The temptation through much of the Texas Southern Plains in 2011 will be to eliminate or reduce acreage of rotation crops and concentrate on cotton while prices are at or near all-time highs.

That could be a mistake, says Texas AgriLife Extension pathologist Jason Woodward. But farmers should choose rotation crops carefully to make certain they disrupt a pest’s life cycle, especially fields infested with root-knot nematodes.

Peanuts, Woodward says, could be an excellent option.

“Peanut farmers are looking to maximize production,” he says. “Growers say they need contracts around $700 per ton to be competitive with $1.00 per pound cotton. Currently, they can get only about $650.”

That disconnect, combined with the price of cotton, will encourage many to reduce peanut acreage to add more cotton. “But don’t neglect the value of that rotation,” Woodward says.

It’s a factor that becomes more and more important as farmers continue to combat nematodes, a problem that will become more difficult to adjust to with the loss of Temik over the next few years.

“In cotton, Temik is used to minimize damage caused by nematodes,” he says.

“The species of root-knot nematode we see in peanuts are different from the one that infects cotton, so a peanut rotation will not create a problem in cotton.”

Soybeans and cotton host the same species of root-knot nematode, so rotation from one to the other may exacerbate the problem.

Woodward says corn, in some cases, may not be injured by root knot nematodes but populations will build on corn roots and then damage cotton planted in subsequent years. “We see the potential for significant yield reductions in fields infested with the southern or cotton root-knot nematode,” he says.

The Texas Rolling Plain may be the most vulnerable for nematode problems in cotton and peanut. “A large area of peanut acreage in this area is infested with root-knot nematodes. We don’t have the same issue with the peanut root-knot nematode on the Caprock,” he says.

The economics make sense.

A peanut-to-cotton rotation reduces population of root-knot nematodes and also adds some nitrogen to the soil for the cotton crop. “Look at rotation from a long-term program standpoint,” Woodward advises. “See how the peanut/cotton system works to provide an economic benefit.”

 

Gain cotton yield

Peanut producers may not see a $700 per ton contract but they stand to gain $150 or more from the subsequent cotton crop because of rotation. “We get a good yield bump from a peanut rotation,” he said. “A 200-pound-per-acre increase in cotton yield, even at 50 cents a pound, will get the peanut revenue closer to where it needs to be.”

And 200 pounds at current prices adds even more to the two-crop system.

Even on the Caprock, growers should get as much information as possible on potential rotation crops to determine the effect on later cotton planting. “Some crops can make nematode populations worse.”

A peanut and cotton rotation demands close watch on weed control.

“Some weeds can serve as hosts to nematodes, allowing for reproduction, potentially negating the benefit of the rotation,” Woodward says.

Losing Temik, he says, will increase the need to rotate. “We don’t use a lot of Temik in Texas on peanuts because most of our peanuts are grown where we don’t have the peanut nematode. Some areas in Texas have heavier infestations, however.”

He said the issues that will evolve with losing Temik are coming “sooner than we think. Don’t forget the value of rotation.”