Management of rice leaf folder (Cnaphalocrosis medinalis Guen.) through INM with emphasis on use of Neem and Karanj cake

An experiment was conducted for two consecutive years, 2012 and 2013 in wet season in the agro-ecological conditions of Jharkhand with the sole objective for management of leaf folder (Cnaphalocrosis medinalis Guen.) through use of organic and inorganic form of plant nutrients and their appropriate and balanced combinations in the right quantity with more emphasis on application of neem and karanj cake. The overall results revealed that neem cake @ 2.5 t ha⁻¹ proved to the most effective in minimizing the incidence of rice leaf folder and karanj cake remained at par. As such, the minimum incidence of the pest interval of leaf damage due to leaf folder (LDLF) 10⁻¹ hills (or plants) was obtained through sole use of neem cake @ 2.5 t ha⁻¹ and the efficacy of karanj cake @ 2.5 t ha⁻¹ remained at almost at par, resulting in as low as 6.36 LDLF 10⁻¹ hills (i.e. plants) of rice followed by neem and karanj cake kept as separate treatment @ 0.5 and 1.0 t ha⁻¹, which in turn remained at par in themselves, in reducing the incidence of the pest. The maximum incidence of leaf folder (24.18 LDLF 10⁻¹ hills) on rice plants receiving the sole use of N @ 80 kg ha⁻¹ (through urea) was registered as against significantly of recommended dose of fertilizer, RDF (N, P, K @ 80, 40, 20 kg ha⁻¹) in inorganic form, which was further lowered down up to the lower level of the pest incidence of 15.66 LDLF 10⁻¹ plants through use of reduction in RDF upto 50 per cent, but supplemented with green manure, @ 10 t ha⁻¹ in the form of Sesbania rostrata L. (dhaincha). The results indicated that sole use of neem cake @ 2.5 t ha⁻¹ realized the maximum grains yield of rice (41.50 q ha⁻¹) which, in turn remained at par with sole use of karanj cake @ 2.5 t ha⁻¹ (38.60 q ha⁻¹) followed by neem cake @ 1.0 t ha⁻¹ plus N, P, K @ 26, 40, 20 kg ha⁻¹ in inorganic form (37.40 q ha⁻¹), karanj cake @1.0 t ha⁻¹ plus N, P, K @ 40, 40, 20 kg ha⁻¹ in the form of inorganic source (36.60 q ha⁻¹); neem cake @ 0.5 t ha⁻¹ + NPK @ 53, 40, 20 kg ha⁻¹ (through chemical fertilizers (35.90 q ha⁻¹). The sole use of nitrogen @ 80 kg ha⁻¹ applied to the plantsthroughurea receivedthemaximum incidenceof thepest(Cnaphalocrosis medinalis Guen.) resultinginsubstantially lower grains yield of rice (22.40 q ha⁻¹).