Seaweed Extract-based Biostimulant Impacts on Nitrate Reductase Activity and Root Viability of Ultradwarf Bermudagrass Subjected to Heat and Drought Stress

Bermudagrass is a warm-season turfgrass species widely used for sports fields, home lawns, and golf courses. Ultradwarf bermudagrass has been course greens, but its quality declines with abiotic stresses. This 2-year study was designed to investigate if foliar applications of seaweed extract-based biostimulant Utilize® could improve ultradwarf photosynthetic function, nitrate reductase activity, root growth, function while under heat stress drought conditions. applied canopy at 0, 88, 117, 175, 234 μL⋅m −2 . Two weeks after the initial application Utilize®, subjected (40/36 °C, day/night) (40–50% evapotranspiration replacement) up 42 days. Heat caused decline turf quality. Foliar biweekly consistently improved leaf color ratings increased chlorophyll carotenoid concentrations, net rate, growth viability. On average, by 9.1%, 12.1%, 10.6%, respectively, rates 32.4%, 45.0%, 35.0%, activity 16.7%, 18.8%, 14.6%, compared control. biomass, length, surface area, volume viability 46.2%, 73.1%, 88.5%, 74.4%, relative The results this suggest that improves nitrogen metabolism, between 117 175 can be considered an effective approach improving performance environments.