Yield Loss in Sorghum Caused by Sorghum Shoot fly and Maize Stalk Borer at Bako

Abstract

A study was conducted for three years (1992-94) to determine the magnitude of grain yield losses caused by sorghum shoot fly (SSF), Atherigona soccata, and maize stalk borer (MSB), Busseola fusca, in sorghum at Bako. A range of planting time (April to June) were used to obtain different gradients of infestation. Each planting time was replicated four times in a randomized complete block design. Paired plant methods were used to estimate the loss. Variations in the level of SSF and MSB infestation were observed between the different planting times in all seasons. Infestation by SSF ranged from 1 to 36% and that by MSB from 5 to 64%, depending on the season, and time o f planting, the highest being in sorghum planted in June in all seasons. Similarly, yield reduction by SSF varied from 1 to 33% while due to MSB from 2 to 27%, depending on the season, planting time and level of infestation. The yield reduction was proportional to the level o f infestation and the association was highly significant (r=0.9962, P < 0.001) for SSF and (r=0.815, P < 0.001) for MSB.