Lysine deficiency is a major nutritional problem faced by poor people living in the arid and semi-arid tropics who depend on sorghum as their staple food. This is because of poor lysine content and digestibility of sorghum proteins, which aggravates when sorghum is cooked in food. To address this nutritional problem, compositing with locally available lysine-rich legumes has been proposed. Therefore, this study investigated the effects of compositing with the African grain legume, cowpea, on the protein and functional quality of important traditional African sorghum foods. Two sorghum cultivars, a red, tannin (NS 5511) and a white tan plant, non-tannin (Orbit) composited with cowpea at 70:30 ratio, were used to prepare three traditional sorghum foods, ugali (unfermented thick porridge), uji (fermented thin porridge) and injera (fermented flatbread). The protein quality of the traditional sorghum foods was determined by measuring their protein contents, lysine and reactive lysine contents, and in vitro protein digestibility. The functional properties of the foods were studied using instrumental texture analysis. Other sensory properties of ugali were determined using a trained sensory panel. Compositing with cowpea increased the protein contents of the foods by up to 35% and 57% for NS 5511 and Orbit foods, respectively. Lysine contents of the food proteins increased by 67% to 139%. Reactive lysine content increased by 10% to 75%. Protein digestibility of the foods increased by 13% to 62%. There was approximately three- and two-fold increase in protein digestibility corrected amino score (PDCAAS) of NS 5511 and Orbit foods, respectively, due to addition of cowpea. However, Orbit-plus-cowpea foods still had better protein quality than NS 5511-plus-cowpea foods, primarily because of the tannins in the latter which bind the proteins thereby lowering their digestibility. Compositing reduced paste peak viscosity (PV) and cool paste viscosity (CPV) of uji porridge by 6% to 23%, and 6% to 12%, respectively, probably as a result of decreasing porridge starch content. Principal component analysis (PCA) showed that compositing contributed 38% of the variation in 17 sensory attributes of ugali. Compositing imparted cowpea flavour to ugali. Most of the variation in sensory properties (59%) of ugali was due to the quality characteristics of the sorghum cultivars. Compositing increased the stiffness of NS 5511 injera by up to 25%, while it reduced the stiffness of Orbit injera by up to 12%. These differences in stiffness suggested a weakening effect of weaker H-bonding between tannins and other food polymers such as proteins instead of stronger covalent bonds like those involved in proteins-protein interactions. Compositing important traditional sorghum foods with cowpea has potential for helping to solve lysine deficiency faced by sorghum consumers in the semi-arid tropics. However, it introduces cowpea flavour which may need to be eliminated, in foods intended for consumers not accustomed to cowpea flavour. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Food Science / unrestricted

Anthracnose of cowpea (Vigna unguiculata (L.) Walp) caused by Colletotrichum dematium (Pers. ex Fr) Grove has serious socio-economic implications. Subsistence farmers rely heavily on cowpea for protein and fodder; therefore, C. dematium poses a threat to production of this crop. The purpose of this study was to investigate the interaction between cowpea and C. dematium. Investigations involved characterising C. dematium field isolates using morphological and molecular techniques, infection studies, biochemical and histochemical analysis and determining factors that influence the severity of the fungus on the host. Random amplified microsatellite profiles of C. dematium grouped the isolates into eleven groups linked to morphological characteristics, pathogenicity and geographic origin. Infection studies indicated that C. dematium is a subcuticular intramural coloniser, that switches to destructive necrotrophy. Pulvinate acervuli were produced at 72 hours post inoculation over water-soaked lesions and complete necrosis of the host tissue occurred at 120 hours. The infection process was favoured by prolonged periods of high humidity and high temperatures, especially in cowpea plants between the ages six to nine-weeks-old. Investigations on the location and patterns of polyphenols in the cowpea seed coats indicated that brown coloured cowpea cultivars contained more soluble phenolic compounds than cream coloured cultivars and they were more resistant to C. dematium. / Thesis (PhD (Botany))--University of Pretoria, 2003. / Plant Science / unrestricted

