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1
Konkle, Samantha N. "Status of Amaranthus Species in Ohio Crop Production." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437400544.
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Norton, Elbert Randall. "Nutrient and crop management studies in irrigated cotton production systems." Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/279773.
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Increased efficiency in agricultural production is becoming increasingly important in the present economic climate. The three studies presented in this dissertation have been developed to help producers achieve a greater efficiency with respect to crop production. The first is the development of the cotton monitoring system (CMS). This software was developed as an end product to over ten years of research into cotton crop monitoring. It allows for the entry of crop growth and development data, along with other crop inputs. All growth indices are plotted against long-term baselines to indicate the crops status in relation to normal growth patterns. Other University of Arizona extension publications are available that are directed at helping the user interpret the data and how best to use it in making management decisions. The second project involves the evaluation of added nitrogen interaction (ANI) effects in irrigated cotton. This was accomplished by comparing two methods of determining nitrogen recovery efficiencies (NREs), the difference technique and the isotopic dilution technique. No differences were observed between the two methods in the first year, 1997 indicating the absence of a ANI. However in 1999, differences were observed between the two methods due to abnormally high vegetative growth experienced by the crop which resulted in increased root growth and subsequent exploration of the soil and an increased uptake of soil N. The third and final project was conducted to examine the loss of N from several different sources of irrigation water around the state of Arizona and to observe the effects of temperature on this process (25, 30, 35, and 40°C). Ammonium sulfate was added to a 350 mL volume of water from which aliquots were drawn at specific time intervals and analyzed for NH₄⁺-N. In a 24 hour period up to 90% of the added N was lost at 40°C). In general, as soluble salts increased the rate at which NH3 was volatilized also increased. The results from this study indicate the need to consider potential N losses from irrigation water when making decisions regarding N fertilizer management.
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Martin, Kent Lee. "Effect of phosphorus placement in reduced tillage crop production." Diss., Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1223.
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Gray, David. "Studies on seed quality and plant establishment in relation to crop production." Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/28147.
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Camarada, Castro Paulino. "A simulation study of crop production systems for the Central Highlands of Angola." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363811.
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Shafiq, Muhammad. "Relative efficiency of crop production in the cotton-wheat cropping system of Pakistan's Punjab." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265175.
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Tawhid, Aslam. "Effects of Soybean Cultivars and Planting Dates on Biomass Production." TopSCHOLAR®, 1994. http://digitalcommons.wku.edu/theses/952.
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Soybean [Glycine max (L.) Merr.] is a valuable source of edible food and organic nitrogen. Soybean cultivar development and cultural practices have been directed toward seed production rather than forage or green manure production. Recent environmental concerns have resulted in renewed interest in the use of organic matter in agriculture. The objective of the present investigation was to determine the effects of cultivar maturity differences and planting dates on biomass production of soybean. The research was conducted on the Western Kentucky University Farm in 1993. The experimental design was a split-split-plot with four replications. The three planting dates (June 2, June 16, and July 6) were main-plots, the three harvest dates were split-plots, and the five cultivars were split-split-plots. The cultivars and their maturity groupings and areas of adaptation are as follows: 'McCall' (00, Minnesota), 'A2506' (II, Iowa), 'FFR561' (V, Kentucky), 'Perrin' (VIII, South Carolina), and 'Laredo1 (undesignated maturity, forage cultivar). Each experimental unit was 45 m2. Seeds were inoculated and broadcast at the rate of 175 kg ha-1 and covered by disking. Average biomass production (oven dry basis) decreased progressively (2918, 2450, and 2088 kg ha-1) for the later planting dates. For the June 2 and June 16 planting dates, biomass yields increased for successive harvest dates; however, for the July 6 planting date, biomass yields did not differ for harvests 2 and 3. When cultivars were compared at the early bloom stage, later maturing cultivars produced more biomass. Laredo was consistently among the highest producers. There were significant interactions involving planting dates, harvest dates, and cultivars. Soybean stands and yields were reduced by inadequate seed covering, by insufficient soil moisture, especially the second planting, and by competition from johnsongrass and pigweed. However, these results indicate that soybean is a good source of green manure during the summer.
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Booker, Bradley L. "No-Till Tomato Production." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/363.
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Tillage increases erosion rates and diminishes the quality of soils but has traditionally been a way to manage weeds and prepare a seedbed. No-till vegetable production can ameliorate the ill-effects of tillage in an economically effective way but has not been studied much in California. The objective of this thesis was to determine the viability of no-till vegetable cropping on the Central Coast of California. Tomatoes were grown in no-till and conventionally tilled treatments. Total yield, fruit weight, weed emergence, soil bulk density, soil aggregate stability, and soil organic carbon content were measured and compared. Yields and soil tests in both treatments were similar while weed emergence in the tilled plots was significantly higher than in no-till plots. The results may help vegetable producers determine how to make vegetable production on the Central Coast more sustainable.
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de, Brito Luis Miguel Cortez Mesquita. "Organic composts as soil amendments to agriculutral land : quantitative studies on their effects on crop production." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386560.
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Deal, Michael William. "Net Primary Production in Three Bioenergy Crop Systems Following Land Conversion." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1309362383.
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Waine, Toby William. "Non-invasive soil property measurement for precision farming." Thesis, Cranfield University, 1999. http://dspace.lib.cranfield.ac.uk/handle/1826/11322.
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This work investigates the application of new sensors to enable agronomists and farm managers to make decisions for variable treatment strategies at key crop growth stages. This is needed to improve the efficiency of crop production in the context of precision farming. Two non-invasive sensors were selected for investigation. These were: 1) The MGD-1 ion mobility gas detector made by Environics OY, Finland. 2) The EM38 electromagnetic induction (EMI) sensor made by Geonics Inc., Canada. The gas detector was used to determine residual nitrogen and to measure carbon dioxide gas as a surrogate indicator of soil quality. In the latter, increased microbial carbon dioxide production was expected on soils with high organic matter content. Overall, the results of gas detection were disappointing. The main problems inherent in the system were; lack of control of the gas sampling, insufficient machine resolution and cross contamination. This led to the decision to discontinue the gas detection research. Instead, the application of electromagnetic induction (EMI) to measure soil variation was investigated. There were two principle advances in the research. Firstly the application of EMI to the rapid assessment of soil textural class. Secondly the mapping of available water content in the soil profile. These were achieved through the development of a new calibration procedure based on EMI survey of the sites at field capacity, working with field experiments from five sites over two years. Maps of total available water holding capacity were produced. These were correlated with yield maps from wet and dry seasons and used to explain some of the seasonal influences on the spatial variation in yield. A product development strategy for a new EMI sensor was considered which produced a recommendation to design a new EMI sensor specifically for available water content and soil texture mapping, that could be mounted on a tractor. For the first time, this procedure enables routine monitoring of the spatial variation in available water content. This enables the effects of seasonal and spatial variation to be included in crop models, targeted irrigation and to aid decisions for the variable application of inputs.
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Widmar, Aaron. "Evaluation of secondary and micronutrients for soybean and wheat production." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/16224.
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Master of Science<br>Department of Agronomy<br>Dorivar Ruiz Diaz<br>The application of micronutrients to increase yields has become more popular with increased commodity prices and higher yielding crops. Two studies were completed evaluating secondary and micronutrient for soybean (Glycine max [L.] Merr.) and wheat (Triticum aestivum).The objective of the first study was to evaluate the response of soybean, under a double crop system after wheat, to soil-and foliar-applied macro and micronutrients. Macronutrients (N, P, K) were applied at 22 kg ha[superscript]-[superscript]1, micronutrients (Fe, Mn, Zn) were soil applied at 11 kg ha[superscript]-[superscript]1and S was applied at 22 kg ha[superscript]-[superscript]1. Plant response parameters were evaluated including changes in nutrient concentration, and seed yield response. Tissue samples were collected at the respective R1 growth stage. Samples were analyzed for the nutrients applied with the fertilizer treatments. Soybean seed yield slightly responded to soil-applied S, Mn, and Zn. When micronutrients were foliar-applied, seed yield was significantly decreased. The second study evaluated the application of S and micronutrients to winter wheat. The objectives were to evaluate the wheat response to sulfur and micronutrient fertilization and evaluate soil testing and tissue analysis as diagnostic tools. Fertilizer treatments consisted of sulfur, iron, manganese, zinc, boron, copper. All of the micronutrients were sulfate-based products and the sulfur treatments were applied as gypsum. Fertilizer treatments were applied as topdress in early spring. Soil samples were collected before fertilizer application and after harvest. Flag leaf samples were collected and analyzed for the nutrients applied with the fertilizer treatments. Significant increases in tissue concentration were observed when Zn, B, and S were applied. Significant increases in soil test Zn, Cu, B, and S were observed compared to the control treatment. Despite the increases in soil test concentration across locations, no significant increases in yield by any of the nutrients or combination of nutrients were observed.
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Kiome, Romano Mungiiria. "Soil and water conservation for improved soil moisture and crop production : an empirical and modelling study in semi-arid Kenya." Thesis, University of East Anglia, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317585.
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Claycomb, David. "An Economic Study of the Relative Profitability of Alfalfa Production and Marketing Practices." TopSCHOLAR®, 1995. http://digitalcommons.wku.edu/theses/903.
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The seasonality of the price of alfalfa hay in Kentucky was studied as well as the potential cost or profitability of storage of this hay. Economic comparison of alfalfa hay production to other farm enterprises was carried out. In addition, an estimate of the value of two qualities of alfalfa hay was calculated based on 1991 prices. The analysis of 41 years of marketing data demonstrated significant differences (P<.01) in price with seasonal lows in June/July and a steady increase in price to a high in March. In general (based on $100 per ton hay and 12% interest) the alfalfa hay producer could lose from $5 to $10 storing hay and selling at a later date. There were some specific conditions where he might have realized a return to storage of $0.16 to $1.48 per ton. A further evaluation of average (KY Feeder) and good (KY Pride) quality hays indicated that current prices of $70-$75 and $100 per ton respectively were the prices where a dairyman would be able to include this hay in the cow's total diet. Even with problems of quality and quantity of alfalfa hay, the economic returns to the production of alfalfa hay were favorable when compared to other crops in Kentucky with the additional benefit of alfalfa being a crop that can result in reduced soil erosion from sloping land. Returns above variable costs can be from $120 to $400 per acre depending upon yield and sale price. However, an understanding of seasonality of price as well as storage costs need to be considered by alfalfa hay producers to assure realizing the above returns.
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Human, Hans Jurie. "Identification of soil and biological factors in crop rotation systems with significance to wheat crop performance in the Overberg production area of South Africa." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019.1/2286.
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Penafiel, Alvarado Juan Leopoldo. "The Study of Alfalfa (Medicago Sativa) Production In the Community of El Troje." BYU ScholarsArchive, 1998. https://scholarsarchive.byu.edu/etd/5420.
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The alfalfa harvest in Ecuador constitutes one of the most important activities, especially as a primary product for animal feeding. The crop is widely distributed in the mountain region of the country. It is important to have studies on the production systems, which facilitate a real and compete vision of those characteristics that interact among them in the agricultural production. With this knowledge it will be possible to look for the most adequate solutions to the conditions of the area where alfalfa is produced. The objectives of the study reported herein were: 1. To make an agricultural, social and economical diagnosis in the community of El Troje, San Luis Parish, Riobamba Canton, Province of Chimborazo. 2. To identify the production system used by the farmers to harvest alfalfa in El Troje community.
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Griffith, Keegan. "Impact of a Winter Rye Cover Crop on Edge-of-Field Nutrient Losses and Corn Silage Production." ScholarWorks @ UVM, 2019. https://scholarworks.uvm.edu/graddis/1011.
