Dissertations / Theses: 'Cowpea'

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Kayitesi, Eugenie. "Micronisation of cowpeas : the effects on sensory quality, phenolic compounds and bioactive properties." Thesis, University of Pretoria, 2013. http://hdl.handle.net/2263/32972.

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Cowpeas (Vigna unguiculata L. Walp) are legumes recognised as a good source of proteins in developing countries. Cowpeas are mostly utilised as cooked whole seeds. This is often achieved only after boiling for up to 2 hours, resulting in high energy consumption and a long time for food preparation. Micronisation of pre-conditioned cowpeas (± 41 % moisture at 153 °C) reduces their cooking time. During micronisation, cowpea seeds are exposed to electromagnetic radiation with a wavelength range of 1.8 to 3.4μm. For biological materials, the penetration of infrared rays into the food material causes intermolecular vibration, this result in a rapid increase in temperature and water vapour pressure within the seed. Micronisation changes physico-chemical properties of cowpea seeds that may affect sensory properties of cooked cowpeas. Micronisation may also affect cowpea bioactive components such as phenolic compounds and hence their antioxidant properties and bioactive properties. This study aimed at (1) determining the effects of micronisation of pre-conditioned cowpeas on sensory properties of cooked cowpeas and (2) determining the effects of mironisation of pre-conditioned cowpeas on the phenolic compounds, radical scavenging properties and their protective effects against oxidative damage of biomolecules (i.e. low density lipoproteins (LDL), deoxyribonucleic acid (DNA) and red blood cells (RBC). © University of Pretoria vi Micronisation significantly reduced cowpea cooking time by 28 to 49 %, depending on cowpea type. There were significant (P<0.05) increases in roasted aroma and flavour, mushy texture and splitting in all micronised samples. Bechuana white, a light brown cowpea type, was more mushy and split than others. There were significant decreases in firmness, mealiness and coarseness after micronisation for all cowpea types. Micronised cowpeas were darker (lower L* values) than unmicronised cooked cowpeas. Darkening was more evident in light coloured than dark coloured cowpea types. Although micronisation reduces cowpea cooking time, it also affects sensory properties of cowpeas. This might have an influence on consumer acceptance of micronised cowpeas. Twenty seven phenolic compounds were identified in the cowpea types studied: 6 phenolic acids, 14 flavonols and 7 flavan-3-ols. Protocatechuic acid, p-coumaric acid, 4- hydroxybenzoic acid and ferulic acid were the major phenolic acids in cowpeas. Catechin, catechin-3-O-glucoside, myricetin, rutin, quercetin and its mono and diglycosides were present in all cowpea types analysed. Dr Saunders (701.7−849.2 μg/g) (red in colour) and Glenda (571.9−708.1 μg/g) (dark brown in colour) contained the highest total phenolic contents, followed by Bechuana white (361.5−602.3 μg/g) (light brown in colour) and Blackeye (152.0−224.5 μg/g) (cream in colour). More of the flavonols were identified in red and dark brown compared to light brown and cream cowpea types. The red cowpea type contained all the dimers and oligomeric flavan-3-ol species identified in this study. In all cowpea types, extracts from unmicronised (uncooked) cowpeas inhibited copperinduced LDL oxidation in a dose dependent manner. Extracts from all samples analysed exhibited protective effects against AAPH (2, 2'-azobis (2-amidinopropane) hydrochloride) induced RBC haemolysis and DNA damage. Extracts from more pigmented cowpeas, i.e. Dr Saunders, Glenda and Bechuana white, had significantly (P<0.05) higher levels of total phenolics, total flavonoids and radical scavenging properties than Blackeye (less pigmented). Extracts from more pigmented cowpeas also offered higher protection against AAPH-induced DNA and copper-induced LDL oxidation damage than extracts from less pigmented cowpeas. These results indicate protection of biomolecules e.g. DNA, LDL and RBC) from oxidative damage and have a potential to reduce oxidative stress implicated in the development of chronic diseases. This is because cowpea phenolic compounds possess the ability to reduce oxidative damage associated with development of these diseases. © University of Pretoria vii Pigmented cowpea types may be recommended for health applications as they show more potential as source of antioxidants compared to the less pigmented cowpeas. Extracts from micronised (uncooked and cooked) samples of Dr Saunders and Glenda cowpeas had significantly higher concentrations of ferulic acid and p-coumaric acid compared with unmicronised samples. Para-coumaric acid concentrations were higher in all micronised samples of Blackeye cowpeas than in unmicronised samples. The micronisation process could release cell wall bound ferulic acid and p-coumaric, increasing their concentrations in micronised samples. On the contrary, extracts from all micronised samples of Bechuana white and Glenda cowpeas had lower concentrations of catechin than unmicronised samples. Results indicated that total extractable phenolics were lower in micronised samples of cowpea types than unmicronised samples. Futhermore, extracts from micronised samples of all cowpea types showed less protective effect against LDL oxidation than extracts from unmicronised samples. However, for most cowpea types there was no significant difference in total flavonoid contents (TFC) and Trolox equivalent antioxidant capacity (TEAC) values of cooked samples of both micronised and unmicronised. Micronisation did not affect the protective effects of cowpeas against AAPH-induced RBC haemolysis and oxidative DNA damage. Micronisation, followed by cooking, may have generated heat-induced antioxidants such as Maillard reaction products contributing to radical scavenging properties in micronised (cooked) cowpea samples. Though micronised samples had lower concentrations of some phenolic compounds and total extractable phenolics than unmicronised samples, micronised cowpea samples still exhibited radical scavenging properties and offered protective effects against oxidative damage of LDL, DNA and RBC and therefore may offer potential health benefits to consumers.
Thesis (PhD)--University of Pretoria, 2013.
gm2013
Food Science
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Mfeka, Nonkululeko. "Morphology and mineral content of cowpea lines in response to planting date and zinc application rate." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2672.

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Thesis (MTech (Agriculture))--Cape Peninsula University of Technology, 2017.
Cowpea (Vigna unguiculata (L.) Walp) is an important grain and fodder legume grown around the world. It is a dual purpose grain legume crop, providing food for man and livestock. Cowpea is identified as a potential crop to diversify food production, minimize production input by improving soil fertility and improve micronutrients of seed, therefore, improving human nutrition. There is limited information available on cowpea production and suitable agronomic practices including planting date to best suit different environmental conditions in South Africa. The objective of this study was therefore to i) evaluate two soil types (sandy and clay soil) and its effect on cowpea, yield components and mineral composition, ii) the effect of different planting date and iii) assess the effect of zinc fertilizer application rate on vegetative, reproductive parameters and mineral content of cowpea seed. A field trial was conducted in Agricultural Research Council (ARC), in two locations Nietvoorbij (clay loam soil) and Bien Donne’ (sandy soil) during the 2015 summer planting season. The trial layout was conducted in a randomised complete block design (RCBD) with five replicates. The factors of the study include three cowpea lines: Cowpea Veg1, M217 and Qukawa with zinc application rate of (0, 15 and 30 kg/ha) through soil application and two planting date (2 October and 2 November 2015). The following agronomic variables were collected, in both locations: germination rate, number of leaves, number of branches, plant height, number of seed per pod, number of pods per plant, pod length, pods per treatment, pod weight, 100 seed weight, morphological traits, moisture content and seed mineral content. Vegetative data was collected on a fourth-night basis on six middle plants per treatment and reproductive parameters were taken after harvest. The variables were subjected to ANOVA using software SAS (2012). Treatments were tested at 5% level of significance and differences between treatments were separated using LSD and DMRT of the SAS 2012 test. The results indicated that vegetative and reproductive parameters measured varied significantly among cowpea lines in each location and across locations due to different cowpea lines and soil type. Line Cowpea Veg1 and Qukawa were the best performing line in both vegetative and yield parameters across the two planting dates in 2015. These lines significantly obtained higher plant height than line M217. Yield and yield parameters were significantly affected by cowpea line. Qukawa obtained the highest seed yield at Bien Donne’ with a mean of 1184.2 kg/ha and seed yield of 686.25 kg/ha for Cowpea Veg1 at Nietvoorbij. The second planting date (2 November 2015) improved germination of plants across the two locations, therefore improving vegetative growth. Zinc (Zn) fertilizer significantly improved plant height across all treatments. An inconsistent response to yield parameters due to Zn application rate was observed. However, though not significant, Zn application of 15 kg/ha increased most of the measured parameters. It was concluded that line Cowpea Veg1 and Qukawa were the best performing lines. The second planting date (2 November) increase germination rate for both locations. It is therefore, recommended that future research should evaluate Zn fertilizer time of application.

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Nagai, Tomokazu. "Competitiveness of cowpea-based processed products a case study in Ghana /." Diss., Connect to online resource - MSU authorized users, 2008.

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Thesis (M.S.)--Michigan State University. Dept. of Agricultural, Food, and Resource Economics, 2008.
Title from PDF t.p. (viewed on Aug. 4, 2009) Includes bibliographical references (p. 317-321). Also issued in print.

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Bett, Bosibori Bwari. "Enhancing the resilience of Bt Cowpea [Vigna unguiculata (l.) Walp] for insect resistance management." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/96968/4/Bosibori%20Bett%20Thesis.pdf.

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Cowpea is an important food security crop in many countries but its production is constrained by the legume pod borer which can cause yield losses of up to 50%. In this thesis, a molecular approach was used to generate genetically modified cowpea plants which were resistant to this insect pest. Several candidate genes were initially identified and the insecticidal activity of their expressed proteins against the pod borer was tested in insect bioassays. The most promising gene was then used to generate GM cowpea plants, some of which were shown to be resistant to pod borer in insect feeding trials.

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Chiulele, Rogerio Marcos. "Morphological and physiological responses of cowpea (Vigna unguiculata (L) Walp.) cultivars to induced water stress and phosphorus nutrition." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/49770.

