Farmers prepare for threat of soybean rust in local crops

Soy biodiesel, insect and weed management, and new production systems were all topics at the Missouri Soybean Association meeting Thursday in Jackson, but that wasn't why most soybean farmers showed up.

They came to hear about soybean rust.

"It's why I missed my dentist appointment," said David Lange, who farms 600 acres of soybeans near Randles, Mo. "That's why a lot of us are here. It could be a big problem."

About 75 Southeast Missouri soybean farmers showed up at the University of Missouri Extension office to hear Dr. Allen Wrather, a professor at the MU Delta Center at Portageville, Mo., give a 45-minute talk on soybean rust.

Asian soybean rust is a fungus that was first discovered in the continental United States in November in a soybean plot in Louisiana. Since then, it has been detected in eight other states, including Missouri. Wrather was the one who discovered soybean rust in the Bootheel last fall.

When left untreated, the disease has caused up to 80 percent yield loss in infected soybean fields in South America. That's why Wrather said soybean farmers should "mentally prepare" for the fact that soybean rust might show up again this growing season.

"Will it overwinter? Probably," Wrather said. "We're not sure, but probably. The fungus dies after leaf tissues die. But in warmer southern states, it probably will survive."

Nobody knows for sure how the spores reached the United States, but Hurricane Ivan is considered the most likely cause because it swept along the South American coast before heading north.

Unlike other foliar soybean diseases, which can be managed through crop rotation and residue management, soybean rust survives only on living plant material, requiring that producers be vigilant when scouting during the growing season.

It will go wherever the wind takes it, Wrather said. He said that farmers should scout their fields, but cautioned that it won't be easy. He said that farmers should check one area of their fields often. If they find the fungus, which creates reddish-brown splotches on growing leaves, then they should treat their entire crop.

"If the weather is really right, it moves fast," he said.

Wrather said he wasn't sure how often to treat soybean rust. It can be treated with fungicides, but farmers would have to spend an additional $20 an acre, which could add up, especially if fields have to be treated more than once.

Regional agronomists will also be checking around the state, he said. If soybean rust is found, a "field day" will be held so farmers can see what it looks like and know what to look for in their own crops.

But Wrather said that farmers should go ahead and produce crops to get the best yield.

However, farmers still said they were worried.

"Everybody is concerned about it," said Charlie Heisserer, a soybean farmer from Scott City. "We're here to find out what to look for. Especially if it's going to cost us another $25 to $50 an acre."

Lange, the farmer from Randles, agreed.

"The big thing is it's going to be a tremendous expense," he said. "Prices are already low, there's little or no profit already. This just makes it a whole lot worse."

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