Harvest 2015 Brings Yield Boost Despite Disease Pressure

Imagine getting a 30 BU/A Boost

Brent Lage, of Anchor, Illinois, usually relies on experience and instinct when it comes to application of fungicide, but in 2015, he wanted to see the data to know for certain if the added cost was paying off at harvest. In a side-by-side comparison, he used two hybrids of corn in two different locations and applied Stratego® YLD at tassel.

After that application and long before harvest, “I could visually see the difference just driving down the road,” Lage says of comparing the treated and untreated crop. “I had used Stratego YLD in the past and had visually seen the benefits, but I’d never done on my own farm side-by side yield checks to see if there really was a difference.”

In each circumstance, the corn treated with Stratego YLD outperformed the untreated corn with yield boosts from 20 – 30 bushels per acre. One hybrid yielded just over 220 bushels per acre untreated and jumped to over 250 bushels per acre treated. The other hybrid untreated yielded 236 – 240 bushels per acre with the same hybrid treated yielding 269 – 276 bushels.

Side by Side Comparison 

Lage said the decision to apply the fungicide at tassel was relatively easy. “Lots of lesions were forming on the leaves” he said. “I was finding northern corn leaf blight, common rust and gray leaf spot.”

The disease pressure Lage witnessed was not unusual for the 2015 season which experienced more rainfall and lower temperatures. “That led to higher disease pressure in fields than growers have seen for a long time,” said Randy Myers, Ph.D., Bayer technical development manager. “The cooler than normal temperatures helped northern corn leaf blight get started early, and the frequent precipitation events allowed the disease to stay very aggressive. Gray leaf spot typically prefers warmer temperatures, but once lesions started to form, inoculum soon spread everywhere, driven by the almost continual wetting of the leaves by dew and rain.”

“The main thing is you must have a healthy corn crop. You think you save money by cutting inputs like nitrogen, chemicals or fungicide, but it always backfires on you.”
- Kevin Kalb

Kevin Kalb of Dubois, Indiana, factors fungicide as part of his inputs each season, but he ramped up use this year with the heavy rainfall and disease.

He recalled, “We saw really strong disease pressure in the corn and responded by applying more fungicide than what we had planned as well as more nitrogen because of the leaching from the flooding. Gray leaf spot was showing up three weeks earlier than we’ve ever seen it, and southern rust was one month earlier than we’ve ever seen it.” His fields received three applications of fungicide – early stage, before silking and brown silk.

Myers encourages growers to seriously consider early application (at the V4 to V7 stages), which carries significant benefits.

Those benefits are what compel Kalb to make fungicide a part of his plan each year, regardless of commodity prices and forecasts. “The main thing is you must have a healthy corn crop. You think you save money by cutting inputs like nitrogen, chemicals or fungicide, but it always backfires on you,” Kalb said. Kalb’s commitment to a healthy crop and high yields has been recognized with top honors in the National Corn Yield Contest sponsored by the National Corn Growers Association. Kalb won first place for Indiana corn yields and second in the nation with a yield of 361 bushels per acre in 2014. Record yields also won him top prize nationally in 2011 and 2013.

An application of fungicide is always a factor in his yield equation.

“We never thought about cutting back,” he said. “I think that hurts you more by skimping on inputs than what it saves you.” In a normal year, he said, “Ninety percent of our corn gets at least one shot of fungicide. This year we ran more passes than we typically would,” he added.

Myers said the early season application helps keep the stalk strong which not only prevents lodging but also keeps the stalk healthy and functional throughout the growing season, allowing for more optimal development and grain fill. This impacts the grower’s bottom line in several ways.

“Early in the season you’re not going to have many disease symptoms present because the plants are growing rapidly…we don’t want even the initial infections to begin. We’re trying to get in front of those so we’re making the application before the infections occur, and one of the biggest benefits of early season application is stalk quality. If we can keep those stalk rot pathogens out of the stalk or at least reduce those populations, then later on in the season we have healthier stalks,” Myers said. That means greener, healthier stalks during the grain fill period.

A strong, healthy stalk benefits growers in two ways. First, the plant stands up nice and straight. With strong straight stalks, there is less lodging. Eliminating lodging directly enhances yields as well as harvest efficiency.

Myers explained, “When plants are standing straight, you can go through the field at a higher rate of speed. When combining, you are burning fuel by the hour, so if you’re going faster and finishing more acres in that hour, you’re reducing fuel costs.”

"Anything you can do to de-stress that plan and keep it healthy, to give it a boost, I think is worth the investment."
- Drew Mummelthei

The second benefit of a strong stalk is general plant health and growth. A healthy stalk allows nutrients and water to come up out of the roots, through the stalk and up the leaves throughout the entire grain fill period. “If the vascular tissue is compromised and cuts off that flow, the leaves can die and I lose the photosynthetic potential from those leaves,” Myers said. “When that occurs before black layer, it reduces my grain fill which directly affects my test weight. So healthy stalks actually provide an increase in yield.”

The Mummelthei family, who farms near Waverly, Iowa, has seen corn yields benefit from a planned, early season fungicide application.

“V5 is when you're setting the rows around the ear, the ear length and so forth. It's just a very critical time in yield establishment,” explained Drew Mummelthei. “Anything you can do to de-stress that plant and keep it healthy, to give it a boost, I think is worth the investment. A healthy plant has healthy stalks. Healthy stalks improve standability, which means the combine can just keep rolling through the field. We credit the standability we’ve seen to the early season fungicide application. It’s a no-brainer.” 

Although growers have no influence on temperatures and rainfall during the growing season, those factors can have a big influence on the resulting disease pressure. Stratego YLD demonstrated its value during the 2015 corn harvest as a proactive approach for growers who keep disease under control while boosting yields.

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