Search

UAN and herbicide applications on emerged corn

June 5, 2019 8:42 AM
Blog Post

Corn planting has been start and stop, and generally delayed this spring. In some situations the decision was made to plant and not apply nitrogen, or planting progressed so quickly that UAN (urea-ammonium nitrate solution) and herbicide applications couldn’t keep up with the planters, and now there is emerged corn.  While UAN and many pre-emergence products can be applied to emerged corn, using UAN as a herbicide carrier enhances the foliar activity of products and may result in foliar damage. Check herbicide labels for restrictions on use of UAN as a carrier.

Category: 

Advice on additional nitrogen for corn

May 6, 2016 4:08 PM
Blog Post

I've been getting a lot of questions about needing additional N for corn; growers are torn between putting some UAN in with herbicides vs. spreading urea. I’d caution them against using UAN as a carrier on emerged corn if they are applying herbicides. Yes, there are a few products that allow this, but the labels also say that crop injury can be expected. I’ve done it, and it was fairly hard on the corn. If we have good growing conditions after the application, the corn may heal up and be fine; on the other hand, it is a lot of stress on the young crop.

Watch for damage from broadcast postemerge UAN applications

Encyclopedia Article

Broadcast postemerge application of urea-ammonium nitrate solution (28 and 32 percent UAN) to corn has the potential to cause phytotoxic symptoms of leaf burn, necrosis, loss of leaves, and plant stunting. Burn symptoms will be visible within 24 to 48 hours after application. With hot-dry conditions, appearance of darkened leaf tissue can begin within a few hours. Depending upon the severity of damage, reduced plant growth may be visible for several weeks after application.

Category: 
Crop: