Photosynthetic Rate and Root Growth Responses to Ascophyllum nodosum Extract–based Biostimulant in Creeping Bentgrass under Heat and Drought Stress

Creeping bentgrass ( Agrostis stolonifera ) experiences quality decline during summer in the United States transition zone and warmer regions. Various bioproducts have been used to improve creeping performance mitigate effects of stress zone. This 2-year study was carried out examine if foliar application seaweed extract (SWE; Ascophyllum nodosum )-based biostimulant Utilize ® could enhance nitrate reductase (NaR) activity, root viability under heat drought conditions. The sprayed biweekly on foliage at 0, 29, 58, 87, 116 µL⋅m −2 , with volume 815 L⋅ha . Two weeks after first application, plants were exposed (35/25 °C, day/night) (40% 50% evapotranspiration replacement) conditions for 42 days an environment-controlled growth chamber. In general, abiotic caused turf reduction. Foliar increased quality, leaf color ratings, chlorophyll, carotenoid content, net photosynthetic rate (Pn). NaR activity by 26.5%, 16.3%, respectively, when compared control. biomass, length, surface area (SA), 58 87 improved 16.3% 30.9%, Our data indicate that SWE-based improves nitrogen (N) metabolism viability. treatment can be considered effective approach improving stress.