Monday, November 5, 2007 - 8:50 AM
72-5

Evaluation of Remote Sensing to Measure Plant Stress in Creeping Bentgrass (Agrostis stolonifera L.) Fairways.

Aaron R. Johnsen, University of Minnesota, 1970 Folwell Ave., 305 Alderman Hall, St. Paul, MN 55108, Brian Horgan, 254 Alderman Hall, 1970 Folwell Avenue, University of Minnesota, University of Minnesota, Department of Horticultural Science, St. Paul, MN 55108, and Van Cline, Toro Company, The Toro Co., 8111 Lyndale Ave. S, Minneapolis, MN 55420.

Water availability is a concern in turfgrass around the world, not only in regions prone to drought.  Therefore, turfgrass irrigation strategies must be more clearly defined to promote water conservation.  Water conservation may be achieved with technology such as remote sensing.  Objectives of this research were to (i) determine if remote sensing can detect plant stress in creeping bentgrass under irrigation and nitrogen stress prior to visual observation, (ii) correlate reflectance measurements from turfgrass under irrigation and nitrogen stress with time domain reflectometry and visual ratings, and (iii) categorize turfgrass reflectance measurements to direct turfgrass irrigation practices.  Research was conducted in the 2006 and 2007 growing season on 3 m2 creeping bentgrass plots maintained under fairway conditions.  Treatments included irrigation at 20, 40, 60, and 80 percent of potential evapotranspiration every 3-d on plots fertilized with 97.65 and 244.12 kg N ha-1.  Currently data is being analyzed and results will be presented.