Suitability and Efficacy of Ground Corncobs as a Carrier of Fusarium solani Spores. W. E. Batson, Professors, Department of Plant Pathology and Weed Science, Mississippi State University, Mississippi State 39762. L. E. Trevathan, Professors, Department of Plant Pathology and Weed Science, Mississippi State University, Mississippi State 39762. Plant Dis. 72:222-225. Accepted for publication 5 October 1987. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0222.

Ground corncobs were tested as a carrier of spores of Fusarium solani for application in pathology investigations. Particles were infested with suspensions of F. solani spores ranging in concentration from 0 to 2.0 × 10⁵ spores per milliliter. The total number of particles developing colonies (CFU) was determined for infested material stored for various periods by incubating on potato-dextrose agar for 4 days. In material stored at 4 C, CFU numbers declined through 16 wk. More than one spore per square centimeter of particle surface was required to obtain a CFU efficiency ?90%. Scanning electron micrographs confirmed that spores were located in protected areas on the particles and that spores stored on corncob particles over time were similar in appearance to freshly harvested spores. F. solani caused significant reductions in emergence of cotton and increased root discoloration of surviving seedlings when spores carried on ground corncob material were used to infest soil at temperatures of 16, 20, and 24 C in root zone chambers. The fungus was recovered from 81% of root systems of surviving seedlings at 16 C and from 100% at 20 and 24 C.