VIEW ARTICLE

Techniques

Evaluation of Inoculation Techniques and Rating Dates for Fusarium Ear Rot of Opaque-2 Maize. T. J. Gulya, Jr., Former graduate research assistant, Department of Botany and Plant Pathology, Iowa State University, Ames 50011, Present address of senior author: Department of Plant Pathology, USDA-SEA-AR, North Dakota State University, Fargo 58105; C. A. Martinson(2), and P. J. Loesch, Jr.(3). (2)Associate professor, Department of Botany and Plant Pathology, Iowa State University, Ames 50011; (3)Research geneticist (deceased), U.S. Department of Agriculture, Science and Education Administration, and professor, Department of Agronomy, Iowa State University, Ames 50011. Phytopathology 70:1116-1118. Accepted for publication 19 May 1980. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1980. DOI: 10.1094/Phyto-70-1116.

Two commonly used inoculation techniques were compared for efficacy in screening resistance to maize ear rot incited by Fusarium moniliforme. Fusarium ear rot severity was greater and resistant genotypes were more easily distinguished when opaque-2 maize inbreds were inoculated by the ear-puncture method compared with the silk-spray inoculation technique. Ear rot severity, rated on a linear 1–100 scale followed by logarithmic transformation, was more efficient and statistically valid than subjective evaluation of ear rot on nonlinear scales. Ear rot development, as measured on ears incubated in moisture chambers for 3 days after collection, reached a maximum 6 wk after inoculation. Thus, evaluation of ear rot resistance may be done before normal harvest of seed in breeding lines.