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Thesis (MScAgric) -- University of Stellenbosch, 2003.
ENGLISH ABSTRACT: Cowpeas are produced under low and irregular rainfall in most of arid and semi-arid areas of sub-Saharan Africa. Growth and yield are therefore reduced due to the occurrence of water stress during the growing season. Knowledge of the responses and adaptive mechanisms of cowpeas to water stress may help to improve the management practices for these areas. Therefore, three glasshouse experiments were conducted at Welgevallen Experimental Farm of the University of Stellenbosch to test the responses of two cowpea cultivars to water stress. In the first experiment, physiological responses were used to identify those physiological parameters, which can be used to distinguish between drought tolerant and susceptible cowpea cultivars. In the second experiment, some of the identified physiological parameters together with some morphological growth responses, yield and grain protein content of the same two cowpea cultivars were used to identify which is the more tolerant cultivar. Tn the third experiment, the hypothesis that increased phosphorus supply may improve the tolerance of cowpea plants to water stress and their ability of recover from the stress was tested. The results showed that water stress affected water relations, morphological growth parameters, yield and grain protein content, but increasing P supply reduced the effect of water stress and promoted more rapid recovery after re-watering. Water relations were affected by water stress because it reduced relative water content, which resulted in reduced water potential and increased leaf diffusive resistance and proline accumulation. Morphological growth responses and yields were affected because water stress reduced the leaf area, which resulted in reduced biomass production and seed yield. Lower leaf area under water stress was the result of the reduced number of leaves and leaf expansion rate, but the number of leaves was the most important parameter. Reduced seed yield was due to reduced number of pods. The responses of the two cultivars tested were different. AB Wit, which performed better under well-watered conditions was more affected by water stress due to its larger leaf area that resulted in excessive water loss by transpiration. ACH14 was more drought tolerant than AB Wit due to a combination of a more rapid stomatal closure and proline accumulation, which induced osmotic adjustment, and which in tum helped to maintain higher water potentials. The increased P supply reduced the effect of the water stress. High-P level plants showed higher root growth, which resulted in more water uptake and larger leaf area during the water stress period, and after re-watering these plants recovered more rapidly. The more rapid recovery from stress was the result of enhanced root growth and leaf expansion rate and most probably due to increased water uptake. High-P level plants also showed more rapid leaf appearance and plant growth at earlier stages compared to the low-P level plants.
AFRIKAANSE OPSOMMING: Akkerbone word onder toestande van lae en wisselvallige reenval in baie ariede en semi-ariede gebiede van Afrika verbou. In hierdie gebiede word groei en produksie dikwels beperk deur water tekorte gedurende die groei seisoen. Kennis van reaksies en aanpassingsmeganismes van akkerbone teenoor water tekorte mag dus help om produksietegnieke in bogenoemde gebiede te verbeter. Om hierdie rede is drie glashuiseksperimente onder gekontroleerde toestande op die Welgevallen Proefplaas van die Universiteit van Stellenbosch uitgevoer. In die eerste eksperiment is fisiologiese reaksies van twee cultivars gebruik om eienskappe te identifiseer wat gebruik kan word om tussen droogteweerstandbiedende en droogte gevoelige cultivars te onderskei. In die tweede eksperiment is sommige van die geidentifiseerde eienskappe asook morfologiese groei, opbrengs en kwaliteitsreaksies van dieselfde twee cultivars gebruik om die meer droogte weerstandbiedende cultivar te identifiseer. In die derde eksperiment is die hipotese dat P-bemesting die droogteweerstandbiedendheid teen en herstelvermoe na droogte kan verbeter, getoets. Die resultate toon dat water tekorte beide plantwaterverhoudings, morfologiese eienskappe asook opbrengs en proteieninhoud beinvloed, maar dat hoe P-peile die invloed van water tekorte verminder en herstelverrnoe na die droogte verbeter. Plant-waterverhoudings is bemvloed omdat water tekorte relatiewe waterinhoud van plante verlaag wat aanleiding gee tot verlaagde plantwaterpotensiale, verhoogde huidmondjie weerstand en 'n toename in prolien inhoud. Morfologiese eienskappe en opbrengs is benadeel weens 'n veri aging in blaaroppervlakte wat fotosintetiese vermoe en gevolglik ook biomassaproduksie en saad opbrengs benadeel. Verlaagde blaaroppervlakte tydens water tekorte was hoofsaaklik die gevolg van 'n vermindering in aantal blare, terwyl verlaagde saadopbrengs grootliks die resultaat van 'n vermindering in aantal peule was. Die cultivar AB Wit wat die hoogste opbrengs onder gunstige groeitoestande gelewer het, is die meeste bemvloed deur water tekorte omdat die welige blaargroei van hierdie cultivar, luukse waterverbruik en groter transpirasie verliese veroorsaak het. Die cultivar ACH 14 daarteenoor het waterverliese beperk deurdat die huidmondjies vinniger gesluit het en verhoogde prolien-inhoude, osmotiese aanpassings veroorsaak het. Dit het gehelp om waterpotensiale instand te hou. Hierdie cultivar was gevolglik meer droogte weerstandbiedend as AB Wit. Hoe vlakke van P-bemesting het die effek van water tekorte verminder weens verbeterde wortelgroei. Dit het wateropname gedurende en na die peri ode van water stremming verbeter sodat plante vinniger herstel het na die droe periode. Plante wat by hoe P-peile gegroei is het ook 'n verhoogde blaarverskyningstempo en 'n toename in groei tydens die vroee ontwikkelingstadiums getoon.

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Pakela, Yolisa Patronella. "Interaction between Colletotrichum dematium and cowpea." Thesis, Pretoria: [s.n.], 2003. http://upetd.up.ac.za/thesis/available/etd-09022005-102127/.

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Ward, Andrew. "Partial application of insecticide to cowpea (Vigna unguiculata Walpers) as a means of controlling cowpea aphid (Aphis craccivora Koch) and the cowpea foliage beetle (Ootheca mutabilis Sahlberg)." Thesis, University of East Anglia, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327417.

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Abreu, Emanuel Felipe Medeiros. "Variabilidade genética do cowpea severe mosaic virus (cpsmv) e cowpea aphid-borne mosaic virus (cabmv) no Brasil." reponame:Repositório Institucional da UnB, 2012. http://repositorio.unb.br/handle/10482/11116.

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Tese (Doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, 2012.
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O feijão-caupi (Vigna unguiculata (L.) Walp.) é uma importante leguminosa para o Nordeste brasileiro e tem sido tradicionalmente cultivada por pequenos agricultores. Doenças virais são consideradas um dos principais fatores limitantes da produtividade do caupi nesta região. A doença do mosaico severo do caupi é causada pelo Cowpea severe mosaic virus (CPSMV), subfamília Comovirinae, gênero Comovirus, juntamente com o Cowpea aphid-borne mosaic virus (CABMV), família Potyviridae, gênero Potyvirus, são consideradas as viroses mais prevalentes da cultura e responsáveis por grandes perdas na produção. O objetivo do presente trabalho foi estudar a variabilidade genética do CPSMV e CABMV obtidos em diferentes municípios do Nordeste brasileiro. Essa informação é crucial para o desenvolvimento de plantas resistentes a essas viroses tanto por métodos convencionais quanto moleculares de melhoramento. Isso é ainda mais crítico para o desenvolvimento de estratégias baseadas em RNA inteferente (RNAi). Plantas com sintomas de infecção pelo CPSMV e CABMV nos estados do Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Distrito Federal, Sergipe e Bahia foram coletadas, e os isolados foram identificados por Dot-blot e RT- PCR. Foram amplificados fragmentos de 2200 pb, (correspondendo a região da Helicase (Hel), Proteína ligada ao genoma viral (VPg), Picornain 3C- protease (Pro) e RNA polimerase) e 997 pb (correspondendo a região da proteína Inclusão Cilíndrica (CI) e da proteína 6K2) dos vírus CPSMV e CABMV por RT-PCR, respectivamente. Alguns fragmentos foram clonados e outros sequenciados diretamente do produto de PCR em ambas as orientações. As sequências obtidas a partir de diferentes isolados foram comparadas com sequências disponíveis no GenBank. Os alinhamentos das sequências foram obtidos usando o programa Clustal W, e uma árvore filogenética foi criado usando o software MEGA 5.1. A análise revelou baixa variabilidade entre isolados de CPSMV, variando entre 98 e 100% para sequências de nucleótidos e 96-100% para a sequência de aminoácidos deduzida. Entre os CABMV isolado, a variabilidade foi maior, variando 84-99% entre as sequências de nucleótidos 91 a 99% das sequências de aminoácidos. Este estudo fornece informações que serão a base para o desenvolvimento de estratégias para a produção de linhagens de caupi resistentes a estes vírus por RNA interferente. Os dados indicam a possibilidade de obtenção de resistência durável e aplicável ao caupi nas principais áreas produtoras no Brasil. _________________________________________________________________________________ ABSTRACT
Cowpea (Vigna unguiculata) is an important plant crop in Northeast Brazil being traditionally cultivated by small farmers. Virus diseases are considered to be the main factor limiting cowpea yield in the region. The severe mosaic disease caused by the Cowpea severe mosaic virus (CPSMV), subfamily Comovirinae, genus Comovirus, seems to be one of the most prevalent diseases leading to high yield losses in this crop. The Cowpea aphid borne mosaic virus (CABMV) belongs to the genus Potyvirus in the Potyviridae family, and infects cowpea worldwide. In the northeastern region of Brazil, both viruses can be found in cowpea planted areas. The aim of the present study was to access the degree of homology among regions amplified of different isolates of CPSMV and CABMV, respectively; obtained in different northeastern regions in Brazil, and to compare it to isolates throughout the world. Plants with CPSMV and CABMV symptoms from the states of Piauí, Ceará, Rio Grande do Norte, Paraiba, Pernambuco, Alagoas, Sergipe, Bahia and Distrito Federal were collected, and the isolates were identified by RT-PCR analysis. Total RNA was extracted from infected tissue and afterwards used for synthesis of cDNA fragments by RT-PCR. The synthetized primers were able to amplify fragments of 2200 and 997 bp of the CPSMV and CABMV virus, respectively. Amplification products were directly cloned into the pGEMT-Easy plasmid vector (Promega), according to the manufacturer’s instructions. Cloned fragments were sequenced in both orientations. Deduced amino acid sequences of the virus were compared to sequences available from GenBank. Multiple sequence alignments were obtained with Clustal W. Phylogenetic trees using the MEGA version 5.1 software package and the neighbour-joining method with Poisson correction. Tree branches were bootstrapped with 1000 permutations. CPSMV and CABMV diseases remain as limiting factors in this crop in Brazil, and breeding programs, either by conventional or engineered approaches, should be targeted at establishing resistance of cowpeas to CPSMV and CABMV.

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Letsoalo, Isaac Motsoeng. "Evaluation of introduced cowpea breeding lines for Aphid (Aphis Craccivora) and bruchid (Callosobruchus Rhodensiansus) resistance in South Africa." Thesis, University of Limpopo, 2015. http://hdl.handle.net/10386/1775.

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Mwangwela, Agnes Mbachi. "Physicochemical characteristics of conditioned and micronised cowpeas and functional properties of the resultant flours." Thesis, Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-07302008-073321.

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Uriyo, Maria. "Effect of germination and drying on enzyme activity in sorghum and cowpeas." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-07102009-040342/.

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Blade, Stanford F. (Stanford Fred). "Evaluation of cowpea lines in Nigerian cropping systems." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=70310.

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The primary hypothesis of this research was that improved cowpea genotypes (selected under sole crop) could yield well in several Nigerian cropping systems, and that there were cowpea characteristics that improved overall system productivity. Cowpea lines were identified which were high yielding and stable in several management systems. Practices such as not applying insecticide and intercropping both reduced cowpea grain yield significantly. Land equivalent ratios were greater than one for all tested intercrop systems: cassava-cowpea (1.21-2.35), maize-cowpea (1.31-4.23), maize-cassava-cowpea (1.63-3.40) and millet-cowpea (1.13-6.88). Nitrogen nutrition of component crops was investigated. Line influenced both maize grain (12.5-28.4 kg ha-1) and total biomass (48.7-69.0 kg ha-1) nitrogen yield. Evidence from pot and field experiments (including $ sp{15}$N-dilution studies) indicated same-season nitrogen transfer. Light interception studies also indicated the increased light harvesting ability of early sole cowpea lines compared to early intercropped lines systems.

