Increased Disease Pressure Expected For State Peanuts

Dec 09, 2014

By Bonnie Coblentz
MSU Ag Communications

Mississippi producers had another successful year of peanut production, but the honeymoon phase for this crop is probably over.

Jason Sarver, peanut specialist with the Mississippi State University Extension Service and Mississippi Agricultural and Forestry Experiment Station, said between 2005 and 2011, Mississippi growers produced an average of 18,000 acres of peanuts a year. The majority of this acreage was in the southern part of the state.

Although Mississippi peanut production has faced relatively light disease pressure in recent years, Mississippi State University experts caution growers to expect a more active battle in the future. (Photo by MSU Ag Communications/Kat Lawrence)
Although Mississippi peanut production has faced relatively light disease pressure in recent years, Mississippi State University experts caution growers to expect a more active battle in the future.

“With an increase in price and an investment in infrastructure, acreage increased to 52,000 acres in 2012,” Sarver said. “Much of that acreage was located in relatively new areas of the state, including across the Delta and in the hills of north Mississippi.”

Sarver said more peanut-growing regions of Mississippi are beginning to experience significant disease problems. He expects growers next year will have to put more effort and money into the disease battle.

“I think we’re right at the leading edge of disease issues in much of Mississippi,” Sarver said. “Outside of south Mississippi, it’s still a fairly new crop across the state, and we’ve not yet had to rely as heavily on fungicides as has much of the Southeast.”

In the Peanut Belt that runs through Georgia, Alabama and Florida, growers commonly spray seven to eight fungicide applications each year. Some Mississippi growers have gotten by spraying just once or twice a year, but Sarver said those days most likely are gone.

“We are used to having problems with leaf spot diseases in the southern part of the state, but we saw it extensively across most of the growing area in the state this year,” Sarver said. “It has overwintered in the state, and we’re probably going to have to get on a prescription fungicide program to control it in the future, especially when using short crop rotations.”

Southern Blight is historically a significant problem in traditional peanut-producing states, and it was no different in Mississippi this year. Normally, this fungus can be easily spotted above ground, and growers have several treatment options, but Sarver said a potentially larger threat occurs when the disease presents itself below ground.

“This can be really scary when you have the disease below ground reducing yields, but you have no above-ground symptomology,” he said.

Fungicides control diseases, but crop rotation significantly helps peanut production, too. Sarver presented crop rotation data at the 2014 Row Crops Short Course held at MSU in early December.

In tested plots in Georgia, he said peanuts grown continuously averaged 3,636 pounds per acre. Those on a two-year rotation with corn averaged 4,714 pounds per acre, and those on a two-year rotation with cotton produced 4,669 pounds per acre.

When cotton, corn and then peanuts were grown in a three-year rotation, the fields yielded 5,295 pounds of peanuts per acre, but the best yields came from peanuts grown after two years of cotton. These fields averaged 5,365 pounds of peanuts per acre.

“Peanuts are very sensitive to disease, and the right crop rotation plan can give a 1,700 pound per acre yield advantage over fields planted in peanuts continuously, according to these results,” Sarver said.

Mississippi had about 30,000 acres of peanuts this year, part of the nation’s 1.3 million acres of the crop. The U.S. Department of Agriculture estimates a state average yield of 3,500 pounds, but Sarver disagrees.

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