Question: Several of my neighbors applied fungicide to their corn after tassel last year. They didn’t find that it raised yield, but it did raise moisture levels. Is this a common outcome of using fungicides? Is there any response benefit to spraying fungicide on corn at V5?
Answer: A common effect from corn fungicide is a healthier, greener plant. This stay green and plant-health effect result in high moisture levels early in the harvest season, and this is a common outcome. The yield response will vary depending on several things: genetics/hybrid, crop rotation and environment. For example, some corn hybrids have more natural defensive characteristics and don’t respond as much to corn fungicides. We have plot data that shows anywhere from a zero response to greater than a 50 bu/a response. Again, the genetics and environment play a big role. Corn-on-corn rotations typically have greater disease issues than rotated corn following soybeans. Remember that the environment each year will be different, whether it’s hot and dry or cool and humid, etc. 2010 was the first year we evaluated the V5 fungicide application on irrigated plots in southern Michigan. The response to applying fungicide on irrigated V5 corn ranged from a low of 1.0 bu/a to a high of 11.8 b/ac increase, again depending on hybrid and crop rotation. The same irrigated plots also evaluated R1 or post-tassel applications, which increased yields from 5.0 to 12.4 bu/a. If feasible, consider setting up some trials on your own farm to evaluate fungicide applications on several of your hybrids.
Focus on Fungicides
Check out this information to evaluate fungicide use in corn.
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