Fungicide has been used with success for fruits and vegetables, but Purdue University Extension crop specialist Greg Shaner says the benefits of fungicides for corn and soybeans is not yet clear.
Growers that decide to apply a fungicide and want to test it out for themselves should choose portions of fields to spray at random, Shaner says. This will provide a better indication of yield results over choosing specific spots to treat because there may be a tendency to treats areas that historically have better yields.
Timing is critical in application, since fungicides work better for prevention than as curatives, Shaner says.
"A general guideline for corn is to make the first application when there are no more than a couple lesions on lower leafs of about half the plants in a corn field," he says.
In some regions, fungicides can be especially helpful in combating soybean rust, Shaner points out.