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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

Expanding pulse production in Mozambique : identifying constraints and new strategies

Gungulo, Ana Lidia January 2013 (has links)
Pulses (common beans and cowpeas) provide a major alternative source of protein, and the rapid rise in food prices has led to an increase in the consumption of inexpensive pulses. The slow growth in pulse production has, however, led to a decline in availability. Thus, to overcome this decline in production, this study concern in expanding pulse production in Mozambique by using the agricultural research survey known as TIA. In addition, this study identified and analysed the critical drivers influencing production, as well as constraints and opportunities to expand pulse production in Mozambique. In studying the participation of smallholder farmers in pulse markets, the Heckman two-step approach was applied to avoid sample selection bias. In the first step a Probit model was estimated to capture the household’s decision of whether or not to participate in the market. The second step comprised of an OLS estimation to determine the significance of variables that contribute to the level of pulse sold. At national level, results indicate that the majority of households receive price information, but few households receive information on fertilizers and improved seed use. Most households also have poor access to credit and improved extension services, and low levels of membership of agricultural associations. A very small percentage of household farmers are engaged in pulse production, with male farmers more dedicated to the production of common beans and female farmers more dedicated to the production of cowpeas. In terms of market participation, the results reveal that female-headed households are less likely to participate in pulse markets. The critical factors that discourage entry into the pulse market are distance to the market and yield loss. The factors that give incentives to smallholders to participate in the pulse market are land size, price information and pulse price. The trade volume of common beans is relatively high and is affected by land size, pulse price and price information. In contrast, the trade volume of cowpeas is highly affected by bicycle ownership and ownership of livestock for animal traction. Cowpea prices also have a positive effect on the volume of cowpeas sold. Yield loss is a major factor that negatively affects the pulse trade, while land size has a negative effect on the volume of cowpeas sold. Land availability and price information provide good opportunities, in Mozambique, for expanding pulse production. The expansion of pulse production is however constrained by household access to public goods and services such as extension services, credit and membership to an agricultural association. Moreover, the expansion of pulse production in the country is also constrained by the absence of the use of productive technologies such as improved seed and fertilizer. Based on the results of the study, the recommendations are to expand extension services, improve access to improved technology, facilitate access to agricultural finance, and improve infrastructure and storage facilities. This would facilitate and give incentive to smallholder to expanding pulse production in Mozambique. / Dissertation (MSc Agric)--University of Pretoria, 2013. / gm2014 / Agricultural Economics, Extension and Rural Development / unrestricted
12

The contribution of cowpeas to dietary diversity and food assess in Peri-Urban Gaborone, Botswana

Olesitse, Olebogeng Boitswarelo 07 1900 (has links)
The study aimed at determining the contribution of cowpeas to dietary diversity and food access, among women living in a peri-urban area of Gaborone called Gabane village in Botswana. Consuming a variety of food groups ensures adequate intake of nutrients for health. Diet diversity measures diet quality, food access and an indication of nutritious diets. Cowpeas are a nutritious vegetable which can contribute to diet diversity, diet quality and food access of many poor rural households who cannot afford to purchase a wide variety of nutritious food (ARC, 2006). Data was collected through administering a Cowpea consumption survey questionnaire which indicated that most of the households consume cowpeas which are essential to improve household food access, diet diversity and diet quality. A socio-demographic questionnaire was also used and it indicated an average number of household members of 6 people. The respondents were mainly the elderly people of 56 years and above with primary school education as the most achieved level of education. A Household Dietary Diversity Score (HDDS) questionnaire was contextualised for local foods consumed in Botswana. Focus group discussions were conducted to collect more data from women regarding their attitude, opinions and perceptions of consuming a variety of foods, cultivating and consuming cowpeas to ensure good health. The focus group results indicated that cowpeas were consumed by most families and 100% of adults and children consume cowpeas as leaves and seeds. Cereals were predominantly consumed by 95% of households, vitamin A rich fruits and vegetables by 52.5%, meat, poultry and fish by 42.5%. Vitamin A rich foods such as vegetables, fruits and organ meat were poorly consumed except green leafy vegetables which included cowpea leaves consumed by 52.5%. Meat, poultry and fish were consumed by 42.5%. Legumes, nuts, seeds and organ meat were also poorly consumed. vii Cowpeas grow well in Botswana, are Batswana’s cultural food, can improve nutritional intake and livelihoods through sold surplus profit. A diet diversity score of 2.9, well below the advised cut-off point of 4 was documented, indicating poor household dietary diversity and poor diet quality and food access. / Agricultural, Animal Health and Human Ecology / Thesis (M.A. (Human ecology) )
13

