Susceptibility of different life stages of Callosobruchus maculatus and Callosobruchus chinensis to ECO2FUME gas and its impact on cowpea seeds quality

ECO2FUME gas is an alternative to toxic phosphine fumigant and as a quarantine treatment for the control of a particularly recalcitrant pest, Callosobruchus maculatus and Callosobruchus chinensis. This gas was used to fumigate stored cowpea piles under gas-proof sheets to assess its performance against different developmental stages of Callosobruchus maculatus and Callosobruchus chinensis. The mortality was determined on four developmental stages of C. maculatus and C. chinensis, employing ECO2FUME at different concentrations 25, 30, 40, and 50 g/m3 for 3-days. All stages of both insect species in packed cowpea stacks were completely controlled at 3-days when applied with an ECO2FUME application rate of 50 g/m3. Cases of pupae of C. maculatus and C. chinensis exhibit the highest resistance than other stages, with 78.2 and 73.93% mortality respectively, at 40 g/m3 after 3-days post-exposure to ECO2FUME. Suppression of F1 generation was obtained after fumigation with the same concentration (50 g/m3). Quality (in terms of cowpea germination) and all chemical constituents of cowpea seeds were non significantly (P≤0.05) affected by the fumigation concentration of 50 g/m3.

Sepia 200cH at 1:1000 dilution ameliorates salt stress in cowpea seedlings but its medium 90% ethanol proves ineffective at the same dilution

Soil salinity severely affects crop yield all over the world. In a recent study we observed that Natrum mur 200cH, a homeopathic remedy, improved growth in germinating cowpea seeds. In the present study we have tested another remedy Sepia, which is complementary to Natrum mur, on cowpea seedlings under salt stress. Cowpea seedlings grown over moist filter paper in petridishes were divided into 4 groups: (1) control in sterile water, (2) in 50mM NaCl solution, (3) seeds pretreated with 90% ethanol diluted with water 1:100 and then transferred to 50mM NaCl solution, (4) seeds pretreated with Sepia 200cH diluted with water 1:100 and transferred to 50mM NaCl solution. In another experiment the groups were same, but the dilution of 90% ethanol and Sepia 200cH was 1:1000 instead of 1:100. The purpose was to further reduce the ethanol content in both the drug and its vehicle 90% ethanol, so that the alcohol effect is minimized or abolished. The data were analysed by ANOVA followed by t-test. Sepia 200cH at both 1:100 and 1:1000 dilutions significantly increased growth, sugar, chlorophyll, protein and water content in seedlings as compared to the untreated salt-stressed group. The effect with the1000th dilution of Sepia 200cH was more pronounced than with its 100th dilution. The vehicle 90% ethanol at 1:100 dilution produced some positive effect on the seedlings, but the 1000th dilution of the vehicle produced no such effect. It is, therefore, concluded that Sepia 200cH could ameliorate salt stress in cowpea seedlings and that the 1000th dilution is more effective than its 100th dilution. The alcohol effect is totally eliminated with the 1000th dilution of 90% ethanol. Thus the 1000th dilution could retain the drug effect and eliminate the vehicle effect.

Poly(vinyl alcohol)-based Electrospun Nanofibers: Characterization and Phytase Immobilization

The aim of this study is to immobilization phytase obtained from cowpea seeds into nanofiber-based on poly(vinyl alcohol) (PVA) and to investigate kinetic properties, optimal pH, and temperature of free and immobilized phytase. The structural analysis and morphological properties of the nanofibers are carried out via SEM and XRD. The results indicated that enzyme stability, pH, and thermal stability are increased after immobilizing phytase into the nanofiber. The optimum pH and temperature of the free and immobilized phytase are found as pH 5.0 and 45-65 oC, respectively. These results indicated that the immobilized phytase could be a good candidate for agriculture, animal feed, food, and medical applications.

Ethnobotanical Study of Cowpea (Vigna Unguiculata (L.) Walp.) in Senegal

Cowpea (Vigna unguiculata) plays a key role in family farming systems in Senegal. It makes an essential contribution to economic, nutritional and food security. Although it is crucial, little is known about how farmers classify the diversity of local varieties or about the social practices associated with them. The aim of this study is to characterize the farming practices associated with growing cowpea in Senegal. Surveys were conducted involving 335 rural farmers living in 37 villages, spread across seven regions that produce cowpea. An average of ten farmers were randomly selected in each village. The results reveal that cowpea is a key feature of cropping systems in the studied area. Our findings highlight the high diversity of local cowpea varieties with 59 local names inventoried. In 75% of cases, the name refers to the seed’s morphology or color. Cowpea production is more diverse in Diourbel and Louga and less diverse in the south. More than half the farmers (57%) acquired their cowpea seeds (early, semi-early and late varieties) outside their village, either from markets, seed suppliers or NGOs. This new understanding of farmers’ expertise in the management of cowpea and its local variability will help to valorise local diversity in breeding programmes.