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Adeyemi, Samson Adebowale. "Evaluation of the possible application of cowpea genotypes in the farming systems of the Eastern Cape Province, South Africa." Thesis, University of Fort Hare, 2012. http://hdl.handle.net/10353/d1007539.

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Characterization studies on the genetic diversity among cultivated cowpea (Vigna unguiculata (L.) varieties are valuable tools to optimize the use of available genetic resources by farmers, local communities, researchers and breeders. Eight cowpea (Vigna unguiculata (L.) genotypes ( Vegetable cowpea, Ivory grey, Okhalweni, Fahari, Fahari dark, 97K-1069-8, IT93K-73h, and 129-3) were subjected to molecular, morphological and agronomical characterization. DNA amplification fingerprinting markers were used to evaluate the genetic diversity among the eight genotypes. Nine random arbitrary primers were used to screen the eight genotypes to assess their ability to reveal polymorphisms in cowpea, and seven of them were selected for use in characterizing the total sample. A total of 43 bands were generated which are all polymorphic. On the average, the primers generated a total of 6.1 polymorphic bands. The resulting data-matrix included 43 analysed bands with a total of 344 characters. Neighbour joining analysis was used to generate the dendrogram, clustering the genotypes into two groups at an agglomerate coefficient of 0.30 irrespective of their geographical origins. The results also showed the presence of significant differences in morphological and quality traits among the genotypes. Fahari yielded the highest concentration of crude protein (46.51 mg/mg dry leaf) while Vegetable cowpea yielded the lowest (24.41 mg/mg dry leaf). The influence of manure was also found to be effective by increasing the crude protein content of the genotypes as shown by Fahari dark with an average of 53.53 mg/mg dry leaf as opposed to 39.85 mg/mg dry leaf without manure application. Although some small clusters grouped accessions of the same growth habits, a general lack of agreement between clustering and morphological features was observed. It can therefore be concluded that the significant differences between the molecular genetic analysis using DAF-PCR markers, morphologic characters and yield traits can be important tools to identify and discriminates the different cowpea genotypes.

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Ravhuhali, Khuliso Emmanuel. "Effects of cowpea cultivar supplementation on productivity of Pedi goat and Dorper sheep fed Ad Libitum buffalo grass." Thesis, University of Limpopo, 2010. http://hdl.handle.net/10386/590.

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Thesis (M.Sc. (Agriculture)) --University of Limpopo, 2010
Two studies were carried out to investigate the effect of cowpea cultivar supplementation on productivity of Pedi goats and Doper sheep fed ad libitum buffalo grass. Experiment 1 investigated the effect of cowpea cultivars supplementation on productivity of Pedi goats fed ad libitum buffalo grass hay using twelve goats that were assigned in a completely randomized design. The Pedi goats were fed ad libitum a basal diet of buffalo grass supplemented with four levels each of four cowpea cultivars namely, Pan 311, Red caloona, Black eye and Agripes. The four levels fed were 50, 100, 150 and 200 g/day. The experiment involved a 25 day preliminary period and a five day collection period during which feed intake, digestibility, live weight changes and nitrogen were measured. Based on available data, all the cowpea cultivars contained more than 15 % crude protein and can therefore be used as protein supplements to goats on low quality roughage. Pan 311 had higher feeding value (p<0.05), although it contained the highest concentration of condensed tannins. The concentration of tannins in Pan 311 did not exert negative effects on intake and digestibility. The data on a in vitro enzymatic digestibility of the cowpea cultivars and buffalo grass hay demonstrated that the cowpea cultivars had higher in vitro DM, OM and protein digestibilities that ranged from 0.64 to 0.75. The cowpea cultivars have high in vitro digestibility values thus implicating their suitability as supplements. Also chemical contents of the cowpea cultivars and the buffalo grass hay had poor capacity to predict forage in vitro digestibility. Forage intake and growth rate of Pedi goats were poorly predicted from in vitro digestibility. Experiment 11 investigated the intake and relative palatability indices of four cowpea cultivars offered to Pedi goats and Dorper sheep fed low quality buffalo grass hay. The experiment was a 2 (animal species goats and sheep) x 5 diets (four cowpea cultivars and buffalo grass hay) factorial arrangement in a completely randomized design. Intake and palatability of the goats and sheep were higher in Pan 311. Sheep had higher voluntary feed intake values than goats, but palatability indices were higher in goats than in sheep. Goats were better than sheep in the palatability indices ranking of the four cowpea cultivars. This seems to demonstrate that goats are better suited for assessing palatability indices ranking of cowpea hays and other similar legumes. Forage intakes and palatability indices ranking were poorly predicted from their nutrient. Growth of the goats was well predicted by forage in vivo digestibility and palatability indices. Also, forage intakes accurately predicted the palatability indices of the cowpea cultivars by the goats and sheep.

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Ndambe, Nzaramba Magnifique. "Inheritance of antioxidant activity and its association with seed coat color in Cowpea (Vigna unguiculata (l.) walp.)." Thesis, Texas A&M University, 2005. http://hdl.handle.net/1969.1/2455.

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Analysis of antioxidant activity (AOA) of entries in the 2002 Regional Southernpea Cooperative Trial revealed not only significant differences among entries, but that entries with pigmented (black and red) seed coats were clustered among the highest, cream types were the lowest, while pinkeye and blackeye types were intermediate. Red colored peas were higher in antioxidant activity than black types. These findings provided strong evidence that compounds responsible for pigmentation were involved in AOA. The objectives of the present investigation were to investigate the inheritance of AOA in cowpea and further study the relationship between AOA and seed coat color. Four advanced selections, ARK95-356 (black), ARK98-348 (red), ARK96-918 (cream), and LA92-180 (cream), were crossed in a complete diallel mating design, generating F1, F1', F2, F2', BC1, and BC2 populations. Individual seeds were ground and samples were extracted in methanol and analyzed for AOA using the free radical 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) method. Combining ability tests using Griffing??s Method I Model I indicated presence of highly significant general combining ability (GCA), specific combining ability (SCA), and reciprocal (REC) and maternal (MAT) effects, with pigmented lines exhibiting positive GCA and MAT, while non-pigmented lines exhibited negative GCA and MAT. AOA in the F1 was not significantly different from the maternal parent, with seed coat color also resembling the maternal parent. Segregation for seed coat color was observed in the F2 and F2'. Additive, dominance, and epistatic effects were significant. The broad sense heritability estimate was 0.87. Minimum number of genes responsible for AOA was estimated at about five. Factors governing high AOA appeared to be the same as those responsible for seed coat color, with apparent pleiotropic effects. In conclusion, breeding for high AOA is possible using highly pigmented parental lines.

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Ochoa, Luisa 1952. "EFFECT OF GERMINATION, ALKALI TREATMENT AND DRY ROASTING ON THE PROPERTIES OF COWPEA FLOUR." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276418.

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17

Omwenga, George Isanda. "Callus Development and Organogenesis in Cultured Explants of Cowpea (Vigna unguiculata (L.) Walp." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4655/.

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Cowpea, Vigna unguiculata (L.) Walp is an excellent source of protein, vitamins and minerals and a major food crop many parts of Africa. Optimal production levels are hampered by insect pests and diseases. Biotechnological techniques such as tissue culture and genetic engineering can aid in the development of varieties with resistance to insect pests and diseases. The objective of this study was to investigate conditions necessary for the development of a reproducible tissue culture system that can be applied to regenerate transformed cells from culture. The in vitro manipulation of cowpea using Murashige and Skoog (MS) medium, auxins and cytokinins resulted in the formation of callus and rhizogenesis. Calli that were formed were separated into six classes based on color and texture. Yellowish friable callus, yellowish compact, soft yellowish callus and green and white were composed of largely vacuolated cells and were non-regenerative. Friable green callus was the most prevalent callus type and could form of roots in some hormone combinations. Green spots were formed on hard compact green callus. The green spots became nodular, forming root primordia and ultimately giving rise to roots. None of the six calli types gave rise to the formation of shoots. Embryogenic callus was induced from cowpea explants cultured on MS medium supplemented with dicamba and picloram. Embryogenic suspension cultures were initiated from callus induced on MS supplemented with 3.0 mg/L dicamba or picloram and conditions for maintenance of embryogenic suspension cultures were evaluated. Somatic embryos were formed in suspension cultures. Attempts to convert and germinate the somatic embryos resulted in the formation of callus or formation of appendages on the somatic embryos or in the death of the embryos. The appendages formed roots on prolonged culture. Further research is needed to determine appropriate optimal conditions for embryo conversion and germination and ultimately plant recovery from culture.

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18

Holness, Claire Louise Lesley. "Isolation and characterisation of mutants of cowpea mosaic virus." Thesis, University of Warwick, 1989. http://wrap.warwick.ac.uk/59381/.

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A nitrous acid-induced, temperature sensitive mutant of cowpea mosaic virus (CPMV) known as 8-14, (Evans 1985, Virology 1985, 141, 275-282), was characterised. The phenotypic defect in 8 -14 was shown not to affect translation of the RNA or the first proteolytic cleavage of the B RNA-encoded polyprotein. The defect is probably at the level of genome replication. The technique of two dimensional RNA fingerprinting showed the mutant genome to be similar to the parental wild-type but did not resolve the genetic alteration(s) specific for the mutation. The mechanism of CPMV translation was investigated by site-directed mutagenesis of a full-length cDNA clone of CPMV M RNA from which infectious RNA could be generated by in vitro transcription. The results obtained confirm the AUG at position 161 is used to direct the synthesis of the 105K protein in vitro. The detection of a 58K protein in infected protoplasts suggests that it is also used in vivo. The synthesis of the 95K protein can be initiated from either of the AUGs at positions 512 and 524. Synthesis of this protein is not essential for CPMV replication in protoplasts. Several deletion mutations were created in the M RNA cDNA clone in order to determine the regions of M RNA essential for replication of M RNA. Analysis of one mutant indicated that sequences between 1446 and 1620 are probably not required for replicase recognition. However, the accumulation of this mutant in protoplasts was reduced, presumably as a result of lack of encapsidation of the RNA as this mutant is thought not to synthesise functional coat protein. Data from several mutants showed that alterations of M RNA around nucleotides 161 and 189 prevent transcript accumulation in protoplasts possibly owing to a severe reduction in replicability of the input RNA.

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19

Law-Cheung, Linda H. Y. "Antibody specificities : stimulated by cowpea mosaic virus-HIV chimeras." Thesis, University of Warwick, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248828.

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20

Graffham, A. J. "Tempe fermentation as a processing option for African cowpea." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240292.

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21

Reiss, Gesa. "Striga gesnerioides parasitizing cowpea : mechanisms of infection and resistance." Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295066.

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22

Mtchotsa, Lydia. "Drivers of trader participation in bean and cowpea marketing." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/16986.

