase and two hemicellulases on plant cell wall degradation." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1004027.
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The cellulosome is a multimeric enzyme complex that has the ability to metabolise a wide variety of carbonaceous compounds. Cellulosomal composition may vary according to the microbe’s nutritional requirement and allows for the anaerobic degradation of complex substrates. The complex substrates of interest in this research study were sugarcane bagasse and pineapple fibre waste, as they represent two important lignocellulosic, South African agricultural crops. The effective degradation of complex plant biomass wastes may present a valuable source of renewable compounds for the production of a variety of biofuels, for example bioethanol, and a variety of biocomposites of industrial importance. The identification of renewable energy sources for the production of biofuels is becoming increasingly important, as a result of the rapid depletion of the fossil fuels that are traditionally used as energy sources. An effective means of completely degrading lignocellulose biomass still remains elusive due to the complex heterogeneity of the substrate structure, and the fact that the effective degradation of the substrate requires a consortium of enzymes. The cellulosome not only provides a variety of enzymes with varying specificities, but also promote a close proximity between the catalytic components (enzymes). The close proximity between the enzymes promotes the synergistic degradation of complex plant biomass for the production of valuable energy products. Previous synergy studies have focused predominantly on the synergistic associations between cellulases; however, the synergy between hemicellulases has occasionally been documented. This research project established the synergistic associations between two Clostridium cellulovorans hemicellulases that may be incorporated into the cellulosome and a cellulosomal endoglucanase that is conserved in all cellulosomes. This research study indicated that there was indeed a synergistic degradation of the complex plant biomass (sugarcane bagasse and pineapple fibre). The degrees of synergy and the ratio of the enzymes varied between the two complex substrates. The initial degradation of the bagasse required the presence of all the enzymes and proceeded at an enhanced rate under sulphidogenic conditions; however, there was a low production of fermentable sugars. The low quantity of fermentable sugars produced by the degradation of the bagasse may be related to the chemical composition of the substrate. The sugarcane contains a high percentage of lignin forming a protective layer around the holocellulose, thus the glycosidic bonds are shielded extensively from enzymatic attack. In comparison, the initial degradation of the pineapple fibre required the action of hemicellulases, and proceeded at an enhanced rate under sulphidogenic conditions. The initial degradation of the pineapple fibre produced a substantially larger quantity of fermentable sugars in comparison to the bagasse. The higher production of fermentable sugars from the degradation of the pineapple fibre may be explained by the fact that this substrate may have a lower percentage of lignin than the bagasse, thus allowing a larger percentage of the glycosidic bonds to be exposed to enzymatic attack. The data obtained also indicated that the glycosidic bonds from the hemicellulosic components of the pineapple fibre shielded the glycosidic bonds of the cellulose component. The identification of the chemical components of the different substrates may allow for the initial development of an ideal enzyme complex (designer cellulosome) with enzymes in an ideal ratio with optimal synergy that will effectively degrade the complex plant biomass substrate.
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Ganyani, Lloyd Munashe. "Evaluating summer cover crop species and management strategies for rainfed maize based cropping systems in the central region of the Eastern Cape Province of South Africa." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/373.
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The overall objective of the whole study was to assess whether conservation agriculture (CA) systems can work in the Eastern Cape Province (EC). The CA systems were engaged through cover cropping to address land degradation problems by emphasizing high biomass production in order to realize short term benefits such as moisture conservation, weed suppression and soil fertility benefits under rainfed conditions in the central region of the Eastern Cape province. Since rainfall is the most limiting factor to crop production in the EC, a within season rainfall distribution analysis was conducted to expose the quality of the season (onset, end and duration) and hence the feasibility of CA systems to guide agronomic decisions by farmers in EC. To assess season parameters, thirty four years of daily rainfall was collected from the University of Fort Hare Research station and used to conduct the rainy pentad (5 day rainfall totals) analysis and the daily rainfall analysis using INSTAT software programme. Based on the pentad analysis, results showed that Alice does not have a rainy season in 1 out of 2 years (50% probability) but has one in 1 out of 4 years (25% probability level). This criterion proved to be harsher and conservative when compared to the daily rainfall approach which is more precise in measuring trends on season parameters. The daily rainfall analysis indicated a 65% feasibility for the dry land cropping systems in the EC. The pentad analysis however was effective in illustrating seasonality and it showed that the wet season begins on the 1st of November, ending on the 22nd of March lasting for 140 days. Though the season duration appeared too long, the existence of dry spells during critical growth stages adversely affects the quality of the season. The daily rainfall analysis also managed to derive a signal which can guide planting decisions. For planting to be successful, this analysis determined that 20 mm of rain should be received in two consecutive days after the 1st of November. A screening trial for cover crop biomass production and weed suppression was conducted on-station Fort Hare Research Farm (32°46' S and 26° 50' E), and Msobombvu village (MSBV) (32°44' S, and 26° 55' E) over two seasons (2007/08 and 2008/09). Six summer cover crops i.e. cowpea (Vigna unguiculata), dolichos lablab (Dolichos argenteus), sunnhemp (Crotalaria juncea), buckwheat (Fagopyrum sagittatum), forage sorghum (Sorghum bicolor) and sunflower (Helianthus annus) were evaluated for biomass yield, and weed suppression. Decomposition rates, moisture conservation and residual effects of these cover crops on the succeeding main crop were also evaluated under dryland conditions. The screening trial was laid in randomized complete block design replicated three times. Forage sorghum (Sorghum bicolor) and sunflower (Helianthus annus) were identified as high biomass producers and their dry matter yields ranged from 8 -12 t ha-1. These cover crops can be useful in generating high biomass in rainfed cropping systems in the EC. Other cover crops produced 3 - 4 t ha-1 of biomass which fell short of the 6 t ha-1 expected benchmark. However, these biomass yields were important in weed management since all cover crop species showed a similar degree of weed suppression which surpassed the weed fallow treatment. As dead mulches, the cover crops failed to show residual moisture conservation and weed control benefits for the succeeding maize crop mainly because of poor residue persistence, and low harvestable fallow rainfall. Buckwheat (Fagopyrum esculentum), was selected for further investigations in a follow up trial on station in 2008/09 season because of its weed smothering qualities, suitability to short cycle rotations, and possible allelopathic properties. The trial aimed at finding weed and cost effective management options of buckwheat that are none detrimental to the succeeding maize crop. Results showed that cropping systems where buckwheat is followed by a main crop may not work as they are unprofitable with respect to R100 rand invested. Though perceived to have allelopathic properties, buckwheat failed to demonstrate the possibilities of allelopathic action against weeds. Intercropping trial was conducted on-station in 2007/8-2008/09 seasons to try and find better ways of fitting legume cover crops into maize based cropping systems without compromising production of staple cereals on limited landholdings. The trials evaluated three factors in factorial combination, cover crop planting date, intercropping strategy, and cover crop species. The trial was laid as 2 x 2 x 3 factorial arranged in a split-split plot design. The main plot factor was cover crop planting date, cover crops simultaneously planted with maize and cover crop planted two weeks after planting maize (DKC 61-25). The sub-plot factor was intercropping strategy, strip intercropping and betweenrow intercropping. The sub-sub-plot factor was cover crop species, Dolichos lablab (Dolichos argenteus (Highworth), and Cowpea Vigna ungiculata (Agrinawa) plus control plots of sole maize. Results showed that same time planting of leguminous cover crops with maize using the in-between row intercropping patterns can derive appreciable system biomass (maize/cover crop) yields, utilize land efficiently whilst getting favourable maize grain yield. Based on the rainfall analysis, results showed that the probability of success when relay seeding cover crops after two weeks into standing maize is low (15% chances of success). This suggests that relay intercropping strategies would not work due to the unavailability of a good quality season.