Susceptibility of different life stages of Callosobruchus maculatus and Callosobruchus chinensis to ECO2FUME gas and its impact on cowpea seeds quality

ECO2FUME® phosphine fumigant was used to fumigate stored cowpea piles under gas-proof sheets to assess its performance against different developmental stages of Callosobruchus maculatus and Callosobruchus chinensis. The mortality was determined on four developmental stages of C. maculatus and C. chinensis, employing ECO2FUME at different concentrations 25, 30, 40, and 50 g/m3 (2% PH3 and 98% CO2 by weight) for 3-days. All stages of both insect species in packed cowpea stacks were completely controlled at 3-days when applied with an ECO2FUME application rate of 50 g/m3. Cases of pupae of C. maculatus and C. chinensis exhibit the highest resistance than other stages, with 78.2 and 73.93% mortality respectively, at 40 g/m3 after 3-days post-exposure to ECO2FUME. Suppression of F1 generation was obtained after fumigation with the same concentration (50 g/m3). Quality (in terms of cowpea germination) and all chemical constituents of cowpea seeds were non significantly (P ≤ 0.05) affected by the fumigation concentration of 50 g/m3.

Optimization of Infrared Heating Conditions for Precooked Cowpea Production Using Response Surface Methodology

The infrared heating of preconditioned cowpea improves its utilization and potential application in food systems. This study investigated the effect of optimizing preconditioning and infrared heating parameters of temperature and time on cooking characteristics of precooked cowpeas using response surface methodology (RSM). The moisture level (32–57%), infrared heating temperature (114–185 °C), and time of processing the seeds (2–18 min) were optimized using a randomized central composite design to achieve optimal characteristics for bulk density and water absorption. A second-order polynomial regression model was fitted to the obtained data, and the fitted model was used to compute the multi-response optimum processing conditions, which were the moisture of 45%, the heating temperature of 185 °C, and time of 5 min. Precooked cowpea seeds from optimized conditions had a 19% increase in pectin solubility. The total phenolic and total flavonoid contents were significantly reduced through complexation of the seeds’ phenolic compounds with other macromolecules but nonetheless exhibited antioxidant properties capable of scavenging free radicals. There was also a significant reduction in phytate and oxalates by 24% and 42%, respectively, which was due to the heat causing the inactivation of these antinutrients. The obtained optimized conditions are adequate in the production of precooked cowpea seeds with improved quality.

INFLUENCE OF ASH ON THE MORTALITY OF ADULTS OF BRUCHIDIUS ATROLINEATUS PIC. (COLEOPTERA-BRUCHINAE), IMPORTANT PEST OF COWPEA (VIGNA UNGUICULATA WALP.) IN SAHELIAN ZONE

Bruchidius atrolineatus (pic) (Ba) is one of the most dangerous pests seeds of cowpea (Vigna unguiculata L. Walp). The infestation begins in the fields of crops and continues in stocks where damage can be considerable in the absence of any protective measure. The importance of these damage justifies the development of appropriate, less expensive and easily applicable peasant struggles. A recommended ash test for the traditional cowpea storage was evaluated on the mortality of Bruchidius atrolineatus (PIC) in the laboratory. During this study, several experiments relating to the influence of Ash on adults of B. atrolineatus were carried out. A negative witness has been made for each case. The treatments have been made according to gender and adults. Ash is a substance that seems to be very effective with respect to B. atrolineatus because has significantly reduced its population. Treatment due to the effect of ash has recorded a mortality rate of 85% on the first day. Then treatments with variations due to the increase in the amount of ash, insects and seeds have induced a respective mortality rate of 31.5%, 43.5%, 93.75% and 100% 62.5%, 33.16%, 30%, 24% and 17.04% and 62.5%, 43.75%, 52.5% and 50% on the 1st after treatment. It is apparent from our study that the female seems to be more resistant than males in almost all treatments. This study showed that the ash could constitute an alternative to the use of chemical insecticides in the conservation of cowpea seeds in the Sahelian zone.