Efficacy of nuclear polyhedrosis virus with adjuvants as high volume and ultra low volume applications againstHeliothis armigeraHbn. on chickpea

Abstract

Abstract Heliothis armigera Hbn. is a major pest on chickpea Cicer arietinum L. causing serious damage to foliage, flowers and seeds. Field studies during 1985–86 have shown that the nuclear polyhedrosis virus (NPV) applied at the rate of 250 LE (1·5 x 1012 POB/ha) four times gave effective control of the pest and was comparable with the control achieved by endosulfan at 350 g a.i./ha by high volume application (500 litres spray fluid/ha). ULV application of NPV in 20% crude sugar (12·5 litres spray fluid/ha) was as effective as high volume application at the same dose of 250 LE/ha. Application of NPV 250 LE + endosulfan 175 g a.i./ha high volume gave the best results recording 1·58 larvae/20 plants, 4·2% leaf damage, 6·9% pod damage and 1159 kg grains/ha as against 3·75 larvae/20 plants, 4·9% leaf damage, 12·5% pod damage and 925 kg/ha of grain in NPV high volume treatment. The untreated check recorded 20·75 larvae/ 20 plants, 18·0% leaf damage, 26·4% pod damage and 590 kg grain/ha. The different adjuvants tested in the high volume application of NPV viz. crude sugar 0·5%, peanut oil cake 1%, chickpea flour 1 % or a combination of these did not improve the efficacy of the virus in the two field experiments.