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Musunda, Bothwell Zvidzai. "Evaluation of cover crop species for biomass production, weed suppression and maize yields under irrigation in the Eastern Cape Province, South Africa." Thesis, University of Fort Hare, 2010. http://hdl.handle.net/10353/347.
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Achieving high biomass yields of cover crops has been a challenge to the success of Conservation Agriculture (CA) practices in the Eastern Cape (EC). A study was conducted to evaluate strategies for optimizing cover crop biomass production. Trials were carried out to screen summer and winter cover crops, as well as evaluate intercropping patterns and planting dates for biomass, weed suppression and subsequent maize yield under irrigation. Four summer legume cover crop species were evaluated under a Randomised Complete Block Design (RCBD) design. The cover crops were fertilized with 13.34 kg ha-1 of N, 20 kg ha-1 P and 26.66 kg ha-1 K. In the 2008/09 summer season a maize crop was superimposed on the 2007/08 screening trial under no-till. The crop was fertilized with 60 kg ha-1 of N. An intercropping trial was conducted over two seasons as a way of investigating the best way of incorporating cover crops into farmers cropping systems. This was done bearing in mind the limitation of resources such as land. The trial evaluated 3 factors laid as a 2 x 2 x 3 factorial arranged in a split-plot design. The main factor was cover crop planting date (planting at maize planting or 2 weeks after maize planting). The sub plot factor was intercropping pattern (strip intercropping and between row intercropping). A trial was also conducted to evaluate the effect of planting date (End of April and mid May) and four winter legume cover crop species on cover crop biomass, weed suppression and maize grain yield. The experiment was laid out as a Randomised Complete Block Design (RCBD) replicated 3 times. In the subsequent summer season a maize crop was superimposed on the winter trial to test the residual effects of the cover crop species. Another study was conducted to evaluate winter cereal cover crop species for biomass accumulation, weed suppression and subsequent maize grain yield. The cover crops as well as a weedy fallow control plot treatments were laid out as a Randomised Complete Block Design replicated 3 times. In the subsequent summer season a maize crop was superimposed on the site under no-till to evaluate the residual effect of the cover crops on maize. The results showed sunhemp, cowpea and lablab as the best cover crops with high biomass and weed suppression whilst mucuna was the least. Sunhemp consistently yielded higher cover biomass averaging 11200 kg ha-1 over the two seasons whilst mucuna had a consistently lowest average biomass yield of 4050 kg ha-1. These cover crops were above the critical 6 t ha-1 for effective weed suppression. There was a significant (p<0.01) relationship of cover crop dry weight and weed dry weight in both seasons. Subsequent maize grain yield was significantly higher in the sunhemp plots (64.2 %) than the weedy fallow plot. Mucuna, lablab and cowpea had maize grain yield increases of 16.6%, 33% and 43.2% respectively. Intercropping cover crops at maize planting yielded higher cover crop dry weights than a delay in intercropping cover crops. A delay in intercropping resulted in significantly higher average maize grain yield of 4700 kg ha-1 compared to intercropping at maize planting (3800 kg ha-1) and sole maize (4300 kg ha-1) over the two seasons. Strip intercropping also yielded higher (5000 kg ha- 1) average maize grain yield compared to row intercropping (3600 kg ha-1) and sole maize (4300 kg ha-1). There was a significant (p<0.05) relationship between cover crop dry weight in the 2007/08 season and maize grain yield in the 2008/09 season. Early planting grazing vetch gave the highest biomass yield of 8100 kg ha-1 whilst early planted red clover had the lowest biomass of 635 kg ha-1. Low weed dry weights were also obtained from the early planted grazing vetch as opposed to the other treatments. There was a significant (p<0.001) relationship of cover crop dry weight and weed dry weight. In the subsequent 2008/09 summer season early planted grazing vetch had the highest maize yield of 7500 kg ha-1 which was 56.3 % more than the weedy fallow plot had 4800 kg ha-1. The weedy fallow plot also had high weed infestation than the cover crop plots. There were significant (p<0.01) relationships between cover crop dry weight and maize grain yield, winter weed dry weight and maize grain yield and summer weed dry weight and maize grain yield. The results also showed triticale (13900 kg ha-1) as the best winter cover crop for biomass production. Italian ryegrass (6500 kg ha-1) produced the least amount of biomass. In The subsequent maize crop white oats gave highest maize grain yield (6369 kg ha-1) which was 33 % more than the weedy fallow plot (4784 kg ha- 1). There were also significant (p< 0.01) relationships of maize grain yield and winter weed dry weight, maize grain yield and summer growing weeds. The various studies demonstrated that there is opportunity for high biomass production under small scale farmers irrigated conditions using cover crops both in winter and summer. Best bet cover crops were sunhemp, cowpea and lablab for summer and triticale, white oats, barley, Italian ryegrass and grazing vetch for winter. Cover crops can also be incorporated into farmers cropping systems as sole crops or intercrops within the maize based cropping systems. Strip intercropping can be used by farmers as a way of introducing cover crops. Critical to achievement of high biomass is the time of planting cover crops with high biomass when planting is done early. A 2 week delay in strip intercropping cover crop into maize can be used as a way of incorporating cover crops into farmers cropping systems with minimal maize yield reduction.