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Cover crops have the potential to reduce environmental impacts of corn production. The objective of this study was to quantify differences in nitrogen (N) and phosphorus (P) loading between corn plots with or without a winter rye cover crop (Secale cerale). Four field plots (30 x 46 m) in Chazy, NY with edge-of-field monitoring were used for the study. Two plots were randomly assigned a rye cover crop treatment and planted with a grain drill at a rate of 112 kg ha-1 after corn silage harvest in 2015 and 2016. Continuous water flows were monitored from surface runoff and tile drain hydrologic pathways dur-ing runoff events. Soluble reactive P (SRP), total P (TP), nitrate-N, total N (TN), and to-tal suspended solids (TSS) concentrations were measured and multiplied by runoff vol-umes to estimate nutrient export. Surface runoff from rye plots had lower nutrient loss compared to control plots. Cumulative nitrate-N exports were similar between treatments (15.7 vs. 14.8 kg nitrate-N ha-1 for rye and control, respectively). Cumulative TN exports were numerically higher for control plots compared to rye plots, (18.8 vs. 21.4 kg TN ha-1). Cumulative TP and SRP exports (surface + tile) for rye were 2.2 and 3-fold greater than control plots, (0.51 vs. 1.19 kg TP ha-1 and 0.33 vs. 0.96 kg SRP ha-1). Total P and SRP loads in surface runoff were 3.0-fold greater for control plots compared to rye plots (0.36 vs. 1.12 kg TP ha-1 and 0.32 vs. 0.94 kg SRP ha-1). TSS load in surface runoff was numerically higher for control plots compared to rye (5.7 vs. 20.6 kg ha-1). Cumulative surface runoff was 1.8-fold greater in control plots compared to rye plots (112.6 mm vs. 207.7 mm), while cumulative tile runoff was numerically higher in rye plots compared to control (83.2 mm vs. 66.1mm). Snowmelt events contributed the majority of phosphorus losses (96% of SRP and 92% of TP), emphasizing the need to implement management techniques that reduce P transport risk during the non-growing season. Winter rye re-duced snowmelt TP export by 3-fold compared to the control plots (0.33 kg TP ha-1 and 1.03 kg TP ha-1). The winter rye cover crop planted after corn silage harvest effectively reduced erosion and P transport in surface water runoff compared to corn silage left fal-low after harvest. In addition to significantly reducing P exports, farms have the option of harvesting rye as a forage crop and double cropping with corn. In this way, more total forage is possible for the farm in addition to offering environmental conservation and wa-ter quality benefits.
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Townsend, Marjorie Louise. "Overseeding the cover crops Hairy Vetch (Vicea Villosa Roth) and Medium Red Clover (Trofolium Pratense L.) into corn (Zea Mays L.) after the last cultivation: effects on corn yield and cover crop production of dry matter and ground cover residue." The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1413464088.
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Galeón, Alcón Mercedes Victoria. "Production of the edible mushroom (Agaricus sp.) under laboratory conditions for their multiplication in different culture media." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/5366.
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Edible mushroom production has two different stages: the vegetative stage and the fruiting stage. The vegetative phase is performed in a biotechnology laboratory and covers the technique for obtaining “spawns”, which parameters include the multiplication and reproduction of the mycelium. The fruiting phase begins with the appearance of edible mushrooms and includes everything that occurs outside the laboratory. In our country, production of edible mushrooms is limited and generally unknown. So, in this study, the vegetative phase was divided into two stages and conducted in the laboratory. Stage 1: We inoculated spores and implants of the edible mushroom species Agaricus in three synthetic growth mediums: PDA (Potato-Dextrose-Agar), PDY (Potato-Dextrose-Yeast), and MEA (Barley-Biphosphate Potassium-Agar). These were incubated in different growth chambers at three different temperatures (17ºC, 20ºC, and 25ºC). The best mushroom development in terms of micellar growth was obtained in the PDA growth medium. The temperature that contributed most favorably to this development was 17ºC. Stage 2: We re-inoculated implants from the crops of the previous step in four natural substrates (brown rice, barley creole, brown rice combined with horse manure, barley combined with horse manure) and incubated them in growth chambers at three different temperatures. It was observed that the best micellar growth occurred in the natural substrate containing barley creole. Also, the most effective incubation temperature was 20ºC. Thus, we established that the barley grains sold in our city work well as a cheap natural substrate to propagate and produce edible mushroom “seed” of the Agaricus species at a temperature of 20ºC.
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Romero, Mancero Romeo Byron. "Comparative study of six different types of subtracts in the production of earthworm humus and its productive effect in vegetables (radish, beet, white onion, cabbage)." BYU ScholarsArchive, 1999. https://scholarsarchive.byu.edu/etd/5432.
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In the province of Chimborazo, found in the Riobamba canton, a study was done with the purpose of comparing different subtracts for the production of earthworm humus (pig feces, guinea pig feces, rabbit feces, bovine feces, market residues, and vegetable residues from the harvest) and its productive effect in vegetables (radish, onion, beet and cabbage). Twenty-four beds, 1.5 m2 (1.5 x 1) in size, as well as sixteen 3 m2 (1 x 3) parcels were used for the study. A design of complete blocks was applied with a monofactorial in the first test, and a bifactorial in the second test. The experiment lasted forty weeks. In general, the best productive behavior by the earthworm humus was distributed among various subtracts. The vegetable residues had the best final weight with a value of 66.75 Kg/parcel. The treatment with guinea pig feces had the best nitrogen content (0.29%). Bovine feces had the best phosphorus content (1.08%). Rabbit feces produced 10.6% of potassium as well as the highest number of earthworms in the harvest (6,900,00). With regards to the production of vegetables, cabbage responded well to almost all of the variables studied. Cabbage obtained superior values than the rest of the vegetables with a 99.5% capture and a 0.25% mortality. The other variables could not be compared because different types of vegetables were used. In the total economic analysis, it was seen that there was a expenditure of 851,960.00 sucres against an income, from the sale of humus and vegetables, of 1,065,000.00 sucres. The net income was 213,120.00 sucres and the benefit/cost was 1.21. It is recommended that this technique be used for small scale production, because the humus improves the ground's physical and chemical characteristics, thus obtaining representative economic gains.
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Giostri, André Faé. "Production and enviromental services of integrated crop livestock systems." reponame:Repositório Institucional da UFPR, 2014. http://hdl.handle.net/1884/38123.
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Orientador : Prof. Dr. Paulo C. de Faccio Carvalho<br>Co-orientador : Prof. Dr. Aníbal de Moraes<br>Co-orientadora : Drª. Laíse da Silveira Pontes<br>Co-orientador : Dr. Abad Chabbi<br>Co-orientador : Dr. Antônio Carlos Vargas Motta<br>Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Agrárias, Programa de Pós-Graduação em Agronomia. Defesa: Curitiba, 27/10/2014<br>Inclui referências<br>Área de concentração: Produção vegetal<br>Resumo: Sistemas diversificados de produção agropecuária, tais como sistemas integrados de produção agropecuário (PISA) são uma alternativa para o aumento produção e melhorias nos ecossistemas. As características distintas destes sistemas de produção são explorar sinergias e propriedades emergentes de interações no compartimentos solo-planta-animal-atmosfera em áreas que integram os PISA, também fornecer interações ecológicas entre os diferentes ecossistemas agrícolas, como a redução da degradação química e física do solo, aumentando a matéria orgânica do solo, preservação dos recursos naturais e benefícios ambientais, como a redução das emissões de gases com efeito de estufa. Assim, a utilização da interação em PISA é fundamental para alcançar sucesso, como resultado final, para aumentar o rendimento e a sustentabilidade ecológica. O primeiro capítulo avalia o efeito árvores de um PISA sobre a qualidade e a produção de seis espécies forrageiras Axonopus catharinensis, Uruchloa brizantha cv. Marandu, capimmombaça cv. Aruana, Hemarthria altíssima cv. Florida, Cynodon spp. híbrido Tifton 85 e Paspalum notatum cv. Pensacola. O segundo capítulo avalia as emissões de N2O em um PISA com rotações de longo prazo: pastagem cortada seguida de três anos com rotações agrícolas . O terceiro capítulo aborda a questão do N2O em sistemas com diferentes manejos de pastagens (cortada vs. pastejada). Concluiu-se que as espécies de forrageiras apresentaram menor rendimento produção no PISA estudado, devido ao efeito do sombreamento das árvores. A adubação nitrogenada aumentou o valor nutritivo e produção de matéria seca das forragens. Os resultados da emissão de N2O mostraram que aração do solo aumenta a emissão de N2O do solo. A pastagem cortada também contribui para o aumento da emissão de N2O solo, comparando com a forragem pastejada. Palavras chave: N2O, rotação de culturas, forragem, manejo de pastagem, gases do efeito estufa.<br>Abstract: Diversified agricultural systems such as integrated crop livestock systems are an alternative for achieving production and ecosystem services. The distinguishing characteristics of these production systems are that they are designed to exploit synergisms and emergent properties of interactions in the compartments soil-plantanimal- atmosphere on areas that integrate crop and livestock production systems (ICLS). ICLS also can provide opportunities to capture ecological interactions among different land use systems to make agricultural ecosystems more efficient at reducing soil chemical and physical degradation, increasing soil organic matter, enhancing biodiversity and preserving natural resources and environmental benefits as reducing greenhouse gas emission. Thus, the use of the interaction in ICLS is key to achieving success, as final result to increase ecological sustainability and yield. The first chapter evaluates the trees effect of an ICLS on the quality and production of six forage species Axonopus catharinensis, Uruchloa brizantha cv. Marandu, Megathyrsus maximus cv. Aruana, Hemarthria altissima cv. Florida, Cynodon spp. hybrid Tifton 85 and Paspalum notatum cv. Pensacola. The second chapter assesses the emission of N2O on an ICLS with long-term rotations: mowed pasture and three years crop rotations. The third chapter addresses the issue of N2O in systems with different pasture management (mowed vs. grazed). It was concluded that the forage species showed lower production in the ICLS, due to trees effect. Nitrogen increased the forage nutritional value and dry matter yield. The results of N2O emission showed that plowing increases the soil N2O emission and the mowed grassland also contributes to the increase in the soil N2O emission, compare to grazing. Key words: N2O, crop rotation, forages, pasture management, greenhouse gas.
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Penick, William Frazier. "Influence of Transplanter Modification and Previous Crop on the Production of No-Till Dark Tobacco." TopSCHOLAR®, 2013. http://digitalcommons.wku.edu/theses/1257.
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Dark tobacco (Nicotiana tabacum L.) has historically been produced usingconventional tillage practices. Soil is cultivated multiple times throughout a growing season leading to an increased incidence of soil erosion. No-till systems have been growing in popularity with the advent of new technology that has enabled the practice to be performed effectively and efficiently. With the recent expansion of no-till practices throughout the agricultural community, many crops have had success in producing comparable yields while reducing input costs and saving soil resources. For this experiment, a traditional tobacco transplanter was modified for use in a no-till environment. All modifications were fabricated without using specialty tools and made possible to be removed if desired or necessary. Frame extensions were designed and built to accommodate row cleaners and coulters. Tillage shanks were also added to aid in optimal furrow formation. Double-disc opening shoes replaced the original round point shoes and the curved edges of the rear drive wheels were removed, creating a flat surface to increase soil contact. Experimental no-till plots in fescue sod and soybean chaff residues were conducted alongside conventional tillage plots at the Western Kentucky University Agricultural Research and Education Complex in summer 2011. Five treatments, one conventionally tilled (Conv) and four no-till, were replicated three times within a randomized complete block design and used to determine the efficacy of transplanter modifications (consistency of depth, furrow closure, observed plant damage), survival of the transplants, and the amount of residue displacement. The four no-till treatments utilized different combinations including: coulter, row cleaner and shank (CRS), row cleaner and shank (RS), coulter and shank (CS), and shank only (S). These treatments demonstrated the functionality of each combination in comparison to conventional treatments. No treatment performed equally well in both residue locations. Plots in fescue residue utilizing a combination of coulter, row cleaner, shank (CRS), exhibited the lowest amount of root exposure, highest survival rate, and comparable cured weight when compared to conventionally tilled treatments. In soybean residue plots, the treatment operating with row cleaners and shanks (RS) had equivalent amounts of furrow closure to conventionally tilled plots. Pairing specific modification combinations with previous crop residue can provide furrow closure, transplant survival, and cured yield equivalent to conventionally tilled dark tobacco.
