Seedling Emergence, Plant Height, and Root Mass of Tall Fescue Grown in Soil Infested with Cochliobolus sativus. L. E. Trevathan, Professor of Plant Pathology, Department of Plant Pathology and Weed Science, Mississippi State University, Mississippi State 39762. . Plant Dis. 76:270-273. Accepted for publication 20 September 1991. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0270.

Plants were grown in test tube culture with Cochliobolus sativus and in the greenhouse in infested fumigated and nonfumigated soil to determine the ability of the fungus to reduce stands in tall fescue (Festuca arundinacea). Germinated seeds in pots were inoculated with conidia or were covered with soil mix containing cornmeal and sand inoculum. Fawn, Kenhy, and Kentucky 31 tall fescue seedlings developed root lesions when exposed to the fungus in test tube culture, and root elongation was inhibited up to 50%. Emergence, establishment of seedlings in pot culture, and growth of leaves and shoots were determined weekly for 4 wk. Survival of all seedlings was reduced when inoculum was applied directly to seed or incorporated into fumigated or nonfumigated soil. Plant growth and root dry weights were also reduced. C. sativus reduced stand establishment and root and leaf growth of tall fescue in the absence of foliar infection.

Keyword(s): spot blotch.