Growth regulators and mowing heights enhance the morphological and physiological performance of Seaspray turfgrass during drought conditions

With the unusually prolonged drought that results from climate change, increasing the ability of plants to resist drought become a necessity. The objectives of this study were to investigate the effects of two plant growth regulators [(trinexapac-ethyl (TE) and abscisic acid (ABA)], three mowing heights (MH) (25, 35 and 45 mm), and four irrigation levels of 30, 50, 70, and 100 % of the daily evapotranspiration (ET) on the turf performance of seashore paspalum [Paspalum vaginatum (Swartz)] grown in PVC container under greenhouse conditions. After 10 weeks of water regimes and MHs initiation, the application of TE/ABA increased turf quality (TQ), leaf photochemical efficiency (Fv/Fm), maximum root length (MRL) and dry weight (RDW), total nonstructural carbohydrates (TNC), and Ca and K contents but reduced ET under drought conditions. Increasing MH increased TQ, ET, Fv/Fm, MRL, RDW, TNC, and proline as well as leaves K and Ca under drought conditions. The co-application of TE/ABA and higher MH will significantly alleviate the negative effects of drought and maintain acceptable quality in Seaspray at 50 % ET. Osmotic adjustment, the accumulation of carbohydrates and protective effects of TE/ABA on photosynthetic efficiency play a major role in drought resistance in ‘Seaspray’.