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Chen, Changping 1958. "Production variability for major Arizona field crops." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/291617.
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Previous variability studies in both U.S. and worldwide agriculture have indicated that crop production has been accompanied by increasing variation. In this research, four different variability indexes were estimated in order to evaluate the production variability associated with the major Arizona field crops. Results show that major Arizona field crops, which are all irrigated, did not have a uniform production variability over the last 24 years and the variability of these crops did not generally increase between the periods of 1967-1978 and 1979-1990. Although biological factors (e.g. pests, weather) influenced variability, the variation of crop production measures over time also was related to market factors (e.g. prices), government farm programs, producers' crop management experience, and the geographical area selected for the analysis. Crops covered by government farm programs usually varied more in harvested acreage and fluctuated less in yield per acre than vegetable crops.
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Schwer, Laura Mary Jane. "SMALL MAMMAL POPULATIONS IN SWITCHGRASS STANDS MANAGED FOR BIOMASS PRODUCTION COMPARED TO HAY AND CORN FIELDS IN KENTUCKY." UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_theses/138.
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Switchgrass (Panicum virgatum), a native warm-season grass, has been investigated as a renewable energy crop that may provide viable wildlife habitat. This study investigated small mammal populations in switchgrass, hay, and corn to assess the relative habitat quality. Four, three-night trapping sessions were conducted at four locations in Kentucky using Sherman livetraps. Trapping occurred in spring (before first hay harvest), summer, fall (before switchgrass and corn harvest), and winter (post-harvest). Relative abundance of small mammals, calculated using a capture per unit effort index (per 100 trapnights), and mean taxonomic richness were used to compare habitats. Switchgrass had a significantly greater mean taxonomic richness than hay but not corn; however, four genera were captured in switchgrass and only two in corn. Switchgrass had a greater relative abundance of small mammals than hay during the summer, and corn and hay during the fall. Vegetative cover was positively correlated with relative abundance of small mammals. No-till corn and three year old switchgrass had a greater relative abundance of small mammals than conventionally tilled corn and two year old switchgrass, respectively. In conclusion, switchgrass stands managed as a renewable energy crop has the potential to be viable wildlife habitat for some small mammal species.
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GANIMEDE, CRISTINA. "REDESIGNING AGNOECOSYSTEMS FOR A SUSTAINABLE CROP PRODUCTION INTENSIFICATION." Doctoral thesis, Università Cattolica del Sacro Cuore, 2017. http://hdl.handle.net/10280/17727.
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L’intensificazione sostenibile delle pratiche agricole rappresenta un paradigma per il passaggio da sistemi agricoli tradizionali all’applicazione di tecnologie e tecniche moderne per la produzione agricola. A livello globale si è diffuso l’interesse verso il modello di Agricoltura Sostenibile (AS), in vista di alcuni problemi che possono minacciare la sicurezza alimentare mondiale: crescita della popolazione mondiale, cambiamenti nella domanda delle produzioni agricole, percentuale elevata di persone sottonutrite, cambiamenti climatici, diminuzione delle risorse naturali. Il progetto “Produzione di cibo appropriato: sufficiente, sicuro, sostenibile”, ancora in corso, lavora per raggiungere alcuni scopi: (1) rilevare e valutare la disponibilità quantitativa e qualitativa degli alimenti destinati al consumo umano, (2) proporre nuovi sistemi di produzione agro-zootecnica, (3) sviluppare tecniche appropriate per processare e conservare gli alimenti, al fine di ottenere uno stato di sicurezza alimentare e sostenibilità ambientale ed economica. L’obiettivo generale di questo lavoro è quello di mostrare quali sono le possibili alternative ai sistemi agricoli tradizionali, sia nei Paesi Sviluppati sia in quelli in Via di Sviluppo, al fine di aumentarne l’efficienza e diminuirne gli impatti sull’ambiente, aumentando lo stato globale di sicurezza alimentare. Per i Paesi in Via di Sviluppo l’attenzione si concentra sulle pratiche di sviluppo rurale integrato, al fine di implementare quantitativamente la produzione alimentare e, conseguentemente, la sicurezza alimentare, preservando nel contempo l'ambiente. Per i Paesi Sviluppati, in cui i rendimenti agricoli sono già potenzialmente molto elevati, l’attenzione viene focalizzata sul migliorare la produttività del suolo, riducendo gli input esterni e le emissioni di gas ad effetto serra, attraverso l’adozione di sistemi agricoli conservativi.<br>Sustainable intensification of agricultural practices represents a paradigm shift from traditional farming systems to the application of modern technologies and techniques to crop production. At global level it has been widespread interest towards Sustainable Agriculture (SA) model, in view of some issues that will may threaten the world food security: growing world population, changes in agricultural product’s demand, high prevalence of undernourishment, climate changes, decreasing of natural resources. The project “Production of proper food: sufficient, safe, sustainable" is still working to achieve some purposes: (1) to detect the availability quantity and quality of food for human consumption, (2) to propose new agro-livestock production systems, (3) to develop appropriate techniques for processing and storage of foodstuffs, in order to achieve food security, environmental and economic sustainability. The objective of this work is to show what are the possible alternatives ways at traditional agricultural systems, both in Developed and Developing Countries, in order to increase the efficiency and to decrease the impacts on the environment, raising a global condition of food security. For Developing Countries the attention is focused on integrated rural development practices in order to implement food production and the state of food security, while preserving the environment. For Developed Countries, in which yields are already potentially higher, the attention is focused on enhance soil productivity while reducing external farming input and greenhouse gases emission by the adoption of conservation agricultural systems.
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Scott, Delia W. "EVALUATING THE SUSTAINABILITY OF FOUR ORGANIC VEGETABLE PRODUCTION SYSTEMS." UKnowledge, 2013. http://uknowledge.uky.edu/pss_etds/23.
Full textAbstract:
A field study evaluating the sustainability of four organic vegetable production systems was conducted in Lexington, Kentucky in 2006 and 2007. The four systems included no-till, raised beds covered with biodegradable black mulch, bare ground with shallow cultivation, and bare ground with shallow cultivation and wood chip mulch. The two-year study compared yield, weed control, labor, and costs associated with each system, as well as physical, chemical, and microbiological soil characteristics. In 2006, tomatoes (Lycopersicon esculentum Mill.) were grown in the four systems, with no significant difference in yield. Summer squash (Cucurbita pepo L.) was grown in the four systems in 2007. The no-till system had significantly lower yields than other systems. The bare ground with cultivation and mulch system had the best weed control in both years.
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Kenney, Ian T. "Regional assessment of short-term impacts of corn stover removal for bioenergy on soil quality and crop production." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/13186.
Full textAbstract:
Master of Science<br>Department of Agronomy<br>Humberto Blanco<br>DeAnn Presley<br>The U.S. agricultural sector is in a prime position to provide crop residues such as corn (Zea mays L.) stover as feedstock for large-scale bioenergy production. While producing renewable energy from biomass resources is a worthy initiative, excessive removal of corn stover from agricultural fields has the potential to increase soil erosion, degrade soil properties, and reduce corn yields. A need exists to objectively assess stover removal impacts on agriculture and the environment on regional scales. This project assessed the effects of removing various rates of corn stover on runoff and erosion and changes in soil physical properties and corn yields on a regional scale across three soils at Colby, Hugoton, and Ottawa in Kansas, USA. The soils were Ulysses silt loam (Fine-silty, mixed, superactive, mesic Aridic Haplustolls) at Colby, Hugoton loam (Fine-silty, mixed, superactive, mesic Aridic Argiustolls) at Hugoton, and Woodson silt loam (Fine, smectitic, thermic Abruptic Argiaquolls) at Ottawa, all with slopes [less than or equal to] 1%. Five stover treatments were studied that consisted of removing 0, 25, 50, 75, and 100% of stover after harvest from no-till and strip-till continuous corn plots. Simulated rainfall was applied in spring 2010 at rates representing 5 yr return intervals at each site and included a dry and wet run. Runoff increased with an increase in stover removal at Colby and Hugoton, but not at Ottawa. At Colby, stover removal rates as low as 25% caused runoff to occur 16 min sooner and increased sediment loss. At this site, runoff and sediment-carbon (C) loss increased as removal rates exceeded 25%. At Hugoton, complete stover removal increased loss by total N by 0.34, total P loss by 0.07, PO[subscript]4-P by 0.003 and NO[subscript]3-N by 0.007 kg ha-[superscript]1. At Ottawa, PO[subscript]4-P loss decreased by 0.001 kg ha-[superscript]1 with 25% removal and by 0.003 kg ha-[superscript]1 with 50% removal. Mean weight diameter (MWD) of wet aggregates decreased with an increase in stover removal on all soils. At Ottawa, stover removal at 75% reduced soil C in the top 5 cm by 1.57 Mg ha-[superscript]1. Soil volumetric water content decreased with stover removal at Colby and Ottawa, but was variable at Hugoton. Soil temperature tended to increase with stover removal during summer months and decrease during winter months. Soil temperature also fluctuated much more widely with stover removal, resulting in more freeze-thaw events compared to no stover removal. No effect of stover removal on soil water retention was observed on any of the soils. In 2009, removal rates [greater than or equal to]50% resulted in greater grain yield at Colby, while removal rates [greater than or equal to]75% resulted in greater grain yields at Ottawa in 2009 and 2010. Results from the first two years of stover management suggest that stover removal at rates above 25% for bioenergy production increased water erosion, degraded soil structural properties, and altered soil water and temperature regimes. Higher rates of removal ([greater than or equal to]75%) can also reduce soil C concentration in the short-term in rainfed regions. However, grain yields may be enhanced by stover removal from irrigated soils and from rainfed soils with adequate moisture. Overall, the increase in water erosion and alteration in soil properties in the short-term suggest that stover removal can detrimentally affect water quality and soil productivity in Kansas. Further long-term monitoring is warranted to conclusively discern stover removal implications.
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Kuykendall, Matti Beth. "Biomass production and changes in soil water with cover crop species and mixtures following no-till winter wheat." Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/19080.
Full textAbstract:
Master of Science<br>Department of Agronomy<br>P. V. Vara Prasad,<br>Kraig L. Roozeboom<br>Replacing fallow with cover crops can provide many benefits, including improved soil quality and reduced nitrogen fertilizer requirements. The addition of cover crops into no-till systems has become popular in recent years as a means of increasing cropping system intensity and diversity. A primary concern of producers in the Great Plains is the possibility that cover crops may reduce the amount of soil water stored in the profile for the next grain crop, potentially reducing yields. Multi-species cover crop mixtures that enhance the ecological stability and resilience of cover crop communities may produce greater and more consistent biomass than single species. Field experiments were established in 2013 and 2014 near Belleville and Manhattan, KS following winter wheat (Triticum aestivum L.) harvest to evaluate the effect of cover crop species and species complexity on changes in soil profile water content and water use efficiency. Along with a chemical fallow control, ten cover crop treatments were tested: six single species, two-three component mixes, a mix of six species, and a mix of nine species. Volumetric water content was measured using a neutron probe and a Field Scout TDR 300. Similar data were collected in 2014 from an experiment established in 2007 comparing fallow, double-cropped soybean, and four cover crop types (summer and winter legumes and non-legumes) in a no-till winter wheat-grain sorghum-soybean cropping system near Manhattan, KS. Results from both studies showed that grasses produced the most dry matter with the highest water use efficiency (up to 618 kg cm-1). Fallow lost up to 7.9 cm less water than all cover crop treatments throughout cover crop growth and in the fall, but captured up to 3.4 cm less moisture in the spring than the cover crops that added residue to the soil surface. Brassica species extracted water from deeper in the soil profile than the other cover crop species. Species complexity affected water use only relative to the proportions and productivity of their individual components, with no advantage in water use efficiency for the more complex mixtures.
