Field efficacy of granular insecticides against rice gundhi bug and yellow stem borer

Four solid formulations of insecticides viz., carbofuran, phorate, cartap hydrochloride @ 1kg.a.i./ha and chlorpyriphos @ 0.5kg.a.i./ha along with the check, liquid formulation of monocrotophos @ 0.5 kg a.i./ha were evaluated against gundhi bug and yellow stem borer (YSB) during wet season 2009 and 2010. Results of 2009 revealed that carbofuran treatment recorded lowest per cent dead heart (DH) (6.6%), white ear head (WEH) (3.6%), gundhi bug damage (7.7%) and highest grain yield of 3.2 t/ha in variety Jaya followed by the treatment phorate, cartap hydrochloride, chlorpyriphos and monocrotophos. In control, YSB damage was high i.e. 9.8% DH, 5.8% WEH, gundhibug damage 13.6% and the grain yield was 2.0 t/ha. The results of 2010 revealed that the same carbofuran treatment recorded lowest per cent of DH (4.1%), WEH (4.6%), gundhibug damage (12.7%) and highest grain yield of 5.2 t/ha followed by the treatment phorate, cartap hydrochloride, chlorpyriphos and monocrotophos. In control, YSB damage was high i.e. 9.8% DH, 8.9% WEH, gundhibug damage 18.9% and the grain yield was 3.6 t/ha. All the tested insecticides significantly reduced YSB and gundhi bug damage and increased grain yield over control.