Rich Keller, Editor, Ag Professional  |   July 11, 2012 resize text

Weather that includes sufficient moisture for good crop growth is usually thought of as a crop that needs protected with fungicides, and crops growing in dry weather are often thought to be unworthy of protecting. That thinking is definitely not the case.

“Many growers understand the importance of fungicide applications in wet conditions to control disease and provide plant health benefits. What’s not as well known is that dry conditions, which can put an equal stress on plants, are a crucial time for strobilurin fungicides, as well,” said Nick Fassler, technical market manager, BASF. “In dry-weather situations, use of strobilurin fungicides can improve water-use efficiency and reduce ethylene production, while providing three to four weeks of disease protection after application, independent of the weather.”

Dry weather definitely doesn’t mean that diseases will be passive in fields. Certain rust species are more aggressive in dry-weather situations, so growers need to keep a close eye out for rust-type diseases, and scouts should also look out for the typical culprits like gray leaf spot and northern corn leaf blight, according to Fassler.

“Dry conditions can have an effect on overall yield loss, which can range from 5 percent to total loss, depending on the severity,” said Fassler. “Applying a fungicide during dry conditions is an effective way to prevent disease and provide plant health benefits protecting yield potential.”

It needs to also be noted that loss can also depend on the seed planted. Some newer corn hybrids seem to mitigate drought stress better than older hybrids and keep growers on the lower end of yield loss, BASF research has demonstrated.

A fungicide application to have good disease control during the grain-fill window can pay a good return per field research. BASF points to its Headline AMP fungicide for corn and Priaxor fungicide for soybeans to provide the benefits mentioned here.

BASF contends benefits from top quality fungicides that occur with disease protection, even in dry weather, include:

• Disease-free leaves are cleaner and produce more energy for maximum yield potential on soybeans and corn.
• Healthy corn stalks are more efficient at transporting water and nutrients.
• Healthy corn stalks mean improved grain fill, less risk of lodged corn and higher yield potential.
• Healthier soybean plants mean improved seed quality and higher yield potential.
• Research shows that for corn, Headline and Headline AMP promote efficient use of nitrogen across variable rates, and better utilization of nitrogen increases yield.    

The application window for most strobilurin fungicide treatments on soybeans is at the R3 stage, and for corn it is the VT to R3 stage.

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Comments (1) Leave a comment 

Princeton, Kentucky  |  July, 17, 2012 at 11:00 AM

The article was discusses "Plant Health" benefits of strobilurins when applied to
corn or soybean under "dry" conditions. The article did not mention the use of
fungicides on crops that have been severely compromised by extended drought
conditions. Everyone knows that extended drought greatly lowers yield potentials
(hence the ability to recover the cost of the fungicide and application is very limited)
AND disease pressure of most fungal diseases that are controlled by strobilurin
fungicides is low. Conversely charcoal rot can very severe on both corn and soybean
in drought years, but this disease is not controlled by any foliar fungicide.
My expert opinion is that pplication of foliar fungicides to corn or soybean under
drought conditions is a bad idea.