Effects of Variety and Spatial Arrangement on Pest Incidence, Damage and Subsequent Yield of Cowpea in a Cowpea/Maize Intercrop

A field experiment was carried out to investigate the effects of variety and spatial arrangement on pest incidence, damage and subsequent yield of cowpea in a cowpea/maize intercrop. Two varieties of cowpea (Tvu 13076 and Ife brown) and two spatial arrangements (2:3 maize/ cowpea & 1:1maize/ cowpea intercrops) were investigated. There was Lower population density of Maruca vitrata among the 1:1 and 2:3 maize/cowpea intercrops compared with the population of Megalurothrips sjostedti. were observed on Ife brown was infested by a higher number of M. sjostedti and M. vitrata than Tvu 13076. Ife brown had higher number of beetles infesting its leaves than Tvu 13076 at the first and fourth weeks but was not significant. The incidence and damage caused by Ootheca mutabilis on the 2:3maize/ cowpea intercrop were not significantly higher than on the 1:1maize/ cowpea intercrop. Ife brown produced significantly higher seed yield (93.62a) than Tvu13076 (64.53b) while 2:3 maize/cowpea intercrop gave significantly higher seed yield (129.43a) than 1:1 maize/ cowpea intercrop (32.72b). Consideration of planting pattern in intercropping appears to be a determinant factor for leaf infestation by this beetle. Intercropping may not necessarily reduce pest load in any given situation it depends on the crop and the pest in question.