Monday, November 5, 2007
75-5

How Well Do Cool-Season Turfgrasses Survive Extended Dormancy without Rainfall?.

Paul Johnson1, Adam Van Dyke1, and Landon Bunderson2. (1) 4820 Old Main Hill, Utah State University, Department of Plants, Soils and Climate, 322 Agric. Sciences Hall, Logan, UT 84322-4820, (2) Biograss Sod, Inc, 9980 S. State St., Sandy, UT 84070

Extended droughts in the western US have resulted in water restrictions being put on landscape irrigation. In severe cases, watering has been banned completely due to shortages. In the event of such water restrictions, turfgrasses often enter summer dormancy and can survive for significant periods of time without water. However, the extremely dry and very warm conditions in the West often exceed the drought tolerance of the grasses even when dormant. Our research is studying both species and variety differences in a number of cool-season turfgrasses. Specifically we are evaluating how long selected turfgrasses can survive without irrigation, variety differences among bluegrasses, and whether small amounts of water can be applied to keep the grasses alive but maintain summer dormancy. We have identified bluegrasses as most tolerant of extremely dry conditions, but with significant varietal differences. Perennial ryegrasses lose significant stands after several weeks as does prairie junegrass. If able to root deeply, tall fescue has tolerated extended drought well.