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Maali, Safiah Hasan. "Biomass production, yield and quality response of spring wheat to soil tillage, crop rotation and nitrogen fertilisation in the Swartland wheat producing area of South Africa." Thesis, Stellenbosch : University of Stellenbosch, 2003. http://hdl.handle.net/10019.1/949.
Full textAbstract:
Thesis (PhD(Agric) (Agronomy))--University of Stellenbosch, 2003.<br>108 leaves printed on single pages, preliminary pages i-vi and numbered pages 1-1 to 1-5 to 9-1 to 9-3. Includes bibliography, list of abbreviations and 22 figures in color. Digitized at 300 dpi grayscale and 300 dpi 24-bit Color to pdf format (OCR), using an HP Scanjet 8250 Scanner.<br>ENGLISH ABSTRACT: A long term experiment was conducted at the Langgewens Experimental Farm, near Malmesbury in the Western Cape province of the Republic of South Africa. The
effect of soil tillage, crop rotation and nitrogen fertiliser rates on mineral-N levels in
the soil, nitrogen levels in plants, wheat growth and yield components, grain yield as
well as quality parameters of spring wheat were determined.
Although the tillage treatments tested were initiated in 1976, present crop rotations
and nitrogen application rates were only applied since 1990. Most of the data that are
discussed however was recorded during the 1997 to 2001 period.
The trial was designed as a randomised complete block with a split-plot arrangement
and four replicates. Main plots were tillage methods namely conventional tillage
(CT), tine tillage (TT), minimum tillage (MT) and no tillage (NT). Crop rotations
used were continuous wheat (WW) and wheatl lupin/wheat/canola (WLWC). Both soil and crop data were
recorded.
The results of this study showed the differences in total mineral-N content of the soil.
N-contents of wheat, wheat growth and yield components as well as wheat quality
parameters were found between tillage treatments, crop rotations used as well as N-
fertiliser rates applied. Response however, varied largely between years due to annual
variation in especially total precipitation and distribution of rainfall. The inclusion of
a legume crop (lupin) and canola in the rotation with wheat was found to have only a
small effect probably due to the fact that lupins were grown once in a four year cycle
only.
Application of different nitrogen rates did increase the mineral-N in the soil, but the
effect did not last very long in most years due to either N-leaching or plant uptake. To
ensure sufficient mineral-N levels, late application of N-fertiliser will therefore be
needed. Minimum tillage or reduced tillage performs better than conventional tillage
in low rainfall years. In general these tillage systems should be combined with crop
rotation to ensure that yields are comparable to that obtained with conventional
tillage.<br>AFRIKAANSE OPSOMMING:
Die ontwikkeling, graanopbrengs en bakkwaliteit van koring (Tritium aestivum L.) in reaksie
teenoor gewasratasie, metode van grondbewerking en N-bemestingspeil is in 'n lang tennyn
sllldie op Langgewens Proefplaas, naby Malmesbury in die Weskaap provinsie van die
Republiek van Suid-Afrika, bepaal.
Hoewel die verskillende grand bewcrkingsmetodes sedert 1976, en gewasrotasies en
slikstofpeile sedert 1990 toegepas is, is daar in hierdie studie gekonsentreer op data wal
gcdurcnde die periode 1997-2001 ingesamel is.
Die eksperiment is as 'n randomiseerde blok ontwerp met vier bewerkingsmetodes nl.
konvcnsionele bewerking (CT), tand bewerking (TT). minimum bewerking (MT) en geen
bewerking (NT), twee gewasratasies nl. monokuhuur koring (WW) en
koring/lupienelkoringiCanola (WLWC) en drie N-peie (60 kg N ha- ', 100 kg N ha- 1
, 140 kg N
ha- I uitgevoer. Aile stikstof is in die vorm van kalksteen-ammoniumnitraat toegedien.
Die reaksie van beide grondfaktore soos die minerale N inhoud en gewaskomponente 5005
biomassa produksie, opbrengs en kwaliteit teenoor bogenoemde faktore het '0 goeie
korrelasie getoon met die heersende klimaatstoestande.
Lae reenval jare (gebiede) sal volgens hierdie stlldie die grootste voordeel verkry met minder
intensiewe grand bewerkingstelsels. terwyl 'n frekwensie van meer as een peulgewas per
siklus van 4 jaar nodig sal wees om grondvrllgbaarhcidsvlakke betekenisvol te verhoog.
Stelsels van rninder intensiewe grondbewerking is ook tot 'n grater mate deur gewaswisseling
bevoordeel as konvensionele melOdes van grondbewerking.
Hocwel minerale-N vlakke in grond deur verskillende N-peile be'lnvloed is, was die
efTektiwiteit van toedienings laag en het verdeelde tocdienings groat voordele ingehou.
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Titolo, Donato. "USING AN ACTIVE OPTICAL SENSOR TO IMPROVE NITROGEN MANAGEMENT IN CORN PRODUCTION." UKnowledge, 2012. http://uknowledge.uky.edu/pss_etds/11.
Full textAbstract:
Corn nitrogen (N) applications are still done on a field basis in Kentucky, according to previous crop, soil tillage management and soil drainage. Soil tests, as well as plant analysis for N, are not very useful in making N fertilizer rate recommendations for corn. Recommended rates assume that only 1/3 to 2/3 of applied N is recovered, variability largely due to the strong affect of weather on the release of soil N and fertilizer N fate. Many attempts have been made to apply N in a more precise and efficient way. Two experiments were conducted at Spindeltop, the University of Kentucky’s experimental farm near Lexington, over two years (2010, 2011), using a commercially available active optical sensor (GreanSeekerTM) to compute the normalized difference vegetative index (NDVI), and with this tool/index assess the possibility of early (V4-V6) N deficiency detection, grain yield prediction by NDVI with and without side-dressed N, and determination of the confounding effect of soil background on NDVI measurements. Results indicated that the imposed treatments affected grain yield, leaf N, grain N and grain N removal. Early N deficiency detection was possible with NDVI. The NDVI value tended to saturate in grain yield prediction models. The NDVI was affected by tillage management (residue/soil color background differences), which should be taken into account when using NDVI to predict grain yield. Side-dress N affected NDVI readings taken one week after side-dressing, reducing soil N variability and plant N nutrition. There is room for improvement in the use of this tool in corn N management.
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Calderwood, Lily. "Top-down and bottom-up tools for integrated pest management in Northeastern hop production." ScholarWorks @ UVM, 2015. http://scholarworks.uvm.edu/graddis/328.
Full textAbstract:
The demand for locally sourced hops from Northeastern microbreweries began the recent resurgence in local hop production. The farming community has increased acreage and improved the quality of hops grown and processed in the Northeast region over the past five years. There was a sharp increase in the number of Northeast hop producers from six in 2009 to over 175 in 2014. Hop growers in the Northeast are new to the crop and have limited experience with pest identification and management. This dissertation encompasses three research projects that were conducted over the 2012-2014 growing seasons. These projects were the first critical steps taken to develop arthropod integrated pest management (IPM) tactics for Northeastern hop growers.
First, the arthropod community in seven Vermont hop yards was evaluated. The objectives of Chapter 2 are to 1) present current hop pest biology and management strategies, 2) report the phenology of arthropod pests observed over three growing seasons, 3) report abundance and peak date for each pest, and 4) document natural enemy abundance in Vermont hop yards. The survey indicates that in cool, wet seasons hop aphid (Phorodon humuli Schrank) is expected to be a pest of concern. Two-spotted spider mite (Tetranychus urticae Koch) is expected to be a pest of concern in hot, dry conditions. Potato leafhopper (Empoasca fabae Harris) is an unpredictable pest of special concern for first year hop plants. When hop aphid or potato leafhopper are sprayed for with broad-spectrum insecticide, two-spotted spider mite secondary outbreak can be expected.
Second, the abundance of major arthropod pests and their natural enemy groups were evaluated under drive row flowering cover crop treatments. The objectives of this study were to 1) measure the effect of cover crops on natural enemy group abundance, 2) measure the effect of cover crops on the three major Northeastern hop pests, and 3) measure the effect of cover crop presence on hop yield and quality. Natural enemy groups and pests were positively correlated yet cover crop treatments had no significant effect on natural enemy abundance. Red clover cover crop treatments served as a trap crop for potato leafhopper. No significant difference in hop yield or quality was observed between flowering cover crop treatments.
Finally, potato leafhopper is a documented but understudied regional pest of hops. The objectives of this study were to 1) measure the physiological response of eight hop cultivars to adult potato leafhopper feeding and 2) measure hop leaf recovery from potato leafhopper injury. Gas exchange (net photosynthesis and transpiration) and chlorophyll content were measured to quantify injury by adult potato leafhopper to first year hop leaves in field and greenhouse studies. Cultivars did not vary significantly in their physiological response to potato leafhopper feeding. Injury significantly reduced gas exchange measures in the field (P < 0.05) and greenhouse (P < 0.05) and when leafhoppers were removed, gas exchange was restored.
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De, Oliveira Ezequiel. "OPTIMIZATION OF DOUBLED HAPLOID PRODUCTION IN BURLEY TOBACCO (Nicotiana tabacum L.)." UKnowledge, 2016. http://uknowledge.uky.edu/pss_etds/75.
Full textAbstract:
Doubled haploidy (DH) is a plant breeding technique that is often utilized by plant breeders to minimize the time required to reach homozygosity in breeding lines. The first objective of this study was to compare two methods of generating DH lines in tobacco (Nicotiana tabacum L.). Inbred burley tobacco varieties TN 90LC and GR 149LC were used to produce both androgenic derived doubled haploids (ADDH) and maternally derived doubled haploids (MDDH). The relative agronomic performance of TN 90LC and GR 149 LC ADDH and MDDH lines was compared when used either as pure-line cultivars or when used for the production of the KT 204LC and TN 97LC hybrid cultivars, respectively. The ADDH method was more efficient than the MDDH method in generating large numbers of haploid plants. On average the ADDH TN 90LC population was statistically inferior to the inbred TN 90LC for several agronomic traits; this inferiority of the ADDH method was not observed in the GR 149LC populations. For both genotypes, the MDDH populations were comparable to the inbred parental genotypes. The ADDH method was inferior for TN 90LC, but several individual TN 90LC ADDH lines were equal or superior to the inbred source. The agronomic variability observed in both ADDH and MDDH lines was decreased when they were used to produce hybrid cultivars. Less variation was observed in the DH-derived hybrids KT 204LC and TN 97LC compared to the ADDH and MDDH TN90LC and GR149LC parental lines, respectively. The significant inferiority of ADDH TN 90 lines in comparison to inbred TN 90LC was not observed in the ADDH derived KT 204 population compared to KT 204LC. The second objective of this study was to compare DH Lines derived from an F1 breeding population versus DH lines derived from a segregating F2 population where plants used for DH were pre-screened for quantitatively inherited resistance to soil-borne diseases black shank (Phytophthora nicotianae) and/or Fusarium wilt (Fusarium oxysporum f. nicotianae). There was a clear difference in susceptibility to black shank between the F1 and F2 derived DH populations, both in terms of average disease incidence, and more importantly, in the percentage of individual lines displaying high disease resistance. For two different burley crosses, DH lines derived from the F1 generation were considerably more susceptible to black shank than DH lines derived from the F2 generation. No differences in the incidence of Fusarium wilt were observed between DH lines of F1 and F2 generations; this was likely due to low overall disease incidence. Although delaying the DH process in tobacco from the F1 to the F2 generation could add time to the development of homozygous breeding lines, the delay may be offset by having to screen fewer finished DH lines to identify superior lines.
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Zinyengere, Nkulumo. "Assessing climate change impacts and agronomic adaptation strategies for dryland crop production in southern Africa." Doctoral thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/20846.
