Effects of mechanical and chemical management of black oat on maize grown in succession and on alexandergrass control

The objective of this experiment was to evaluate the effects of mechanical and chemical management of oat straw and of sowing dates of maize after oat desiccation on maize grain yield and on alexandergrass (Brachiaria plantag inea Link) infestation. In 1997/98, treatments were composed by two mechani cal management systems of oat (rolled or not) and bare area as the control, by two herbicides (glyphosate and paraquat) applied to desiccate oat straw and by two maize sowing dates after desiccation (one and 15 days). In the 1998/99 growing season, five management systems of oat straw (rolled, clear ed and desiccated with glyphosate, glufosinate and paraquat) and a bare are a used as check were tested. Delay of maize sowing date in 15 days after oa t straw desiccation increased N accumulation, dry matter production per pla nt and grain yield of maize. Maize grain yield in succession to oat was not influenced by management system of oat straw. Rolling oat straw provided t he best control of alexandergrass infestation.