Determining if preemergent herbicide injury on ThryvOn cotton alters management strategies

Glyphosate‐resistant Palmer amaranth ( Amaranthus Palmeri S. Wats.) caused cotton growers to increase the use of preemergence (PRE) herbicides. These herbicides can cause crop injury, which increases the susceptibility window of cotton to thrips ( Thysanoptera : Thripidae ). With the use of PREs in cotton, management strategies for ThryvOn varieties are unknown. In this study, PRE herbicides at multiple rates (none, 1x, and 2x) were evaluated for ThryvOn (Deltapine [DP] 2211 B3TXF) and non‐ThryvOn (DP 2127 B3XF) varieties with or without a foliar insecticide treatment (acephate [200 g ai ha −1 ] applied at one‐leaf stage) to determine the combined effects of herbicide injury and thrips management on the growth of ThryvOn and non‐ThryvOn cotton. Experiments were conducted in Tifton, GA, and Prattville, AL, in 2023 and 2024. Generally, herbicide injury was greater in DP 2127 B3XF and thrips injury was greater for any treatment of DP 2127 B3XF than any DP 2211 B3TXF treatment. Herbicide injury early in the season did not increase thrips injury in ThryvOn cotton. Plant heights, total nodes, shoot fresh biomass, and lint yield were only impacted by cultivar. Although one cultivar had ThrvyOn and the other did not, differences cannot be attributed to the trait alone as the two varieties evaluated were not isolines. Fruit retention and cutout date were not significantly different. Therefore, these results indicate agronomic management should not generally differ between ThryvOn and non‐ThryvOn cotton.