Fungal occurrence, disease incidence and severity, and yield of maize symptomatic for seedling disease in Mississippi

A study was conducted in Mississippi from 1995 to 1997 comparing soil rhizo sphere fungi isolated from Pioneer 3167 hybrid maize (Zea mays L.) planted on Brooksville silty clay and Memphis silt loam soils. Maize seedlings were collected over four sampling dates from conventional and no-tillage plots. Eleven fungal genera consisting of nineteen species were isolated from the se plants; Trichoderma spp. were most frequently isolated, followed by Fusa rium spp. The highest disease incidence occurred in tilled plots of the lat est planting date on Brooksville silty clay when samples were collected 17 days after planting. Root disease was most severe in 1996 from seedlings pl anted on the last planting date in tilled plots sampled 17 days after plant ing. Yields were significantly (P less than or equal to 0.05) higher on Bro oksville silty clay soil than on Memphis silt loam in both 1995 and 1996. Y ields were highest from no-tillage plots and from maize planted on the earl iest date. There was a significant correlation between incidence of root in fection and disease severity. There was no correlation between the incidenc e of root infection and yield or between disease severity and yield at eith er location.