In a screen cage study, the pattern of flower and pod development at the various flowering nodes of three cowpea varieties with known susceptibility to the pod-borer Maruca testulalis, was mapped out. The period of flower opening over the whole plant spanned an average of 13 days in TVu946, 17 days in ICV-2 and 18 days in Vita-1 with 85–100° of the pods retained to maturity coming from flowers opening within 8 days of anthesis. The efficiency of pod production from open flowers was highest in TVu 946 (54°), lowest in Vita-1 (11°) and median in ICV-2 (31°). However, as a consequence of the individual pod size, the overall pod and seed characteristics in decreasing order were Vita-1, ICV-2 and TVu 946. The bulk of flowers and pods on the plants were produced at the basal plant nodes where primary branches were developed.
Pod elongation and enlargement were initially rapid in all varieties, but the TVu 946 pods reached physiological maturity 2 days before the other two varieties. The eventual pod size and rate of pod growth appear to be important factors in the susceptibility of cowpea to the pod-borer attack.
