Seasonal Variation in Cowpea Crop Performance at Ile-Ife, Nigeria and the Relationship to Insect Damage
The trends in flowering, podding and seed yield of four cowpea varieties planted at different times of the growing season in 1975 and 1976, were studied along with the associated pest activity. Flowering, podding and seed yield were found to decrease over the season from April to September irrespective of whether the crop was protected against insect pests or not. However, there seemed to be two peak periods of pest activity—April to July and October to December—when severe damage to the crop occurred in unprotected plots. Planting in June or July usually led to an escape from several major pests even though the cool night temperatures and incidence of overcasts at that period seem to preclude optimal reproductive performance of the crop.
The pattern of insect pest succession on the crop over the season is discussed and it is suggested that for small farm holders in Southern Nigeria, who are unlikely to apply insecticides, planting in June is advisable.
Key WordsSeasonal variation cowpea Vigna unguiculata cowpea pests Maruca testulalis Cydia ptychora
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