Análise molecular da adaptabilidade hospedeira de Cowpea aphid-borne mosaic virus e caracterização de um novo tymovírus infectando Cassia hoffmannseggii

NICOLINI, Cícero 01 September 2011 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-21T13:55:26Z No. of bitstreams: 1 Cicero Nicolini.pdf: 1169299 bytes, checksum: e932282294084c1947939ed928971bcb (MD5) / Made available in DSpace on 2017-02-21T13:55:26Z (GMT). No. of bitstreams: 1 Cicero Nicolini.pdf: 1169299 bytes, checksum: e932282294084c1947939ed928971bcb (MD5) Previous issue date: 2011-09-01 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Brazil is the world’s largest passion fruit producer. The sanitary problems, mainly diseases caused by viruses are among the limiting factors for increasing productivity and longevity of the plantations. In Brazil, passion fruit woodiness, caused by Cowpea aphid-borne mosaic virus (CABMV) is the major viral disease of this crop. CABMV is also causing agent of the potyvirus mosaic, a viral disease that produces serious damages in cowpea. This crop in Brazil is important mainly in the Northeastern region and represents a relevant source of protein and starch for the population. Some years ago, in the state of Pernambuco it was found a potyvirus naturally infecting “lava-pratos”, leguminous plant native to Atlantic Forest commonly found on the margins of passionflower and cowpea crops. In the city of Paudalho it was found a group of “lava-pratos” plants presenting very intense symptoms with yellow spot on the leaves. From those plants, preparations examined in a transmission electron microscope showed the presence of elongated flexuous particles and cylindrical inclusions typical of potyvirus as well as isometric particles in high concentration and vesicles on the periphery of the chloroplasts which suggested the occurrence of a tymovirus. Serological analyses and coat protein sequencing to identify the potyvirus as well as studies on host adaptation in passionflower and cowpea, using isolates from these crops were undertaken. The virus with isometric particles was chemically purified to produce polyclonal antiserum and subjected to serological studies, host range and genome sequencing for characterization. It was concluded that the potyvirus found in “lava-pratos” is CABMV and phylogenetically observed the host adaptation of this virus to the families Fabaceae and Passifloraceae. For some strains geographical distance was not the strongest factor for genetic grouping and the Brazilian isolates form a large group distinct to other countries. According to the criteria of taxonomy, using amino acid sequence of coat protein and conserved region "tymobox", it was determined the presence of a tymovirus in “lava-pratos”, for which was proposed to be a new species named Cassia yellow mosaic-associated virus (CAYMaV). / O Brasil é o maior produtor mundial de maracujá. Os problemas fitossanitários especialmente as doenças ocasionadas por vírus estão entre os fatores limitantes ao aumento de produtividade e longevidade dos plantios. A principal virose do maracujazeiro no Brasil é o endurecimento dos frutos causado por Cowpea aphid-borne mosaic virus (CABMV). O CABMV também é o agente do mosaico de potyvírus em feijão-caupi, virose que provoca sérios danos nessa cultura. No Brasil, o feijão-caupi é produzido principalmente na Região Nordeste e representa fonte importante de proteína e amido para a população. Há alguns anos atrás, um potyvírus foi encontrado em Pernambuco infectando naturalmente o lava-pratos, uma leguminosa nativa da Mata Atlântica comumente encontrada nas bordas de cultivos de maracujá e feijão-caupi. No município de Paudalho foi observado um grupo de plantas de lava-pratos apresentando sintomas muito intensos com manchas amarelas nas folhas. Dessas plantas, ao ser analisadas preparações em microscópio eletrônico de transmissão, além da presença de partículas alongadas flexuosas e de inclusões cilíndricas típicas de potyvírus foram detectadas partículas isométricas em alta concentração e vesículas nas bordas dos cloroplastos, o que sugeria ser de um tymovírus. Foram realizadas análises sorológicas e seqüenciamento da capa protéica para identificação do potyvírus, assim como estudar a adaptação hospedeira a maracujazeiro e feijão-caupi, utilizando-se isolados obtidos dessas culturas. O vírus com partículas isométricas foi purificado quimicamente para produção de antissoro policlonal e submetido a estudos sorológicos, gama de hospedeiros e seqüenciamento de parte do genoma para caracterização. Concluiu-se que o potyvírus encontrado em lava-pratos é o CABMV e filogeneticamente se observou que ocorre adaptação hospedeira deste vírus em plantas das famílias Fabaceae e Passifloraceae. Para alguns isolados, a distância geográfica não foi o fator mais forte para agrupamento genético e os isolados brasileiros formam um grande grupo distinto aos de outros países. De acordo com os critérios de taxonomia, usando-se seqüência de aminoácidos da capa protéica e região conservada “tymobox”, foi determinada a presença em lava-pratos de um tymovírus, para o qual foi proposto ser uma nova espécie nomeada Cassia yellow mosaic-associated virus (CAYMaV).
14

