An experiment was carried out under greenhouse conditions to study the effects of soil coverage with sugarcane harvest straw residue (0, 5, 10 and 15 ton ha-1) on the emergence of six weed species (Brachiaria decumbens, Digitaria horizontalis, Sida spinosa, Ipomoea grandifolia, Ipomoea hederifolia and Ipomoea quamoclit) at the Department of Phytosanitation of Universidade Estadual Paulista, Jaboticabal-SP, Brazil. Each experimental unit consisted of one plastic pot (diameter = 21.50 cm; total volume = 4 L). 0.112 g of D. horizontalis seeds, 2.12 g of I. quamoclit and 50 seeds of the other species seeded per pot. Seedlings under the straw coverage were counted 6 and 32 days after seeding (DAS), and 30, 60 and 90 days after straw removal (DASR). Soil coverage with 5, 10 and 15 t ha-1 of sugarcane harvest straw residue inhibited the emergence of B. decumbens and S. spinosa seedlings. The same was observed for D. horizontalis submitted to coverage with 10 and 15 t ha-1 of sugarcane harvest straw residue. On the other hand, the number of I. grandifolia and I. hederifolia seedlings did not differ among the amounts of straw. Emergence of I. quamoclit seedlings increased with the presence of sugarcane harvest straw residue coverage. N expressive weed fluxes were observed after straw residue removal.
Brachiaria decumbens; Digitaria horizontalis; Sida spinosa; Ipomoea spp.; mulching
