The h.v. (312 litre/ha) sprays were applied by using a manually‐operated knapsack sprayer. The l.v. (31 litre/ha) and u.l.v. (undiluted) sprays were applied by using a motorized‐knapsack sprayer. The h.v. (e.c.) and the u.l.v. (l.v.c.) treatments were at par, and gave better performances than the l.v. (e.c.) treatment, on the basis of rosetted flowers, infestation of green bolls, shed fruiting‐bodies, harvested bolls and loculi, and population of bollworms in the shed material and seed‐cotton. The least effective treatment was that of the u.l.v. (e.c). The highest yield of 1408–1563 kg/ha of seed‐cotton was also obtained in the h.v. and the u.l.v. (l.v.c.) treatments, compared to 1363 kg/ha in the l.v., and 1211 kg/ha in the u.l.v. (e.c), treatments.