Thesis(M.Sc.(Agriculture Horticulture)) -- University of Limpopo, 2019 / Innovative methods of preserving the quality of traditionally processed green leafy vegetables are underway in Africa. Improvement of processing and preservation methods of leafy vegetables is another way of overcoming perishability restrictions and guaranteeing continued quality food supply in rural areas. The objectives of this study were: to determine the effect of time-based oven-drying on (1) mineral composition, (2) proximate composition and (3) microbial profiling of cowpea (Vigna unguiculata). Separate experiments were conducted for raw and cooked cowpea leaves with four treatments, viz 0 (sun dried), 24, 48 and 72 hours of oven-drying, arranged in a randomised complete block design with 5 replications. In raw cowpea leaves, relative to control (sun-drying), oven-drying period 48hrs, significantly decreased Potassium (K), Manganese (Mn), and Sodium (Na) content in raw cowpea leaves by 6, 9 and 13%, respectively. Similarly, oven-drying period 72hrs significantly decreased Ca, Fe, Mg, Zn, P and S by 5, 11, 16, 18 and 57%, respectively. In cooked cowpea leaves, relative to control (sun-drying), oven-drying period 24hrs significantly increased Na by 18%. Similarly 48hrs oven-drying periods increased Fe and K by 6 and 8%, respectively. Similarly, oven-drying period 72hrs significantly increased Ca, Mg and Mn by 8, 8 and 3%, respectively. In contrast, oven-drying period 72hrs significantly reduced Zn, P and S by 16, 10 and 39%, respectively. Relative to control (sun-drying), oven-drying period 24hrs significantly increased fat by 46% in raw cowpea leaves, however oven-drying period 72hrs significantly decreased protein, moisture, ash, fibre and carbohydrate by 10, 29, 18, 0.5, and 7% respectively. In contrast, relative to control (sun-drying), 72hrs increased energy by 3%. In cooked cowpea leaves, relative to control (sun-drying), ovendrying period 24hrs significantly increased energy by 1%. In contrast, relative to control (sun-drying) 72hrs oven-drying period decreased energy by 1%. Similarly, oven-drying 72hrs significantly decreased protein, moisture, ash, fat, fibre and carbohydrate by 8, 14, 13, 19, 0.4 and 10% respectively. Relative to control (sun-drying), oven-drying periods 24hrs significantly increased Staphylococcus spp. in raw cowpea leaves by 6%, respectively. Relative to control (sun-drying) 72hrs oven-drying period significantly decreased Shigella spp. by 92%, respectively. In cooked leaves, relative to control (sundrying), 72hrs drying periods decreased both Shigella spp. and Staphylococcus spp. by 99 and 21%, respectively. Total coliforms unit of Salmonella spp, Escherichia coli, Pseudomonas spp, and Bacillus cereus were absent and/or at an undetectable level according to the Tempo Biomerieux system results. In conclusion, cooked leaves retained most essential mineral elements as compared to raw when subjected to 72hrs of ovendrying as there was an improvement in the concentration of Ca, Fe, K, Mg, Mn and Na. However, in both raw and cooked cowpea leaves proximate composition was negatively affected as there was a decrease in protein content. Oven-drying period of 24 hours can be used to minimize the loss of protein. Cooked cowpea leaves subjected to 72hrs of oven-drying had least total coliforms for both Shigella spp and Staphylococcus spp, therefore have potential to serve as an alternative to sun-drying to reduce microorganism causing spoilage in leafy vegetables. Drying raw cowpea leaves under oven-drying periods less than 72 hours should be avoided as it reduces the mineral concentration and increase microbial count of microorganisms responsible for spoilage / National Research Foundation (NRF)

