A 60 acre cotton field was divided into 6 equally sized plots for a two treatment, three replication test to compare the effectiveness of insecticidal sprays applied with ground driven equipment during daylight hours and during the hours of darkness. Multiple (three) insecticide applications were made during July and August to determine the effectiveness of Karate 1 E.C. at 0.03 lb. A.I./Acre plus Lannate 2.4 E.C. at 0.25 lb. A.I./Acre against the bollworm (BW) Helicoverpa zea (Boddie), and tobacco budworm (TBW), Heliothis virescens (F.) complex. The field was located in Morehouse parish in Northeast Louisiana. The plots were sampled 10 hours after treatment for TBW moths by randomly selecting 4 locations in each plot and counting dead or dying TBW moths in 25 feet of row. Larvae infestations were recorded 3 days after treatment by checking 100 squares and 100 terminals per plot. Both the day and night applications had the same efficacy ratings for larvae infestations. Plots sprayed at night had higher TBW moth mortality than day applications.

Although the results are from a single year, the data indicates that cotton insecticides can be efficaciously applied during daylight hours as well as during the hours of darkness. This will allow greater utilization of ground driven equipment while maintaining equally effective control.