A New Corn Disease Caused by Longidorus breviannulatus in the Midwest. R. B. Malek, Associate Professor of Nematology, Department of Plant Pathology, University of Illinois, Urbana 61801. D. C. Norton, Professor, Department of Plant Pathology, Seed and Weed Sciences, Iowa State University, Ames 50011; B. J. Jacobsen, Associate Professor and Extension Specialist in Plant Pathology, and Nelia Acosta, Former Graduate Student, Department of Plant Pathology, University of Illinois, Urbana 61801. Plant Dis. 64:1110-1113. Copyright 1980 American Phytopathological Society. DOI: 10.1094/PD-64-1110.

Longidorus breviannulatus can cause severe stunting, chlorosis, and occasional mortality of corn in irregular patches in sandy soils during the first 6-8 wk after planting. Later, damaged plants may become as tall as unaffected ones, but stalks remain slender, and if formed, ears are much reduced in size. Root symptoms include yellow discoloration, slightly swollen root tips, stubby-root, pruning of laterals, and scarcity of small feeder roots. When soil moisture is high, seminal roots are destroyed and brushlike crown roots proliferate near the soil surface. The prop root system is unaffected. The disease has been found in Illinois, Iowa, and Indiana and is most severe on soils containing more than 90% sand.

Keyword(s): ecology, pathogenicity, Zea mays.