Full textAbstract:
Dryland farmers in southern Africa operate under harsh conditions; infertile soils, erratic rainfall regimes, sub-optimal input levels etc. Crop yields have generally been low, negatively affecting food security and livelihoods. Climate change is anticipated to aggravate these already existing challenges. In the recent past, a wide range of studies has sought to understand how climate change will affect crop production. However, there are only few detailed localised studies that focus on understanding climate change impacts and adaptation under heterogeneous conditions that dryland farmers in southern Africa operate. This study sought to understand how climate change will affect food crop production in southern Africa's drylands and to provide insight on the potential of on-farm agronomic management strategies for adaptation. The study focused on three locations representing some of the agro-ecological conditions of southern Africa i.e. Big Bend in Swaziland (low altitude, hot and dry), Mohale's Hoek in Lesotho (high altitude, cool and wet and dry), and Lilongwe in Malawi (mid altitude, wet with moderate temperatures). The study was performed largely using a climate-crop model simulation approach supported by a review of similar approaches in the region, data collected from reported agricultural experimental trials, regional experts, downscaled climate projections (using up to 9 GCMs) and surveys.
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Alkadri, Dima <1979>. "Fusarium species responsible for mycotoxin production in wheat crop: involvement in food safety." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4884/.
Full textAbstract:
Fusarium Head Blight (FHB) is a worldwide cereal disease responsible of significant yield reduction, inferior grain quality, and mycotoxin accumulation. Fusarium graminearum and F. culmorum are the prevalent causal agents. FHB has been endemic in Italy since 1995, while there are no records about its presence in Syria. Forty-eight and forty-six wheat kernel samples were collected from different localities and analyzed for fungal presence and mycotoxin contamination. Fusarium strains were identified morphologically but the molecular confirmation was performed only for some species. Further differentiation of the chemotypes for trichothecene synthesis by F. graminearum and F. culmorum strains was conducted by PCR assays. Fusarium spp. were present in 62.5% of Syrian samples. 3Acetyl-Deoxynivalenol and nivalenol chemotypes were found in F. culmorum whilst all F. graminearum strains belonged to NIV chemotype. Italian samples were infected with Fusarium spp for 67.4%. 15Ac-DON was the prevalent chemotype in F. graminearum, while 3Ac-DON chemotype was detected in F. culmorum. The 60 Syrian Fusarium strains tested for mycotoxin production by HPLC-MS/MS have shown the prevalence of zearalenone while the emerging mycotoxins were almost absent. The analysis of the different Syrian and Italian samples of wheat kernels for their mycotoxin content showed that Syrian kernels were mainly contaminated with storage mycotoxins, aflatoxins and ochratoxin whilst Italian grains with mainly Fusarium mycotoxins. The aggressiveness of several Syrian F. culmorum isolates was estimated using three different assays: floret inoculation in growth chamber, ear inoculation in the field and a validated new Petri-dish test. The study of the behaviour of different Syrian wheat cultivars, grown under different conditions, has revealed that Jory is a FHB Syrian tolerant cultivar. This is the first study in Syria on Fusarium spp. associated to FHB, Fusarium mycotoxin producers and grain quality.
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Ballard, Todd Curtis. "Mathematical Models of Zea mays: Grain Yield and Aboveground Biomass Applied to Ear Flex and within Row Spacing Variability." TopSCHOLAR®, 2008. http://digitalcommons.wku.edu/theses/41.
Full textAbstract:
Field studies were conducted during the summers of 2007 and 2008 at the Agricultural Research and Education Complex, Western Kentucky University, Warren County, KY and commercial production fields in Caldwell County, KY, Warrick County IN, and Vanderburgh County, IN. The goals of these studies were to further validate the Duncan grain yield model, the Russell aboveground biomass model, and to study the effect of inconsistent spacing within rows on Zea mays L. yield. Plant spacing other than uniform decreases grain yield and profitability. The population experiments conducted at the Warren County location were a randomized complete block design with three planting densities, three varieties (c.v. DeKalb DKC6547, DeKalb DKC6346, DeKalb DKC6478) in 2007 and (DeKalb DKC6478, DeKalb DKC6342, and DeKalb DKC6544) in 2008, and three replications. Seeds were planted in rows 76 cm apart and 9.1 m long with four rows per plot in a no-till system on a Crider Silt Loam with pH of 6.8 and 1.5% organic matter. The effect of variable within row spacing was evaluated in commercial production fields by randomly selecting five adjacent rows of 5.3 meters in length at each location. Grain yield for each row was then curve fitted both linearly and exponentially.
Minimizing interspecies competition was essential to evaluating the effects of competition within Zea mays L. A burn-down application of 2,4-D and glyphosate was used prior to planting. The most common weeds in the plots were Sorghum halepense L. (johnsongrass), Trifolium repens L. (white clover), and Taraxacum officinale L. (common dandelion) . Glyphosate was reapplied throughout the growing season due to reemergence of S. halepense and Ipomoea hederacea Jacq. (ivyleaf morningglory).
The weight of each ear was recorded and one row from each plot was randomly selected to shell. The moisture content was measured from a subsample twice each row using an electrical conductivity moisture meter. The mean of the two moisture readings was used as the moisture content from the plot. Cob weights from shelled ears were recorded to determine the grain/cob mass ratio. This ratio was used to project the grain weight for the remaining harvested rows.
Duncan’s grain yield model and Russell’s biomass model were curve fitted to the data for areas of 0.00040 hectares at the p < 0.05 significance level or greater in all population density plots. Individual plant grain masses were curve fitted to Duncan’s model with p < 0.05 significance in 3 out of 15 plots. Grain mass was negatively correlated (R < 0) with standard deviation of within row spacing in 14 of 15 plots. A linear fit to this trend was significant in only 2 of 15 plots. The Duncan yield curve and the Russell aboveground biomass model fit all 6 genotype by environment interactions for 2007 and 2008 to the α = 0.05 level of confidence when evaluated over a 5.3 meter length on 76.2 cm wide rows. Individual plants fit linearly at α = 0.05 in 9 out of 15 plots. Individual plants fit the Duncan yield curve at α = 0.05 in 4 out of 15 plots.
Standard deviation of within row spacing fit grain yield loss significantly at &#; = 0.05 in two of 15 plots. The individual plant spacing and local population density collectively fit nine plots significantly at α = 0.05 or better.
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Edlin, Diana J. "Heirloom and Hybrid Tomato Yield and Quality in Organic and Conventional Production Systems." TopSCHOLAR®, 2009. http://digitalcommons.wku.edu/theses/135.
Full textAbstract:
Due to the recent changes in the economy of Kentucky tobacco production, some producers are seeking an alternative crop that will provide similar economic gains to tobacco without needing more acreage. Tomatoes are an existing crop in Kentucky that have been declining in acreage over the last five years. There is evidence to suggest that, through niche and local marketing, tomatoes may be able to fill the void left by tobacco. However, there is concern among producers that they will lose yield and/or quality if they switch to one of these niche production systems or cultivars.
A two year study at Western Kentucky University compared the yield and quality of three tomato cultivars, two heirlooms and one hybrid, under organic and conventional management techniques to see if producers concerns are valid. The heirloom cultivars used were 'Cherokee Purple' (CP) and 'Mr. Stripey', (MS) the hybrid cultivar was 'Crista' (CR). The study was a split block design, with four randomized replications within each block. Plants were grown under black plastic mulch, with drip irrigation under the mulch. Plants were harvested weekly throughout the season and data were collected on individual fruit weight, size, grade and the number of fruit produced per plant. Production and quality were compared between management techniques for each cultivar, and the cultivars were compared to each other under individual management techniques.
When comparing organic and conventional management practices, CP produced significantly (p<.05) larger, heavier, and higher quality fruit under organic practices and showed no significant differences in fruit number in 2008. MS and CR showed no significant differences between production systems for fruit weight or size, CR produced significantly higher quality fruit under conventional treatment and MS produced significantly more fruit per plant in 2008. In 2009, CP did not produce enough fruit under organic management to allow statistical comparison between management systems. MS however did not show any significant differences between management systems for any of the traits studied. CR produced significantly larger fruit under organic management, but no other differences were observed.
When comparing cultivars in 2008, CP and CR produced fruit of similar weight but significantly heavier than MS under both production systems. CP produced the largest fruit under organic management, with CR following and MS producing the smallest fruit. Under conventional management, CP and CR produced fruit of similar size and both were larger than MS. MS produced the highest quality fruit under organic management, and CR produced the nicest grade under conventional management. No differences were seen for number of fruit per plant between cultivars under organic management, while MS produced the most fruit per plant under conventional management. In 2009 CP did not produce enough fruit to be statistically compared to the other cultivars under organic management. MS and CR produced fruit of similar weight under both organic and conventional management, while CP produced the greatest weight under conventional management. CR produced larger fruit than MS under organic management, while under conventional management CP and CR were of similar size as were CR and MS, but CP was significantly larger than MS. No significant differences were found between cultivars for fruit grade or number of fruit per plant under either management system in 2009.
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Wang, Zheng. "THE INFLUENCE OF PRODUCTION PRACTICES, TILLAGE, AND ENDOPHYTIC BACTERIA ON BELL PEPPER PRODUCTIVITY AND PHYSIOLOGY UNDER DIFFERENT IRRIGATION REGIMES." UKnowledge, 2015. http://uknowledge.uky.edu/pss_etds/55.
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To evaluate the strip tillage in organic bell pepper (Capsicum annuum L.) production as an integrated system for sustainable vegetable cropping two-years of field trials were conducted in 2011 and 2012. The field trials were conducted to determine the viability of strip tillage in conventional and organic bell pepper production systems by comparing plant growth, water status, and fruit yield to plastic mulch grown plants application under different irrigation regimes. The two-year field data demonstrated that organic pepper with strip tillage application was a viable combination that produced comparable yield to conventional plastic mulch system and utilized water more economically.
In 2011 and 2013, strip-tilled rows and plastic mulched rows were used to evaluate the impact of tillage on soil hydraulic conductivity and water internal drainage characteristics. Results indicated that strip-tilled plots had significantly higher in-row penetration resistance compared to the plastic mulch system at depths up to 20 cm, but no differences between the systems were found for layers below 25 cm. In addition, there were no differences in hydraulic conductivity between strip tillage and plastic mulch in both study years over a 30-day period. Also, significant main effects were found for soil layer and time scale on hydraulic conductivity in the first 24 hour of the study in 2013.
During field trials in 2011 and 2012, plant tissues were sampled for endophytic bacteria isolation and identification. Differences in endophytic bacteria were obtained among different production combinations. In 2013, endophytic bacteria isolates from 2011 and 2012 trials were re-inoculated to bell pepper grown in greenhouse to assess plant growth. Two Pseudomonas sp. and one Bacillus thioparans strain were screened to evaluate their affects on plant growth under both drought and non-drought conditions. After growth comparisons, the three endophytic strains were used to subsequently study the impacts of endophyte inoculation on regulating plant drought-linked gene expressions in 2014 by conducting real-time PCR. Results demonstrated that plant drought-linked genes, which especially involved plant ethylene biosynthesis, were significantly down-regulated after inoculating the endophytic bacterial strains.
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Flomo, Stephen T. "Investigation of Yield and Quality of Grafted Heirloom and Hybrid Tomatoes." TopSCHOLAR®, 2010. http://digitalcommons.wku.edu/theses/138.
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Tomatoes (Lycopersicon esculentum Mill) are one of the most popular vegetable crops grown for fresh market and processing in the U.S. Grafting involves the uniting of a shoot or bud scion with a rootstock to form a compound plant, mainly for managing soil-borne diseases and increasing crop yield. The objectives were to examine the effects of reciprocal and self grafts on tomato fruits, number of fruits, weight, and quality of the cultivars, ‘Cherokee Purple’, ‘Mister Stripey’, ‘Crista’, and ‘Maxifort’. Grafted seedlings were planted at WKU Farm on raised beds, protected with red or black plastic mulch under drip irrigation system with regular supply of water. Matured fruits were harvested, weighed, and number of fruits from each plant recorded. The highest yielding combination was the scion ‘Cherokee purple’ on ‘Maxifort’ rootstock, which produced 304g and 745g heavier fruits than ‘Crista’ and ‘Mister Stripey’, respectively. The quality grade of ‘Crista’ was superior to ‘Cherokee Purple’ and ‘Mister Stripey’ while ‘Mister Stripey’ produced the greatest number of fruits but were of lower quality. Fruits from plants grown on red plastic mulch were significantly larger, heavier, and were of higher quality than those grown on black plastic mulch. However, plants grown on black plastic mulch produced significantly more fruits per plant. There was little advantage for self-grafting of ‘Cherokee Purple’ and ‘Crista’. However, ‘Mister Stripey’ was responsive to self-grafting and merits further investigation. The best rootstock was ‘Maxifort’ which produced the biggest, heaviest fruits of the best quality. ‘Cherokee Purple’ as a scion produced the largest and heaviest fruits, while ‘Crista’ produced the highest quality fruits. ‘Mister Stripey’ was the most prolific in terms of number of fruits per plant.