The contribution of cowpeas to dietary diversity and food assess in Peri-Urban Gaborone, Botswana

Olesitse, Olebogeng Boitswarelo 07 1900 (has links)
The study aimed at determining the contribution of cowpeas to dietary diversity and food access, among women living in a peri-urban area of Gaborone called Gabane village in Botswana. Consuming a variety of food groups ensures adequate intake of nutrients for health. Diet diversity measures diet quality, food access and an indication of nutritious diets. Cowpeas are a nutritious vegetable which can contribute to diet diversity, diet quality and food access of many poor rural households who cannot afford to purchase a wide variety of nutritious food (ARC, 2006). Data was collected through administering a Cowpea consumption survey questionnaire which indicated that most of the households consume cowpeas which are essential to improve household food access, diet diversity and diet quality. A socio-demographic questionnaire was also used and it indicated an average number of household members of 6 people. The respondents were mainly the elderly people of 56 years and above with primary school education as the most achieved level of education. A Household Dietary Diversity Score (HDDS) questionnaire was contextualised for local foods consumed in Botswana. Focus group discussions were conducted to collect more data from women regarding their attitude, opinions and perceptions of consuming a variety of foods, cultivating and consuming cowpeas to ensure good health. The focus group results indicated that cowpeas were consumed by most families and 100% of adults and children consume cowpeas as leaves and seeds. Cereals were predominantly consumed by 95% of households, vitamin A rich fruits and vegetables by 52.5%, meat, poultry and fish by 42.5%. Vitamin A rich foods such as vegetables, fruits and organ meat were poorly consumed except green leafy vegetables which included cowpea leaves consumed by 52.5%. Meat, poultry and fish were consumed by 42.5%. Legumes, nuts, seeds and organ meat were also poorly consumed. vii Cowpeas grow well in Botswana, are Batswana’s cultural food, can improve nutritional intake and livelihoods through sold surplus profit. A diet diversity score of 2.9, well below the advised cut-off point of 4 was documented, indicating poor household dietary diversity and poor diet quality and food access. / Agricultural, Animal Health and Human Ecology / Thesis (M.A. (Human ecology) )
15

