First Report of Phoma terrestris Causing Red Root Rot on Sweet Corn (Zea mays) in North Carolina

作者：S. R. Koenning, Jason W. Frye, J. K. Pataky, Martin Gibbs, David Cotton · 发表于：Plant Disease · 年份：2007 · DOI：10.1094/pdis-91-8-1054c · 被引用次数：11 · 研究领域：Plant Pathogens and Fungal Diseases、Plant Pathogens and Resistance、Plant Disease Resistance and Genetics

Red root rot, caused by Phoma terrestris E. M. Hansen, caused premature senescence and yield reductions to fresh-market sweet corn in Hyde County, North Carolina in July 2006. Foliar symptoms developed over a period of 5 to 8 days approximately 1 to 2 weeks after anthesis and included desiccation of leaves and poor development of ears. By 3 weeks after pollination, when the sweet corn was harvested, crowns and the first aboveground internode of affected plants were rotted and reddish colored, but roots appeared normal. The root mass of affected plants tended to be greater than that of unaffected plants. Incidence of symptomatic plants was greater than 30% in some fields and was lower on crops planted and harvested early. Symptomatic and asymptomatic plants were adjacent in affected fields. Diseased plants were more common in fields of sweet corn that followed soybean (Glycine max) or a double-crop of onions (Allium cepa) than in fields that followed corn. Incidence of symptomatic plants also differed among adjacent plantings of different sweet corn hybrids. Hybrids '173A', '182A', '378a', and 'XTH1178' had a high incidence of symptomatic plants and '372A', '278A', '8101', and '8102' were less affected. Samples of symptomatic plants of the hybrid '182A' were examined at the North Carolina Plant Disease and Insect Clinic during August. Olivaceous black pycnidia with long setae around the ostioles were imbedded in the stalk near the first node aboveground. Numerous conidia (1.8 ...