Rare, hardy weed worries N.W. Ohio ag scientists

Apple of Peru, sometimes called `shoo-fly,' can choke out crops such as soybeans and resists herbicides.

Apple of Peru produces a winsome trumpet-shaped flower.

It can be such an effective insect repellant it has been dubbed “shoo-fly.” A tea made from its leaves can be a rinse for head lice, according to plant guides.

But scientists who first spotted it in Sandusky and Seneca county farm fields several years ago are worried.

Apple of Peru has a very shady side. A single plant can grow to 7 feet tall, with a six-feet-wide leaf spread. When even a few plants grow close together in farm fields, crops can't compete.

“They'll just smother everything,” said Jerry Cunningham, a crop scout for Country Spring Farmers Co-Op in Fremont. He has seen the weed primarily in pepper fields, but also among soybeans in the Fremont area.

Most worrisome, perhaps, is that Apple of Peru has thrived in some soybean fields that were sprayed with the herbicide Roundup, which kills almost every weed.

“We think it's something to worry about. We're convinced it is not just an oddity,” said Douglas Doohan, a weed ecologist at the Ohio Agricultural Research and Development Center.

He and his colleagues, who were in Sandusky and Seneca counties last week to monitor the weed infestations, are far more concerned about it than most crop scouts and farmers, Mr. Cunningham said.

The weed, scientifically known as nicandra physalodes, is almost unknown in the United States and is not listed in many popular agricultural weed guides. It is so rare that David Jackson, a crop adviser with Widmer & Associates Ltd., based in Gibsonburg, who sees vegetable fields daily, has seen it only in pictures.

Scientists don't know why the weed is rearing its head now. Nor can they say how the United States and Europe have managed to avoid Apple of Peru for so long. It is a major problem in soybean and sugarcane fields in Brazil and in other crops in Asia and Africa. In Japan and Australia, it has cut yields in infested corn fields by 30 percent.

“There are a significant number of fields in northwestern Ohio where Apple of Peru is firmly entrenched,” Mr. Doohan said. “Is this going to be the weed that eats the Midwest? Well, we don't know that.”