Plant maturity and yield responses of selected cotton varieties (NuCOTN 33^B and Stoneville 474) were measured after 7 levels (0, 2.5, 5, 10, 20, 40, and 80%) of simulated bollworm, Helicoverpa zea (Boddie), damage were applied during each of the first 4 weeks of flowering in 1997. Each treatment was independent so that plots were only damaged one time. The oldest bolls on plants within each plot were selected and tagged to receive each level of injury. At the end of the season, crop maturity based on percent open bolls and seedcotton weights were recorded.