Effects of Northern Leaf Blight and Detasseling on Yields and Yield Components of Corn Inbreds. Kira L. Bowen, Former Graduate Research Assistant, Department of Plant Pathology, University of Illinois. W. L. Pedersen, Associate Professor, Department of Plant Pathology, University of Illinois, Urbana 61801. Plant Dis. 72:952-956. Accepted for publication 18 May 1988. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0952.

Variation in yield of three corn inbreds infected with Exserohilum turcicum, the causal agent of northern corn leaf blight, was best explained by the area under the disease progress curve, whereas variation in number of kernels per plant and in 200 kernel weight was best explained by leaf blight severity assessed just after completion of flowering and at physiologic maturity, respectively. Higher disease severities were correlated with decreased seed size, although disease and seed size were not correlated with seed germinability. Yields were lowered 10% by detasseling by cutting and 1% by detasseling by pulling. The detrimental effects of detasseling and northern leaf blight on yields were additive.