Northern Corn Leaf Blight in Sweet Corn
Julie Kikkert, Team Leader, Extension Vegetable Specialist
Cornell Vegetable Program
![Northern Corn Leaf Blight in Sweet Corn](https://rvpadmin.cce.cornell.edu/images/submission/image393.jpg)
The fungus Exerohilum turcicum that causes NCLB survives as spores or mycelia on corn debris over the winter. The inoculum can be splashed onto the current corn crop or can arrive by wind. The spores can be moved long distances by wind. Early infections come from within the field and are more damaging. As the season progresses and the numbers of spores in the air increases, all fields become susceptible. Infection is favored by leaf wetness and cool weather (64-81 F) as typically occurs later in the growing season.
Lesions of NCLB begin as grayish green and become tan as they mature. The slender oblong shape, with tapered ends, gives them a cigar or boat-shaped appearance. Lesions range from 1 to 6 inches in length and may coalesce to cover the entire leaf. Spores are produced on the underside of the leaves, and appear as dusty green fuzz.
Resistant varieties and cultural practices to reduce inoculum and disease risk are the best practices. Fields should be scouted whorl through tassel. There is a scouting video for field corn developed by the NYS IPM Program (see list of resources below). Several fungicides are labeled and a listing can be found in the Cornell Vegetable Guidelines.
ADDITIONAL RESOURCES
NYS IPM Scouting video:
Cornell NCLB fact sheet includes lists of fungicides and their relative effectiveness. Note: check labels for sweet corn.
Vegetable MD Online, Sweet Corn Diseases
![more crops](images/more_crops_left_sm.gif)
![more crops](images/more_crops_right_sm,.gif)
Upcoming Events
Niagara Region Vegetable Meeting
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August 14, 2024
Clarence Center, NY
We'll start this meeting off at Root Down Farm to hear late season disease management updates in peppers and cole crops, plus current best management practices to limit fungicide resistance. Potato variety recommendations and disease control questions in potatoes will be addressed.
Then we'll head to Kreher's beet field to view and discuss alternative weed control technologies. The beet field is an on-farm demonstration of various flame weeding protocols in comparison with stacked tool cultivation equipment. One or two weeding robots will be on-hand for live demonstrations and discussion of the technology's current abilities and future potential. We'll also cover industry updates and a review of late summer disease management in squash.
2.0 DEC credits will be available in categories 23, 1a, and 10.
2024 Chipping Potato Twilight Meeting
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August 20, 2024
Dansville, NY
Join us for a brief, on-farm meeting including insect pest updates and viewing of the chipping potato variety trial. 1.0 DEC credits in categories 10, 1a, and 23 will be offered. Dinner follows!