Ag Chem, a division of AGCO, has developed a quick-reference spray guide to help growers and dealers apply fungicides for Asian soybean rust.

The guide “Spraying Fungicides is Different” details simple adjustments an applicator can make to assure better fungicide coverage, including appropriate droplet size, nozzle selection, pump pressure and boom height.

“Precision application of fungicides can mean the difference between success and failure in battling Asian soybean rust,” said Nyle Wollenhaupt, worldwide agronomy manager for Global Technologies of AGCO. “What we've laid out in ‘Spraying Fungicides is Different’ are some simple adjustments the applicator can make to better assure that fungicides will be applied correctly.”

Acknowledging the use of fungicides has not been widespread in the areas that may be hit by soybean rust, the spray guide outlines fungicide application strategies in the context of spraying herbicides — and how the two are different.

“Custom applicators and growers accustomed to spraying herbicides will need to consider several preseason and in-cab changes in spraying routines in order to effectively manage soybean rust,” said Wollenhaupt. “We urge everyone to prepare now, so they can act quickly to minimize the effect of soybean rust if it hits their area.”

The pocket-size spray guide from Ag Chem provides simple instructions for improving fungicide coverage.

The steps include:

  • Reducing droplet size and increasing carrier volume. Fungicides need to be applied in small to medium-sized droplets of about 200 to 350 microns and are best applied with at least 20 gallons of water per acre. Compare that to 400 microns and 10 gallons or less per acre for herbicides.

  • Choose nozzles that provide the proper angle and spray pattern. Coverage is critical for fungicides, meaning you need a nozzle and spray tip combination that allows the spray to penetrate the crop canopy for thorough leaf coverage.

  • Lower the boom height. As crop canopies close in, it becomes more difficult to uniformly reach lower leaves, where soybean rust first infects the plant. While boom heights of 15 inches to 20 inches are normal for herbicides, it is important with fungicides to lower the spray boom as far as possible while maintaining overlap of approximately 30 percent — typically around 12 inches above the plant.

To receive a free copy of “Spraying Fungicides is Different,” call Ag Chem toll free at 877-454-3347.