Seasonal Incidence of Early Shoot Borer, Chilo infuscatellus (Snellen), in Autumn, Spring and Ratoon Planted Sugarcane (Saccharum officinarum L.), with a Proposed Framework for Chemical Management
Indrajeet Jaiswal *
Department of Entomology, College of Agriculture, ANDUAT, Kumarganj, Ayodhya, Uttar Pradesh, India.
R. C. Sharma
Department of Entomology, ANDUAT, Ayodhya, India.
Shailendra Singh
SMS Plant Protection, KVK, Belipar, Gorakhpur, India.
Chandresh Kumar Chaudhary
Department of Entomology, ANDUAT, Ayodhya, India.
*Author to whom correspondence should be addressed.
Abstract
Sugarcane productivity is substantially constrained by early shoot borer, Chilo infuscatellus (Snellen), making an understanding of its seasonal incidence essential for timely and effective pest management. A field study was conducted at Dobhiara village in the vicinity of N.D. University of Agriculture & Technology, Kumarganj, Faizabad, Uttar Pradesh, to record the seasonal incidence of early shoot borer, Chilo infuscatellus (Snellen), on autumn-planted sugarcane (2011–12) and spring-planted and ratoon sugarcane (2012–13), cv. CoS 8436. Shoot borer infestation was recorded fortnightly on 20 randomly tagged plants in three farmers' fields (autumn and spring crops) and at one agronomy farm plus three farmers' fields (ratoon crop). Infestation first appeared during the 7th–9th standard week (SW), built up steadily and peaked during the 18th–19th SW, reaching a maximum of 27.22 per cent in the autumn-planted crop, 20.55–21.66 per cent in the spring-planted crop and 15.83 per cent in the ratoon crop, before declining to nil by the 26th–28th SW. The overall mean infestation across the crop season was 11.29 ± 2.02, 10.52 ± 1.78 and 6.13 ± 1.29 per cent (mean ± standard error of the mean, SEm) in autumn, spring and ratoon crops, respectively, indicating that the autumn-planted crop was most susceptible and the ratoon crop least susceptible to the pest. An insecticidal evaluation trial comprising eight treatments — cartap hydrochloride 4G, fipronil 0.3G, fenpropathrin 30% EC, quinalphos 25% EC, chlorpyriphos 20 EC, chlorantraniliprole (Coragen) 20 SC, neem oil 2% and an untreated control — was laid out in a Randomised Block Design with three replications, to be applied at the economic threshold level (>10% infestation), as a proposed framework for the future economic management of the pest; treatment-wise bio-efficacy, yield and cost-benefit outcomes are not yet available and are therefore not reported as results here. The seasonal-incidence findings provide a week-wise infestation calendar that can guide the timing of insecticide application in this agro-climatic zone once the management trial is completed.
Keywords: Sugarcane, chilo infuscatellus, early shoot borer, seasonal incidence, standard meteorological week, dead heart, autumn planting, spring planting, ratoon crop, economic threshold level