An evaluation was performed on the saprophytic survival of Stenocarpella macrospora and S. maydis in corn (Zea mays) debris, under no-till cropped corn in commercial fields in the Planalto Médio of Rio Grande do Sul, during the 1998 and 2000 growing seasonsThe presence of infected corn residue at sowing time was shown to ensure the presence and viability of Stenocarpella spp. In the 1995 growing season corn residue decomposed 78.5% of its weight under the no-till system after 29 months of field exposure. In 1998, it was shown that decomposition of corn residue segments infected by S. maydis and S. macrospora, kept at the soil surface, was slower than when buried. In spite of the fact that the frequency of pycnidia of S. maydis and S. macrospora decreased over time its presence was detected for up to 320 days in corn stalks kept at the soil surface. Isolations and conidia viability of S. maydis and S. macrospora in stalks kept at the soil surface were higher than 90% after 320 days in the field. Data showed that when corn is cultivated under the no-till system, the presence of infected residue ensures the presence and viability of S. maydis and S. macrospora.