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Oosthuizen, Hamman Jacobus. "Modelling the financial vulnerability of farming systems to climate change in selected case study areas in South Africa." Thesis, Stellenbosch: Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95831.
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Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Numerous studies indicate that the agricultural sector is physically and economically vulnerable to climate change. In order to determine possible impacts of projected future climates on the financial vulnerability of selective farming systems in South Africa, a case study methodology was applied. The integrated modelling framework consists of four modules, viz.: climate change impact modelling, dynamic linear programming (DLP) modelling, modelling interphases and financial vulnerability assessment modelling. Empirically downscaled climate data from five global climate models (GCMs) served as base for the integrated modelling. The APSIM crop model was applied to determine the impact of projected climates on crop yield for certain crops in the study. In order to determine the impact of projected climates on crops for which there are no crop models available, a unique modelling technique, Critical Crop Climate Threshold (CCCT) modelling, was developed and applied to model the impact of projected climate change on yield and quality of agricultural produce. Climate change impact modelling also takes into account the projected changes in irrigation water availability (ACRU hydrological model) and crop irrigation requirements (SAPWAT3 model) as a result of projected climate change. The model produces a set of valuable results, viz. projected changes in crop yield and quality, projected changes in availability of irrigation water, projected changes in crop irrigation needs, optimal combination of farming activities to maximize net cash flow, and a set of financial criteria to determine economic viability and financial feasibility of the farming system. A set of financial criteria; i.e. internal rate of return (IRR), net present value (NPV), cash flow ratio, highest debt ratio, and highest debt have been employed to measure the impact of climate change on the financial vulnerability of farming systems. Adaptation strategies to lessen the impact of climate change were identified for each case study through expert group discussions, and included in the integrated modelling as alternative options in the DLP model. This aims at addressing the gap in climate change research, i.e. integrated economic modelling at farm level; thereby making a contribution to integrated climate change modelling.
AFRIKAANSE OPSOMMING: Die fisiese sowel as ekonomiese kwesbaarheid van die landbousektor as gevolg van klimaatverandering word deur verskeie studies beklemtoon. ‘n Gevallestudie-benadering is gebruik ten einde die potensiële impak van klimaatsverandering op die finansiële kwesbaarheid van verskillende boerderystelsels te bepaal. Die geïntegreerde klimaatsveranderingmodel bestaan uit vier modelleringsmodules, naamlik: klimaatsverandering, dinamiese liniêre programmering (DLP), interfases en finansiële-kwesbaarheidsontleding. Empiries afgeskaalde klimatologiese data van vyf verskillende klimaatmodelle dien as basis vir die geïntegreerde klimaatsveranderingmodel. Die APSIM gewas-model word aangewend om die impak van klimaatsverandering op gewasse-opbrengs te bepaal. Vir sekere gewasse is daar egter nie modelle beskikbaaar nie en het gevolglik die ontwikkeling van ‘n nuwe model genoodsaak. Die Kritiese Gewasse Klimaatsdrempelwaarde (KGKD) modelleringstegniek is ontwikkel ten einde die impak van klimaatsverandering op die opbrengs en kwaliteit van gewasse te kwantifiseer. Die geïntegreerde klimaatsveranderingmodel neem ook die verwagte verandering in besproeiingswaterbeskikbaarheid (ACRU-hidrologiemodel) en gewas-besproeiingsbehoeftes (SAPWAT3-model) as gevolg van klimaatsverandering in ag. Die model lewer waardevolle resultate op, naamlik: geprojekteerde veranderinge in gewasse-opbrengs en -kwaliteit, geprojekteerde verandering in beskikbaarheid van besproeiingswater en gewasse-besproeiingsbehoeftes, die optimale kombinering van boerdery-aktiwiteite om netto kontantvloei te maksimeer, asook ‘n stel finansiële resultate wat die impak van klimaatsverandering kwantifiseer. Die finansiële kriteria sluit in: interne opbrengskoers, netto huidige waarde, kontanvloeiverhouding, hoogste skuldverhouding en hoogste skuldvlak. Deur middel van deskundige-groepbesprekings is aanpassingstrategieë vir elk van die gevallestudies geïdentifiseer en by die geïntegreerde model ingesluit as alternatiewe opsies in die DLP-model. Die studie poog om die gaping in die huidige klimaatsveranderingnavorsing met betekking tot ‘n geïntegreerde ekonomiese model op plaasvlak aan te spreek en sodoende ‘n bydrae tot geïntegreerde klimaatveranderingmodellering te maak.
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Von, Doderer Clemens Cornelius Christian. "Viability of producing lignocellulosic biomass in the Cape Winelands District Municipality for bioenergy generation." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1646.