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Semet, Paul. "Taxonomy, Biogeography and Pest Status of Marmara sp. in Northern Mexico and California Citrus Production." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/338.
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A novel lepidopteran sex pheromone lure which was thought to be species-specific to the citrus pest Marmara gulosa (Lepidoptera: Gracillariidae) Guillén (McElfresh et al. 2009) has attracted male moths exhibiting two distinct morphologies. The morphological features examined were the sclerotized parts that make up the male genitalia; which include the valvular lobes, costal lobes, cucullar lobes, and the aedeagus. The sclerotized parts were methodically dissected and mounted on microscope slides. Digital images captured of the slide-mounted specimens proved to be inconsistent with the illustrations provided in the original Marmara gulosa species description (Guillén et al. 2001).
The morphologies of all specimens from both the San Joaquin and Coachella valley show remarkable consistency; regardless of host plant origin, collection method, and collection date. Two specimen groups (one from an orchard in Northern Mexico and the other from backyard citrus in Riverside, California) exhibited entirely different morphological features in which the three lobes mentioned above are fused together. This difference in morphology can only be noticed when examining the sclerotized parts of the male genitalia under a microscope; it is otherwise indistinguishable from M. gulosa via macroscopic features such as antennae shape and wing pattern. These two specimen groups with fused lobes are considered a new species belonging to the genus Marmara and currently remain undescribed.
A genetic study conducted at UC Riverside, which concentrated on the CO1 region of mitochondrial DNA, reported significant differences in genetics based on the geographic origins of specimens (Vickerman and Stouthammer 2006). Geographically, the genetic distribution described in the 2006 study does not coincide with the distribution of morphologies described in this paper. The species description of Marmara gulosa is in need of revision. In addition, further collection and research is required in order to describe and name the newly discovered Marmara species.
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Patterson, R. G. "A study of the soils and agronomy of a high country catchment." Lincoln University, 1993. http://hdl.handle.net/10182/1315.
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This study was undertaken to research the principles and practices behind increased pasture productivity on Longslip Station, Omarama. A range of landscape - soil - climate - plant systems were identified, then analysed and the legume responses measured. By isolating cause and effect and appreciating the driving variables of each system, lessons learnt could be reliably and objectively transferred to the rest of the farm. Extrapolation to the balance of the property (15,150 ha) permitted immediate large-scale development and engendered confidence to lending institutions, Lands Department, catchment authorities and ourselves. Soil (land) cannot be well managed and conserved unless it is mapped reliably and its characteristics measured and interpreted by skilled observers (Cutler, 1977). Soil resource surveys, and their interpretation, are an essential ingredient of rational resource evaluation and planning. This thesis is a figurative and comparative survey and study of the soil catenary bodies, resident vegetation, legume establishment and pasture production characteristics of a 400 hectare catchment, in relation to, and as influenced by soil landscape unit, slope component, altitude, aspect and time. The inherent diversity in landform, soil properties and vegetation communities in a single catchment in the high country has not previously been fully studied or appreciated. This has lead to blanket recommendations for fertilizer, seed and management regimes both within and between properties and even regions. This study reports on the diversity of, yet predictable change in soil properties with slope position (upper, middle and lower) aspect and altitude in terms of both soil physical properties e.g. soil depth and water holding capacity and soil chemical properties such as pH, BS%, %P, %S, %N and %C. The composition of the resident vegetation and its differential response to oversowing and topdressing and subsequent change through time is reported and discussed. Finally an epilogue gives an insight into the problems and frustrations of farming practices in the high country from a motivation and personal perspective and political point of view that it is essential to come to terms with.
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Varella, Alexandre Costa. "Modelling lucerne (Medicago sativa L.) crop response to light regimes in an agroforestry system." Lincoln University, 2002. http://hdl.handle.net/10182/1477.
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The general goal of this research was to understand the agronomic and physiological changes of a lucerne crop in distinct physical radiation environments and to verify the potential of lucerne to grow under shaded conditions. To achieve this, the research was conducted in four main steps: (i) firstly, experimental data collection in the field using two artificial shade materials (shade cloth and wooden slats) under inigated and non-irrigated conditions; (ii) a second experiment with data collection in a typical temperate dryland agroforestry area under non-irrigated conditions; (iii) generation of a light interception sub-model suitable for shaded crops and (iv) a linkage between the light interception sub-model and a canopy photosynthesis model for agroforestry use. In experiments 1 and 2, lucerne crop was exposed to 6 different light regimes: full sunlight (FS), shade cloth (FS+CL), wooden slats (FS+SL), trees (T), trees+cloth (T +CL) and trees+slats (T+SL). The FS+SL structure produced a physical radiation environment (radiation transmission, radiation periodicity and spectral composition) that was similar to that observed in the agroforestry site (f). The mean annual photosynthetic photon flux density (PPFD) was 41 % under the FS+CL, 44% under FS+SL and 48% under T compared with FS in clear sky conditions. Plants were exposed to an intermittent (sun/shade) regime under both FS+SL and T, whereas under FS+CL the shaded light regime was continuous. The red to far-red (RIFR) ratio measured during the shade period under the slats was 0.74 and under the trees was 0.64. However, R/FR ratio increased to 1.26 and 1.23 during the illuminated period under FS+SL and T, respectively, and these were equivalent to the ratio of 1.28 observed under the FS+CL and 1.31 in FS. The radiation use efficiency (RUE) of shoots increased under the 5 shaded treatments compared with full sunlight. The pattern of radiation interception was unchanged by radiation flux, periodicity and spectral composition and all treatments had a mean extinction coefficient of 0.82. However, the magnitude of the decrease in canopy growth was less than those in PPFD transmissivity. The mean lucerne annual dry matter (DM) yield was 17.5 t ha⁻¹ in FS and 10 t ha⁻¹ under the FS+CL, FS+SL and T regimes. This declined to 3.4 t DM ha⁻¹ under T+CL (22% PPFD transmissvity) and 4.1 t DM ha⁻¹ under T+SL (23% transmissivity). A similar pattern of response was observed for leaf net photosynthesis (Pn) rates under the shade treatments compared with full sun. In addition, spectral changes observed under the trees and slats affected plant motphology by increasing the number of long stems, stem height and internode length compared with full sunlight. Thus, there were two main explanations for the increase in RUE under shade compared with full sun: (i) preferential partition of assimilates to shoot rather than root growth and/or (ii) leaves under shade were still operating at an efficient part of the photosynthetic light curve. The changes proposed for the canopy Pn model were appropriate to simulate the radiation environment of an agroforestry system. However, the model underestimated DM yields under the continuous and intermittent shade regimes. These were considered to be mainly associated with plant factors, such as overestimation in maintenance respiration and partitioning between shoots and roots in shade and the intermittency light effect on leaf Pn rates. Further investigation in these topics must be addressed to accurately predict crop yield in agroforestry areas. Overall, the lucerne crop responded typically as a sun-adapted plant under shade. It was concluded that lucerne yield potential to grow under intermediate shade was superior to most of C3 pastures previously promoted in the literature.
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Moraine, Marc. "Conception et évaluation de systèmes de production intégrant culture et élevage à l'échelle du territoire." Thesis, Toulouse, INPT, 2015. http://www.theses.fr/2015INPT0050/document.
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L’intégration culture – élevage à l’échelle territoire représente une voie pour améliorer le fonctionnement métabolique et les services écosystémiques fournis par les systèmes agricoles, malgré les contraintes de spécialisation des exploitations. Cette thèse propose une méthodologie de conception de systèmes culture – élevage au niveau du territoire, dans une démarche participative structurée en trois grandes étapes : diagnostic des enjeux, conception d’options techniques et organisationnelles, évaluation multicritère. Chaque étape est outillée par un cadre conceptuel et une grille d’évaluation multicritère adaptée aux dispositifs de terrain menés sur le bassin versant de l’Aveyron. Les scénarios construits présentent deux modèles de l’intégration culture – élevage : une « filière territorialisée » pour la production de luzerne dans les systèmes de culture de l’aval du bassin à destination des élevages de l’amont, un « collectif d’agriculteurs bio » échangeant directement de la luzerne, des méteils et du fumier dans des groupes locaux. Chaque scénario présente des performances de durabilité améliorées et pourraient être complémentaires pour le changement de pratiques sur le territoire. La méthodologie développée permet la conception multi-niveaux et multi-domaines de scénarios d’intégration, et pourrait être renforcée par une évaluation quantitative des bénéfices attendus et des coûts de coordination entre acteurs<br>Crop-livestock integration at territory level may be a pathway to impove metabolic functions and delivery of ecosystem services in agricultural systems, overcoming the constraints of farm specialization. This thesis builds on a methodology of participatory design of integrated crop-livestock systems at territory level in three steps: diagnosis of issues, design of technical and organizational options for change, multicriteria assessment. Each step is supported with a conceptual framework and a multicriteria grid adapted to the case study in Aveyron river basin. The designed scenarios show two approaches of crop –livestock integration: the introduction of alfalfa in downstream cropping systems sold to upstream livestock systems through a local supply chain and the direct exchanges of alfalfa, cereal-legume mixtures and animal manure in local groups of organic farmers. Both scenario present improved sustainability performances and could be complementary to initiate more sustainable practices in local farming systems. The methodology allows designing multi-level and multi-domain scenarios of crop-livestock integration. It could be improved with models for quantitative assessment of benefits and coordination costs among stakeholders
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Mavuthu, Abednego Kiwia. "Effect of the National Accelerated Agricultural Inputs Access Subsidy Program on Fertilizer Usage and Food Production in Kakamega County, Western Kenya." ScholarWorks, 2017. https://scholarworks.waldenu.edu/dissertations/3803.
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Despite 25 years of concerted efforts by African governments to adopt consistent policies for increasing food production, hunger and poverty are still prevalent in the continent. Using Bernanke's conceptualization of the credit channel theory of monetary policy, the purpose of this correlational study was to investigate whether a subsidy program, the National Accelerated Agricultural Inputs Access Program (NAAIAP), affected the rates of fertilizer usage and food production in Kakamega County, Western Kenya. Purposive stratified sampling was used to select 114 participants consisting of 72 farmers in each of the 2 groups: NAAIAP beneficiaries and nonbeneficiaries. Participants completed a survey on fertilizer usage rates, income earned, and surplus maize yield. Data were analyzed using multiple regression to test whether there was a difference between the beneficiary and nonbeneficiary groups regarding income, surplus product, and the dependent variable of fertilizer usage. Results indicated that beneficiaries of NAAIAP credit program bought and prepared to use fertilizers significantly earlier than did their counterparts. Further, the results of multiple regression indicated significant positive correlation (p <.05) between income earned from sale of surplus maize yield and quantity of fertilizer used by farmers in Kakamega County. These findings suggest that NAAIAP improved food security and farmers' income in Kakamega Count. This study contributes to social change by recommending to subsidy program administrators in Kakamega County to consider policy changes. Such policy changes may improve program outreach to resource-poor farmers and improve income and product yield in the agricultural sector of Kenya.
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Shoko, Munashe. "Exploring phosphorus, mucuna (Mucuna pruriens)and nitrogen management options for sustainable maize production in a depleted kaolinitic sandy loam soil of Zimbabwe." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1364.
