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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Long-term agronomic and environmental impact of aspen control strategies in the Aspen Parkland

LaRade, Shawna Elizabeth 11 1900 (has links)
Since European settlement the Aspen Parkland has been subject to agricultural intensification. This research assessed the agronomic, ecologic and economic impact of native Parkland conversion into tame pasture, by building on a study initiated in 1980 investigating the short-term agronomic responses within three landscape-level treatments: an intensive Clear & Break (C&B), a Spray & Burn (S&B) and a burnt Native Check (NC). Historical information was supplemented with recently collected data (2005-2006). Production remained high within the NC relative to the others after 25 years, in part due to contributions from browse in areas with increasing woody species. Plant species composition also demonstrated considerable convergence (i.e. overlap) between native and tame grasslands, and although not different in soil organic matter, microfaunal activity differed marginally. Net present value (NPV) economic analysis indicated the NC and S&B provided greater aggregate returns over the study period, and has implications for aspen management in the future. / Rangeland and Wildlife Resources
12

Consumer Color Preferences and the Economics of Bean Consumption in Malawi

Mbamba, Austin January 1900 (has links)
Master of Agribusiness / Department of Agricultural Economics / Major Professor Not Listed / Different dry bean crop varieties with different colors are produced in Malawi. Yet, little is known about the drivers of consumer preferences for the different dry bean varieties grown based on color. Literature shows that consumers link bean color to taste, cooking time, gravy quality and other desirable characteristics. The main objective of this research was to assess factors that determine consumption of different types of dry beans in Malawi based on color to determine preferences for different consumer segments and hence the potential value of these preferences communicated across the dry bean supply chain, to enhance the probability of success for breeders’ efforts and the bean value chain’s initiatives. The research used survey data that was collected by the Bean Value Chain Research Network in Lilongwe District, Malawi. The sample size of the dataset was 687 households from three different economic strata. The research focused on four dry bean colors: Red, Red Mottled, White and Cream Mottled bean. These were found to be the most prominent colors by sales and stated preference in Malawi. Two econometric approaches were used in the data analysis. A bivariate analysis using Pearson’s chi-square was used to test the significance of the association between bean consumption (dependent variable) and household as well as product characteristics explanatory variables. A logit model was run on each of the four color types to assess the extent to which the explanatory variables influence consumer preferences for alternative colors of dry bean products. Results showed that 40.8% of the respondents consumed red beans, 12.6% consumed red mottled, 14.6% consumed White and 32% consumed Cream mottled beans. In terms of demographic characteristics, respondents’ marital and employment status as well as household size were found to have no significant influence the consumption of all the four colors. Being educated decreased probability of consuming white and cream mottled beans. Household characteristics were also found to influence preferences for color. For example, households in low and middle-income households were shown to have a lower likelihood of consuming white beans. The characteristics of the beans were also important in influencing preferences. For example, medium grain size beans influenced preference for red beans while fast cooking beans negatively affected the consumption of mottled red beans. The results provide insights for bean breeders in their attempts to contribute to increased producer incomes through a careful response to consumer preferences and not just producer demands for agronomic traits.
13

Desenvolvimento de plantas de sorgo submetidas a diferentes níveis de lençol freático

