Issue No. 18, Article 5/July 22, 2005
Northern Corn Leaf Blight--Will It Be Common in Illinois Again This Season?
As was reported in Illinois and a number of other states in the Corn Belt in 2004, northern corn leaf blight (NCLB) may be an increasing problem. A few fields in Illinois were reported with significant levels of this disease in 2003, and many more fields seemed to be affected in 2004. Now in 2005, Matt Montgomery has reported NCLB in Sangamon County. Corn foliar diseases can only be expected to increase now as the crop canopy has filled in and rain has fallen recently in many parts of the state.
The reasons for the increased incidence of NCLB in recent years are not entirely clear, but the weather, hybrid susceptibility, and presence and virulence of the pathogen may all have played some part. One thing is clear--there are differences in susceptibility and resistance among hybrids. Because NCLB seems to be increasing and there should be plenty of the residue-borne inoculum in many fields from 2004, the disease should be considered when scouting cornfields. Take note of which hybrids have significant levels of NCLB.
More information on NCLB and a picture of its symptoms can be found at http://cropdisease.cropsci.uiuc.edu/corn/.--Dean Malvick