Bermudagrass quality affected by irrigation level, fertilization, a soil surfactant, and trinexapac‐ethyl

Abstract Limited information is available on the effect of fertility and chemical management under drought conditions. A study investigated the effects of the plant growth regulator trinexapac‐ethyl (TE; applied at 1.6 L ha −1 month −1 ) and the soil surfactant Revolution® (applied at 20 L ha −1 month −1 ) on Princess 77 bermudagrass ( Cynodon dactylon L. Pers). The experiment included two reference evapotranspiration replacement levels (ET o ) of 45% and 75% combined with a 2 × 2 factorial of N (23 and 45 kg N ha −1 month −1 and Fe (0 and 2 kg Fe ha −1 month −1 ) fertility levels. At 75% ET o , turfgrass quality remained above acceptable levels (6.7), with the lowest quality observed in control plots receiving low N without iron. Normalized difference vegetation index (NDVI) was higher at 75% ET o , but plots receiving TE with high N and no iron and irrigated at 45% ET o had NDVI values similar to plots irrigated at 75% ET o . Under drought conditions (45% ET o ), 14 out of 16 treatment combinations maintained acceptable turfgrass quality, except for the control with low N and iron (5.7) and Revolution® with high N but no iron (5.4). Overall, the results suggest that TE plus/or ad soil surfactants may improve turfgrass quality and NDVI under drought conditions.