Tanaka, Adriana Aki [UNESP] 08 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-08Bitstream added on 2014-06-13T19:55:04Z : No. of bitstreams: 1 tanaka_aa_me_botfca.pdf: 1361532 bytes, checksum: 970971193b9ba4eee43bbce205ace3c3 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / A planta de sorgo, apesar de possuir menor valor nutritivo que o milho, tolera mais o déficit de água e o excesso de umidade no solo, assim como situações ambientais muito secas e/ou muito quentes nas quais a produtividade de outros cereais é antieconômica. Possui muitas aptidões, dentre as quais a de forrageiro para silagem e/ou sacarino; forrageiro para cobertura morta e granífero. O objetivo do trabalho foi avaliar o desenvolvimento das plantas de sorgo (Sorghum bicolor L. Moench) submetidas a diferentes níveis de lençol freático. O presente projeto foi realizado em estufa de vidro, sobre bandejas com reservatórios de água que permitiam a subirrigação e vasos constituídos de tubos de PVC (15 cm de diâmetro) com diferentes alturas simulando diferentes níveis de lençol freático com seis profundidades (0,17m; 0,31m; 0,45m; 0,59m; 0,73m e 0,87m de profundidade; tratamentos T1; T2; T3; T4; T5 e T6 respectivamente) em delineamento inteiramente casualizado. Os parâmetros analisados foram: massa da matéria fresca, seca, altura e diâmetro das plantas; massa da matéria fresca, seca comprimento das panículas; massa da matéria seca das raízes total e particionada em diferentes profundidades (7cm); área foliar; número de folhas; evapotranspiração da cultura (ETc); coeficiente da cultura (Kc) e eficiência do uso da água. A análise estatística dos dados foi feita pela comparação de médias, teste Tukey com 5% de probabilidade. O tratamento T6 não foi considerado nas análises por falta de plantas suficientes. Os resultados nas condições deste experimento permitiram as seguintes conclusões: foram observadas diferenças no desenvolvimento das plantas submetidas a diferentes níveis de lençol freático; as profundidades de níveis de lençol freático abaixo de 73 cm, não seriam... / This study aimed to evaluate the development of sorghum plants (Sorghum bicolor L. Moench) submitted to different water table treatments. The experiment was carried out in a glasshouse on trays with water reservoirs that allowed sub irrigation, and vases made of PVC tubes (15 cm diameter) with different heights simulating different levels of a water table with six depths (17cm; 31cm; 45cm; 59cm; 73cm and 87cm; treatments T1; T2; T3; T4; T5 and T6 respectively) in a entirely random design. The analyzed parameters were: fresh matter, dry matter, length and diameter of plants; fresh matter, dry matter and length of panicles; total dry matter of roots and parted into rings (7cm); leaf area; crop evapotranspiration; Kc and water use efficiency. The data statistical analysis was done by comparing means using Tukey‟s test at 5%. Treatment T6 was not considered in the analysis because of the lack of sufficient plants. Under the conditions of this experiment, it was possible to observe that were differences in plant growth under different levels of water table; the water table under 73 cm were not recommended, because there was not emergence of plants and water table depths of less than 17 cm would not be recommended, because there was the less-developed root system damaging plant growth; the water table depths between 45 and 59cm were the best, with higher values for both matter, fresh and dry; to the panicle, the highest values for matter fresh and dry weight and length tended to higher values for the water table of 59 and 73 cm; regarding the stem diameter, there was no statistical significance among the treatments at 45, 59 and 73 cm, however, they were significantly different from the plants cultivated at water table levels closer to the surface, observing... (Complete abstract click access to e below)
14

Autecology, ethnobotany and agronomy of Balsamorhiza sagitta: Northwestern Plateau, British Columbia

Chambers, Kimberlee 05 December 2017 (has links)
This research examines an edible and medicinal plant species, Balsamorhiza sagittata Pursh (Nutt) (balsamroot, or spring sunflower). Included are: 1) a study of literature concerning previous uses and potential agronomic applications of B. sagittata; 2) an ecological study to assess the general habitat requirements of B. sagittata at three populations in the Northwestern Plateau of British Columbia; and 3) an agronomic study of B. sagittata, the main purpose of which is to explore the development of the species in a cropping system or as a horticulture plant. Ethnobotanical literature confirms that B. sagittata has a long tradition as a highly significant food and medicinal resource on the Northern plateau. A review of botanical and range literature indicates that the species is an ecologically important forb in sagebrush ecosystems. Ecological data collectci:l was significantly different between the field sites. The only variable that was statistically similar at the Pavilion Mountain, Hat Creek Valley and Botanie Valley research locations was the number of blooms on the B. sagittata plants. Furthermore the data did not indicate significant correlations to explain variation in the number of B. sagittata plants between sample plots. Preliminary agronomic experiments indicate that B. sagittata can be propagated by seed, both in a greenhouse and at a field location. Treating seeds with ethylene before stratification significantly increased seed germination. / Graduate
15

Can biofortified plants accumulate trace elements essential to the growth and development of humans?

