Influence of cowpea genotype and millet-cropping system on cowpea damage by thrip and aphid pests in the Sudan Savannah of Nigeria
A study was carried out to investigate the effect of cowpea genotype and row arrangement on aphids and thrips infestation on cowpea intercropped with millet during the 1999 and 2000 cropping seasons at Minjibir in the Sudan savanna zone of Nigeria (lat. 12008’ N long. 8032’ E,
500m above sea level). Treatments consisted of six genotypes made up of one local Danila and five improved (IT90K-277-2, IT95K-1090-3, IT96D-740, IT96D-757 and IT96D-772) and four row arrangements (1M:1C, 2M:2C, 1M:2C, and 2M:4C, reflecting millet to cowpea rows). These were laid down in a split plot design with three replications. Cowpea genotype had significant effect on number of days to 50% flowering. In 1999, IT90K-277-2 and IT95K-1091-3 had significantly shorter days to 50% flowering than the other genotypes. Number of days to maturity, aphids and thrips damage on cowpea was significantly affected by cowpea genotype, where IT90K-277-2 and IT95K-1091-3 attain maturity significantly earlier than the other genotypes in both seasons. In 2000, IT90K-277-2 had the least thrips damage compared to the other cowpea genotypes while Danila recorded the highest damage. On row arrangement, plants at 1M:1C row arrangement took significantly longer days to attain 50% flowering compared to 2M: 2C, 1M: 2C and 2M: 4C row arrangements. The results indicated that IT90K-277-2 recorded the highest yield and had some tolerance for aphids and thrips, and could be recommended to farmers in the Sudan Savanna of Nigeria.