Tall Fescue and Kentucky Bluegrass Cultivars Subjected to Deficit Irrigation in the Field.

Tall fescue (Festuca arundinacea Schreb.) and Kentucky bluegrass (Poa pratensis L.) are cool-season turfgrass species widely-used throughout the transition zone for their ability to remain relatively green throughout the entire year. However during the summer as temperatures rise and drought stress increases, these species can begin to decline in turfgrass quality due to weather conditions and insufficient amounts of moisture available to the turfgrass. The use of improved cultivars that have shown superior drought stress is one tool to maintain turf quality at an acceptable quality during times of drought stress. Additionally research has observed that using evapotranspiration-based irrigation scheduling, is another method to reduce water use, while still maintaining turfgrass at an acceptable quality. The objectives of this research were to investigate visual and physiological differences between standard varieties and improved drought-tolerant cultivars of tall fescue and Kentucky bluegrass under deficit irrigation in the field. The cultivars used in this research consisted of drought tolerant and drought susceptible cultivars of tall fescue (TF) and Kentucky bluegrass (KBG). Deficit irrigation treatments replaced 80, 64, and 40% reference evapotranspiration (ET_O). While 2016 and 2017 weather conditions were not favorable for conducting drought research, the results of this research indicate that irrigating tall fescue and Kentucky bluegrass during "wet weather conditions" at 40% ET does not result in unacceptable turfgrass quality. Drough tolerant cultivars irrigated at 80% ET_O resulted in greater green turfgrass coverage (%) than drought susceptible cultivars under the same irrigation level.