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Thesis (PhD(Agric) (Agronomy))--University of Stellenbosch, 2009.<br>ENGLISH ABSTRACT: Continuous cropping without replenishing the nutrient component of soils will eventually lead to the depletion of soil nutrients. Small scale farmers in Zimbabwe often do not have the financial means to buy fertilizer and this problem is exacerbated by scarcity of commodities such as fertilizers. The use of herbaceous legumes such as mucuna (Mucuna pruriens) can assist to recapitalize soil fertility depletion and improve subsequent maize productivity in sandy loam soils in the small holder farming sector of Zimbabwe. In this study the effect of phosphorus (P) application to a mucuna crop, the effect of mucuna management options and the application of nitrogen (N) to the subsequent maize crop was investigated.
The experiment was carried out during the 2007 to 2009 seasons at the Grasslands Research Station in Marondera in Zimbabwe. The soils are classified as humic ferrolsols and are predominantly of the kaolinitic order with sandy loams of low fertility and are slightly acid (pH CaCl = 5.2). A randomized complete block design was used for the effect of P on mucuna productivity and the effect of P and mucuna management options on the soil properties. The treatments were two P rates (P0 and P40 = 0 kg P ha-1 and 40 kg P ha-1 respectively) applied to a preceding mucuna crop, four mucuna management options [1) fallow (F) (no mucuna planted = control), 2) mucuna ploughed-in at flowering (MF), 3) all mucuna above ground biomass removed at maturity and only roots were ploughed-in (MAR) and 4) mucuna pods removed and the residues ploughed-in (MPR)]. A split-plot design was used to study the effect of P application to mucuna, mucuna management options and N rates on the growth and yield of the subsequent maize crop. The four N treatments [N0 = 0 kg N ha-1, N40 = 40 kg N ha-1, N80 = 80 kg N ha-1 and
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N120 = 120 kg N ha-1] were applied to a subsequent maize crop. Growth and development parameters such as biomass production, leaf area index, nutrient content of the foliage and grain yield were determined in the mucuna and maize crops. Soil parameters investigated included nutrient content, pH, bulk density and porosity.
Phosphorus application in these particular soil conditions positively influenced mucuna biomass production and therefore enhanced the role of mucuna as a rotational crop by increased positive effects on the subsequent maize crop. The incorporation of above-ground biomass of mucuna had positive effects on all soil properties investigated. The MF and MPR management options increased the soil organic matter (OM) and reduced bulk density which leads to an improvement in porosity (f) of the soil. Mucuna incorporated at flowering (MF) and P40 treatment combination resulted in the highest mineral N, P, potassium (K), calcium (Ca) and magnesium (Mg) levels.
A significant three-way interaction (P<0.05) between mucuna management options, nitrogen rates and time was observed in terms of biomass production and all nutrients in the leaves of the subsequent maize crop. The main findings were that the MF management option had the highest biomass and foliar nutrient accumulation through-out all the treatment combinations. In general the MF management option gave the highest maize yield across all the treatment combinations.
Incorporation of mucuna biomass into the soil prior to planting a maize crop therefore improve soil physical and chemical qualities resulting in improved soil conditions for a subsequent maize crop which in turn lead to higher maize yields. Including a mucuna rotational crop have a similar effect on maize yield than application of 80 kg ha-1 of fertilizer N.<br>AFRIKAANSE OPSOMMING: Aanhoudende verbouing van gewasse op dieselfde grond sonder om voedingstowwe aan te vul lei uiteindelik tot die agteruitgang van die grond se vrugbaarheid. Kleinboere in Zimbabwe het meestal nie die finansiële vermoëns om bemestingstowwe te koop nie en die probleem word vererger deur die onbekombaarheid van kommoditeite soos bemestingstowwe. Die gebruik van kruidagtige peulplant gewasse soos mucuna (Mucuna pruriens) kan bydra om grondverarming teen te werk en om die produksie van ‗n daaropvolgende mielie aanplanting in sandleemgronde in ‗n kleinboerstelsel in Zimbabwe te verhoog. In hierdie studie is die invloed van fosfor (P) toediening aan ‗n mucuna aanplanting, die invloed van bestuursopsies van die mucuna en die toediening van stikstof (N) aan die daaropvolgende mielie aanplanting ondersoek.
Die eksperiment is tydens die 2007 tot 2009 reënseisoen by die Grasslands Research Station in Marondera in Zimbabwe uitgevoer. Die grond word geklassifiseer as humiese ferrolsols en is hoofsaaklik sanderige leemgrond van die kaolinitiese orde met lae vrugbaarheid en is effens suur (pH CaCl = 5.2). ‘n Volledig ewekansige blokontwerp is gebruik om die invloed van P op die produktiwiteit van mucuna te bepaal asook die invloed van P toediening en mucuna bestuursopsies op grondeienskappe. Die behandelings was twee P vlakke (P0 = 0 kg P ha-1 en P40 = 40 kg P ha-1) wat aan ‗n voorafgaande mucuna aanplanting toegedien is, vier mucuna bestuursopsies [1) braak (F) (geen mucuna geplant = kontrole), 2) mucuna ingeploeg met blomtyd (MF), 3) alle bogrondse mucuna biomassa verwyder by rypwording en slegs wortels ingewerk (MAR) en 4) mucuna peule verwyde en die res van die bogrondse material ingeploeg (MPR)] en vier N behandelings [N0 = 0 kg N ha-1, N40 = 40 kg N ha-1, N80 = 80 kg N ha-1 en N120 = 120 kg N ha-1] toegedien aan ‗n daaropvolgende mielie aanplanting. Groei en ontwikkeling parameters soos biomassa produksie, blaaroppervlakindeks, nutriëntinhoud van die blare en graanopbrengs is in die mucuna en mielie aanplantings ondersoek. Grondeienskappe soos nutriëntinhoud, pH, bulkdigtheid en porositeit is gemeet. Fosfaat toediening aan hierdie spesifieke grondtipe het mucuna produksie positief beïnvloed en dus die rol van mucuna as rotasiegewas verbeter deur positiewe reaksies in die daaropvolgende mielie aanplanting. Die inwerk van bogrondse mucuna biomassa het al die fisiese grondeienskappe wat ondersoek is positief beïnvloed. Die MF en MPR bestuursopsies het organiese materiaal inhoud van die grond verhoog en bulkdigtheid verlaag wat lei tot verbeterde grondporeusheid (f). Mucuna wat tydens blomvorming ingewerk is (MF) lei tot die hoogste minerale N, P, kalium (K), kalsium (Ca) en magnesium (Mg) vlakke.
‗n Betekenisvolle drie-rigting interaksie (P < 0.05) tussen mucuna bestuursopsies, N vlakke en tyd is waargeneem in terme van biomassa produksie en in terme van al die nutriëntvlakke in die mielieblare wat ondersoek is. Die hoofbevindinge was dat die MF bestuursopsie die hoogste biomassa produksie en blaarnutriënt akkumulasie oor alle behandelingskombinasies tot gevolg gehad het. In die algemeen het die MF bestuursopsie die hoogste mielie-opbrengs oor alle behandelingskombinasies tot gevolg gehad.
Die inwerk van mucuna materiaal in die grond voordat mielies geplant word verbeter dus fisiese en chemiese toestande in die grond wat grondtoestande verbeter vir die daaropvolgende miegewas en uiteindelik lei tot hoër mielie-oeste. Die insluiting van mucuna as ‘n rotasiegewas het diesefde effek op mielie-opbrengs as die toediening van 80 kg ha-1 N bemesting.
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Mills, Annamaria. "Understanding constraints to cocksfoot (Dactylis glomerata L.) based pasture production." Phd thesis, Lincoln University. Agriculture and Life Sciences Division, 2007. http://theses.lincoln.ac.nz/public/adt-NZLIU20070717.161658/.
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This research examined the mechanisms by which temperature, water availability and nitrogen (N) affect the dry matter (DM) yield potential of cocksfoot (Dactylis glomerata L.) dominant pastures. The experiment was a split plot design with main plots of fully irrigated (I) or dryland (D), sub-plots of N fertiliser at 800 kg N/ha in 2003/04; and 1600 kg N/ha in 2004/05 (+N) or 0 kg N/ha (-N). The potential environmental yield of an established 8 year old cocksfoot dominant pasture was 21.9 t DM/ha/y from I+N pastures compared with 9.8 t DM/ha by I-N pastures and 15.1 t DM/ha/y by D+N pastures. The lowest yields were from dryland pastures with no N which produced 7.5 t DM/ha/y in 2003/03 and 5.0 t DM/ha/y in 2004/05.
The effect of seasonal temperatures on the DM production, when periods of water stress were excluded, was quantified using thermal time accumulated above a base temperature of 3°C as 7.0 kg DM/°Cd/ha for N fertilised pastures and 3.3 kg DM/°Cd/ha for pastures with no N.
The 2.5 t DM/ha difference in yields of D-N pastures in 2003/04 and 2004/05 was the result of the duration, extent and timing of the water stress period. In both years the critical limiting deficit (DL) was calculated as 78 mm from the soil moisture deficit in the 0-0.8 m soil layers. Beyond DL yield decreased at a rate of 1.45%/mm in +N and N pastures, relative to fully irrigated control pastures.
Yields of D+N and D-N pastures were similar during periods of water stress with 0.4±0.1 t/DM/ha produced during the rotation ending 30/12/2003. This was less than from either the I-N (1.2 t DM/ha) or I+N (3.5 t DM/ha) pastures due to the reduction in the amount of photosynthetically active radiation intercepted by the canopies of the dryland pastures. However, in the rotation ending 2/5/2004, after autumn rain alleviated drought conditions, yield of the D+N pasture was 2.1 t DM/ha compared with 1.7 t DM/ha by I+N pastures.
The effect of N on yield was described using a nutrition index which showed that as DM yield increased N% in the herbage declined. This is a function of the ratio between metabolic and structural N requirements rather than caused by ontogeny alone. Specific leaf N was determined at two harvests and appeared constant at a given point in time (1.0-1.6 g N/m² leaf). In contrast, specific pseudostem N increased from 0.8-1.0 g N/m² pseudostem at an NNI of 0.4 in N pastures to 2.6-3.0 g N/m² pseudostem at an NNI of 1.2 in the +N pastures.
Differences between the yields of +N and N pastures were caused by differences in radiation use efficiency (RUE) as determined by the linear relationship (R²=0.76) between RUE and the nitrogen nutrition index (NNI).
In this thesis, empirical relationships for the effects of temperature, water availability and N were derived and the physiological mechanisms which underlie these descriptions were identified. These relationships provide clear and simple explanations of the effects of environmental variables on the productivity of cocksfoot based pastures which will enhance understanding of the benefits and limitations of cocksfoot, particularly in dryland farming systems.
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Murphy, Donal Patrick Lee. "Crop structure and crop productivity in winter barley, (Hordeum sativum)." Thesis, University of Newcastle Upon Tyne, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262202.
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Brito, Adriana Uchôa. "Produção de biomassa aérea, teor e rendimento de extrato das folhas de crajiru [Arrabidaea chica (Bonpl.) B. Verl.] em função de adubação orgânica em Manaus, AM." Universidade Federal do Amazonas, 2012. http://tede.ufam.edu.br/handle/tede/2737.
