Abstract

This study aimed to evaluate the Aries Guineagrass (Megathyrsus maximus sin. Panicum maximum Jacq. cv. Aries) and the weed community dynamics under different soil tillage and sowing methods in Southern Brazil, to create alternatives for sustainable farming in areas where weed chemical control is restricted. The experiment was carried out in split-plot design with randomized blocks and four replications; the main plots were three tillage methods: I) conventional, II) reduced tillage with moldboard plow, and III) reduced tillage with harrow plow; and the split-plots included two sowing methods: in line, (a) with seeds placed into the drill and (b) with seeds deposited on the soil surface. Aries Guineagrass and weeds were analyzed for phytosociological parameters during the pasture establishment. Lower weed densities and relative frequencies were found where the Aries Guineagrass was established under reduced tillage with moldboard plow and seeding on the soil surface. The Guineagrass establishment was effective as verified by the high plant survival rates (>75%) in the summer following the one that the pasture was sown. The results showed that, adequate soil tillage and sowing methods can further promote Aries Guineagrass development in areas where chemical control with herbicides is not allowed.

Key words: Perennial pastures, phytosociology, tillage, weeds.