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Master of Agribusiness
Department of Agricultural Economics
Vincent Amanor-Boadu
Beans and cowpeas are considered nutritionally dense and good sources of protein. In this sense, they are considered excellent food in poor households, especially in those that exhibit high levels of malnutrition or under-nutrition. To address food security and nutrition security in poor countries, there has been an increasing interest in encouraging farmers to grow beans and cowpeas. This has spurred research in value chains for these crops in many countries, especially those that do not traditionally grow them as primary staples. Most of these research efforts have focused on the producer and consumer issues, with little or no attention paid to traders who operated between these two players in the value chain. The objective of this study, therefore, is to contribute to the literature on the bean and cowpea value chain research by identifying the factors influencing the participation decisions of traders in this segment of the agricultural economy in Zambia. Using data collected by the Pulse Value Chain Initiative – Zambia in 2011, a probit model was used to analyze data. The dependent variable trader participation in wholesale marketing of beans and cowpeas in Lusaka and its principal food markets. The explanatory variables encompass trader demographic characteristics and available assets or resources. The research explored the effect of the assets or resources on the choice to trade cowpeas or beans at the wholesale level in Lusaka with and without controlling for traders’ demographic characteristics. Three procurement sources are identified in the study: the local market within which the traders operate; producers/suppliers within Lusaka District; and producers/suppliers outside Lusaka District. The results indicate that the procurement source for beans and cowpeas influenced trader decision to operate at the wholesale level. For example, traders who purchased their produce from locations outside Lusaka District were about 37% more likely to participate in wholesale trade compared to those sourcing their produce within the market in which they operate when demographic characteristics of traders are not controlled for in the model. When the demographic factors are controlled, the likelihood of those procuring from outside Lusaka District participating in the wholesale trade declines slightly to about 34%. These coefficients were both statistically significant at the 1 percent level. The results also showed that traders using credit from friends and family were nearly 18% less likely to participate in wholesale trade than those borrowing from other traders, significant at the 5% level. Controlling for demographic characteristics led to a reduction of this likelihood to about 16.7%, significant only at the 10% level. There were no statistical differences between traders for all education levels and those without any education except for respondents with lower primary and lower secondary education. Traders with lower primary and lower secondary education had a 31% higher likelihood of operating at the wholesale level compared to those without any formal education while those with upper secondary education had about 26.7% higher likelihood of operating at the wholesale level compared to those without any formal education. Marital status was not a discriminant in the decision to operate at the wholesale level. However, males had about a 9% higher probability than females in operating at the wholesale level. Wholesalers tend to move larger volumes of produce and, hence, create wealth much quickly than retailers. Wholesalers are also more likely to be engaging processors when these exist in the supply chain. Given that traders sourcing their produce from outside Lusaka District are more likely to engage in wholesale trading, it recommended that further research into the intricate characteristics of these traders are explored. This future research will do well to explore the factors that specifically differentiate these traders from the others. Understanding these and their potential effects could allow policymakers to provide support and services to this class of traders to engage in structured relationships with larger organizations such as processors and exporters.

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Ferreira, Antonia DÃbora Camila de Lima. "Black aphid preference to cowpea landraces from Pentecoste, CearÃ." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14777.

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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior
Currently the production of cowpea is taking ever greater proportions, and thereby arousing the interest of many producers for this culture. The attack of pests is among factors that affect production, being the black aphid considered key pest. The control of this pest can be accomplished through the use of resistant plants, resistance may occur in cultivars or in landraces. The objective of this study was to compare natural resistance of cowpea landraces genotypes against Aphis craccivora as well as the effects caused in its biology. In the first trial a free choice test was done using 21 genotypes compared to four standards. In this trial sowings were performed in 300 mL polystyrene cups arranged in a randomized block design consisting of 6 replicates and 25 treatments. It was found that the analyzed genotypes presented genetic variability in relation to against A. craccivora, resistance, and formed seven groups: Highly resistant (BRS Guariba, TVU 408 P2, Enrica pobre, Das Almas, CE-13 Selection and Ritinha), Resistant (CE-55, 40 dias 1, Praiano), Intermediate (SeridÃ, Sel. CE-42, 7 semanas), susceptible (Vinagre 1, PitiÃba, Rabo de calango FÃgado de galinha, BR 17-Gurgueia) and highly susceptible (RoxÃo 1 (CE-13), Cabecinha, Isabel 1, VITA-7, Rita Joana, Milagroso, Bengala). After screening of these genotypes, six were selected to compose the second trial, which corresponded to the determination of biological parameters, four resistants: Ritinha, Enrica Pobre, Das Almas e Sel. CE-13, and two susceptible: RoxÃo 1(CE-13) e VITA-7. This test consisted of six treatments and six replications arranged in a randomized blocks at a greenhouse. Daily observations were made to determine the biological parameters: time of one generation, generation mortality, overall fertility, reproductive period, post-reproductive period and period of a cycle. From these dada, the population parameters were calculated: Intrinsic rate of increase (rm) and the finite rate of increase (λ). The different genotypes influence the biology A. craccivora. VITA-7 and RoxÃo1 (CE-13) were more suitable for the development of aphid providing superior fertility, greater reproductive period and longevity of adults. Genotypes Das Almas and Ritinha provided deleterious effects in individuals, causing 100% morality, being antibiose the main resistance mechanism.
Atualmente a produÃÃo de feijÃo-de-corda vem tomando proporÃÃes cada vez maiores, e com isso, despertando o interesse de muitos produtores. O ataque de pragas estÃ entre os fatores que afetam a produÃÃo, sendo o pulgÃo-preto considerado como praga chave. O controle dessa praga pode ser realizado atravÃs do uso de plantas resistentes, e a resistÃncia pode ocorrer em materiais nÃo comercializados como as variedades locais. Objetivou-se com este trabalho comparar genÃtipos locais de feijÃo-de-corda quanto a sua resistÃncia natural contra Aphis craccivora, bem como os efeitos provocados na sua biologia. No primeiro ensaio foi realizado teste com chance de escolha para definir quais dos 21 genÃtipos testados possuÃam resistÃncia genÃtica comparados a quatros padrÃes. Neste ensaio as semeaduras foram realizadas em copos de poliestireno de 300 mL arranjados em um delineamento de blocos casualizados constando de seis repetiÃÃes e 25 tratamentos. Verificou-se que os genÃtipos analisados apresentaram variabilidade genÃtica em relaÃÃo Ã resistÃncia contra o A. craccivora, sendo formados sete grupos: Altamente Resistente (BRS Guariba, TVu 408 P2, Enrica Pobre, Das Almas, SeleÃÃo da CE 13 e Ritinha), Resistente (CE-55, 40 dias1, Praiano), IntermediÃrio (SeridÃ, Sel. CE-42, 7 semanas), SusceptÃvel(Vinagre 1 PitiÃba Rabo de calango FÃgado de galinha BR 17-Gurgueia) e Altamente SusceptÃvel (RoxÃo 1 (CE-13), Cabecinha, Isabel 1, VITA-7, Rita Joana, Milagroso, Bengala). ApÃs a triagem destes genÃtipos, foram selecionados seis para compor o segundo ensaio, que correspondia Ã determinaÃÃo dos parÃmetros biolÃgicos, sendo quatro resistentes: Ritinha, Enrica Pobre, Das Almas e Sel. CE-13 e dois suscetÃveis: RoxÃo 1(CE-13) e VITA-7. O ensaio constou de seis tratamentos e seis repetiÃÃes dispostos em blocos casualizados dentro de casa de vegetaÃÃo. Foram realizadas observaÃÃes diÃrias para determinar os parÃmetros biolÃgicos: tempo de uma geraÃÃo, mortalidade na geraÃÃo, fecundidade total, perÃodo reprodutivo, perÃodo pÃs-reprodutivo e perÃodo de um ciclo. A partir destes, foram calculados os seguintes parÃmetros populacionais: taxa intrÃnseca de crescimento (rm) e a razÃo finita de crescimento (λ). Os diferentes genÃtipos influenciaram na biologia A. craccivora. VITA-7 e RoxÃo1 (CE-13) mostraram-se mais adequados ao desenvolvimento do afÃdeo por permitirem maior fecundidade, maior perÃodo reprodutivo e maior longevidade do adulto. Os genÃtipos Das Almas e Ritinha proporcionaram efeitos deletÃrios causando moralidade em 100% dos indivÃduos sendo a antibiose o principal mecanismo de resistÃncia envolvido.

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24

Cleveland, S. Matthew. "HIV-1-specific antibody responses to a plant virus-HIV chimera." Thesis, University of Warwick, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340090.

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25

Sprent, JI, DW Odee, and FD Dakora. "African legumes: a vital but under-utilized resource." Oxford University Press, 2010. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001196.

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Abstract Although nodulated legumes have been used by indigenous peoples in Africa for centuries, their full potential has never been realized. With modern technology there is scope for rapid improvement of both plant and microbial germplasm. This review gives examples of some recent developments in the form of case studies; these range from multipurpose human food crops, such as cowpea (Vigna unguiculata (L.) Walp.), through to beverages (teas) that are also income-generating such as rooibos (Aspalathus linearis (Burm. f.) R. Dahlgren, honeybush (Cyclopia Vent. spp.), and the widely used food additive gum arabic (Acacia senegal (L.) Willd.). These and other potential crops are welladapted to the many different soil and climatic conditions of Africa, in particular, drought and low nutrients. All can nodulate and fix nitrogen, with varying degrees of effectiveness and using a range of bacterial symbionts. The further development of these and other species is essential, not only for African use, but also to retain the agricultural diversity that is essential for a changing world that is being increasingly dominated by a few crops such as soybean.

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26

Naab, JB, SMB Chimphango, and FD Dakora. "N2 fixation in cowpea plants grown in farmers' fields in the Upper West Region of Ghana, measured using 15N natural abundance." Symbiosis, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001478.

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Abstract Few studies have assessed the levels of symbiotic N nutrition in legumes grown by fanners in Africa. In this study, the shoots of cowpea plants were sampled from 63 farms in 12 villages within 5 districts of the Upper West Region of Ghana, and assessed for growth and symbiotic N nutrition. The data revealed considerable differences in cowpea plant density per m2 , plant growth, 15N natural abundance (OI5N), %Ndfa, and N-fixed among different farms under one village, and between villages under the same district, and between districts in the Upper West Region. In farms where there were fewer cowpea plants per m2 , plant growth was better and dry matter yield per plant significantly greater, leading to strong variations in O!5N values. Except for four farms at Bamahu which had cowpea shoot Ndfa values of 12.1%,30.0%,36.5% and 46.6%, one farm at Babile with Ndfa value of 58.1%, and three farms at Silbelle with Ndfa values of56.8%, 57.9% and 68.7%, the remaining 55 out of the 63 farms studied showed high shoot Ndfa values, ranging from 70.6% to 99.7%, which clearly indicates that cowpea cultivated by farmers in the Upper West Region of Ghana meet a large proportion of their N requirements from symbiotic fixation. At the district level, isotopic analysis showed that, on average, the 15N natural abundance values (%0) of cowpea shoots were -0.496±0.04 for Jirapa, -O.083±0.06 for Nadowli, 0.368±O.08 for Lawra, l.333±0.29 for Wa and 0.365±0.09 for Sissala district. Estimates of the legume's N derived from fixation were 66.3% for Wa district, 89.9% for Nadowli, 79.4% for Lawra, 78.9% for Sissala and 80.9% for Jirapa district. The amount ofN-fixed ranged from 402.3 mg.plant' for Nadowli, 176.5 mg.plant" for Wa, 235.4 mg.plant' for Sissala, 179.0 rng.plant' for Lawra to 249.2 mg.plane! for the Jirapa district. Expressed on per-hectare basis using cowpea density per m2 , the total amount ofN-fixed was around 16.6 kg ha-! in the Nadowli district, 19.1 kg ha-! in Wa, 23.0 kg ha' in Sissala, 21.1 kg ha-I in Lawra and 17.6 kg ha-1in the Jirapa district. Averaged across all 5 districts, N-fixed by cowpea was about 19.5 kg ha-! in the Upper West Region of Ghana. These data suggest that, increasing N2 fixation in fanners' fields in Ghana would require optimization of cowpea plant density rather than biological manipulation of the symbiotic process (as %Ndfa values were generally very high).

