Field grain losses and insect pest management practices in subsistence agriculture: Farmers' perceptions

Abstract

A farm survey was conducted in subsistence farming communities to document the major grain crops, insect pests, indigenous pest control methods (PCM) and farmer perceptions of grain losses associated with identifiable pest species and perceived efficacies of the PCMs. Maize, beans and sorghum were identified as the major staple food crops, with the major pests being cutworm, stem borers, aphids, beanfly, pod borers, armyworms and termites. Statistical analyses revealed that the level of crop yield losses was dependent upon the area cropped, total yield and respondents' background. There was, however, a negative correlation between crop yield loss due to insect pests and the efficacy of PCM applied. Farmers lost, on average, 24.75% of their crop to insect pests with high value crops suffering the greatest insect pest attack in terms of species diversity and magnitude of damage incurred. The occurrence of field insect pests varied from season to season with most species reportedly occurring during the long rains. Most (72.6%) farmers never applied any PCM against all the insect pests of food crops. The use of synthetic pesticides and alternatives accounted for less than 10%. Seventy one percent of the respondents crops, with the major pests being cutworm, stem borers, aphids, beanfly, pod borers, armyworms and termites. Statistical analyses revealed that the level of crop yield losses was dependent upon the area cropped, total yield and respondents' background. There was, however, a negative correlation between crop yield loss due to insect pests and the efficacy of PCM applied. Farmers lost, on average, 24.75% of their crop to insect pests with high value crops suffering the greatest insect pest attack in terms of species diversity and magnitude of damage incurred. The occurrence of field insect pests varied from season to season with most species reportedly occurring during the long rains. Most (72.6%) farmers never applied any PCM against all the insect pests of food crops. The use of synthetic pesticides and alternatives accounted for less than 10%. Seventy one percent of the respondents reported that the efficacy of the PCMs applied was unknown. Some of the indigenous PCMs reportedly used included crude powders and aqueous extracts of local botanical plants such as Tobacco, Tephrosia, and Basil. The study recommends that bioassay-guided investigations be instituted to develop and rationalise the use of identified PCM strategies compatible with the target user domains. Keywords : Farmer perceptions yield loss, indigenous pest control Journal of Agriculture, Science and Technology Vol. 8 (1) 2006: pp. 24-42