Fungicide proved its worth in hot and dry conditions

It was hot and dry last summer across the Midwest, the right conditions for seeing positive results from applying a fungicide on corn. Wait a minute, that cannot be true, but oh yes it can be true, according to ag retailers who assisted their clients in applying either a V4 to V8 strobilurin fungicide application and/or a late-season VT tassel-stage fungicide application.

“We had some dryland fields that customers weren’t going to spray with a fungicide, even though they had planned to do so earlier in the year, and then they went ahead and sprayed at VT. They ended up harvesting 15 to 20 bushels more than the dryland corn they didn’t treat with a fungicide,” explained Jason Perdue, location manager for Wilbur-Ellis at York, Neb.

“You cannot spray a dead plant and bring it back to life,” Perdue said, “but a late-season spray of corn that wasn’t in the greatest health stayed greener longer after the fungicide treatment and filled out its ears better.”

As for an early-season V4 to V8 fungicide application, he said, drive-by observation didn’t show plants were much different in color from treated to untreated, but a closer look showed stalks were being maintained as stronger and healthier for nutrient flow from the soil when the early-season application was made.

Randy Myers, Ph.D., Stratego YLD fungicide product manager, reported, “The more traditional fungicide timing at tassel, on average, didn’t result in as high a yield increases last year as we have consistently seen in previous years.  The newer application, earlier application between V4 and V8, showed yield increases very much in line with what we’ve seen before. The averages that we saw in commercial fields for 2010 and 2011 were about 6.96.8 bushel per acre increases, and in 2012, even under the dry conditions, the average across the Midwest was 5.9 bushel increases.”

No wonder Myers reports that the overwhelming majority of corn growers who have used the early-season application of Stratego YLD strongly favor doing the same treatment again next year. The use of Stratego YLD at the tassel stage became a popular choiceno-brainer for a huge percentage of customers prior to the promotion of the early-season application. Now the movement is on for a two-hit approach of the fungicide during the growing season, much of it because of support from ag retailers who have done side-by-side trials with farmers.

Going along with what Perdue said, Myers said the early season application “does a good job of keeping those stalks healthy.” He said, “You help keep that stalk’s vascular tissue doing its job of getting water and nutrients from the soil into the upper parts of the plant. If the vascular tissue starts to shutdown, the first thing you will see is the leaves on the top starting to suffer.”

Under stress, a corn plant will “start to cannibalize the stalk” as photosynthesis is not keeping pace with the plant’s needs to fill grain on the cob. An early-season fungicide application helps keep the nutrient and water flow for leaves to maintain photosynthesis and also protect the stalk and middle canopy leaves by delaying disease infections originating from soil inoculum that can virtually climb from bottom leaves to the top leaves of the plant, Myers explained.

“There are a whole lot of cascade reactions that are triggered inside a plant because of the way that Stratego YLD works,” Myers said, which further explains why a fungicide application can result in a yield increase even in situations that aren’t perfect for harboring disease.