Ag Line: Corn yield improvement by applying fungicides
By Wade Parker County Extension Coordinator

As dry weather continues to bear down on our county, spraying a fungicide on corn is probably the last thing on a grower's mind. However, there is data that shows a yield increase when a fungicide has been applied. The strobilurin class of fungicides may have some properties that improve the yield of corn when sprayed at specific growth stages in the absence of any pathogens.

When it comes to obtaining a yield response from applying fungicides to corn, there is a lot that pathologists and agronomists don't understand. It seems that hybrids do respond differently, some years there is a wide range of response (from none to definitely economical).

The data in 2006 from Tifton varied considerably in two different tests. In one test, there was no statistical difference between the control and fungicide treatments at the tasseling stage. In another test, there was a significant difference. Corn yields ranged from 186 Bu/A to 201 Bu/A with one application of Quadris at the tasseling stage and 214 Bu/A with two applications (Quilt at tasseling followed two weeks later by Quadris).

I am taking a conservative approach on managing diseases in corn. Strobilurin fungicides should be used to protect the crop from pathogens (southern leaf blight, southern leaf rust, etc.) that cause severe yield loss in susceptible hybrids. However, timing is critical. Fields that are near or at tasseling with no disease pressure present are not good candidates for a fungicide application, especially with disease resistant hybrids. On the flip side, applying a fungicide on a disease susceptible variety during rainy and humid weather will likely be economically feasible.

Jenkins and Burke counties' Extension Offices conducted a corn fungicide test in 2006 at two different farms. The trial in Burke County showed very little difference, but the trial in Jenkins County showed over an eightbushel difference between the untreated and the top treatment (Headline). The variety in Jenkins was Pioneer 31G98, and Dekalb 69-72 in Burke.

****** Lunch with the Congressman Congressman John Barrow will be at the Jenkins County Extension Office on Thursday, May 31, for an agriculture listening session. As Congress begins writing a new farm bill, Congressman Barrow is making his rounds through the district to hear concerns. It is very important that we have a large show of farmers and agribusiness persons. We will eat lunch at 11:30 a.m. and proceed with the meeting afterwards.

Please call the office at 982- 4408 if you are interested in attending so we can get an accurate head count.

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