Müller, Francuois Lloyd January 2013 (has links)
Magister Scientiae (Biodiversity and Conservation Biology) / This study aimed to determine the nutrient content (Co, Cr, F, I, Se and V) of various vegetable based food items collected from the Cape Town area in the Western Cape Province of South Africa. This was done to determine which vegetable crops provided the highest concentrations of essential trace elements, and how much they contribute to the daily recommended intake (DRIs) of these trace elements. It also aimed to assess the effects of the addition of the trace elements (Co, Cr, F, I, Se, Si, Sn and V) on seed germination and root growth under controlled conditions in order to calculate their phytotoxicity, and then to biofortify four vegetable crop species, grown in sand culture, with a composite treatment of the trace elements to determine how the addition of these elements will affect the vegetable crops grown under these experimental conditions. From this study, it was shown that trace element content in vegetable crops in the Western Cape Province of South Africa varied between different geographic locations and that certain trace elements were absent from several items collected from some areas. Although some crop species contained sufficient amounts of certain trace elements to satisfy our daily recommended intakes, most of the crops were found to contain insufficient amounts of many of the trace elements to satisfy our needs. Leafy vegetables and tubers were identified as the better vegetable types to biofortify with essential trace elements as they already contain higher concentrations of several of the essential trace elements and should thus be assessed for their effectiveness as crops to be biofortified. When the trace elements were applied directly to cress and lettuce seeds, it was found that all the trace elements, as well as the composite treatments, exerted phytotoxic effects on cress and/or lettuce seeds when applied athighconcentrations. Lettuce was found to be more prone to the effects of these elements. Seed germination was strongly inhibited by fluoride, while several elements affected root growth. When fluoride was left out of the composite treatment, phytotoxicity only occurred at high concentrations. The addition of the trace elements at the high concentrations to already established spinach, cabbage, lettuce and turnip plants were found to affect the uptake of several essential plant nutrients, but the concentrations of the elements affected generally remained higher than the concentrations needed for adequate growth of agricultural crops. Several of the trace elements supplied to the plants were also found to be retained in the roots of the vegetable crops however, as the concentrations supplied to the plants increased, so did the concentrations found in the edible portions of the crops
16

Can bio fortified plants accumulate trace elements essential to the growth and development of humans?

Müller, Francuois Lloyd F. January 2013 (has links)
>Magister Scientiae - MSc / Micronutrient and trace element deficiencies are a problem affecting nearly two billion people globally. The people affected the most by these deficiencies are those living in poor and rural communities in the developing countries and thus cannot always afford the diverse diet as advocated by WHO and the FAO. Millions of these people living in the poor and developing countries die yearly, either directly or indirectly, as a result of micronutrient and trace element deficiencies. Thus, this study aimed to determine the nutrient content (Co, Cr, F, I, Se and V) of various vegetable based food items collected from the Cape Town area in the Western Cape Province of South Africa. This was done to determine which vegetable crops provided the highest concentrations of essential trace elements, and how much they contribute to the daily recommended intake (DRIs) of these trace elements. It also aimed to assess the effects of the addition of the trace elements (Co, Cr, F, I, Se, Si, Sn and V) on seed germination and root growth under controlled conditions in order to calculate their phytotoxicity, and then to biofortify four vegetable crop species, grown in sand culture, with a composite treatment of the trace elements to determine how the addition of these elements will affect the vegetable crops grown under these experimental conditions. From this study, it was shown that trace element content in vegetable crops in the Western Cape Province of South Africa varied between different geographic locations and that certain trace elements were absent from several items collected from some areas. Although some crop species contained sufficient amounts of certain trace elements to satisfy our daily recommended intakes, most of the crops were found to contain insufficient amounts of many of the trace elements to satisfy our needs. Leafy vegetables and tubers were identified as the better vegetable types to biofortify with essential trace elements as they already contain higher concentrations of several of the essential trace elements and should thus be assessed for their effectiveness as crops to be biofortified. When the trace elements were applied directly to cress and lettuce seeds, it was found that all the trace elements, as well as the composite treatments, exerted phytotoxic effects on cress and/or lettuce seeds when applied at high concentrations. Lettuce was found to be more prone to the effects of these elements. Seed germination was strongly inhibited by fluoride, while several elements affected root growth. When fluoride was left out of the composite treatment, phytotoxicity only occurred at high concentrations. The addition of the trace elements at the high concentrations to already established spinach, cabbage, lettuce and turnip plants were found to affect the uptake of several essential plant nutrients, but the concentrations of the elements affected generally remained higher than the concentrations needed for adequate growth of agricultural crops. Several of the trace elements supplied to the plants were also found to be retained in the roots of the vegetable crops however, as the concentrations supplied to the plants increased, so did the concentrations found in the edible portions of the crops. Agronomic biofortification of vegetable crops with simultaneous additions of multiple trace elements, under these experimental conditions, was thus considered to be a viable option to increase the concentrations of essential mineral nutrients in the edible portions of vegetable crops. However, these modified nutrient fertilizers should only be given to established crops or without the addition of fluoride. Further research on a wider variety of seeds and vegetable crops, as well as research under field conditions is needed to determine whether these findings remain relevant under these conditions.
17

Preferred information sources and delivery channels for receiving agronomic crop related information for farmers, agricultural retailers, and private crop consultants in Mississippi

Stokes, Charles Louis 01 May 2020 (has links)
ABSTRACT The purpose of this study was to explore the preferred information sources and delivery channels for receiving agronomic crop related information for farmers, agricultural retailers, and private crop consultants in Mississippi. The Mississippi State Extension Agronomic Crops Team can use this information to better serve their agronomic crop clients throughout the state of Mississippi. An electronic survey was developed and disseminated at the Mississippi State Row Crops Short Course, Winter Producer Meetings, and Farm Trade Shows to farmers, agricultural retailers, and private crop consultants who attended throughout Mississippi (n=298). The highest-ranking interpersonal information source was MSU Extension, followed by agricultural retailers, and crop consultants. The lowest ranking interpersonal information sources were other farmers, seed and chemical companies, and government agencies. The highest ranking information delivery channels were email, text messaging, and the Mississippi Crops Blog. The lowest ranking information delivery channels were postal mail, Facebook, Instagram, and Twitter. Face-toace conversations, private consultants, and field days were the highest rated information source preferences. In contrast, respondents rated television and radio the lowest. Respondents were asked to give a numeric ranking on where they would fall on adopting a new agricultural technology (e.g. smart phone crop app). The majority of respondents placed themselves in the “Early Majority” group as it relates to Rogers Diffusion of Innovation. The smallest percentage placed themselves in the “Laggards” group. Internet use among farmers was found to be influenced by age, highest level of education, internet connection type, and other devices used. Findings in this study support the Uses and Gratifications Theory. The majority of respondents still place value in the MSU Extension Agronomic Crops Team when it comes to frequency of contact. Respondents number one answer was making contact ten or more times a year with the appropriate Crops Specialist for their agronomic crops needs. Extension educators should remember that not all of their clientele are equally connected to the internet. Marketing efforts for programs and educational materials available only online are not being accessed by all potential clientele. Programs targeting older clientele should be marketed using other methods in addition to the internet.
18

Systematic optimization of yield-enhancing applications in soybeans

Haverkamp, Bryson January 1900 (has links)
Master of Science / Department of Agronomy / Kraig Roozeboom / High soybean [Glycine max.] commodity prices in recent years have led to an increase in use of yield enhancing and protecting products. These products need to be evaluated to determine if the use of multiple inputs has a positive impact on yield and how these inputs interact with agronomic practices. The objectives of this study were to evaluate products individually and collectively in input systems, examine interactions between varieties and input systems (IS), seeding rates (SR) and IS, and row spacing (RS) and IS. Field experiments were conducted at high-yielding locations in Kansas and Minnesota in 2012 to 2014 to meet these objectives. Sixteen treatments consisting of individual inputs and inputs combined in systems were evaluated in one experiment. A second experiment evaluated the variety by IS interaction by constructing 18 treatments from a factorial combination of six glyphosate [N-(phosphonomethyl) glycine] resistant varieties and three IS’s: untreated control (UTC), SOYA (combination of possible yield-enhancing products representative of those currently being marketed), and SOYA minus foliar fungicide (SOYA – foliar F). A third experiment evaluated the SR by IS interaction by constructing 12 treatments from a factorial arrangement of six SR’s and two IS’s: UTC and SOYA. A fourth experiment evaluated the RS by IS interaction by constructing 12 treatments from a factorial arrangement of three RS’s and four IS’s: UTC, fungicide and insecticide seed treatment plus foliar fungicide (STFF), SOYA, and SOYA – foliar F. Very few interactions between IS and agronomic practices were detected in any of the experiments. Varieties had an effect on multiple growth parameters but yield differences were marginal; linear-plateau and non-linear models found that seeding rates that maximized yield in this study were similar to University recommendations; and in general, narrow rows produced the greatest yields. The use of inputs and IS’s typically increased seed mass and yield above the UTC across all experiments. However, given current costs and soybean prices, yield response to IS’s was not great enough to cover the additional costs. Overall, it appears producers would be better served by focusing on agronomic practices rather than implementing input systems.
19

Economic feasibility of alternative crops in Northeast Iowa to sustain family incomes

