Evaluation of Simulated Late Season Tarnished Plant Bug Damage on Cotton Yield in ThryvOn and non-ThryvOn Cotton Technology

A split-split plot experiment was conducted in Stoneville, MS in 2022 and 2023 to establish more precise insect termination timing to reduce insecticide applications for tarnished plant bug during late bloom in cotton. The main-plot factor was cotton technology that included non-ThryvOn and ThryvOn cotton. The subplot factor was removal timing. In each year, manual removal of squares took place during the fourth or fifth week of bloom. The sub-subplot factor was level of square removal consisting of 0, 50, and 100% above the uppermost first position white flower. To understand plant growth, maturity measurements were taken beginning at the first week of bloom until defoliation. These measurements included plant height, total node counts, nodes above white flower, and nodes above cracked boll. Cotton yield was also recorded. Results from 2022 and 2023 showed differences in plant maturity when 100% square removal was done during the fourth week of bloom. Due to differences among varieties, ThryvOn cotton had greater yields than non-ThryvOn cotton. These data combined with previous research suggest that insecticide termination could occur after the fourth week of bloom without significant yield loss.