Relationship Between Anthracnose Leaf Blight and Losses in Grain Yield of Sorghum. M. E. K. Ali, Graduate Research Assistant, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907. H. L. Warren, and R. X. Latin. Professor of Plant Pathology and Research Plant Pathologist, ARS, USDA, and Assistant Professor, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907. Plant Dis. 71:803-806. Accepted for publication 10 April 1987. 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, 1987. DOI: 10.1094/PD-71-0803.

In a 2-yr field study, the relationship between anthracnose leaf blight (ALB) severity index and losses in grain yield of three sorghum lines inoculated with nine isolates of Colletotrichum graminicola was determined. Highly significant (P < 0.01) positive correlations between percent loss in grain yield and ALB severity index occurred in 1984 and 1985 and for the pooled data of both years, with correlation coefficients of 0.86, 0.84, and 0.85, respectively. Correlations between percent loss in 100-seed weight and ALB severity also were highly significant (P < 0.01) for the individual and pooled data of both years. The highly significant (P < 0.01) positive correlations between percent loss in grain yield and percent loss in 100-seed weight indicate that ALB reduces grain yield of sorghum largely by decreasing seed weight.

Keyword(s): Sorghum bicolor.