Downy Mildew Season in Full Force | VideoAmy Fox | 7/10/2012
"When we see infection in downy mildew is when we get a driving rain that pounds the dirt back up on the bottom of the younger leaves and that`s when we`re going to see the infection,” said Sun Prairie Seed Sales Manager Dan Sem. "The spores are in the ground already, so when we get these driving rains, the spores get knocked down to the bottom of the leaves."
According to Sem, Downy Mildew is a fast-growing fungal disease found in sunflowers.
"This year, we`ve had some heavier rains at times, so we`ve got the spores in the ground that bread the downy mildew, so we`re really on the watch for at this time frame for downy mildew."
After heavy rains, spores begin to form in the ground, causing the bacteria to spread quickly.
"We found over time here and studying the disease that it can be air-borne, so a field across from ours, that`s been in a heavy rotation of sunflowers can have the spores can come through the air and through the wind into another field," Sem said.
But, how do you know if you have Downy Mildew?
Pay close attention to the leaves. On the top, you may notice bumps or some discoloration. On the bottom, you`ll notice a white residue, which is the mildew.
"If you see Downy Mildew in your field, rotate your crops with something that doesn`t have the disease host, would probably be your best rotation and best way to help get away from the disease," said Tim Stanislawski, Dakota Agronomy Partners Sales Manager.
But, as Sem explains, there`s no way to get rid of all of the bacteria. "There`s really not a cure for downy mildew,” he said. "There`s some things that we can do with some fungicides that will, let’s say, hold it back. But, defiantly, there`s no real cure for it as far as going out and spraying for it."
If you have Downy Mildew? Sem recommends evaluating your rotation and deciding what you will plant in its place.