Storage fungi and mycotoxins associated with cowpea

Kritzinger, Quenton 26 May 2006 (has links)
Cowpeas (Vigna unguiculata (L.) Walp) is an important African indigenous legume crop for the livelihoods of many relatively poor people residing n less developed countries of the tropics. Rural families derive a nutritious food, animal feed and in income from the production of this crop. Storage of seed is certainly the most important post-harvest operation but the losses incurred are great. These losses, due to an inability to effectively control physical and biological factors, result in problems with storage insects, moisture and associated fungi. Seeds are particularly susceptible to fungal contamination when stored at high ambient temperatures and relative humidities. To determine the storage fungi associated with cowpea seeds, surface-sterilised cowpea seeds (200 seeds from each of nine cultivars) were plated out n malt extract agar. After 5-7 days incubation at 25°C, the most dominant and common fungi recorded were Alternaria spp. followed by Penicillium spp., Aspergillus flavus and A. niger. The influence of a three-year cold storage period at ± 5°C on the fungi associated with the seeds was also investigated. Alternaria, Aspergillus and Penicillium spp. appeared to dominate. Some fungal species recorded prior to cold storage were not recorded thereafter. Certain storage fungi are known to produce mycotoxins, which are secondary fungal metabolites that are toxic to both farm animals and humans, under poor storage conditions. The presence of the fusarial mycotoxins, fumonisin BI, B2 and B3 in four cowpea cultivars (Bechwana Whit, Glenda, Iron Grey, Rhino) was investigated. The samples were extracted with methanol/water (70:30 v/v) and cleaned-up on strong anion exchange solid phase extraction cartridges. High performance liquid chromatography with pre¬column derivatisation using o-phthaldialdehyde (OPA) was used for the detection and quantification of fumonisin Bl, B2 and B3. All sampIes were contaminated with FBI, with levels ranging from 81-1002 ng g-I. Fumonisin B2 and B3 were not detected in any samples. This is believed to be the first report of fumonisin BI in cowpea seeds. Since the known fumonisin-producing Fusarium species were not found in the six different Fusarium species isolated from these four cultivars, further investigations are required to determine which fungal species are species are responsible species are responsible for the FBI production. An alternative approach to the prevention and control of fungal contamination and mycotoxin production of seeds by treating cowpea seed with essential plant oils was tested. The inhibitory activity of five essential oils (thyme, clove, peppermint, soybean and peanut) was investigated, in vitro and in vivo, on five fungal species (A. flavus, A. niger, Penicillium chrysogenum, Fusarium oxysporum and F. equiseti) commonly associated with cowpea seeds and on two cowpea cultivars. Thyme and clove oil significantly inhibited the growth of all five fungal species in vitro at 500 and 1000 ppm, while peppermint oil was successful at 2000 ppm. Peanut and soybean oil did not show any significant inhibition of fungal growth. The in vivo effect of thyme, clove and peppermint oils on naturally infected seed revealed that only thyme at 1000 ppm reduced fungal growth of storage fungi in the PAN 325 cultivar. In the PAN 311 cultivar, thyme and clove oils at 1000 ppm and peppermint oil at 2000 ppm significantIy reduced growth of storage fungi. In artificially infected seed, all three oils significantly inhibited the growth of P. chrysogenum. Thyme reduced the growth of F. oxysporum and F. equisetii, whilst peppermint oil inhibited only F. oxyspomm. These oils did not seem to adversely affect the germination nor emergence of cowpea seed. The storage fungi significantly reduced percentag germination and emergence of the white (IT 93K452-1) seed but had little or no effect on the brown (CH 14) seed. Furthermore, all three oils significantly inhibited the storage fungi on the white seed, possibly increasing the percentage germination and emergence. / Dissertation (MSc (Botany))--University of Pretoria, 2006. / Plant Science / unrestricted

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