Storing cowpea (Vigna unguiculata) seeds in active cattle kraals for suppression of Callosobruchus maculates

Abstract

Post-harvest seed damage of cowpeas (Vigna unguiculata) by cowpea weevils (Callosobruchus maculates) is increasingly becoming a threat to food security among marginal communities. Effects of storing cowpea seeds in active cattle kraals (ACK) as an alternative to pesticide for suppression of C. maculates and improving seed quality were studied in three marginal communities of South Africa. A set of 500 seeds in 10 containers were infested with 20 C. maculates and inserted in 30-cm-deep holes within the ACK, while similar containers served as controls at the farmer level. At 120 days, relative to controls, ACK had reduced the final weevil population density by 76 to 82%, floating seeds by 86 to 98% and damaged sunken seeds by 36 to 53%, but increased undamaged sunken seeds by 358 to 572%. The treatment increased seedling emergence by 14 to 32%. In conclusion, suppression of weevil numbers and improvement of seed quality suggested that ACK may serve as alternative to pesticides in storage of cowpea seeds for planting in marginal communities and therefore, ensuring continued food security of this important crop.

Keywords: Active cattle kraal, Callosobruchus maculates, seed quality, Vigna unguiculata