Simulation of economic injury levels for leaf folder (Cnaphalocrocis medinalis Guenee) on rice (Oryza sativa L.)

Abstract

Leaf folder incidence on rice (Pusa Sugandha 3) was 1.2-20.5% folded leaves with highest infestation between 45-55 days after transplanting (DAT). Two spray applications with endosulfan 35 EC at 50 and 70 DAT were found optimum for preventing yield loss (26%) due to pest. Leaf folder damage was calibrated and validated through a generic crop growth model, InfoCrop. Validated model was used for simulating economic injury levels (EILs) of the pest. Simulated EIL was found to be 9, 11 and 12% folded leaves at 50 DAT and 12, 15 and 14% at 70 DAT during 2003, 2004 and 2005, respectively. Simulation models could account for changes in weather, inputs and crop-pest interactions, and therefore, could be potential tools for formulating site specific EILs for pests.