Apple growers, you should pay attention to soybean rust, too

SALEM, Ohio – Soybean growers aren’t the only ones who need to keep their eyes on Asian soybean rust.
Apple producers should pay attention, too.
Although the rust won’t attack apples, a fungicide used to protect soybeans will destroy the fruit.
The fungicide, azoxystrobin, will hurt Macintosh and Macintosh-derived apples by burning the leaves and hurting the fruit’s finish, said Mike Ellis, Ohio State fruit pathologist.
“It’s just azoxystrobin and just certain types of apples,” Ellis said. “But if you get these together, it can cause quite a bit of damage.”
Concerns. The concern is if a soybean field is near an apple orchard and the soybean grower is spraying the damaging fungicide. Drift could then damage the apples, Ellis said.
Another concern, though, is if azoxystrobin was in a spray tank that will later be used for apples. Even if it’s been cleaned thoroughly, there will still be enough residue to cause a problem in apples, Ellis said.
This is how the problem was first detected in the mid-1990s, he said. Azoxystrobin is often used on grapes and strawberries as a fungicide and producers then used the same tank for apples.
Since the problem has been found, however, most growers are aware of it and check labels to see if azoxystrobin is an active ingredient, he said.
The fungicide is labeled as Abound or Quadris and can be under the trade names Amistar, Bankit, Dynasty, Ortiva or Priori, said Erik Draper, horticulture educator with Geauga County Extension.
Wait and see. Although both Ellis and Draper say the fungicide is devastating to apples, they add it’s unlikely it will be a major concern this year.
First of all, not many soybean fields are bordered by apple orchards, Draper said.
In addition, the farthest north soybean rust has been found so far this year is Georgia.
Last fall it was found in nine Southern states, which was the first time it hit the U.S. mainland.
Experts predict it could cause 50 percent yield losses in the southern U.S. and more than a 10 percent loss in states farther north, like Ohio.
Previous damage estimates in South America have been as high as 80 percent.
(Reporter Kristy Hebert welcomes feedback by phone at 800-837-3419, ext. 23 or by e-mail at


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