COMPARISON OF WASHED AND UNWASHED PLANT-TISSUE SAMPLES UTILIZED TO MONITOR THE NUTRIENT STATUS OF CREEPING BENTGRASS PUTTING GREENS

Plant tissue analysis can be utilized by golf course superintendents t o monitor a fertility program and to determine the nutrient status of turfgrass. The objectives of this study were to compare washed and unw ashed plant tissue samples and to assess the nutrient status of golf c ourse putting greens of creeping bentgrass (Agrostis palustris Huds. ' Penncross'). Turfgrass clippings were collected monthly from 18 puttin g greens from January through June, 1993. A portion of each sample was washed with deionized water, while the remainder of the sample was no t washed. Plant tissue was dried at 70-degrees-C for 72 hr at which ti me dry weights were determined. Samples of both washed and unwashed pl ant tissue were analyzed for both macro- and micronutrient composition . There were differences between the washed and unwashed tissue sample s for macro- and micronutrients for certain months. The range in conce ntration for the unwashed samples for a given nutrient in a given mont h was generally greater than the range in values for the washed sample of the given nutrient. This indicates the possibility of soil contami nation from cultural practices and/or course player use for the unwash ed samples. Nutrient analyses of the washed plant tissue samples gave a more consistent and reliable status of the nutrient content of creep ing bentgrass on the greens.