EFFECTS OF RYEGRASS AND FORAGE BLACK OATS CULTIVATION ON ROOT DISEASES AND YIELD OF WHEAT

During five seasons (1985 to 1989), the effects of several cultivation systems with ryegrass (Lolium multiflorum) and with black oats (Avena strigosa) for forage were evaluated in the National Center for Resear ch on Wheat (EMBRAPA), Passe Fundo, RS, for root disease intensity and grain yield of wheat (Triticum aestivum). The treatments consisted of the following cultivation systems for wheat: 1) monoculture of wheat; 2) rotation of a winter crop with wheat and two with ryegrass; 3) rot ation of a winter cereal with wheat and two with black oats; 4) rotati on of a winter crop with wheat and three with black oats. The wheat wi th two consecutive winter crops with ryegrass showed, in absolute valu es, a higher percentage of root disease intensity and less grain yield . For the parameters studied, this treatment had a worse performance t han wheat in monoculture.