Effect of Potash Application on Incidence of Bollworms in Bt Cotton Hybrid

Investigations on “Effect of potash application on incidence of bollworms in Bt cotton hybrid” were carried out at the Main Cotton Research Station, Surat during Kharif 2018-19 with twelve treatment combinations comprising three levels of potash (K2O) applications (0, 40 and 80 kg ha-1) as main treatments and two levels of potash mobilizing bacteria (KMB) @0 and 2.5 lit ha-1 and two levels of foliar sprays of potassium nitrate (KNO3) @0 and 3% at squaring, flowering and boll development as sub treatments under ETL based interventions in split plot design with three replications.The main treatment sub treatment and interactiion effect on bollworm were discussed.The treatment combination viz., K2O application @80 kg ha-1 along with the application of potash mobilizing bacteria (KMB) @2.5 litre ha-1 as basal application at 15 days after sowing and foliar sprays of potassium nitrate (KNO3) @3% during squaring (60DAS), flowering (75DAS) and boll development stages (90DAS) on G. Cot. Hy. 8 BG II recorded highest seed cotton yield (2777 kg ha-1), provided effective management of bollworms requiring one spray against pink bollworm affording good protection against ABW and SBW.