On the degree of weed infestation in a pasture of Panicum Maximum Jacq

[摘要] A pasture of Guineagrass (Panicum maximum Jacq.) submitted to continuous grazing and periodic clearing revealed, after six years from its planting, a high degree of weed infestation. Bahiagrass (Paspalum notatum Flügge) exhibited a frequency of 85% and a relative dry epigeous biomass of 20,9%. Dicotyledons as a whole exhibited a frequency of 95% and a relative biomass of 38,7%. On the other hand, Guineagrass, although with a frequency of 95%, exhibited a relative biomass of only 32,2% equivalen t to a decrea se of 67,8%. This great floristic and vegetational change may be ascribed to mechanical selective action of the scythe and to grazing selection and zoochorous dissemination of Bahiagrass by cattle.

[学科分类] 农业科学（综合）

[关键词] Weeds;Pastures;Panicum maximum Jacq.;Paspalum notatum Flügge;Competition.