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27

Thuenemann, Eva. "Virus-like particle production using cowpea mosaic virus-based vectors." Thesis, University of East Anglia, 2010. https://ueaeprints.uea.ac.uk/20539/.

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28

JÃnior, JosÃ Edvar Monteiro. "Biochemical, functional and structural characterization of two cowpea recombinant cystatins." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8391.

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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
mRNA sequences coding for two cystatins were isolated from leaves of hydroponically growing cowpea plants. The sequences were ligated in the expression vector pET302NT-HIS, which was introduced into Escherichia coli, ArcticExpress (DE3) cells. The expression was induced by addition of 0.5 mM IPTG and the recombinant proteins VuCys1 (Vigna unguiculata one-domain cystatin) and VuCys2 (Vigna unguiculata two-domain cystatin), both fused to an N-terminal 6x-His tag, were purified by homogeneity using an affinity matrix containing Ni2+ immobilized to Sepharose. The apparent molecular masses for VuCys1 (yield of 10 mgP.L-1 culture) and VuCys2 (yield of 22 mgP.mL-1 culture) were 14 and 26 kDa, respectively. Both inhibitors were strongly active against the proteinases papain and chymopapain, while bromelain and particularly cathepsin B were less susceptible to in vitro inhibition. No inhibition was detected against the serine proteinase trypsin. Thermal stability tests revealed that both cystatins are thermostable proteins able to achieve a minimum residual proteolytic inhibition activity against papain of 95% (VuCys1) and 85% (VuCys2) when incubated at 100 C for 60 minutes. Similar stability results were also obtained when the proteins were tested to the ability of to inhibit papain activity after incubation in pH values ranging from 2.0 to 11.0. Circular dichroism spectroscopy measurements demonstrated that the secondary structure arrangement of both cystatins undergoes only fewer alterations when both proteins were incubated in temperatures varying from 10 to 90 C and pH values varying from 2.0 to 11.0, as well. These data are in agreement with the thermal and pH stability results previously obtained on papain inhibition assays. Biological assays conducted with different phytopathogenic fungi didnât show any negative impact on spore germination as well as on mycelial growth of the tested fungi. Different human pathogens, including the pathogenic yeast Candida albicans were shown to be insensible to VuCys1 and VuCys2. Some scientific reports have proposed the use of cystatins as potential molecules in the control and inhibition of the activity of cysteine proteinases related to carcinogenic process. However, cytotoxicity assays performed on three tumor cell lineages revealed no toxic effects of VuCys1 and VuCys2. Inhibitor activities were also tested against digestive enzymes isolated from third instar larvae of the bruchid insects Callosobruchus maculatus and Zabrotes subfasciatus, two major cowpea plagues. Both cystatins were able to cause high inhibition of C. maculatus enzymes; however they were poorly active against Z. subfasciatus counterpart. Feeding tests were conducted in which both cystatins were added to artificial seeds at final concentrations of 0.025, 0.05 and 0.1% and supplied to C. maculatus. Despite the in vitro inhibition of C. maculatus larvae enzymes, the bioassay data suggest that larvae and adult insects appear to develop adaptive mechanisms which can make them insensible to the ingestion of the inhibitors. Crystallographic studies were carried out in order to solve the tridimensional structure of cystatins. 576 different crystallization conditions were tested in which three were favorable to the formation and growth of diffractable crystals of VuCys1 protein. These crystals belong to the orthorhombic space group P212121 and the unit cell dimension was a = 41.48 Ã; b = 64.68 Ã and c = 87.91 Ã, α = β = γ = 90. V. unguiculata one-domain cystatin presents a typical 3D domain swapped dimmer molecular structure, which was solved at 1.95 Ã resolution. No crystals were obtained for VuCys2. The physiological importance of this structure to the plant, the structural stability of both inhibitors and the results raised from biological assays are all discussed in this work.
SequÃncias de mRNA que codificam para duas cistatinas foram isoladas de folhas de plantas de feijÃo-caupi cultivadas em sistema hidropÃnico. As sequÃncias foram ligadas no vetor de expressÃo pET302NT-His, o qual foi introduzido em cÃlulas de Escherichia coli, ArcticExpress (DE3). A induÃÃo da expressÃo foi realizada por meio de adiÃÃo de IPTG (0,5 mM) e as proteÃnas recombinantes VuCys1 â (cistatina de um domÃnio de Vigna unguiculata) e VuCys2 â (cistatina de dois domÃnios de V. unguiculata) ambas fusionadas a uma cauda de histidina N-terminal, foram purificadas por homogeneidade em matriz de afinidade constituÃda de Ni2+ imobilizado Ã Sepharose. VuCys1 apresentou uma massa molecular aparente de 14 kDa e um rendimento de 10 mgP.L-1 de meio de cultura, jÃ a proteÃna VuCys2 mostrou uma massa molecular aparente de 26 kDa e um rendimento de 22 mgP.L-1 de meio de cultura. As duas proteÃnas foram fortemente ativas contra as proteinases papaÃna e quimopapaÃna, moderadamente ativas contra bromelaÃna e apenas fracamente ativas contra catepsina B, enquanto que nenhuma atividade inibitÃria foi detectada contra a proteinase serÃnica tripsina. Ensaios de estabilidade tÃrmica mostraram que as duas cistatinas sÃo proteÃnas termoestÃveis, uma vez que, mesmo apÃs incubaÃÃo a 100 C por 60 minutos apresentam atividade inibitÃria residual contra papaÃna superior a 95% (VuCys1) e superior a 85% (VuCys2). Resultados similares de estabilidade tambÃm foram obtidos quando as proteÃnas foram testadas quanto Ã capacidade de inibir a atividade de papaÃna, apÃs incubaÃÃo em valores de pH variando de 2,0 a 11,0. AnÃlises espectroscÃpicas de dicroÃsmo circular revelaram que o padrÃo de estruturas secundÃrias de ambos inibidores sofre pouca alteraÃÃo apÃs incubaÃÃo em temperaturas variando de 10 a 90 C e em valores de pH variando de 2,0 a 11,0. Estes dados estÃo de acordo com os resultados de elevada estabilidade tÃrmica e a extremos de pH previamente obtidos nos ensaios de inibiÃÃo in vitro de papaÃna. Ensaios biolÃgicos realizados com diferentes espÃcies de fungos fitopatogÃnicos nÃo mostraram nenhum efeito negativo das proteÃnas sobre a germinaÃÃo de esporos ou crescimento micelial dos fungos testados. Os inibidores tambÃm nÃo se mostraram ativos contra diferentes patÃgenos humanos, incluindo a levedura patogÃnica Candida albicans. Alguns relatos cientÃficos propÃem o uso de cistatinas como agentes em potencial no controle e inibiÃÃo da atividade de proteinases cisteÃnicas relacionados a processos carcinogÃnicos. Contudo, testes de citotoxicidade dos inibidores para trÃs diferentes linhagens de cÃlulas tumorais nÃo mostraram potencial citotÃxico. Os inibidores tambÃm foram testados quanto Ã capacidade de inibir a atividade de enzimas digestivas isoladas do intestino de larvas de terceiro instar dos insetos bruquÃdeos Callosobruchus maculatus e Zabrotes subfasciatus, duas importantes pragas do feijÃo-caupi. Ambas as cistatinas apresentaram elevado potencial inibitÃrio contra as enzimas de C. maculatus sendo, porÃm, fracamente ativas contra as de Z. subfasciatus. Bioensaios foram realizados nos quais as cistatinas foram inseridas em sementes artificiais nas concentraÃÃes finais de 0,025; 0,05 e 0,1% e administradas a C. maculatus. A despeito da inibiÃÃo in vitro das enzimas digestivas das larvas de C. maculatus, os resultados do bioensaio sugerem que, tanto larvas como insetos adultos, parecem desenvolver mecanismos adaptativos Ã administraÃÃo dos inibidores que os tornam insensÃveis Ã sua ingestÃo. Estudos cristalogrÃficos foram realizados na tentativa de solucionar a estrutura tridimensional das cistatinas. 576 condiÃÃes de cristalizaÃÃo foram testadas das quais trÃs levaram Ã formaÃÃo e crescimento de cristais difratÃveis de VuCys1. Os cristais pertencem ao grupo espacial ortorrÃmbico, P212121, e a cÃlula unitÃria apresentou dimensÃes de a = 41,48; b = 64,68 e c = 87,91 Ã, α = β = γ = 90. VuCys1 apresenta uma estrutura molecular de dÃmero de domÃnios trocados a qual foi resolvida a uma resoluÃÃo de 1,95 Ã. Cristais de VuCys2 nÃo foram obtidos nas condiÃÃes testadas. O significado fisiolÃgico desta estrutura para a planta, a estabilidade estrutural de ambos inibidores e os resultados referentes aos diferentes bioensaios sÃo discutidos no presente trabalho.

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29

Nelson, Suzanne Cathleen. "Genotype and cropping system effects on cowpea growth and yield." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186596.

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Genotype X cropping system interactions may complicate the plant breeders' task of increasing crop yields, since selection and improvement in one cropping system may not result in improved performance in a different cropping system. Field experiments were conducted in 1990 and 1991 to examine the effects of cowpea (Vigna unguiculata (L.) Walp.) genotypes and cropping systems on cowpea yield, yield components, biomass, and leaf area. When cowpea was grown in sole crop and in intercrop with pearl millet (Pennisetum americanum (L.) Leeke), a significant genotype X cropping system interaction for seed yield occurred in both years. In sole crop, 'California Blackeye 46' (CB46) yielded more than 'Tohono O'odham' (TOC). By contrast, in intercrop, there was no difference in yield between genotypes in 1990, but TOC outyielded CB46 in 1991. More vegetative biomass and leaf area was produced by TOC than CB46 and more was produced in sole crop than intercrop. In intercrop, TOC produced more leaf area in the furrow and higher in the intercrop canopy than CB46. TOC had a more negative effect on millet than CB46. In intercrops differing in row-spatial arrangement (within- and between-row intercrops), TOC outyielded CB46 in both the within- and between-row intercrops, and more yield was produced in the between-row than within-row intercrop. To identify plant traits associated with cowpea seed yield under intercropping, three F₂ cowpea populations were grown in intercrop with millet. All three yield components (pod number, seeds per pod, and mean seed weight) were significantly correlated with cowpea seed yield. The number of pods accounted for most of the variation in seed yield. There was a negative association between seeds per pod and mean seed weight. Plant length, number of nodes, and number of branches were also correlated with seed yield, as were the number of pods produced on basal and distal branches and from the longest (> 10 cm) internode category. Plant traits associated with yield in intercrop may differ from those associated with yield in sole crop. Hence, selection criteria for indirectly selecting yield will differ between cropping systems.