Quandahl, Kendal January 1900 (has links)
Master of Agribusiness / Department of Agricultural Economics / Vincent R. Amanor-Boadu / The purpose of this thesis is to identify which alternative crops could be enhance the income of Quandahl Farms the most by moving the smallest acreage from the farm’s traditional corn and soybean enterprises into its production. The considered crops are grapes, raspberries, and black currants. The objectives of this study included assessing the technical feasibility of producing the selected crops in Northeast Iowa given the agronomic conditions in the region and the agronomic requirements of the crops. The other was the assessment of the economic feasibility of the selected crops and determining the minimum acres required for each to enhance the farm’s financial situation and still allow for corn and soybeans to be the main crops. The analyses were conducted using secondary data on the selected crops from published budgets and government and extension reports as well as the historical financials of Quandahl Farms. The analyses were conducted over a 10-year horizon to ensure a significant duration of cash flow and allow the establishment of the alternative crops. In that 10-year period, the net present value of Quandahl Farms income is $214 per acre per year. Additionally, the analyses were evaluated under four alternative scenarios of prices and yield for each of the crops in addition to the base scenario. The results shows that grapes and black currants were not economically feasible in Northeast Iowa even though they were agronomically feasible. On the contrary, raspberries were found to be both technically and economically feasible in Northeast Iowa. The net present value under that base scenario for raspberries was $23,267 at a discount rate of 4.5%. Based on the net present value of corn and soybean revenue of the same period, it is estimated that taking 22 acres from the current production and putting it into raspberries would increase average farm income by $60,000. The study shows there is an opportunity to allocate a relatively small proportion of current corn and soybean acreage to raspberries to significantly increase farm incomes. As a result, it is recommended to the principals of Quandahl Farms to consider making this small investment in raspberries to protect the farm from the frequent vicissitudes of farm incomes. The next step after their agreement is to develop the business plan to implement such an investment.
20

Evaluation of secondary and micronutrients in Kansas

Gutierrez Rodriguez, Miriam Nicole January 1900 (has links)
Master of Science / Department of Agronomy / Dorivar Ruiz Diaz / The limitation of an essential nutrient for plant growth can affect crop yield. Research has been focused mainly on macronutrients, nevertheless micronutrients are equally important. This thesis is divided into three studies, which had the purpose of assessing frequent questions that producers have about micronutrient fertilizers and their effect on several crops in Kansas. The objective of the first study was to summarize and analyze results from studies since 1962 until 2015 to verify responses to zinc (Zn) and sulfur (S) fertilization in corn (Zea mays), sorghum (Sorghum bicolor (L.) Moench), wheat (Triticum aestivum) and soybean (Glycine max (L.) Merr). The treatments evaluated consisted of fertilizer Zn or S application versus their respective unfertilized treatments. Zinc fertilization significantly increased corn yield; no significant response was found for sorghum, wheat and soybean. Sulfur fertilization did not increase yields on corn and wheat. The objectives of the second study were: (i) to evaluate soybean response to S and micronutrients boron (B), copper (Cu), manganese (Mn), and Zn fertilizer application and to assess soil test and soybean seed and tissue nutrient concentration with fertilization. Treatments consisted of an unfertilized control, micronutrient fertilizer as individual nutrient for B, Cu, Mn, S and Zn applied broadcast pre-plant, in addition to a blend of these nutrients using two different placements (broadcast and band). Secondary and micronutrient fertilization showed no significant effect on soybean yield at any of the ten locations. Zinc fertilization showed significant effects on soybean tissue and seed Zn concentration. The objective of the third study was to evaluate soybean tissue nutrient response to micronutrient fertilizers in field strips with high variability in soil properties in the area evaluated. The study consisted of two strips (with and without fertilizer) and replicated three times. The treatment with fertilizer included a blend of Cu, Mn and Zn at a rate of 11.2 kg ha⁻¹ and B at a rate of 2.8 kg ha⁻¹. Initial soil tests B, Cu, Mn and Zn were not good indicators of soybean tissue response. Within-field variability of soybean Zn and B tissue content were affected by soil pH and organic matter; and these factors may be used to help explain field variability in plant availability. The micronutrient blend treatment showed higher tissue Zn and B values compared to the control. When pH ranged from 5.5 to 7.6, B in soybean tissue was higher on the control than the micronutrient blend treatment. Copper concentration in soybean tissue did not show significant difference between treatments at any location, regardless of pH and organic matter levels.

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