Determination of Economic Threshold for Cotton Bollworms (Earias spp. and Heliothis armigera Hb.) on Hybrid-4 Cotton
N. B. Rote
Corresponding author
B. K. Patel, N. P. Mehta and A. H. Shah
Abstract
An experiment to find out economic threshold levels based on larval units was conducted during the years 1978-79, 1979-80, and 1980-81 at Main Cotton Research Station, Surat. Four different threshold levels, viz., 5, 10, 15, and 20 larval units for spotted bollworms (Earias spp.) and 3, 7, 12, and 15 larval units for American bollworms (Helicoverpa armigera Hb.), were tested in comparison to the recommended schedule for Hybrid-4 cotton. From the results, it was found that the threshold level of 10 larval units was the most ideal and economical for spotted bollworms on Hybrid-4 cotton.