-5- 



Its symptoms are similar to those of southern com leaf blight. In its early stages, 

 yellow leaf blight produces symptoms that resemble those of nitrogen deficiency, es- 

 pecially on the lower leaves. Close examination, however, shows that the chlorosis 

 is caused by a large number of individual elongated yellow spots. The spots, 1/4 to 

 1/2 inch long, are elliptical to oval and have tan to cream-colored centers. You can 

 expect the disease to move to the upper leaves and the leaves of more susceptible va- 

 rieties and inbreds to die. Aerial application of Dithane M-45 has been recommended 

 as a control by Wisconsin plant pathologists although its effectiveness has varied 

 somewhat. 



This weekly report was prepared as follows: 



INSECTS: H.B. Petty, Steve Moore, Hosooe Randell, Don Kuhlman, and Stephen Sturgeon, 

 University of Illinois College of Agriculture, Urb ana-Champaign, and Illinois Natural 

 History Survey. 



WEEDS: E.L. Knake and M.D. MoGlamery, Department of Agronomy. 



DISEASES: E.E. Burns, Department of Plant Pathology . 



AG COMMUNICATIONS : Del Dahl. 



The information for this report was gathered by these people, staff members, county 

 Extension advisers, and others, in cooperation with the USDA Agricultural Research 

 Service, Plant Pest Control Branch. 



