Grazing Management of Flaccidgrass Pastures in Autumn

Abstract

Carostan' flaccidgrass {Pennisetum flaccidumGriseb.) is a perennial warm-season grass with potential for pasture, but appropriate autumn (September to November) management is needed to maintain forage mass (FM) production and prevent declines in plant density. We evaluated 10 treatments over 3 yr consisting of an ungrazed control, four treatments with multiple grazing events (MG), four treatments with a single grazing event (SG), and one treatment grazed after frost. The winter residues after the treatments were greatest (P < 0.01) when ungrazed compared with the grazed treatments (3347 vs. 2265 kg ha"'') and differed (P < 0.01) among and between (P < 0.01) the MG and SG treatments. Plant density decreased from 13 to 27% with 8 to 10 wk of regrowth before frost. Greater plant density decline (60%) occurred when plots were grazed three times and only allowed 4 wk of regrowth before frost. Total nonstructural carbohydrates (TNC) of ungrazed basal stems, crowns, and roots sampled in December were 158, 193, and 250 g kg-\ respectively, and when grazed were 124, 183, and 253 g kg-\ respectively. By April TNC had declined 56, 35, and 25%, respectively. Plant density was not related to autumn total FM, FM regrowth, or overwintering residue but was related (P < 0.02) to TNC of December roots (r = 0.59) and TNC of April basal stems (r = 0.42), crowns (r = 0.61), and roots (r = 0.66). Allowing 6 wk of regrowth before frost minimized plant density losses for flaccidgrass.