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Dallali, Ali. "Characteristics of a 38 KD protein induced in cowpea plants following infection with tobacco ringspot virus." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3052168.

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Thosago, Setshele Standford. "Response of selected cowpea lines to low soil phosphorus and moisture stress conditions at Ukulima Farm in Limpopo Province." Thesis, University of Limpopo, 2015. http://hdl.handle.net/10386/1585.

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Thesis (M. Sc.(Agronomy)) -- University of Limpopo, 2015
Cowpea (Vigna unguiculata L. Walp) is an important grain legume grown in many parts of the world mostly by smallholder (SH) farmers. Low soil phosphorus (P) and drought stress are major constraints to legume production and threaten food security. Root architecture is a spatial configuration of the root system which is influenced by moisture status and P uptake. A field experiment was conducted at Ukulima farm near Modimolle in Waterberg district during 2012/13 summer growing season. The treatments comprised of two levels each for soil P (low and high) and moisture status (water stress and well-watered); and eight cowpea genotypes (Tvu 4632, Tvu 6365, Tvu 9848, Tvu 15445, Tvu 16408, Tvu 15143, Oloyin and IT00K-1217). The low P level implied the available P in the soil measured in situ, which was less than 8 mg kg-1 while the high P level entailed fertilization at the rate of 40 kg P ha-1 application to achieve approximately 35 mg P kg-1 of soil . The root traits measured included angle of adventitious and basal roots, number of basal roots, tap root diameters at 5, 10, 15 and 20 cm soil depths; lateral branching densities at depth 5,10 and 15 cm, nodule score, deep score, shallowness score, 3rd order branching density, and 1.5 branching densities at 5 and 10 cm depth. Plant parameters measured were plant height, number of pods per plant, number of seeds per pod, length of the pods, unshelled weight, shelled weight and number of primary and secondary branches. Photosynthetic parameters measured were photosynthetic rate, intercellular CO2 concentration, water conductance, transpiration rate, vapour pressure deficits, sample cell CO2, sample cell H2O and relative humidity in the cell. All treatment factors were combined as split-split plot arrangement fitted into randomized complete block design; with four replicates. Results indicate that the lateral root branching density at 5 and 10 cm differed significantly (P≤0.05) across cowpea genotypes. Genotype showed significant effect on taproot diameter at 10 cm. Moisture status and P level exerted significant effect on cowpea genotypes 15 cm. There were significant differences (P≤0.05) for lateral root branching density observed at 5 and 10 cm depth in P rates x genotype interaction. Statistical analysis showed that P levels and cowpea genotypes had significant effects (P≤0.05) on mean plant height, biomass and highly significantly effects (P≤0.01) on number of branches, days to physiological maturity and mean pod length. The interaction between cowpea genotype and moisture stress condition significantly (P≤0.05) affected hundred (100) seed weight. Cowpea genotype Tvu16408 obtained highest grain yield of 3240 kg ha-1 and lowest was by IT00K1217 which obtained grain yield of 1256 kg ha-1. Results showed that photosynthetic rate, water conductance, transpiration rate, sample cell CO2, sample cell H2O, relative humidity in the cell, intercellular CO2 and vapour pressure deficit differed significantly (P≤0.05) across cowpea genotypes. Soil moisture condition and cowpea genotype exerted significant (P≤0.01) effect on photosynthetic rate, water conductance, transpiration rate, sample cell CO2, sample cell H2O and relative humidity in the cell. Variation in P levels had no significant effect on the measured photosynthetic parameters. Oloyin genotype had the highest photosynthetic rate followed by Tvu 4632 while cowpea genotype Tvu 9848 had the least photosynthetic rate. Interaction of moisture stress and cowpea genotype had a significant effect on intercellular CO2 concentration. Water stress reduced the intercellular CO2 concentration of Oloyin, Tvu 6365 and 4632 but resulted in a significant increase in intercellular CO2 concentration in Tvu 9848 genotype. Results showed that variation in soil P level exerted a significant (P≤0.05) effect on grain tissue P content and uptake, and a highly significant (P≤0.01) difference in P content across the various cowpea genotypes. Moisture stress exerted a significant (P≤0.05) difference on P uptake. The results showed that P levels and cowpea genotype variation exerted significant (P≤0.05) effects on P content, P uptake and nitrogen (N) uptake. Moisture status and cowpea genotype variation exerted significant (P≤0.05) effects on total N and N uptake. Cowpea genotype Tvu 9848 obtained more total N content (4.37%), while the lowest total N content was obtained by cowpea genotype Tvu 15445 with 3035 mg kg-1. The interaction between cowpea genotype and moisture status exerted a significant (P≤0.05) effect on N and P uptake of immature green pods harvested. There is a need to conduct more studies to identify cowpea genotypes, their root architecture and agronomic measures that can do well under xvii drought stress and low soil P conditions. Research needs to be conducted to enhance cowpea productivity under both low soil P and drought stress. Keywords: cowpea genotypes; moisture stress; phosphorus fertilisation; root traits

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Makoi, JHJR, SBM Chimphango, and FD Dakora. "Effect of legume plant density and mixed culture on symbiotic N2 fixation in five cowpea (Vigna unguiculata L. Walp.) genotypes in South Africa." Symbiosis, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001476.

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Abstract A field experiment involving two plant densities (83,333 and 166,666 plants per hectare), two cropping systems (monoculture and mixed culture) and five cowpea (Vigna unguiculata L. Walp.) genotypes (3 farmer-selected varieties: Bensogla, Sanzie and Omondaw, and 2 breeder-improved cultivars: ITH98-46 and TVuI509) was conducted for two years in 2005 and 2006 at Nietvoorbij (33°54S, 18°14E), Stellenbosch, South Africa, to evaluate the effect of these treatments on the growth and symbiotic performance of cowpea. The results showed that, of the five cowpea genotypes, plant growth and N2 fixation were significantly greater in the three farmer-selected varieties (Sanzie, Bensogla and Omondaw) relative to the two improved cultivars (ITH98-46 and TVuI509). Furthermore, plant growth and symbiotic performance (measured as tissue N concentration, plant N content, 15N natural abundance and N-fixed) were significantly (P:50.05) decreased by both high plant density and mixed culture (intercropping). However, the %Ndfa values were significantly (P:S0.05) increased by both high plant density and mixed culture compared to low plant density or monoculture (or monocropping). Whether under low or high plant density, the cv. Sanzie was found to accumulate significantly greater total N per plant in both 2005 and 2006, followed by the other two farmer varieties relative to the improved cultivars. Similarly, the actual amount ofN-fixed was much greater in cv. Sanzie, followed by the other farmer varieties, under both low and high plant density. The data also showed better growth and greater symbiotic N yield in cowpea plants cultivated in monoculture (or low plant density) relative to those in mixed culture (or high plant density). Our data suggest that optimising legume density in cropping systems could potentially increase N2 fixation in cowpea, and significantly contribute to the N economy of agricultural soils in Africa.

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Belane, AK, and FD Dakora. "Measurement of N, fixation in 30 cowpea (Vigna unguiculata L. Walp.) genotypes under field conditions in Ghana, using the 15N natural abundance technique." Balaban, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001672.

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Abstract In 2005 and 2006, 30 and 15 cowpea genotypes were respectively evaluated for plant growth and symbiotic performance at Manga in Northern Ghana, in order to identify Nz-fixing potential of these cowpea genotypes as source of N for cropping systems. The results showed differences in biomass production by the 30 or 15 cowpea genotypes. In 2005, cultivars Fahari, Mchanganyiko, IT97K-499-39, IT93K-2045-29 and IT84S-2246 produced the most shoot biomass, while Apagbaala, Brown Eye, ITH98-46, Vita 7 and Iron Grey produced the least. Of the 15 genotypes tested in 2006, cv. TVu1l424 produced the largest amount of biomass, and ITH98-46, the least. Isotopic analysis of 15N in plant parts also revealed significant differences in 1)15N of the cowpea genotypes studied. As a result, the percent N derived from fixation (% Ndfa) also differed among the cowpea genotypes tested in 2005, with only 5 out of the 30 cultivars obtaining over 50% of their N from symbiotic fixation. Whether expressed as mg Nplant' or kg N.ha-I , the levels of Nz fixation by the cowpea genotypes varied considerably during 2005 and 2006, with values ofN contribution ranging from 14.1 kg N.ha-1 by cv. TVul509 to 157.0 kg N.ha-1by IT84S-2246 in 2005. The amounts ofN-fixed in 2006 ranged from 16.7 kg N.ha-1 by cv. ITH98-46 to 171.2 kg N.ha-1 by TVu11424, clearly indicating genotypic differences in symbiotic N yield. Re-evaluating 15 out of the 30 cowpea genotypes for Nz fixation in 2006, revealed higher % Ndfa values (>50%) in all (15 cowpea genotypes) relative to those tested in 2005, indicating greater dependence on Nz fixation for their N nutrition even though, the actual amounts of fixed-N were lower in 2006. This was due, in part, to reduced plant biomass as a result of very late sampling in 2006, close to physiological maturity (72 DAP in 2006 vs. 46 DAP in 2005) when considerable leaf matter was lost. The amount ofNfixed in 2006 can therefore be considered as being under-estimated.

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Mendonca, A. P. A. "Some aspects of the host involvement in cowpea mosaic virus replication." Thesis, University of East Anglia, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370391.

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Ishiyaku, Mohammad Faguji. "Inheritance of time to flowering in cowpea [Vigna unguiculata (L.) Walp]." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360060.

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Silva, Felipe Barreto da. "Efeitos do carlavírus Cowpea mild mottle virus em cultivares de soja /." Botucatu, 2019. http://hdl.handle.net/11449/183629.

