VIEW ARTICLE

Disease Detection and Losses

Evaluating a Crop Loss Model for Head Smut of Sorghum. D. M. Tuleen, Former research associate, Department of Plant Sciences, Texas A&M University, College Station 77843; R. A. Frederiksen, professor, Department of Plant Sciences, Texas A&M University, College Station 77843. Phytopathology 72:1278-1280. Accepted for publication 24 March 1982. Copyright 1982 The American Phytopathological Society. DOI: 10.1094/Phyto-72-1278.

A model simulating grain sorghum yields relative to the incidence of head smut was evaluated. Grain sorghum hybrids were inoculated in the seedling stage with Sphacelotheca reiliana by the hypodermic injection technique in four field trials at three locations in Texas. Percentages of infection were determined at anthesis; grain crop yields were calculated in grams per panicle and kilograms per hectare. The percentage of grain yield loss relative to uninoculated plots was directly proportional to the percentage of plants with smutted or phylloid panicles with regression coefficients from 0.84 to 1.09 and R² from 0.39 to 0.80.