STUDIES ON BIOLOGICAL-CONTROL OF PIGEONPEA POD BORERS IN INDIA

Results of two field experiments, one on SA 1 pigeonpea in rainfed and the other on Co.5 pigeonpea in irrigated conditions revealed that Bac illus thuringiensis var. kurstaki (B.t.k.) (Delfin), its combinations with nuclear polyhedrosis virus of Heliothis armigera and Chrysoperla carnea were as effective as endosulfan in reducing the pod borers, Hel iothis armigera and Exelastis atomosa. However, B.t.k. 1.25 kg + endos ulfan 175 g/ha or B.t.k. 2.5 kg + HaNPV 250 LE/ha gave better control of damage to flowers and pods than B.t.k. applied alone on SA 1 pigeon pea. The yield differences between these treatments were not significa nt. A combination of HaNPV 250 LE/ha + endosulfan 175 g/ha was superio r to B.t.k. Similar trend was seen on Co.5 pigeonpea. Release of C. ca rnea second instar larvae 1 lakh/ha was not effective in increasing th e yield of pigeonpea.