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Thesis (MScAgric (Agricultural Economics)--University of Stellenbosch, 2009.The growing scarcity of fossil energy, expressed by rising real prices, justifies an investigation into the viability of utilising alternative, sustainable energy sources. Another motivation is to mitigate CO2 pollution resulting from using fossil fuels, causing climate change. Biomass has the potential to become a major global primary energy source during the next century. In South Africa, a limited amount of land is suitable for high‐potential biomass energy sources like sugar cane or grain. Large areas of South Africa are, however, dry and more suitable for woody biomass production. Cultivating trees in short‐rotation‐system plantations provides a sustainable and effective way of producing biomass. The first part of this study investigated the physical capacity of the Cape Winelands District Municipality (CWDM) for woody biomass production in short‐rotation systems, based on a land availability assessment using Geographic Information Systems (GIS). The CWDM comprises about 2.3 million hectares, of which about 175 000 ha with a slope of less than 35% have been identified as suitable for woody biomass production. Within the CWDM, the following land use classes were excluded: nonagricultural land, such as urban areas, bare rock and mines; ecologically sensitive areas; as well as areas with slope gradients that are too steep for biomass production, due to limited accessibility and trafficability. This was followed by an assessment of suitable tree species and their productivity rates – also using GIS with climate data (i.e. temperature extremes, frost and mean annual precipitation) and terrain data. By combining the identified biomass production sites with the productivity rates of the identified species, an annual supply of woody biomass for energy generation at a medium productivity of about 1 412 000 tonnes of fresh biomass is expected, using exotic species like Eucalyptus claducalyx ( and about 1 306 000 tonnes, using indigenous species like Acacia karoo).
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Muchara, Binganidzo. "Analysis of food value chains in smallholder crop and livestock enterprises in Eastern Cape Province of South Africa." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/d1000983.
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The study was conducted in Mbozi and Ciko villages in Mbhashe Local Municipality of the Eastern Cape Province of South Africa. Two irrigation projects in the area were studied. Consumers and agricultural commodity traders in Willowvale Town, Dutywa, Butterworth and East London were also interviewed. The major objective of the study is to profile and map cabbage, maize and cattle food value chains broadly, and to understand their nature, constraints and opportunities in smallholder agriculture. A multi-stage random sampling procedure was used in which the first stage involved selecting the local government areas. This was followed by the selection of the district and then the respondents. A total of 168 participants were sampled in the proportion of 82 smallholder farmers, 41 consumers, 26 hawkers and 20 agricultural commodity traders. Focus group discussions and key informant interviews were also used during the data collection process. Value Chain mapping was done using the commodity based approach. All value chains under study indicated that they are short and commodities were transacted in unprocessed form. As cabbages and maize move from the farm to retail outlets, value addition start to take place through transportation to the market and processing in supermarkets. The cattle value chain however does not have a forward linkage beyond the two administrative boundaries of the two communities. Less than 3% of the farmers traded livestock, and this was mostly through private sales to neighbours. The farmers‘ major goal in agricultural production is assumed to be an important aspect in lengthening the value chain. As such, results of a Pearson‘s correlation exercise indicated that there is a significant relationship at 0.05% level between goals of the farmers and the village of origin. Some factors that showed significance (p=0.05) in influencing farmers‘ goals are membership of an irrigation project and household sources of income. An analysis of determinants of technical efficiency at farm level was performed using the stochastic frontier model for cabbage, maize and cattle enterprises. The results showed that rainfall adequacy, input costs, market channels and quantity sold are important determinants of cabbage production efficiency. On the other hand, maize production efficiency is positively determined by market price, area under production and rainfall adequacy. Market related variables are major drivers of the cattle value chain efficiency and these include cattle prices, market satisfaction, market channel and farm labour.
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Von, Doderer Clemens Cornelius Christian. "Determining sustainable lignocellulosic bioenergy systems in the Cape Winelands District Municipality, South Africa." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71838.
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Thesis (PhD(Agric))--Stellenbosch University, 2012.ENGLISH ABSTRACT: The energy paradigm shift from fossil fuels to renewable energy sources is driven, among others, by a growing sustainability awareness, necessitating more sophisticated measurements in terms of a wider range of criteria. Technical efficiency, financial profitability, environmental friendliness and social acceptance are some of the factors determining the sustainability of renewable energy systems. The resulting complexity and conflicting decision criteria, however, constitute major barriers to processing the information and decision-making based on the information. Seeking to implement local bioenergy systems, policymakers of the Cape Winelands District Municipality (CWDM), South Africa, are confronted with such a problem. Following a case study approach, this study illustrates how life-cycle assessment (LCA), multi-period budgeting (MPB) and geographic information systems (GIS) can aid the decision-making process by providing financial-economic, socio-economic and environmental friendliness performance data in a structured and transparent manner, allowing for a comparison of the magnitude of each considered criterion along the life-cycle. However, as the environmental impacts cannot readily be expressed in monetary terms on a cardinal scale, these considerations are given less attention or are omitted completely in a market economy. By measuring the various considerations on an ordinal scale and by attaching weights to them using the multi-criteria decision analysis (MCDA) approach, this study, illustrates how to internalise externalities as typical market failures, aiding policymakers of the CWDM to choose the most sustainable bioenergy system. Following the LCA approach, 37 lignocellulosic bioenergy systems, encompassing different combinations of type of harvesting and primary transport, type of pretreatment (comminution, drying, and fast pyrolysis) and location thereof (roadside or landing of the central conversion plant), type of secondary transport from the roadside to the central conversion plant, and type of biomass upgrading and conversion into electricity, were assessed against five financial-economic viability criteria, three socio-economic potential criteria and five environmental impact criteria. The quantitative performance data were then, as part of the MCDA process, translated into a standardised ‘common language’ of relative performance. An expert group attached weights to the considered criteria using the analytical hierarchy process (AHP). The ‘financial-economic viability’ main criterion received a weight of almost 60%, ‘socio-economic potential’, nearly 25% and ‘lowest environmental impact’, the remainder of around 16%. Taking the prerequisite of financial-economic viability into consideration, the preferred option across all areas of the CWDM (despite various levels of productivity) comprises a feller-buncher for harvesting, a forwarder for primary transportation, mobile comminution at the roadside, secondary transport in truck-container-trailer combinations and an integrated gasification system for the conversion into electricity.
