Damage and yield loss estimate in maize varieties owing to stem borer (Chilo partellus Swinhoe) infestation and insecticidal control

Stem borer (Chilo partellus Swinhoe) is one of the most damaging and yield reducing pest in maize. Field experiments were organized to assess extent damage loss due infestation stem maize following two factors randomized complete block design with three replications at National Maize Research Program, Rampur, Chitwan, Nepal, during consecutive spring seasons 2020 2021. varieties; Rampur Hybrid (RH)-8, RH-10, RH-12 (CAH-1715), RH-14 (RML-86/RML-96), RH-16 (RML-95/RML-96), TX-369, Arun-2, ZM-401, ZM-627 Composite used as a test variety (First factor) whereas control conditions (spray non-spray) was considered second factor experiments. The sprayed plots (protected plots) kept completely free from by using application standard dose insecticide (spinosad 45% [email protected]/L) 10 days interval non spray (unprotected selected for natural borers. Standard agronomical practices such time planting, row spacing, seed rate, irrigation, weeding fertilizer doses adopted raise crop. Among tested varieties Arun-2 found susceptible attack both experimental years resulted higher % dead hearts (6.04%), no exit hole (4.72), foliage before tasseling stage (12.17%) tunnel length (4.62cm). Quantitative increased increase borer's infestation. ranged 25 different borer. Highest quantified open pollinated varieties, ZM-401(44.61%) followed (41.39%) (41.22%). Spraying enabled recently introduced hybrid produce more be less vulnerable damage.