Level of disease should determine corn fungicide use
In fields infected with gray leaf spot or southern rust, Bradley has also looked at a late-season fungicide application reducing stalk rot. Again, in general, if disease pressure justified a fungicide application then stalk rot problems could be reduced compared to untreated disease infected corn plants. But hybrids resistant to the disease were less likely to show an improvement in stalk quality, he explained to the Crop Management Conference crowd in Columbia, Mo.
As for applying a fungicide when corn is in the V6 stage of growth, Bradley isn’t sold on that application, and if an ag retailer is going to sell a farmer on trying an application at that stage then it should be done in a trial situation with treated and untreated corn next to each other in a field, he suggested.
He said, “My take on the V6 application is that there really is not much level of disease out there at that time, and a V6 application is not going to give protection throughout the entire season. So, I think the verdict is still out a little on those V6 applications.”