Creeping bentgrass (CBG; Agrostis stolonifera) and annual bluegrass (ABG; Poa annua) are two golf course putting green species that are sensitive to drought and traffic stress. A two-year field study evaluated the effects of irrigation treatments [8, 12, and 16% volumetric water content (VWC)] and traffic stress (none, low, and moderate) on CBG and ABG putting green plots. Leaf relative water content (RWC), leaf electrolyte leakage (EL), canopy chlorophyll content, normalized difference vegetative index (NDVI), root biomass, ethylene production, ABG invasion into CBG, quantity of water leached and soil VWC from plots were measured. A 12% irrigation treatment was determined to be optimal when compared to 8% (deficit) and 16% (excessive) when measuring leachate volumes and soil VWC. Moderate traffic treatments decreased turfgrass quality and increased ABG invasion into CBG plots. However, CBG had significantly higher turfgrass quality (through measuring RWC, EL, NDVI and chlorophyll content) than ABG under irrigation and traffic treatments. Ethylene gas production increased at the 8 and 16% irrigation treatment and increased in response to traffic treatments on ABG. The method of quantifying ethylene gas production in this study may be a practical technique to detect turfgrass stress incidence from putting green canopies. A more in depth analysis of ethylene gas production under other abiotic stress conditions may be necessary to investigate the role of ethylene gas within CBG and ABG.
Read