AFRIKAANSE OPSOMMING: Die energie paradigma verandering van fossielbrandstowwe na hernubare energiebronne word gedryf deur ‘n groeiende klem op volhoubaarheid, wat ook meer gesofistikeerde meting in terme van ‘n wyer verskeidenheid maatstawwe vereis. Tegniese doeltreffendheid, finansiële winsgewendheid, omgewingsvriendelikheid en sosiale aanvaarbaarheid is sommige van die faktore wat die volhoubaarheid van hernubare energie stelsels bepaal. Die verskeidenheid oorwegings bring egter kompleksiteit en konflik mee by die verwerking van inligting en die besluitneming wat daarop berus. Beleidmakers van die Kaapse Wynland Distriksmunisipaliteit wat ten doel het om plaaslik bio-energie stelsels te implementeer, word met hierdie probleem gekonfronteer. Hierdie ondersoek illustreer aan die hand van ‘n gevallestudie benadering hoe lewensiklus analise, multiperiode begroting en geografiese inligtingstelsels besluitneming kan ondersteun deur die voorsiening van finansieel-ekonomiese, sosio-ekonomiese (indiensneming) en omgewingsvriendelikheid prestasie data op ‘n gestruktureerde en deursigtige wyse. Dit maak die vergelyking van die waardes van al die kriteria by elke fase van die lewensiklus moontlik. Aangesien die omgewingseffekte nie geredelik in monetêre terme op ‘n kardinale skaal gemeet kan word nie, kry hulle binne die markekonomie minder aandag of word selfs buite rekening gelaat. Deur hierdie verskeidenheid kriteria op ‘n ordinale skaal te meet en gewigte met behulp van multikriteria besluitneming aan hulle toe te ken, toon hierdie ondersoek hoe om eksternaliteite as tipiese markmislukkings te internaliseer om beleidmakers van die Kaapse Wynland Distriksmunisipaliteit in staat te stel om die mees volhoubare bio-energie stelsel te kies. Met behulp van lewensiklus analise is 37 lignosellulose bio-energie stelsels geïdentifiseer as verskillende kombinasies van oes van die bome, primêre vervoer van houtstompe, vooraf verwerking (verspaandering, droging, vinnige pirolise), die ligging van hierdie aktiwiteite (langs ‘n plantasie of by ‘n sentrale omsettingsaanleg), tipe sekondêre vervoer van houtspaanders vanaf die plantasie na die sentrale omsettingsaanleg en tipe biomassa opgradering en omsetting van die houtspaanders na elektrisiteit. Die verskillende stelsels is gemeet aan die hand van vyf finansieel-ekonomiese kriteria, drie indiensneming potensiaal kriteria en vyf omgewingsimpak kriteria. Die kwantitatiewe metings is deur middel van multikriteria besluitneming omgeskakel na ’n gestandaardiseerde “gemeenskaplike taal” van relatiewe prestasie. Lede van ‘n ekspertgroep het gewigte is aan die onderskeie kriteria met behulp van die analitiese hierargie proses toegeken. Aan die finansieel-ekonomiese lewensvatbaarheid hoof kriterium is ‘n gewig van by die 60% toegeken, aan die indiensnemingspotensiaal bykans 25% en aan omgewingsvriendelikheid sowat 16%. Die voorkeur kombinasie vir al die areas van die Kaapse Wynland Distriksmunisipaliteit sluit in ‘n saag-bondelaar vir die oesproses, ‘n plantasie-vragmotor vir primêre vervoer, mobiele verspaandering langs die plantasie, ‘n vragmotor-skeepshouer-treiler kombinasies vir die sekondêre vervoer van houtspaanders en ‘n geïntegreerde vergassingstelsel vir die omsetting van houtspaanders na elektrisiteit.
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Roux, F. A. "Die invloed van spesifieke grond en klimaats parameters op wingerdprestasie, wynkwaliteit en -karakter." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1343.
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Snyman, Sandra Jane. "Development of a transformation system for sugarcane (Saccharum spp. hybrids) in South Africa using herbicide resistance as a model system." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52764.
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Ngxetwane, Vuyolwethu. "Integrated crop-livestock farming system for sustainable economic empowerment of small-scale and emerging farmers in the former homeland of the Eastern Cape province of South Africa: a case study of Ciskei area in Nkonkobe municipality." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/459.
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For decades, there has been significant investment in the development of agricultural technologies that aim to increase productivity of smallholder farmers in Africa. But farm output and productivity have stagnated and poverty rates have remained high and even increasing in some areas. At the same time, increases in human population levels have resulted in rising demand for food as well as for arable land. The growing intensification of farming has been accompanied by degradation of wild lands, including tropical forests and wetlands, at an alarming rate. Further pressure on fragile land has come from associated urbanization, leading to agricultural land being converted to residential and industrial uses with serious consequences for agricultural production and food supply. The recent increases in food prices across the globe as well as South Africa have drawn attention to this problem even more strongly. The main objective of the current study was to investigate farmer’s perception of the relative importance of crop-livestock integration in the small holder farming systems. Data were collected from 70 emerging and smallholder farmers selected by stratified random sampling in the communities surrounding Alice, Middledrift and the Seymour- Balfour area of Nkonkobe municipality of the Eastern Cape Province. To collect the data, a semi-structure questionnaire was administered to the respondents through face-to-face interviews. Descriptive statistics were used to characterize the farmers in terms of their socio-economic and demographic backgrounds. A series of multiple linear regression models and a binary logistic regression equation were fitted to determine the factors influencing farmers’ perception and how these in turn contribute to the decision to adopt or not to adopt crop-livestock integration. The results of the study reveal that small farmers in the Nkonkobe municipality have the possibility of realizing immense benefits from the integrated systems which also have the potential to lead to substantial improvements of the physical, chemical and biological soil properties. There is clear evidence of widespread interest to experiment with the practices based on the strong positive perceptions that a majority of the survey farmers exhibited during the course of the survey. But the farmers are facing challenges in coping with the associated complexities of competition on land, and management skill which are often in limited supply. That in most cases is not enough and efficient even to manage one of these two enterprises alone and reduction in crops yield due to use of manure as a substitute of fertilizer. Constraints to integrating crops and livestock include the competition for resources, especially land. Managing two types of farming on the same farm was perceived as difficult and many respondents held the view that use of waste of one enterprise as input to the other enterprise can reduce productivity. For example some farmers considered that the use of manure to improve soil fertility may not lead to output growth to the same extent as the use of fertilizer. A number of farmers (86%) pointed out that they only market their produce after deducting their consumption share, highlighting the crucial role of food security as a motivation for crop-livestock integration. Complementation of inputs rather than substituting inputs is required to render the system more productive and sustainable as costs are minimized and output is boosted. Associations of grain and livestock producers are useful for filling these gaps which include limited access to credit, technology and knowledge and can promote the adoption of a crop-livestock system.
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Stones, Wilna Anneke. "The evaluation of the subtropical crops extension and advisory service (Subtrop) as perceived by farmer members and extension advisors in the subtropical regions, South Africa." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/29115.
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In order to minimize duplication, consolidate resources and strengthen industry representation to government, the South African Avocado Growers Association (SAAGA), South African Litchi Growers Association (SALGA), South African Macadamia Growers Association (SAMAC) and the South African Mango Growers Association (SAMGA); amalgamated under an umbrella organization called Subtrop. This study focuses on the pre and post effect the amalgamation had on Extension services to the abovementioned organizations. The effect was measured by conducting a survey. The survey measured both Subtrop member and relevant Subtrop staff responses. The survey used two questionnaire types, one for Subtrop members and one for Subtrop extension advisors. The questionnaires were designed to complement the SPPS V19.0® statistical package. The questionnaires were completed at group interview sessions. A total of 127 farmer respondents, divided in two groups, namely 90 farmer respondents and 37 opinion leader respondents participated in the external survey. The internal survey comprised of six Subtrop extension advisor respondents. Farmer and opinion leader respondents, (hereafter called respondents), provided their perceptions and rated the extension services of the technical department of Subtrop. Results showed that the respondents used the Extension services for on farm advice and group based Extension services like study groups. The Subtrop Extension services received a higher rating after the Subtrop amalgamation than before the amalgamation. Subtrop extension advisor responses showed a need for training and coaching, as well as some reconciliation with respect to the increase in work load afforded by the amalgamation. Pre-amalgamation extension advisors served one commodity, while post amalgamation extension advisors now serve four commodities. The respondents indicated their satisfaction with the organizing of study groups. They also indicated that the study groups met their needs. Although the respondents understood the value of intercommunication and participation, the study showed that the minority realized the need to take ownership of study groups. All the extension advisors indicated that organizing study groups was the single activity that used most of their time. The Subtrop study groups were rated higher after the Subtrop amalgamation than before. The Subtrop newsletters were rated higher after the Subtrop amalgamation. The respondents indicated the newsletters as valuable and therefore proved newsletters as an appropriate extension communication tool. The Subtrop websites were indicated as somewhat valuable. Most respondents indicated a lack of awareness of the websites, indicating a need to promote the websites better. Although very few respondents completed the marketing related services section of the survey, those that completed this section were all aware of this service. The following recommendations emerged: For extension advisors: - The development of a curriculum of Subtrop commodities for training purposes;
- Regular technical and soft-skill training;
- The development of a mentorship program; and
- For new extension advisors an orientation program which includes the above mentioned.
- Study group management needs to be improved, combine newsletters, improve awareness of research and promote websites and market services.
- Further: develop an extension policy, maximize area committee involvement and regular member feedback surveys.
Dissertation (MSc)--University of Pretoria, 2012.
Agricultural Economics, Extension and Rural Development
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Jukes, Michael David. "The isolation, genetic characterisation and biological activity of a South African Phthorimaea operculella granulovirus (PhopGV-SA) for the control of the Potato Tuber Moth, Phthorimaea operculella (Zeller)." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1017908.
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The potato tuber moth, Phthorimaea operculella (Zeller), is a major pest of potato crops worldwide causing significant damage to both field and stored tubers. The current control method in South Africa involves chemical insecticides, however, there is growing concern on the health and environmental risks of their use. The development of novel biopesticide based control methods may offer a potential solution for the future of insecticides. In this study a baculovirus was successfully isolated from a laboratory population of P. operculella. Transmission electron micrographs revealed granulovirus-like particles. DNA was extracted from recovered occlusion bodies and used for the PCR amplification of the lef-8, lef-9, granulin and egt genes. Sequence data was obtained and submitted to BLAST identifying the virus as a South African isolate of Phthorimaea operculella granulovirus (PhopGV-SA). Phylogenetic analysis of the lef-8, lef-9 and granulin amino acid sequences grouped the South African isolate with PhopGV-1346. Comparison of egt sequence data identified PhopGV-SA as a type II egt gene. A phylogenetic analysis of egt amino acid sequences grouped all type II genes, including PhopGV-SA, into a separate clade from types I, III, IV and V. These findings suggest that type II may represent the prototype structure for this gene with the evolution of types I, III and IV a result of large internal deletion events and subsequent divergence. PhopGV-SA was also shown to be genetically more similar to South American isolates (i.e. PhopGV-CHI or PhopGV-INDO) than it is to other African isolates, suggesting that the South African isolate originated from South America. Restriction endonuclease profiles of PhopGV-SA were similar to those of PhopGV-1346 and PhopGV-JLZ9f for the enzymes BamHI, HindIII, NruI and NdeI. A preliminary full genome sequence for PhopGV-SA was determined and compared to PhopGV-136 with some gene variation observed (i.e. odv-e66 and vp91/p95). The biological activity of PhopGV-SA against P. operculella neonate larvae was evaluated with an estimated LC₅₀ of 1.87×10⁸ OBs.ml⁻¹ being determined. This study therefore reports the characterisation of a novel South African PhopGV isolate which could potentially be developed into a biopesticide for the control of P. operculella.
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Jakavula, Siyabulela Cornelius. "Effectiveness of the high value crop-based extension model in improving rural livelihoods." Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1007533.
