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Dormant Disease has Reappeared and Threatening Iowa Corn

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NEWTON, Iowa -- A rare fungus has reared its ugly head once again and its target is Iowa corn. Physoderma Maydis, also known as Northern Leaf Blight was first detected in America in 1911.

Joe Manning, an Agronomist with Heartland Co-Op said, "It`ll promote pre-maturity in the corn, it can hurt yield and stops photosynthesis in the upper canopy, which right now is the factory the corn needs."

After lying dormant for decades, it`s now keeping crop dusters like Michael Sullivan in heavy demand. "I`ve been spraying in a 30 mile radius of Newton, Iowa, just spraying with fungicide," said Sullivan.

Manning said he's seen crews working almost non-stop to help fields stay protected. "The last ten days have been full time.  We`ve been real busy walking fields this morning and lined up another couple thousand acres," he said.

Plant pathologists at Iowa State University are studying the disease that is capable of killing off the yields of affected crops to nearly zero. Manning said, "We are talking 30 bushels an acre and with all the acres in Iowa, that`s pretty significant."

He says farmers' wallets won`t be the only ones that feel the impact. "Less yield means higher prices for consumers," said Manning.
Heavy rainfall in the spring has provided ripe conditions for the fungus to reappear. "A year like this, it was cool and wet early. We`ve stayed wet and that promotes the diseases we`ve got," said Manning.

The infection can be spotted in two ways, brown spots on corn leaves and stalk rot causing the plant to fall over and break.
Sullivan said, "Right now your only choice is either an aerial application or ground rig.  Once the disease is in the crop you`ve got to do something or it`ll continue to spread to more plants."

While ISU scientists say there is little farmers can do this year if they have already discovered the disease, it helps to be preventative. "The best case scenario is protect the yield they`ve got, which with the potential in central Iowa, looks tremendous," said Manning.

Iowa State pathologist Alison Robertson recommends that farmers rotate corn out of an infected field in following years or changing seed varieties to a less susceptible hybrid which can also help.