Corn benefits from early-season fungicide protection

Date:05-30-2012

An early-season corn fungicide application program has proved to be beneficial, according to field trials the past two years.

Syngenta Crop Protection kicked off the early-season application program initiative in 2010.

"More growers have been experiencing the use of fungicides early, as well as the late applications,” said Eric Tedford, Syngenta fungicide technical brand manager.

"By early, I mean the V4 to V8 window of early application of either Quadris at six ounces or Quilt Xcel at 10.5 ounces in that window and recognized early disease protection, as well as the yield benefits and the plant performance benefits that we get.

"By plant performance benefits, I refer to the physiological benefits that are associated with strobilurin fungicides like azoxystrobin that is in both Quadris and Quilt Xcel, and they result in plants stay greener longer so we have more utilization of the sun’s energy put in the photosynthetics to create the plant and generate the yield.

"It also enhances water use efficiency, and this is what relates to the effects that we see with benefits during times when it’s drier than normal, and also we see effects on nitrogen utilization.”

Tedford referred to the results of commercial-sized trials conducted by Syngenta over the past two years comparing non-treated and Quadris-treated corn.

"There were 617 observations using Quadris applied at V5, and the average yield benefit from those locations was 5.7 bushels per acre,” he said. “There were 339 observations with Quilt Xcel applied at R1, and the average yield increase was 14.3.

"The combination of Quadris applied at V5 followed by an application of Quilt Xcel at R1, there were 156 of those observations and the average yield increase was 17.5 bushels per acre.”

Fifty-two side-by-side trials in 26 locations using two hybrids at each location were conducted last year.

"At each location, we had an untreated field, another with Quadris applied at V5, another with Quilt Xcel applied at R1 and then the combination,” Tedford said.

"The results of those trials with 52 going into the mean showed Quadris at V5 was 5.2 bushels per acre, which was very close to the 5.7 that we saw in 2010. Quilt Xcel applied at R1 was 11.2, and the combination was 14.2.

"So this actually substantiates that the data that we saw in the 2010 strips trials, albeit not all replicated, not all side-by-side were actually good representations of what we see when we do it in a more scientific manner.

"Growers are used to seeing these yield benefits, but above and beyond the yield benefits, there are benefits growers see with enhanced quality of the stalk and, therefore, the reduction of lodging.

"Those are important for obvious reasons, and also the plant stays greener longer. The plant staying greener long allows the plant to utilize the sun’s energy for a longer time.”

Fungicides do not allow a plant to do something it is not genetically capable of doing.

'Quadris and Quilt Xcel fungicides allow the plant to better recognize their full genetic yield potential,” Tedford said.

"There are a lot of things that would like to take away from that yield, and that include insects, it includes fungal pathogens that nibble away yield, it includes improper nitrogen and it includes a lot of things that can take away from yield.

"When you start off at the beginning of the year with the seed in your hand, it’s kind of at 100 percent (potential), and it can only go downhill from there.

"The fungicides allow you to better recognize that full yield potential. They do it by providing disease control, therefore allowing the plants to stay more photosynthetically viable.”

He used a plant with heavy gray leaf spot pressure as an example.

"Your leaf is no longer functioning as it would if it was healthy, so it’s less able to photosynthesize, and therefore what happens when the corn starts to develop cob? It needs to be in nutrient sync, and it needs energy to go into the development of the corncob,” he said.

"If it’s not getting the proper nutrients from the leaf because the leaf has been compromised, has been compromised from disease, it will actually pull it from the inside of the stalk and actually digest the starches that are in the pith. It will also take it from the roots, as well.

"But it’s that process of taking the starch from the pith of the stalk that actually compromises the integrity of the stalk, and therefore you get a greater amount of lodging.”

There were numerous reports of lodging last growing season.

"Sometimes plants sit out there longer than normal, and it could be easier for them to blow over. But by having good stalk integrity, you can improve the harvest efficiency,” Tedford said.

Syngenta used economic models to measure the benefits of fungicide applications.

"In the trials, we recognized that the combine can go almost two miles per hour faster in the treated compared to the untreated. Although it doesn’t sound very fast, it is in fact a saving of about $10 per acre at least on cost of fuel, labor, equipment, maintenance and what not,” Tedford said.

"In addition to that, by reducing lodging you’re reducing the amount of corn seeds that are introduced to the ground and the amount of volunteer corn and that can have a significant impact on your yields in the subsequent crop.

'For example, corn can be really good weed if you’re growing soybeans the next season. There is some data that suggests that for every volunteer corn plant per five foot of row, you can decrease soybean yields by 9.6 percent. That percent in yields almost triples to 27 percent when you have two volunteer corn plants per five foot of row.

"If you have clusters per five foot of row, you can reduce yields 43.5 percent. That goes up to 56.8 percent if you have two clusters of volunteer corn per five-foot row.

"This adds up pretty quickly with soybeans at $11.30 per acre or whatever price. You can see those would multiply out pretty quickly.”