Thesis(M.Sc.(Agriculture Horticulture)) -- University of Limpopo, 2019 / Innovative methods of preserving the quality of traditionally processed green leafy vegetables are underway in Africa. Improvement of processing and preservation methods of leafy vegetables is another way of overcoming perishability restrictions and guaranteeing continued quality food supply in rural areas. The objectives of this study were: to determine the effect of time-based oven-drying on (1) mineral composition, (2) proximate composition and (3) microbial profiling of cowpea (Vigna unguiculata). Separate experiments were conducted for raw and cooked cowpea leaves with four treatments, viz 0 (sun dried), 24, 48 and 72 hours of oven-drying, arranged in a randomised complete block design with 5 replications. In raw cowpea leaves, relative to control (sun-drying), oven-drying period 48hrs, significantly decreased Potassium (K), Manganese (Mn), and Sodium (Na) content in raw cowpea leaves by 6, 9 and 13%, respectively. Similarly, oven-drying period 72hrs significantly decreased Ca, Fe, Mg, Zn, P and S by 5, 11, 16, 18 and 57%, respectively. In cooked cowpea leaves, relative to control (sun-drying), oven-drying period 24hrs significantly increased Na by 18%. Similarly 48hrs oven-drying periods increased Fe and K by 6 and 8%, respectively. Similarly, oven-drying period 72hrs significantly increased Ca, Mg and Mn by 8, 8 and 3%, respectively. In contrast, oven-drying period 72hrs significantly reduced Zn, P and S by 16, 10 and 39%, respectively. Relative to control (sun-drying), oven-drying period 24hrs significantly increased fat by 46% in raw cowpea leaves, however oven-drying period 72hrs significantly decreased protein, moisture, ash, fibre and carbohydrate by 10, 29, 18, 0.5, and 7% respectively. In contrast, relative to control (sun-drying), 72hrs increased energy by 3%. In cooked cowpea leaves, relative to control (sun-drying), oven-drying period 24hrs significantly increased energy by 1%. In contrast, relative to control (sun-drying) 72hrs oven-drying period decreased energy by 1%. Similarly, ovendrying 72hrs significantly decreased protein, moisture, ash, fat, fibre and carbohydrate by 8, 14, 13, 19, 0.4 and 10% respectively. Relative to control (sun-drying), oven-drying periods 24hrs significantly increased Staphylococcus spp. in raw cowpea leaves by 6%, respectively. Relative to control (sun-drying) 72hrs oven-drying period significantly decreased Shigella spp. by 92%, respectively. In cooked leaves, relative to control (sundrying), 72hrs drying periods decreased both Shigella spp. and Staphylococcus spp. by 99 and 21%, respectively. Total coliforms unit of Salmonella spp, Escherichia coli, Pseudomonas spp, and Bacillus cereus were absent and/or at an undetectable level according to the Tempo Biomerieux system results. In conclusion, cooked leaves retained most essential mineral elements as compared to raw when subjected to 72hrs of oven-drying as there was an improvement in the concentration of Ca, Fe, K, Mg, Mn and Na. However, in both raw and cooked cowpea leaves proximate composition was negatively affected as there was a decrease in protein content. Oven-drying period of 24 hours can be used to minimize the loss of protein. Cooked cowpea leaves subjected to 72hrs of oven-drying had least total coliforms for both Shigella spp and Staphylococcus spp, therefore have potential to serve as an alternative to sun-drying to reduce microorganism causing spoilage in leafy vegetables. Drying raw cowpea leaves under oven-drying periods less than 72 hours should be avoided as it reduces the mineral concentration and increase microbial count of microorganisms responsible for spoilage. / National Research Foundation

No description available.

Situated on the western edge of Africa's harsh Sahel region, Senegal faces a number of agricultural production constraints. Limited rainfall, poor soil fertility, and insufficient agronomic inputs all contribute to low yielding millet production systems. This study was initiated to assess the potential for intercropping either cowpea (Vigna unguiculata (L.) Walp.) or mungbean (Vigna radiata (L.) Wilczek) into traditional pearl millet (Pennisetum glaucum (L.) R. Br.) cropping systems. During the 2013 and 2014 growing seasons two varieties of cowpea (upright and viney), and one variety of mungbean (upright) were grown in monoculture and subsequently intercropped with millet to evaluate the potential for increasing millet and overall yields. Millet was also planted with a mulch (2 t/ha of neem leaves) to test the effectiveness of increased ground cover on millet yields. In addition to yield data, soil moisture and plant NDVI data were also collected. Millet grain yields increased when intercropped with either cowpea or mungbean compared to millet that was grown alone, with grain yield increases of up to 55%. Additionally, the combined grain yields (millet + bean) were up to 67% higher than the traditional monoculture millet. The addition of mulch was the most effective treatment and increased millet grain yields up to 70%. Soil moisture increased up to 14% in mulched treatments over millet monoculture treatments. All yield increases were achieved without the addition of fertilizers or nutrient amendments. In an attempt to mimic local practices our experiment was rainfed and no soil amendments were introduced. / Master of Science