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Orientador: Renate Krause Sakate
Coorientador: Cristiane Müller
Banca: Marcelo Agenor Pavan
Banca: Jorge Alberto Marques Rezende
Resumo: Doenças causadas por vírus são importantes fatores contrários a produção de soja. Entre elas, a doença da necrose da haste causada pelo Cowpea mild mottle virus (CPMMV) e transmitida pela mosca-branca Bemisia tabaci já foi observada em todas as principais regiões produtoras de soja do Brasil e a queima do broto (Tobacco streak virus - TSV) que têm ocorrência mais restrita nas regiões dos Estados do Paraná e de São Paulo. Os impactos causados por ambas doenças à sojicultura brasileira ainda são desconhecidos. Nesse contexto, o objetivo do presente trabalho foi avaliar os efeitos do CPMMV nas cultivares de soja mais utilizadas nas principais áreas produtoras da região sudeste e centro-oeste do Brasil e avaliar, por sequenciamento de nova geração (NGS) a ocorrência de vírus em uma área comercial de soja na região de Mogi Mirim. Para avaliar os efeitos do CPMMV em cultivares de soja, os experimentos foram conduzidos durante a safra 2017/2018 em quatro regiões: Botucatu e Mogi Mirim no estado de São Paulo, Pedra Preta no estado do Mato Grosso e Planaltina no Distrito Federal. O delineamento experimental foi feito em blocos casualizados, com dois tratamentos: plantas infectadas artificialmente com CPMMV e plantas sadias, e cinco repetições. As parcelas compreenderam 6 linhas (5 m), 0,45 m entre linhas e uma média de 14 plantas por metro. Seis cultivares comerciais foram utilizadas e distribuídas de acordo com a frequência que elas são utilizadas nessas regiões. Para a infecção arti... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Diseases caused by virus are important constraints to soybean production. Among then, stem necrosis caused by Cowpea mild mottle virus (CPMMV) a whitefly-Bemisia tabaci transmitted were observed in all the main soybean producer areas in Brazil and the bud blight (Tobacco streak virus - TSV) occurs strictly in regions Parana and Sao Paulo States. The impacts caused by both diseases on soybean production are still unknown. Therefore, the goal of this study was to evaluate the effects of CPMMV on the major soybean cultivars used in the main growing areas of the Southern and the Midwestern regions of Brazil, and evaluate through next generation sequencing (NGS) the presence of virus in a commercial field of soybean in Mogi Mirim County. To evaluate the effects of CPMMV in soybean cultivars, the experiments were conducted during the 2017/2018 season in four regions: Botucatu and Mogi Mirim Counties, in the state of Sao Paulo, Pedra Petra County in the state of Mato Grosso and in Planaltina County, in the Federal District. The experimental design was completely randomised, with two treatments (plants infected by sap transmission and healthy plants) with five replications. The plot was comprised of six rows (5m), 0.45 m between rows and an average of 14 plants per meter. Six commercial cultivars were used and distributed according to the frequency that they are planted in those regions. For the field inoculation, the virus was readily sap-transmitted in soybean plants 30 d after sowing using infected leaves ground in phosphate buffer 0.01 M, pH 7, using approximately two hundred soybean plants per plot. The presence of the virus was detected by RT-PCR using primers specific for CPMMV. Plant height (cm), number of pods per plant, 1.000-grain weight and grain yield were evaluated during harvest time. Although some cultivars tested presented asymptomatic infection for the virus, CPMMV reduced significantly ...
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Makoi, Joachim HJR. "Seed flavonoid concentration in cowpea genotypes and the effect of plant density on growth, N₂ fixation and rhizosphere phosphatases and grain yield of cowpea intercropped with sorghum." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/727.

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Thesis (DTech (Faculty of Applied Sciences)--Cape Peninsula University of Technology, 2009
A 3-factorial experiment involving two cowpea densities (83,000 and 167,000 plants.ha-1), two cropping systems (i.e. monoculture and mixed culture) and five cowpea genotypes (i.e. three farmer-selected cultivars, Bensogla, Sanzie and Omondaw and two improved varieties, ITH98-46 and TVu1509) was conducted in the field for two consecutive years in 2005 and 2006. The aim was to assess the effect of plant density, cropping system and cowpea genotypes on: (i) chlorophyll and gas-exchange, (ii) rhizosphere mineral concentration and tissue uptake of nutrients, (iii) acid and alkaline phosphatase activities in the rhizosphere, (iv) plant growth and symbiotic performance, and (v) concentration of flavonoids and anthocyanins in seed extracts and plant organs and their effect on pest infestation and diseases. The results showed that high plant density (167,000 plants.ha-1) and mixed culture significantly decreased gas-exchange parameters, leaf chlorophyll content, 13C and %C in both cowpea and sorghum plants compared with low plant density (83,000 plants.ha-1) and monoculture. The data also showed significantly higher 13C and lower %C in ITH98-46 and TVu1509 compared with Bensogla, Omondaw and Sanzie genotypes with a significant correlation between 13C and water-use efficiency. At harvest, grain yield of cowpea and sorghum was significantly decreased by high plant density and mixed culture compared with low plant density and monoculture. Sanzie genotype was generally superior in grain yield (2,550 kg.ha-1) followed by cvs. Omondaw and Bensogla (2,250 and 2,150 kg.ha-1, respectively) compared with the improved cultivars. Sorghum plants in mixture with cv. TVu1509 or cv. ITH98-46 performed better (1,570 and 1,550 kg.ha-1, respectively) compared with those in mixture with other cultivars. The results also showed greater land equivalent ratio (LER = 1.42 to 1.52), suggesting that mixed culture produced greater total yields per unit land area compared with monoculture.

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Thobatsi, Jacob Thobatsi. "Growth and yield responses of maize (Zea mays L.) and cowpea (Vigna unguiculata L.) in an intercropping system." Diss., Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-10122009-184005.

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39

Ngugi, Eliud Chege Kahiu. "The genetics of carbon isotope discrimination in cowpea (Vigna unguiculata L. Walp)." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239598.

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40

Sainsbury, Frank. "Development of cowpea mosaic virus-based vectors for molecular farming in plants." Thesis, University of East Anglia, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502194.

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Expression vectors based on the bipartite Cowpea Mosaic Virus (CPMV) have been investigated for use in molecular farming in plants. Agroinfiltration into Nicotiana benthamiana of two full-length RNA-2 constructs containing different marker genes in the presence of RNA-1 showed that two foreign proteins can be efficiently expressed within the same cell in inoculated tissue. However, segregation of the RNA-2 molecules was observed upon systemic spread of the recombinant viruses. Thus efficient assembly of heteromeric proteins is likely to occur only in inoculated tissue. Therefore vectors based on full-length RNA-2 molecules do not have an advantage over vectors based on deleted versions of RNA-2 that are restricted to infiltrated tissue.

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41

Silva, Weslley Costa. "Answers of cowpea to different irrigation with water saline and doses biofertilizer." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17328.

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nÃo hÃ
The objective of this study was to evaluate the responses of cowpea (Vigna Unguicullata L. Walp) produced under the effect of different irrigation with saline water and liquid biofertilizer doses. Held this experiment in an experimental area Federal Institute of CearÃ, located in the municipality of Umirim - CE with the cultivar of cowpea âBRS Pujanteâ. The experiment obeyed in a randomized block, in a split plot, totaling sixteen treatments and four repetitions. The plot consisted application of four different irrigation water with saline water (75; 100; 125 and 150% of crop evapotranspiration - ETc) and the subplots consisted of four different biofertilizer doses (0; 60; 120 e 180ml/plant). To perform irrigation was using a system drip. The water utility is classified as C4S1 and has electrical conductivity 3.81 dS.m-1. The biofertilizer was prepared in aerobic system, using water and cattle manure in the proportions of 1:1. The doses used were divided in three applications, this being performed at 10, 40 and 70 days after sowing â DAS. To 15, 45 and 75 DAS, they were analyzed chlorophyll content A e B and gas exchange in plants of cowpea, and the end of the experiment the growth, productive components and grain yield per plant. The results were subjected to the analysis of variance by F and their means compared by test Tukey and regression analysis. The results showed significant interaction between factors, getting meaningful answers to 75 DAS for the chlorophyll A. For gas exchange dose 120ml / bio-fertilizer plant was the best interacted with the laminae to 15 and 45 DAS. To 75 DAS the water depth was significant, adjusting the linear model for photosynthesis and stomatal conductance and quadratic for the concentration internal CO2 and transpiration. For growth , the increase in water depth provided to increase dry matter and total leaf Ãrea, being observed respectively adding up 32,42 and 64%. The increase of biofertilizer dose provided increment the number of sheets , fitting the quadratic model and reaching peak on the dose of 80 ml/plant. The production of dry grains , the interaction between the factors was significant , with higher averages in the blades of 100% of ETc and reaching a production of 23.76 and 23.07 g under the doses of 0 and 60 ml/plant of biofertilizers, respectively. Thus the application of different irrigation responded significantly culture , observed higher values when applied blades above 100 % of the ETc. For biofertilizers its application did not respond significantly the variables analyzed.
O objetivo deste trabalho foi avaliar as respostas do feijÃo-caupi (Vigna Unguicullata L. Walp) produzido sob efeito de diferentes lÃminas de irrigaÃÃo com Ãgua salina e doses de biofertilizante lÃquido. Para isso realizou-se este experimento em uma Ãrea experimental do Instituto Federal do CearÃ, localizado no municÃpio de Umirim - CE com a cultivar de feijÃo-caupi âBRS Pujanteâ. O experimento obedeceu ao delineamento em blocos ao acaso, em parcelas subdivididas, totalizando dezesseis tratamentos e quatro repetiÃÃes. As parcelas consistiram na aplicaÃÃo de 4 diferentes lÃminas de irrigaÃÃo com Ãgua salina (75; 100; 125 e 150% da evapotranspiraÃÃo da cultura - ETc) e as subparcelas diferentes doses de biofertilizante bovino (0; 60; 120 e 180 ml/planta). Para realizaÃÃo da irrigaÃÃo foi utilizado um sistema por gotejamento. A Ãgua utilizada foi classificada como C4S1 e possui condutividade elÃtrica de 3,81 dS.m-1. O biofertilizante foi preparado em sistema aerÃbico, utilizando Ãgua e esterco bovino fresco nas proporÃÃes de 1:1. As doses utilizadas foram parceladas em trÃs aplicaÃÃes, sendo estas realizadas aos 10, 40 e 70 dias apÃs a semeadura â DAS. Aos 15, 45 e 75 DAS, foram analisados o Ãndice de clorofila A e B e trocas gasosas em plantas de feijÃo-caupi, e ao final do experimento o crescimento, os componentes produtivos e produÃÃo de grÃos por planta. Os resultados obtidos foram submetidos a anÃlise de variÃncia pelo teste F e feito o teste de Tukey e anÃlise de regressÃo. Os resultados demonstraram interaÃÃo significativa entre os fatores, obtendo respostas significativas aos 75 DAS para o Ãndice de clorofila A. Para as trocas gasosas, a dose 120 ml/planta de biofertilizante foi a que melhor interagiu com as lÃminas de irrigaÃÃo aos 15 e 45 DAS. Aos 75 DAS a lÃmina de irrigaÃÃo foi significativa, ajustando-se ao modelo linear para a fotossÃntese e condutÃncia estomÃtica e quadrÃtica para a concentraÃÃo de interna de CO2 e transpiraÃÃo. Para o crescimento, o aumento da lÃmina de irrigaÃÃo proporcionou aumento para a matÃria seca total e Ãrea foliar, sendo observado respectivamente, acrÃscimo de atÃ 32,42 e 64%. O aumento da dose de biofertilizante proporcionou incremento ao nÃmero de folhas, ajustando-se ao modelo quadrÃtico e atingindo ponto mÃximo sobre a dose de 80 ml/planta. Quanto a produÃÃo de grÃos secos, a interaÃÃo entre os fatores se mostrou significativa, apresentando maiores mÃdias sob a lÃminas de 100% da ETc e atingindo uma produÃÃo de 23,76 e 23,07 g sob as doses de 0 e 60 ml/planta de biofertilizante, respectivamente. Desta forma Ã aplicaÃÃo de diferentes lÃminas de irrigaÃÃo respondeu de forma significativa a cultura, sendo observados maiores valores quando aplicado lÃminas acima de 100% da ETc. Para o biofertilizante sua aplicaÃÃo nÃo respondeu de forma significativa as variÃveis analisadas.

