VIEW ARTICLE

Ecology and Epidemiology

Effect of Moisture and Temperature on Development of Septoria tritici Blotch in Wheat. Dale E. Hess, Graduate research assistant, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907; Gregory Shaner, Professor, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907. Phytopathology 77:215-219. Accepted for publication 8 July 1986. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/Phyto-77-215.

Septoria tritici blotch, caused by Mycosphaerella graminicola, is a major disease of wheat in many parts of the world. The effects of temperature (11, 18, and 25 C) and wetness duration (24, 48, 72, and 96 hr) on Septoria tritici blotch development were examined by inoculating four wheat cultivars that differ in susceptibility to M. graminicola. There was a positive correlation between increase in postinoculation moisture and postinfection temperature and disease severity. Percent necrosis on the susceptible cultivar Morocco and moderately susceptible cultivars Beau and Arthur was influenced more by change in temperature and moisture treatments than was percent necrosis on the resistant cultivar Auburn. For cultivars Morocco and Arthur, percent necrosis and pycnidial density increased with increase in temperature. For cultivars Beau and Auburn, temperature and percent necrosis were positively correlated but pycnidial densities increased only for the high temperature treatment. Necrotic leaf tissue, pycnidial volume and density, and spore production in the resistant cultivar Auburn were reduced in comparison with the susceptible cultivars.