Thesis (M.Sc. (Agriculture)) --University of the North, 2001

Thesis (MSc. Agriculture(Soil Science) -- University of Limpopo, 2018 / Soil acidity is one of the abiotic stress factors that greatly limit the productivity of crops on farmers’ fields. A greenhouse study was carried out over two summer growing seasons to evaluate the effect of lime and phosphorus (P) application rates on the growth, yield and root attributes of a determinate cowpea variety on acid soil. The experiment was laid out as a 4x5 factorial arrangement with 4 replications. Treatment factors comprised of variable rates of Vaalburg dolomitic lime (0, 2, 4 and 6 t ha-1) and P (0, 15, 30, 45 and 60 kg ha-1) using single super phosphate, 10.5% P. The two treatment factors were combined resulting in a total of 20 treatment combinations. Data collected included cowpea growth parameters, crop phenology, yield attributes and root characteristics. While cowpea plants with no P application consistently gave the least plant height, stem diameter, number and length of trifoliate leaves, the 6 t ha1 lime rate appears to be completely disadvantaged for all measured parameters with generally lower values than in soil filled pots without lime application. Results showed that soil pH was increased with 6 t ha-1 lime application while soil electrical conductivity (EC), percent of organic matter (OM) and total organic carbon (TOC) were all increased with increasing P and lime rates. All measured cowpea growth attributes such as plant height, stem diameter, number of trifoliate leaves, and leaf area were significantly increased (p≤0.05) with increasing P and lime rates. During the two planting seasons, P and lime application resulted in reduced (p≤0.05) duration to flowering, pod formation and physiological maturity. The 6 t ha-1 lime application produced higher number of pods (2.50) compared to the other rates. Application rates of 45 kg P ha-1 and 6 t ha-1 of lime produced superior number of seeds per pod with high values of (13.71) and (12.85), respectively. However, cowpea root attributes namely number of nodules per plant, the third branching root diameter, angle of adventitious root, tap root diameter at 5 and 10 cm, shallow and deep score were significantly increased at moderate P rate of 30 kg P ha-1. Overall, findings of this study revealed that application of both P fertiliser and lime were able to ameliorate the negative effect of P deficiency from soil acidity on the evaluated cowpea variety and promoted increased yield. Keywords: Acid soil, grain cowpea, P fertiliser, lime, growth, root characteristics, yield / National Research Foundation (NRF) and Department of Agriculture, Forestry and Fisheries (DAFF)

Thesis (M.Sc. (Horticulture)) --University of Limpopo, 2009 / Field experiments were conducted at the University of Limpopo experimental farm, Syferkuil during 2005/06 and 2006/07 production seasons. This was initiated to examine the effect of leaf removal on cowpea biomass, protein content and grain yield under sole and binary cultures. Treatments consisted of cowpea varieties (Pan 311 and Red caloona), cropping systems (sole and intercropping) and cowpea-leaf pruning regimes (pruning and un-pruned). Sweet corn was planted, as a component crop in the intercropped plots while sole sweet corn plot was included as a treatment. All treatment combinations were laid out as Randomize complete block design (RCBD) with four replicates. Supplementary irrigation was carried out during the plant growth period. Fully expanded leaves were harvested once on all cowpea plants in the two middle rows from designated plots at seven weeks after planting for each year. Growth and yield data were collected from component crops during the course of the trial while the protein content of harvested leaves and immature pods as well as the different cowpea plant parts at harvest were determined. Results of the study revealed that leaves of cowpea variety, Pan 311 harvested prior to the reproductive stage had significantly higher protein content than those of Red caloona. Protein content of immature Pan 311 pods had higher (18.8 to 25.1%) than Red caloona (17.9 to 20.7%) during both planting seasons. The percent protein content of cowpea stem obtained at harvest for Pan 311 varied between 9.3 and 9.4%, and between 9.9 and 12.3% for Red caloona during both planting seasons. Grain yield obtained for Pan 311 and Red caloona were 1703.7 kg ha-1 and 1479.8 kg ha-1, respectively during 2005/06 and 1290.7 kg ha-1 and 511.7 kg ha-1 respectively during 2006/07 planting seasons. Sweet corn intercropped with Red caloona during both planting seasons had higher average grain yield than when intercropped with Pan 311. Although intercropping decreased the partial land equivalent ratio (LER) value of individual component crops, the combined LER values of between 1.1 and 2.3 under intercrop for the different treatment combinations implies that the practice is advantageous. The results of post harvest soil analyses revealed that topsoil has the pH value of 7.11-7.29 indicating neutral soil while subsoil pH value of 6.27-6.91 indicated slightly acidic to neutral soil during both planting seasons. Based on the findings of this study, cowpea variety Pan 311 can be recommended as a better vegetable crop than Red caloona since it has higher leaf and immature pod protein content. It also had higher grain yield than Red caloona when intercropped with sweet corn. Sweet corn had high grain yield when intercropped with Red caloona than when intercropped with Pan 311. Keywords: Cropping systems, protein content, grain yields, leaf pruning and cowpea.

