Farmer-participatory evaluation of cowpea integrated pest management (IPM) technologies in Eastern Uganda

Abstract

A three-season study was conducted with the goal of verifying integrated pest management (IPM) technologies developed at Makerere University for management of cowpea field pests. Ten IPM-field schools with 10–20 farmers were run for three consecutive seasons of 2000 A (first rains), 2000 B (second rains), and 2001 A. Each school evaluated seven treatments that included farmers’ practices; cowpea monoculture and cowpea/sorghum intercrop mixtures, and five varying insecticide spray regimes. The key insect pests targeted by the sprays included aphids, Aphis craccivora Koch, flower thrips, Megalurothrips sjostedi Trybom, the legume pod borer, Maruca vitrata Fabricius (formerly M. testularis Geyer), and a range of pod sucking bugs (i.e., Nezera viridula Linnaeus, Clavigralla tomentosicollis Stal., Riptortus dentipes Fab.). The experiment was a randomized complete block design with farms (i.e., field schools) as replicates. Results indicated that combining cultural practices and spraying once each at budding, flowering, and podding stages was more effective and profitable than spraying cowpea weekly throughout the growing season. An IPM practice which combined early planting, close spacing cowpea (30×20 cm 2), and three insecticide applications once each at budding, flowering and podding stages, had the highest yields of 791 kg/ha with a 51% yield gain over the farmers’ traditional practices. Farmer evaluation over the three seasons revealed that this practice was most preferred by farmers, with a farmer preference of 46.4%, 57.1%, 71.4%, and 89.3% at planting, vegetative, flowering and harvesting evaluation stages, respectively.