Abundance, infestation and disease transmission by thrips on groundnut as influenced by climatic variability at Kadiri, Andhra Pradesh

Abstract

Ab undance, infestation and d isease tran sm ission by thrips studied on g ro und nu t at Kadiri o fAnantapur (Andhra Pradesh) over six kharif seasons of 2011-16 indicated sign ificantly high er abundanceof thrips in 2016 over 2 011 to 2015 with infestations on par among 2013, 201 4 and 2016 and higher overother seaso ns. Pean ut bud necrosis disease ( PB ND ) transmission by thrip s was significantly lower in2015 and 2016 and higher in 2014. Associations of abu nd ance of thrips with infestation and PBND weresignificant. Signif ic an t inf lu en ce of P BND by the t hrips infe station of only t he curr en t w ee k impli edsignificance o f c o ncu rren t p o pu la tion in diseas e tra nsmiss io n. Signific ant p osit ive effect of minim umte mpe rature on in cid enc e of P B ND a n d ne g ativ e effe c t of r ainf a ll on thrips infes tatio n wer enoted .Prediction s of thrip s abun da nc e, infestation and PBN D through m ultiple linear regression (MLR)models revealed pos itive influence of minimu m temperatu re lagged by a week. Distribution of rainfal lover it s amount assoc iated with th rip s infestatio n besides negative role of w ind with PBND was noted.Prediction models of P BN D incid ence combin ing weather and thrips abundance ( R2:0. 39 ) and weatherand inf estatio n (R2:0 . 53 ) sh ow ed tha t the PBND incidence was d ep en den t on relative hum id ity andprevalent wind over previous two weeks in addition to thrips abundance or infestation