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JÃnior, JosÃ Maria TupinambÃ da Silva. "Standard colonization arbuscular mycorrhizal in plants barabdos cherry, corn and cowpea bean." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17281.

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nÃo hÃ
Improve technologies that seek to reduce the use of phosphate fertilizers is essential, considering that most Brazilian soils have low availability of phosphorus (P), ultimately limit the growth of plants and generating a high dependence of phosphate fertilizers. The use of microorganisms as the arbuscular mycorrhizal fungi (AMF) which are associated with the majority of plant species is now a viable alternative, mainly by beneficial effects of these fungi for plant growth such as increased absorption of nutrient, especially, P. Association between AMF and fruit or annual plants can enhance productivity of these species, in addition to reducing the consumption of phosphate fertilizers. So to evaluate the morphological pattern of colonization by AMF, two studies were conducted, the first in areas of family farmers who grow acerola and reside in Maranguape-Ce. The second study was conducted in a greenhouse and in Soil Microbiology Laboratory of the Department of Soil Science of the University Federal of CearÃ, with cowpea plants and corn fertilized with increasing doses of P. In the first survey, Paris morphology, the presence of intracellular vesicles and hyphae was observed in all areas collected. With the extraction of soil AMF spores, the predominance of genres, Glomus sp. and Scutelospora sp, was found in the four areas where soil samples were collected. In research conducted in the greenhouse, it was observed that the growth of the cowpea and corn was favored by phosphorus fertilization to dose 150 mg P kg-1 soil and 120 mg P kg-1 soil, respectively. The mycorrhizal colonization was reduced by higher doses of P added to the soil and the morphology of mycorrhizal colonization intermediate was observed in both species, not occurring influence of phosphorus fertilization on their morphology. In addition, they identified up to fifteen morphotypes especeis AMF in the soil cultivated with cowpea or corn.
Aprimorar tecnologias que buscam a reduÃÃo do uso de fertilizantes fosfatados Ã essencial, considerando que grande parte dos solos brasileiros possui baixa disponibilidade de fÃsforo (P), acabando por limitar o crescimento das plantas e gerando uma dependÃncia elevada de adubos fosfatados. O uso de micro-organismos, como os fungos micorrÃzicos arbusculares (FMA), que se associam com a maioria das espÃcies vegetais Ã uma alternativa viÃvel principalmente pelos efeitos benÃficos desses fungos para o crescimento das plantas, como maior absorÃÃo de nutrientes, notadamente o P. A associaÃÃo entre FMA e plantas frutÃferas ou anuais poderÃ fomentar a produtividade dessas espÃcies, alÃm de reduzir o consumo de adubos fosfatados. Com o intuito de avaliar se diferentes manejos impostos ao sistema solo planta podem alterar o padrÃo de colonizaÃÃo micorrÃzica arbuscular em plantas cultivadas foram realizados dois estudos, o primeiro em Ãreas de agricultores familiares que cultivam acerola e residem em Maranguape-Ce. O segundo estudo, foi conduzido em casa de vegetaÃÃo e no LaboratÃrio de Microbiologia do Solo pertencente ao Departamento de CiÃncias do Solo da Universidade Federal do CearÃ, com plantas de feijÃo de corda e milho adubadas com doses crescentes de P. Na primeira pesquisa, o padrÃo morfolÃgico Paris, com a presenÃa de hifas intracelulares e vesÃculas, foi observado em todas as Ãreas coletadas. Com a extraÃÃo de esporos de FMA do solo, a predominÃncia dos gÃneros, Glomus sp. e Scutelospora sp, foi constatada nas quatro Ãreas em que foram coletadas amostras de solo. Na pesquisa conduzida em casa de vegetaÃÃo, observou-se que o crescimento do feijÃo de corda e do milho foi favorecido pela adubaÃÃo fosfatada atÃ a dose 150 mg P kg-1 solo e 120 mg P kg-1 solo, respectivamente. A colonizaÃÃo micorrÃzica foi diminuÃda pelas maiores doses de P adicionados ao solo e o padrÃo morfolÃgico de colonizaÃÃo micorrÃzica intermediÃrio foi observado nas duas espÃcies vegetais, nÃo ocorrendo influÃncia da adubaÃÃo fosfatada sobre sua morfologia. AlÃm disso, foram identificados atÃ quinze morfotipos de espÃcies de FMA no solo cultivado com feijÃo de corda ou milho.

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43

Wright, Andrew William. "Fecundity and oviposition behaviour of the cowpea seed beetle, Callosobruchus maculatus (Fabricius)." Thesis, Royal Holloway, University of London, 1986. http://repository.royalholloway.ac.uk/items/edf20917-cbba-4f3b-b9e0-a68a60e3ed74/1/.

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The reproductive biology of three strains of Callosobruchus maculatus F. (Coleoptera: Bruchidae), the cowpea-seed beetle, was studied. This beetle is a serious pest of stored legume seeds in the semi-arid tropics. As females aged, energy reserves were depleted and aspects of this decline were related to the number of eggs laid in order to explain the observed daily egg laying pattern of C. macuiatus. Various factors affected the fecundity of females. The initial adult weight of females showed a strong positive relationship with the number of eggs laid. Substances, which could be extracted from cowpeas, were shown to be necessary to allow normal oviposition on an artificial substrate, glass beads. The male contribution to female fecundity was also investigated. Approximately half of the study was concerned with factors which govern a female's choice of oviposition site. The presence of a pheromone which enabled females to distribute their eggs more efficiently among cowpeas was demonstrated. This demonstration necessitated the development of a bioassay using a choice chamber which allowed beetles to choose between cowpeas marked with pheromone and control cowpeas. Using the bioassay, the solubility of the pheromone in different solvents was examined. The persistence of the pheromone over different periods of time was investigated and it was shown that the pheromone can remain active for at least thirty days. In addition to the marking pheromone, the role of physical characteristics of the oviposition substrates was also studied. The surface area and weight of such substrates were shown to affect the choice of oviposition site by females. The results obtained are discussed in the context of previous work on bruchids, particularly models of oviposition behaviour proposed by some workers.

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44

Bergman, Christine Joy 1960. "Soft wheat pasta supplemented with cowpea: Nutritional, sensory and cooking quality studies." Thesis, The University of Arizona, 1990. http://hdl.handle.net/10150/291602.

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Pasta was produced from soft wheat supplemented with cowpea. Acid detergent fiber values increased from 0.4% in the soft wheat pasta (SWP) to 1.1% in the 30% cowpea pasta (CP). Cowpea supplementation provided an increase in total and available lysine from 42 to 113% and 39 to 117%, respectively. Chemical scores for preschool children increased from 56 in the SWP to 89 in the 30% CP. For school children the 20% CP provided a score of 102. The in vitro protein digestibility (IVPD) of cowpea was lower than that of soft wheat; as a result cowpea reduced the IVPD of SWP from 84% to a value of 78% for the 30% CP. The protein content of SWP was 10.9% while the CP ranged from 11.3 to 14.2%. Considering IVPD values, SWP contained 9.2% digestible protein and CP from 9.2 to 11.1%. After cooking, only the 30% CP displayed trypsin inhibitor activity. Upon visual examination, cowpea improved the color of SP making it comparable to the durum semolina control (DSC) but lacking its translucency. A sensory panel reported no difference in acceptability among treatments. Cooked weights were similar to the SWP, except with 30% replacement when a decrease was observed. CP, after 10 minutes of cooking demonstrated reduced loss as supplementation was increased. After 20 minutes all treatments had similar cooking loss compared to the SP. All treatments displayed cooking quality results significantly different from the DSC.

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45

Ranade, S. A. "Molecular studies in plant genomes with special reference to cowpea and pigeonpea." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1986. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3263.

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46

Profit, Michael Alastair. "Bionomic variation, oviposition strategy and larval competition in West African Bruchid populations." Thesis, Royal Holloway, University of London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266395.

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47

MOHAMED, IBRAHIM ELBASHIR. "EFFECTS OF PRE-PLANT APPLICATION OF NITROGEN FERTILIZER ON SYMBIOTIC NITROGEN FIXATION AND YIELD OF COWPEAS (VIGNA UNGUICULATA (L.) WALP.)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/187957.

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The responses of two cowpea (Vigna unguiculata (L.) Walp.) cultivars inoculated with granular inoculum (a mixture of rhizobia) at different levels of applied nitrogen were evaluated. California Blackeye 5 (Ca5) and Knuckle Purple Hull (KPH) cowpeas were examined under field conditions for percent nodulation, nodule number, and nodule mass per plant, and nitrogenase activity at various times during the 1983 and 1984 growing seasons. Data were also obtained for shoot and root dry weights, seed yield, and protein content. Significant differences between inoculated and uninoculated plots were found at all nitrogen treatments for both cultivars with respect to nodulation percentage, nodule number, nodule mass, and nitrogenase activity. An inverse trend linear and quadratic was noted between nitrogen increments and nodulation (nodule number and nodule mass) of Ca5 and KPH cowpeas. High N (168 kg N ha('-1)) was more inhibitory to nodulation than low (28 kg N ha('-1)) N applied. Nitrogenase activity of both cultivars was significantly stimulated with low and inhibited by high levels of ammonium nitrate. Effects of nitrogen treatments on nodulation and nitrogenase activity were influenced by the stage of growth and cowpea cultivar. At the pod-fill stage, higher nodule numbers and nitrogenase activity were recorded for Ca5 as compared to KPH cowpeas. Morphological differences, with Ca5 plants being erect with few vines, whereas KPH plants were semi-erect and bushy, were observed between inoculated and uninoculated plants of Ca5 and KPH cowpeas at all levels of applied nitrogen. Dry weights of vegetative components of both cultivars were significantly improved when low (28 kg N ha('-1)) rather than high (168 kg N ha('-1)) nitrogen was added. Inoculation significantly increased seed yield of Ca5 cowpeas. When conditions were favorable seed yield of inoculated Ca5 exceeded that of inoculated KPH in all comparisons within the same increments of applied N. Seed yield of both cultivars was adversely affected when high levels of nitrogen were applied. Seed, leaf, petiole, and stem protein content were significantly higher with respect to inoculated than uninoculated plots. However, nitrogen fertilizers tended to decrease protein content of the measured parameters for Ca5 and KPH cowpeas.

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Badiwe, Mihlali. "Effect of Fusarium oxysporum on the physiological and molecular responses of cowpea plants." The University of the Western Cape, 2017. http://hdl.handle.net/11394/5793.

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Magister Scientiae - MSc (Biotechnology)
Cowpea is a tropical, drought-tolerant legume crop that is indigenous to Africa. The crop is of nutritional importance to both animals and humans as part of their diet. Stress to crop plants is defined as any factor that negatively influences the growth and reproduction of a plant below the capabilities of the genotype.

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49

Taylor, Kathryn. "Structure-based refinement of peptide presentation on the surface of cowpea mosiac virus." Thesis, University of East Anglia, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389325.

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50

Spall, Valerie. "The development of a novel system for epitope presentation using cowpea mosaic virus." Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296864.

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Dissertations / Theses on the topic 'Cowpea'

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