The culture of caupi (Vigna unguiculata) represents an important alternative in the suppliment of the proteins necessities of small agriculturists in the Northeast region of Brazil. In this work the effect of the severe mosaic, (Cowpea severe mosaic virus - CPSMV), was determined, on the production and content of chlorophyll of plants of caupi, cv. Sempre verde in conditions of controlled inoculations and evaluation of the job of the inductor of Acibenzolar-S-metil resistance (ASM) as an option to reduce the losses of the culture caused by the illness. For analysis of the losses two experiments at distinct times had been lead. In these experiments the plants had been submitted the inoculations at two different times, being first to the 14 or 19 days and second to the 29 or 34 days after plantation (DAP). The effect of the illness on the content of chlorophyll was evaluated comparing it concentration of chl orophyllin leves of plants inoculated with leves of plants not inoculated, using a portable measurer (SPAD). To evaluate the potential of the ASM as alternative for the reduction of the severity of the severe mosaic one evaluated the number of string beans for plant and the weight of grains of plants dealt and not treated (seeds and/or aerial part) with ASM. The losses in the income had varied of 42 91 %, being that the more precocious the inoculations most drastic had been the losses, suggesting that measured of control, as the reduction of the population of the vectors must be concentrated in the initial phases of the culture. The reduction in the productivity of plants of caupi can be explained in part, for the reduction of the number of plants for parcel, therefore many plants inoculated to the 14 or 19 DAP had died in result of the infection and for the reduction of the concentration of chlorophyll that it was observed in the inoculated plants. The treatment of plants of caupi with ASM, (seed and/or aerial part), did not promote reduction of the severity of the illness nor the increase of the productivity of the plants. / Fundação de Amparo a Pesquisa do Estado de Alagoas / O cultivo do caupi (Vigna unguiculata) representa uma importante alternativa no suprimento das necessidades protéicas de pequenos agricultores na região Nordeste do Brasil. Neste trabalho foi determinado o efeito do mosaico severo, (Cowpea severe mosaic vírus - CPSMV), sobre a produção e teor de clorofila de plantas de caupi, cv. Sempre Verde em condições de inoculações controladas e avaliação do emprego do indutor de resistência Acibenzolar-S-metil (ASM) como uma opção para reduzir as perdas da cultura ocasionadas pela doença. Para análise das perdas foram conduzidos dois experimentos em distintas épocas. Nesses experimentos as plantas foram submetidas a inoculações em duas épocas diferentes, sendo a primeira aos 14 ou 19 dias e a segunda aos 29 ou 34 dias após o plantio (DAP). O efeito da doença sobre o teor de clorofila foi avaliado comparando-se a concentração de clorofila em folhas de plantas inoculadas com folhas de plantas não inoculadas, empregandose um medidor portátil (SPAD). Para avaliar o potencial do ASM como alternativa para a redução da severidade do mosaico severo avaliou-se o número de vagens por planta e o peso de grãos de plantas tratadas e não tratadas (sementes e/ou parte aérea) com ASM. As perdas no rendimento variaram de 42 a 91 %, sendo que quanto mais precoce as inoculações mais drásticas foram as perdas, sugerindo que medidas de controle, como a redução da população dos vetores devem ser concentradas nas fases iniciais da cultura. A redução na produtividade de plantas de caupi pode ser explicada em parte, pela diminuição do número de plantas por parcela, pois muitas plantas inoculadas aos 14 ou 19 DAP morreram em decorrência da infecção e pela redução da concentração de clorofila que foi observada nas plantas inoculadas. O tratamento de plantas de caupi com ASM, (semente e/ou parte aérea), não promoveu redução da severidade da doença nem o aumento da produtividade das plantas.