Crop loss assessment of cowpea due to damage by Cydia ptychora Meyrick.
ABSTRACT: Caged experiments indicated that a population level of 6 mated females of C. ptychora per
12 plants could cause a seed damage of about 33070 resulting in a significant loss in seed weight (P< 0.01) of about 21 %. There were highly significant correlations between the numbers of infesting females and seed damage and between the numbers of infesting females
and loss in seed weight. The relationship between seed damage and loss in seed weight was curvilinear and showed that 10% seed damage would result in about 5.0% weight loss in seed. This is equivalent to a loss of 50kg ha-1 based on an average yield of 1000kg ha-1 obtainable under improved management practices.