Sweet potato weevils (Cylas puncticollis and C. formicarius) are notorious pests of sweet potato and cause severe losses in marketable yield. The study tested the use of Beauveria bassiana ((Balsamo) Vuillemin) (Deuteromycota: Hyphomycetes) for controlling sweet potato weevils. An experiment was conducted using four treatments: 1) dipping sweet potato cuttings in solution of 1 g/litre B. bassiana before planting, 2) spraying with the registered chemical Deltametrin at 50ml/100litre every 2 weeks for four months after planting, 3) spraying the leaves every 2 weeks with B. bassiana (10 g/100 litre) for four months after planting; and 4) a control (sprayed with distilled water). The experimental design was a Latin square with split plot design: pest management strategy as main plot factor and cultivars (Bophelo, Ndou and Blesbok) as subplot factors. Spraying with B. bassiana significantly reduced the percentage of insect damaged roots (5.31%) compared to the control (13.75%). Dipping did not significantly reduce the number of insect damaged roots (12.13%). There was no significant difference between the chemical spray (5.88% insect damage) and spraying with B. bassiana (5.31% insect damage). The preliminary investigation indicated that B. bassiana can be considered as an alternative control method for the sweet potato weevil.

No abstract

Pineapple (Ananas comusus) production generates hard currency and, as a labor-intensive industry, it creates jobs. The profitability of pineapple farming in South Africa faces several challenges, including low yield potential and cadmium (Cd) contamination of soils, which damaged the reputation of the industry. To increase the income of pineapple farmers, research was conducted to evaluate the utilization of pineapple crop residue for oyster mushroom (Pleurotus ostreatus) production and to establish the Cd levels in the mushrooms produced on Cd-contaminated pineapple crop residue. Treatments were maize residue (M), pineapple residue (P), and a mixture of maize and pineapple residues [at 1:1 ratio (on a dry weight basis), M + P]. Biological efficiencies of 90%, 77.6%, and 29% were recorded for the M + P, P, and M treatments, respectively. The P and M + P substrates significantly increased mushroom yield. Mushroom protein contents were 23.3%, 18.86%, and 18.81% (on a dry weight basis) in the M + P, P, and M treatments, respectively. Mushrooms in the P substrate had the highest Cd level (3.3 mg/kg). In the M + P substrate, Cd reduced to a safe level (0.15 mg/kg). This indicates that mushrooms have biosorption capacity, and could be used to solve the problem of Cd pollution and increase the income of pineapple production.

Collective operation of smallholder farmers and cooperatives has been attributed to many mishaps and malfunctions. Such knowledge creates misperceptions regarding agricultural cooperatives and their usefulness in development. This study investigated member commitment, group cohesion and membership retention in agricultural production cooperatives. The main aim was to identify possible practical measures for enhanced performance and increased sustainability in farmer organizations. Data was collected from 92 participants that were currently operating as cooperative members. A combination of descriptive statistics, Perceived Cohesion (PC) and Binary Logistic Regression methods were employed for analysis. Results of the study indicate that group cohesion is influenced by trust among members, internal communication, financial performance of the cooperative, involvement of members in decision making, and role of the organization in the community. Strategies for increased group cohesion that were recommended in the study include information sharing and transparency at all levels of operation, and collective decision making and planning in organizations.

Sweet potatoes present an opportunity for improving food security and income generation in South Africa. The yield of sweet potatoes is highly dependent on the quality of sweet vines used in production. This study aimed at identifying the most cost effective and best storage bag type, between polyethylene and hessian bags, to prolong vine storage. Three bag treatments namely polyethylene bag without holes, polyethylene bag with 12 holes and dry hessian with vines from sweet potato cultivar "Bophelo" were stored for 3, 6, 9, 12 and 15 days at ambient temperature during summer. The costs effectiveness of using different types of bags when transporting and storing vines was calculated using the incremental cost-effectiveness ratio (ICER). The results of the study showed that hessian bags offer the best option to prolong storage (12 days) as compared to polyethylene bags (6 days), however hessian bags are more expensive (R49.10/1 day quality) ($4.08 as at 24/01/2018). Polyethylene bags can be used if the farmer is not willing to pay the additional cost for an addition day of quality. Holes need to be made in polyethylene bags in order to allow air circulation.