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The problem that is researched in this study relates to the effectiveness of the extension model applied in the High Value Crop programme in improving rural livelihoods in the Eastern Cape. The extent of poverty in rural areas in the Eastern Cape motivated for the intervention of the Is‘Baya through the introduction of Integrated Village Renewal Programme (IVRP). The need to improve the quality of life of rural households through the promotion of agriculture and industry gave rise to the collaborative effort between the Is‘Baya Development Trust and Agricultural Research Council (ARC) in South Africa. The HVC programme was established to mitigate the effects of food shortage and poverty through the production of fruit trees, herbs and vegetables at household level. Evaluation of the effectiveness of this collaborative effort was carried out in four local municipalities of the OR Tambo District and these included: King Sabata Dalindyebo municipality (Zangci); Nyadeni municipality (Hluleka); Port St Johns municipality (Noqhekwana) and Ngquza Hill municipality (Hombe). An equal number of villages where Siyazondla was implemented by DRDAR were visited for the survey to relate the extension model applied with HVC. The villages visited included: OR Tambo (Mhlontlo local municipality) Xhokonxa village; Amathole (Amahlathi local municipality) Ndakana village, (Ngqushwa local municipality) Mgababa village and (Mbhashe local municipality) Mbanyana village. The broad objective of the study therefore, was to evaluate the effectiveness of the extension model applied on the HVC programme as well as to identify the roles and responsibilities of different stakeholders involved in the model. The specific objectives of the study were to describe the HVC based extension model as it is currently organized and implemented in the Eastern Cape Province of South Africa in relation to the erstwhile Siyazondla programme, to establish the effectiveness of the extension model in terms of skills transfer and capacity development, to determine the socio-economic impact of the extension model on the livelihood of involved households, to establish the extent to which the extension model has empowered women and youths and to study the factors that has contributed to the sustainability of the extension model. In carrying out this research and in line with the practice of Agricultural Research for Development (ARD), qualitative and quantitative methods of information gathering were applied. Group approach such as the Rural Rapid Appraisal (RRA) and the Participatory Rural Appraisal (PRA) methods of data collection were used. These tools include semi-structured interviews, focus-group discussions, transect walks, seasonal calendars, key-informant interviews, resource maps and secondary data. A sample of 149 respondents was selected from eight villages in the OR Tambo and Amathole districts. The HVC model was analysed using qualitative approach, descriptive statistics and inferential statistics. The Is‘Baya/ARC extension model is thus said to be effective in meeting the objectives of the HVC programme due to the efficient transfer of skills and technology and its positive impact on the livelihood of the people. There was also an improvement of the income and food security status of the rural dwellers in O.R Tambo district. The regression analysis model was applied and the results of the model were significant to the highest income earned. Out of 22 explanatory variables fitted in the regression model, 12 were significant. The R² and adjusted R² are 73 percent and 68 percent respectively which shows the significance of the fitted variables in the model. The very high F value of 15.427 shows strong significance of the fitted variables to the model. The study therefore concluded that the HVC based extension model implemented by Is‘Baya and ARC was very effective in improving rural livelihoods. The study further recommended investment in infrastructure, market linkages, value adding, public-private partnerships, creation of tenure security, investigation of different funding sources, investment on agricultural research, extension of skills provided and implementation of similar model by the public sector.
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Venter, Annari. "Comparing plant yield and composition with soil properties using classical and geostatistical techniques." Diss., University of Pretoria, 2003. http://hdl.handle.net/2263/23916.
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Plant nutrient management plays a vital role in the success or failure of modern Lucerne production. In South Africa, Lucerne is produced under a wide range of climatic conditions, under dryland and irrigation and in some areas throughout the year. This means that there is a continuous demand for nutrients under a wide range of environmental conditions. The most important factors affecting the nutrient requirement of Lucerne is yield, the cutting schedule, climate and management practices. To enable site-specific crop requirements, the spatial variation of soil and plant properties within a field can be managed with the use of geostatistical techniques. Some work has also been done to evaluate the use of geostatistics in the design of agricultural field experiments to provide better field characterization and improve plot layout. The aim of this study was to compare plant yield and composition with soil properties using both classical and geostatistical techniques. The study was conducted from June 2001 to February 2002 on an 18ha Lucerne stand in the Brits district in the North West Province. A rectangular area of 160m X140m was demarcated as the study area and comprised of two soil units (Hutton and Shortlands forms). Seventy-two sampling points (nodes) were laid out on a 20m square grid, with an additional 90 sampling points laid out on a 2.5m square grid at six randomly selected node points. Soil (0-300 mm) and plant samples were taken within a 0.6m square at each of the sampling points for chemical analysis. Starting in June 2001, yield sampling was done on six occasions, at approximate intervals of 5 weeks. A randomized complete block design trail layout was superimposed on the geostatistical grid design and consisted of seven pseudo treatments, replicated four times. Basic statistical analysis were performed and spatial presentations of the variation of the plant and soil properties and Lucerne yield were made using geostatistical analyses. Analyses of variance were used to test for differences between pseudo treatments for all plant and soil properties. The two soils on the stud site, exhibited differences in certain properties, which caused a bi-modal population in the data. Poor correlations were found between plant nutrient uptake and soil properties as well as yield, with little or no resemblance when comparing their spatial distribution. This emphasizes the fact that the uptake of elements is not solely dependant on the concentrations thereof in the soil solution, but on other factors. Temporal variations in Lucerne yield were also observed. Although there were large differences in spatial variation of Lucerne yields across harvesting events, similar spatial patterns were evident. From an analysis of variance of the RCB design it was concluded that the experimental field was homogeneous enough to lay out a standard block design experiment. However, scrutiny of the structure of spatial variability of pH(H2O) revealed that the standard RCB designs did not provide homogeneous blocks with respect to soil variability. The consequent redesign of the experiment whereby all plots were randomly allocated to treatments and replications, led to dramatically different results: significant differences were obtained for plant and soil properties as a function of the pseudo treatments. From this study it is clear that spatial variability of soil and plant properties can jeopardize the results of a standard block design field experiment and it is therefore recommended that the layout of field experiments should be designed to the cognizance of the spatial variation of a soil property that correlated highly with a chosen response variate.Dissertation (MSc (Soil Science))--University of Pretoria, 2007.
