BLOOMINGTON, Ill. — Despite the calendar date, farmers need to keep a close watch for corn diseases as the crop enters its final growth stage.

Andrew Fisher, Syngenta commercial product lead for Quilt Xcel fungicide, said disease is starting to show up later than normal due to the delayed planting.

Fisher said very little disease was showing up in late July, but then became more visible later.

“What most folks I think have to remind themselves is the disease spores could actually be inside the crop and be built to a pretty high level for 21 days within that plant before it ever becomes visible on the leaf surface,” he said.

“So the caution is as you’re scouting fields today and see a handful of small lesions on a plant, be it gray leaf spot or northern corn leaf, those spots will continue to grow and you could probably expect a lot more of the disease to show up over the next few weeks.”

He recommends applying Syngenta’s Quilt Xcel at the R1 growth stage due to its two modes of action.

“It will actually stop the disease that’s already in the plant from growing, and it will prevent any additional spores from coming into the crop,” he said.

“Having two modes of action — propiconazole and azoxystrobin — into one product goes a long way as far as giving you the optimal disease control and also crop enhancement benefits of improved stalk quality.

“This corn is going to stand out in the field later than normal this year with the delayed planting and so more growers are starting to see the harvest benefits with Quilt Xcel along with the excellent disease control that they’ve become used to.”

Fisher noted that some people say the fungicide delays the plant’s senescence, but he believes it actually allows the crop to senesce properly versus die early.

“It keeps the plant greener longer. It keeps it growing. I always said it’s like keeping the factory working for you longer, and it goes a long way at the end of the year in tip-fill,” he said. “With a 32,000 planting population and an extra couple kernels per year equals an additional bushel. It doesn’t take a lot to really add up.”

Fisher said the threshold in determining when to apply Quilt Xcel “isn’t black and white.”

“The threshold is really the individual’s level of risk,” he said. “Many growers will look at commodity price, but ultimately this R1 application has been giving us very consistent average returns of 14 to 15 bushels per acre.

“So if they see any disease start to show up at all or they have a good crop and they want to maximize their yield through the end of the year as far as getting their return on their investment, it’s a very good bet. More and more farmers have made it just part of their practice.

“I’ve personally walked enough treated and non-treated fields in the Midwest in all kinds of weather conditions including the terrible experience we all went through last year with the dry weather, and I’ve always seen a very, very good percentage of return on your investment and a percentage of trials winning.

“I have no problem looking a person in the eye and say it’s worth their investment year in and year out.”

The fungicide’s benefits were apparent during the 2012 drought based on the data he received from 80 on-farm trials, according to Fisher.

“We saw about a 10-bushel increase from an early application at V4 to V8, and again we saw a 14.5-bushel increase at an R1 timing. That R1 is very consistent year in and year out,” he said. “We’ve probably had over 400 trials the last three year that had an R1 application, and every year it’s been between 14, 15 bushels per acre.

“The early application — which is really more for stress because there’s no disease there at the time — showed the biggest benefit last year for V4 to V8 application. We saw a 10-bushel increase, and for the two years prior, we were averaging around six-bushels-per-year increase.”

Fisher said the difference in corn that had Quilt Xcel applied can be found in the roots and stalk quality.

“If the plant doesn’t have enough nutrients to feed the ear, it will start pulling from its stalk. That’s what gives you that brittle stalk,” he said.

“Spraying with Quilt Xcel has shown a benefit of making that plant healthier and allowing it to give it the needed nutrition to maximize that ear-fill and maintain some of the integrity within the stalk. That’s what helps it stand out there later in the year.

“It was very visible last year on the ability to withstand high temperatures and periods of dry weather. In the untreated, the leaves would roll much quicker than the treated. The treated would still have an open leaf, maximizing photosynthesis. It’s able to conserve most of the moisture that’s in the plant.”