Influence of insect pest control and tillage practice in corn varieties on the occurrence of asiatic corn borer

A field experiment was conducted to evaluate the influence of pest control and tillage practice in hybrid and open-pollinated corn varieties at different growth stages on the occurrence of Asiatic corn borer (ACB) (OstriniafurnacalisGuenee) Pyralidaeand to assess its damage; and to determine the influence of pest control, tillage practice and varieties onpredator population.The experiment was laid out in Split-split plot in Randomized Complete Block Design (RCBD) with three replications. The three factors were: Main Treatment (A) – pest control (P1- with insecticide and P2- without insecticide); Sub treatment (B) – tillage practice (T1- zero tillage and T2- conventional tillage and Sub-sub treatment (C) – variety (V1- P30D44, V2- NK-8840, V3- Improved Silangan(IS) (check variety) and V4- IES CN5.Based from the results obtained, the treated plots and the hybrid NK-8840 had lower ACB larvaeand ACB eggmasspopulation. ThehybridNK-8840also had the lowest tunnel count in the ears shank. Overall plant damage was lowest in NK-8840 and IES CN5 whether subjected with pest control or not and under zero tillage or conventional tillage. All test varieties had a rating scale of 1.0 both in leaf injury and overall plant damage which means that they had no obvious damage or injury on leaves at 60 days after planting (DAP); and they had slight leaf injury and little or no damage on stem at 90 DAP. The Coccinellid beetle (HarmoniaoctomaculataFabricius) Coccinellidae was the only predator observed.