Plant Production and Soil Science
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Schreuder, F. A. "An investigation into global distribution systems in the crop protection industry and the development of distribution system managment model for particular application in South Africa and Australia." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/21185.
Full textAbstract:
Thesis (PhD)--Stellenbosch University, 2002.ENGLISH ABSTRACT: The traditional ways in which manufacturers of crop protection products exercised control over distribution systems have diminished in their impact. Control was based on quality products, the power of the brand, an installed customer base and a broad portfolio of mostly patented products. Manufacturers of crop protection products need to review the manner in which these products are marketed, which distribution system management models are to be used, and the importance that is placed on distribution system management in the marketing mix. The primary aim of this study was defined as: "The development of appropriate distribution system management models for application in South Africa and Australia~. The secondary aim was defined as: "Establishing the key factors which determine the relationship between manufacturers and distributorsn . The dominant economic characteristics of the global crop protection industry are deemed to consist of a global market valued at US $28,090 mio, a mature market in a decline phase, the rapid consolidation of industry players, increased generic product manufacturer activity and an overall decline in manufacturer profitability. In South Africa crop protection product manufacturers use approximately 46 independent distributors to market products on farms through 600 affiliated commissioned sales agents. In Australia the distribution of crop protection products is much more concentrated. Distribution is essentially controlled by five national distributors and their coupled salaried representatives. Manufacturers therefore rely on third parties for the marketing of their products to farmers in both countries. The applicable problem statement has been formulated to select a distribution system management model that will: (i) optimally balance direct distribution related cost and subsequent levels of control over distributors; (ii) maximise the probability that a distributor will buy and actively promote the complete product portfolio of a for high levels of interpersonal relationship maintenance; and (vi) manufacturers have to instill the philosophy that distribution system management is part of a manufacturer's strategic business and marketing focus and not simply a task to be performed by a third party.
AFRIKAANSE OPSOMMING: Die tradisionele maniare waarop die vervaardigers van oesbeskermingsprodukte beheer kan uitoefen oor verspreidingsisteme is nie meer so suksesvol nie. Beheer was gebaseer op kwaliteil produkte, die mag van die handelsmerk:n gevestigde klientebasis en 'n wye produktereeks,bestaande uit gepatenteerde produkte, Vervaardigers van oesbeskermingsprodulcte moet die wyse waarop hierdie produkte bemark word, watter verspreidingsisteem bestuursmodelle gebruik word en die belangrikheid wat geplaas word op die bestuur van die verspreidingsisteme in die totala bemarkingspoging in heroorweging neern. Die primere doelstelling van hierdie studie is: "Die ontwikkeling van toepaslike verspreidingsisteem bestuursmodelle vir toe passing in Suid-Afrika en Australia. "Die sekondere doelstelling is: "Die vas stelling van die sleutelfaktore wat die verhouding tussen velVaardigers (verskaffers) en verspreiders bepaar. Die dominante ekonomiese kenmerke van die globale oesbeskermingsindustrie is 'n markwaarde in VSA $ 28,090 miljoen, 'n stagnante mark in 'n agteruitgang lase, die drastiese konsolidasie van die industrie spelers, 'n toename in die aktiwiteite van die generiese produkvervaardigers en 'n algemene daling in die winsgewindheid van die vervaardigers. In Suid-Afrika gebruik die vervaardigers van die oesbeskermingsprodukte ongeveer 46 onafhanklike verspreiders om die produkte op plaasvlak te bemark met behulp van 600 geaffilieerde kommissie agente. Die verspreiding van oesbeskermingsprodukte is baie meer gekonsentreerd in Australie. Verspreiding word in wese beheer deur vyf nasionale verspreiders en hulle spanne van verkoopsteenwoordigers wat 'n salaris verdien. In beide lande moet velVaardigers van oesbeskermingsprodukte staatmaak op onafhanklike instansies vir die bemarking van hul produkte op plaasvlak. Die probleemsteiling is dus die uitdaging om 'n verspreidingsisteem bestuursmodel t9 ontwikkel wat: (i) . n optima Ie balans sal gee tussen direkte verspreidingskoste en gekoppelde vlakke van beheer oor verspreiders; (ii) die waarskynlikheid dat . n verspreider die betrokke produkreeks van die vervaardiger sal aankoop en aktief sal promoveer; (iii) dit kan bereik in . n mark waar verspreiders talle bronne het van soortgelyke produkte teen kompeterende pryse. Gebaseer op die sekondere navorsing wat gedoen is wit dit blyk dat daar 'n algemene konsensus is dat daar n nei9in9 weg is van transaksie spesifieke besigheidsverhoudings na besigheidsverhoudings gebaseer op vennootskap gebaseerde benaderings in die interaksie tussen vervaardigers (verskaffers) en verspreiders. Hierdie tipe besigheidsverhouding word gekenmerk deur hoe vlakke van onderlinge vertroue, wedersydse verbintenis, konflik hanteringsmeganismes en goeie wedersydse kommunikasie. Primere navorsing is in Suid-Afrika (253 respondente) en Australia (180 respondente) gedoen. Implikasies vir die konstruksie van verspreidingsisteem bestuursmodelle wat voortvloei uit hierdie navorsing sluit in die belangrikheid dat on vervaardiger on wye en gesogte produkreeks het, die vereiste dat produkte beproefde effektiwiteit het, produkte kompeterend geprys is, die vereiste vir hoe vlakke van verskaffer opvolgdiens en die vereiste vir goeie interpersoonlike verhouding tussen werknemers van beide die vervaardigers en die verspreiders. Hierdie elemente moet ondermeer gerugsteun word deur goeie kommunikasiesisteme. Die "idea Ie" verspreidingsisteem bestuursmodelle is vervolgens voorgestel vir beide Suid-Afrika en Australie, gebaseer op die bevindinge van ondermeer die sekondere- en primere navorsing. Hierdie mode lie het ten doel om toepaslike strukture en besigheidsbenaderings vir vervaardigers daar te stel om hulle behulpsaam te wees om die geidentifiseerde behoeftes van die verspreiders aan te spreek.