Standing Crop and Vigor of Defoliated Russian Wildrye in Southeastern Colorado

Abstract

Russian wildrye plants were clipped at all possible combinations of three clipping dates (April 15, May 15, June 15) at two intensities (35 and 65% harvest of current year's growth). From 1974-1977 increasing frequency and intensity of defoliations increased total biomass removed over the 4-year period. There was no trend for reduced yield over time with any clipping treatment. However, percent plant crown alive (1976-1978) and end-of-season standing crop (1978) both indicated that increasing frequency and/or intensity of defoliation decreased plant vigor.