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Previous issue date: 2012-05-11<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The Arrabidaea chica specie, also known as crajiru, pariri, chica, cross-vine, among other names, belongs to the Bignoniaceae family. It is commonly used to treat wounds, impigem, skin diseases of different origins, and ovarian inflammations, conjunctivitis, intestinal cramps, etc. This work aimed to evaluate the production of biomass, content and yield of crajiru extract for different sources of organic fertilizer in Manaus, AM. The seedlings were obtained from cuttings and planted in polystyrene trays (72 cells) with a commercial substrate, which remained in nursery for 60 days before being planted in field, with spacing of 1.0 m x 1.0 m. The experiment was conducted in a factorial arrangement 5x3 with a randomized block design where levels of factors were different sources of organic fertilizer: compost 5.0 kg/m2, chicken manure 3.0 kg/m2, guarana bark 4.0 kg/m2, cattle manure - 4.0 kg/m2 and control (absence), and the three crajiru morphotypes. After 240 days the production of leaves and stems, leaf / stem relation, nutritional analysis of leaves, content and yield of extracts were evaluated. The data were submitted to analysis of variance and averages the Tukey Test at 5% probability. It was observed that the sources of organic fertilizer promoted better development for the plants of A. chica, except for morphotype 1 which showed no significant differences in relation to the sources used, and the chicken manure was the fertilizer provided higher nutrient concentrations, biomass production, content and yield of extracts.<br>A espécie Arrabidaea chica, também conhecida como crajiru, pariri, chica, cipó-cruz, dentre outros nomes, pertence à família Bignoniaceae. Popularmente é usada para o tratamento de feridas, impigem, enfermidades da pele de diferentes origens, inflamações uterinas e ovarianas, conjuntivite, cólicas intestinais, dentre outros. Este trabalho teve o objetivo de avaliar a produção de biomassa aérea, teor e rendimento de extrato de crajiru em função de diferentes fontes de adubo orgânico em Manaus, AM. As mudas foram obtidas por estaquia e plantadas em bandejas de poliestireno expandido (72 células) contendo substrato comercial, as quais permaneceram em viveiro durante 60 dias até serem plantadas em campo, no espaçamento de 1,0 m x 1,0 m. O experimento foi conduzido em esquema fatorial 5x3 com delineamento em blocos casualizados onde os níveis dos fatores foram as diferentes fontes de adubo orgânico: composto 5,0 kg/m2, esterco de aves 3,0 kg/m2, casca de guaraná 4,0 kg/m2, esterco de gado 4,0 kg/m2 e controle (ausência), e os três morfotipos de crajiru. Após 240 dias foram avaliadas a produção de folhas e caules, relação folha/caule, análise nutricional de folhas, teor e rendimento de extratos. Os dados foram submetidos à análise de variância e as médias ao Teste de Tukey, a 5% de probabilidade. Observou-se que as fontes de adubo orgânico promoveram melhor desenvolvimento para as plantas de A. chica, exceto para o morfotipo 1 que não apresentou diferenças significativas em relação às fontes utilizadas, sendo que o esterco de aves foi o adubo que proporcionou maiores concentrações de nutrientes, produção de biomassa, teor e rendimento de extratos.
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Paula, Vericía Fernanda Sales de. "Efeito da aplicação pré-colheita de bioestimulante e espaçamento de plantio na produção, qualidade e conservaçao de melancia." Universidade Federal Rural do Semi-Árido, 2015. http://bdtd.ufersa.edu.br:80/tede/handle/tede/180.
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Previous issue date: 2015-02-06<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Currently, the use of growth biostimulant in vegetable crops has been used by some producers of watermelon. However, its effective influence on yield and quality of watermelon is not well established. The main objective of this study was to evaluate the growth promoter preharvest application Crop Set® and planting spacing on quality and seedless watermelon conservation (hybrid Style) and seed (hybrid Quetzali). The experiments were conducted in the community of Pau Branco, Mossoró-RN, following the experimental randomized block design in a factorial 3 x 2, three spacing between plants (40, 45 and 50 cm), with and without application of Crop Set ®, with four replications. Harvesting occurred at 65 days after sowing for the two hybrid watermelons (Style) and (Quetzali), being evaluated in each plot (combination of factors), the number of total and the weight of the total fruit and productivity. The fruits of each plot were analyzed for mass loss (PM), pulp firmness (FP), soluble solids (SS), titratable acidity (AT), soluble solids / titratable acidity (SS/AT), pH and total soluble sugars (AST) in zero time and in the range of 14, 21 and 28 days of storage. The Style cultivar was stored in cooling chamber set at 10° C and 90% RH and the Quetzali cultivarwas stored at 20°C and 60% RH. In step laboratory, it was adopted a completely randomized design with split plot storage time with six replications. The data were submitted to analysis of variance with the aid of SISVAR program, and the significant variables were compared using the mean test and regression analysis. For the watermelon seedless 'Style', the biostimulant application and crop spacing promoted mass loss, soluble solids, SS/AT ratio and pH differentiate of fruits depending on the storage time. Application of Crop Set® did not favor the accumulation of SS in fruit on harvest, but during storage, the values of SS vary with the spacing and bioestimulant application. At 28 days, the pH of the fruit did not differ with the application of Crop Set® and crop spacing. The SS/AT of fruits increased during the storage period, regardless of biostimulant in all crop spacings. In contrast, the fruit AT and FP AT decreased during the storage period. The AST content of the fruit was not influenced by the Crop Set® application. But, at 28 days, the spacing of 40 cm provided fruit with lower AST content fruit. For the production characteristic, only the number of fruits per plant was affected by treatment, the largest number of fruits was evidenced in cultivation spacing of 50 cm with Crop Set® application. In the first harvest, 78% of fruit were picked. For watermelon with seed (Quetzali), the Crop Set® application, plant spacing and storage times made significant effect on mass loss, soluble solids, total soluble sugars and acidity of fruit. For production characteristics evaluated, only the average weight of fruits per plot was influenced by treatment, with heaviest fruits detected in 50 cm of spacing without Crop Set® application. The biostimulant application in all plant spacing resulted in fruit with higher mass loss during storage. The highest SS value was obtained in fruit provided of spacing of 50 cm without Crop Set® application. The Crop Set® application provided higher AST on cultivated fruits at spacing of 50 cm at 14 days of storage. Regardless of the Crop Set® application, the higher AT was verified in fruit at zero time, when cultivated at spacing of 50 cm, and decreased during storage. The FP decreased and the SS/AT ratio and pH of fruit increased during storage<br>Atualmente, o uso de bioestimulante de crescimento nas olerícolas tem sido utilizado por alguns produtores de melancia, entretanto a sua efetiva influencia na produção e qualidade de melancia ainda não está bem estabelecida. Dessa forma, este trabalho teve por objetivo avaliar a aplicação pré-colheita do bioestimulante Crop Set® e espaçamentos de plantio na qualidade e conservação de melancia sem semente (híbrido Style) e com semente (híbrido Quetzali). Os experimentos foram instalados na Fazenda Jardim, comunidade de Pau-Branco, Mossoró-RN, seguindo o delineamento experimental em blocos casualizados em esquema fatorial 3 x 2, três espaçamentos entre plantas (40, 45 e 50 cm), com e sem aplicação do bioestimulante Crop Set®, com quatro repetições. A colheita dos frutos de ambas as cultivares ocorreu aos 65 dias após a semeadura, sendo avaliado em cada parcela, o número de frutos totais (NFT), número de frutos por planta (NFP), peso dos frutos totais e a produtividade. Os frutos de cada parcela foram analisados quanto à perda de massa (PM), firmeza de polpa (FP), sólidos solúveis (SS), acidez titulável (AT), relação sólidos solúveis/acidez titulável (SS/AT), pH e açúcares solúveis totais (AST), no tempo zero e no intervalo de 14, 21 e 28 dias de armazenamento em câmera de refrigeração regulada a 10ºC e 90% UR (cultivar Style) e a 20ºC e 60% UR (cultivar Quetzali). No laboratório, foi adotado o delineamento inteiramente casualizado com parcelas subdivididas no tempo de armazenamento com seis repetições. Os dados foram submetidos à análise de variância com auxílio do programa SISVAR, e as variáveis significativas comparadas pelo teste de médias e análise de regressão. Para a melancia Style , a aplicação de bioestimulante e espaçamento de cultivo promoveram perda de massa, sólidos solúveis, relação SS/AT e pH dos frutos diferenciados dependendo do período de armazenamento. A aplicação de Crop Set® não favoreceu o acúmulo de SS dos frutos na ocasião da colheita, e durante o armazenamento os valores variaram com o espaçamento e aplicação de Crop Set®. Aos 28 dias, o pH dos frutos não diferiram com a aplicação de Crop Set® e espaçamento de cultivo. A relação SS/AT dos frutos aumentou durante o período de armazenamento, independentemente da aplicação de Crop Set® em todos os espaçamentos de cultivo. Já a AT e FP dos frutos diminuíram durante o período de armazenamento. O teor de AST dos frutos não foi influenciado pela aplicação de Crop Set®. Porém, aos 28 dias, o espaçamento de 40 cm propiciou frutos com baixo teor de AST. Para a característica de produção, apenas o NFP foi influenciado por tratamento, com maior número de frutos evidenciado no espaçamento de cultivo de 50 cm, com aplicação do Crop Set®. A colheita inicial foi de 78% dos frutos. Para a melancia com semente Quetzali a aplicação de Crop Set®, espaçamentos de cultivo e tempos de armazenamento propiciaram efeito significativo na PM, SS, AST e AT. Apenas o peso médio dos frutos por parcela, nas características de produção, foi influenciado por tratamento, com frutos mais pesados detectados no espaçamento de 50 cm, cultivado sem Crop Set®. A aplicação de bioestimulante em todos os espaçamentos de cultivo propiciou maior PM dos frutos durante o armazenamento. E o maior valor de SS ocorreu em frutos cultivados no espaçamento de 50 cm sem Crop Set®. A aplicação de Crop Set® propiciou maior AST nos frutos cultivados no espaçamento de 50 cm, aos 14 dias de armazenamento. Independentemente da aplicação de Crop Set®, a maior AT foi verificada, no tempo zero, quando cultivada no espaçamento de 50 cm, diminuindo durante o armazenamento. A FP diminuiu e a relação SS/AT e pH dos frutos aumentou durante o armazenamento
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Monks, D. P. "The vegetative and reproductive development of balansa clover." Lincoln University, 2009. http://hdl.handle.net/10182/1337.
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The vegetative and reproductive development of balansa clover (Trifolium michelianum Savi.) were quantified in relation to the environmental drivers of each phenophase in field and controlled environments. In a grazed experiment over 6 years, balansa clover sown with cocksfoot (Dactylis glomerata) contributed 1.6 t DM/ha/year, or ~20% of the total DM production. However, grazing management for increased seed production during flowering in the establishment year strongly influenced balansa clover regeneration. The earliest closed plot (September) averaged between 2.2 and 4.3 t DM/ha/year of balansa clover across all six years. In an incubator, balansa clover required 29°Cd for germination with an optimum temperature of 14°C and a maximum of 40°C. The base temperature for germination was 0°C. A field experiment determined that 38°Cd were required for emergence with an optimum soil temperature (Topt) of 8.5°C. The time from emergence until the first leaf appeared, the phyllochron and timing of axillary leaf appearance were compared with perennial ryegrass (Lolium perenne) and white clover (Trifolium repens L.). The rate of each was found to increase linearly with temperature. The balansa clover cultivar ‘Frontier’ required 97°Cd from sowing for the first leaf to appear, had a phyllochron of 47°Cd and secondary leaves appeared after 490°Cd. For each vegetative stage, the base temperature was 2.5°C. The timing of flower appearance depended on the quantity and direction of change of the photoperiod at emergence. A balansa clover plant, cv. ‘Bolta’, which emerged on 1 December into an increasing photoperiod of 15.6 hours flowered after 574°Cd (Tbase = 2.5°Cd) or 58 days after emergence. In contrast, if the plant emerged on 16 January into a similar but decreasing photoperiod it took 1503°Cd or 227 days to flower. This length of time became progressively shorter until remaining constant after the shortest day. In contrast, ‘Frontier’ took a constant 390 and 690 °Cd in increasing and decreasing photoperiods, respectively. The time which an individual inflorescence took from pollination until seeds were physiologically mature was 250 °Cd for both ‘Bolta’ and ‘Frontier’. The re-establishment of balansa clover each year relied on a large seed set (>1000 kg/ha) in the establishment year. The continued survival of balansa clover would then depend on a similar seeding event within a 4-5 year period to maintain the seed bank. Management considerations for balansa clover persistence and survival are discussed.
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Williams, John Henry Howatson. "Control of assimilate partitioning in crop plants." Thesis, Bangor University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328915.
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