Taking Control Of Nematodes

 

Any number of factors can drive a cotton producer’s decisions from year to year. For Johnny Cochran, one of those factors has remained consistent on his Sylvester, GA cotton and peanut operation: Nematodes.

 

Located amid the picturesque pine forests of South Georgia, Cochran’s operation is a pleasant place. His wife prunes a lush rose garden not far from his farm shop. At harvest time, his fields are flush with showy cotton.

 

But don’t be fooled by the aesthetics. In addition to its beauty, South Georgia also has a reputation for harboring yield-robbing pests like resistant pigweed and, most notably to Cochran, nematodes.

 

The microbial pests impact any number of Cochran’s in-season decisions. They’ll even dictate what crop he should plant in a given field.

 

“Cotton root knot nematodes, on these sandier soils we have, have been our number one problem,” Cochran says. Like countless cotton producers across the country, Cochran was forced to re-evaluate his crop protection program when Temik was phased out of use in the cotton industry due to Environmental Protection Agency regulation.

 

In the year immediately following the loss of the aldicarb product, Cochran knew he had a serious problem on his hands.

 

“We would see nematode numbers just going up, with our soil sampling, so we knew we were going to have to do something,” he says. “We were seeing hotspots develop. That first year we planted a small plot of DP 1558NR B2RF, and we saw a significant reduction in root knot nematode population. So I knew then that this had a lot of potential for – not replacing aldicarb – but helping deal with the loss of aldicarb.”

 

As a participant in the New Product Evaluator program, Cochran is able to get a first look at pre-commercial Deltapine varieties. In 2014, that meant he was able to plant what would eventually be named DP 1558NR B2RF on his own farm, one of the earliest nematode resistant varieties from Deltapine. He soil sampled for nematode populations the year prior to planting the variety, and then again after he had harvested it.

 

“We saw drastic reductions in nematodes,” he says. “So we know that the technology works.”

 

Still, the loss of Temik caused significant challenges.

 

Like many other cotton producers across the Cotton Belt, it’s hard to overstate how heavily Cochran relied on the nematicide to help control an often rampant root knot nematode population. He says he used the aldicarb product in both his cotton and peanut fields, year in and year out. “We were keeping them suppressed with Temik,” Cochran says.

 

Without that tool in his toolbox, he was forced to get creative in how he dealt with the pest. Cochran developed a crop rotation system that helped keep the nematodes in check.

 

“We grow about 2/3 of our acreage in cotton and 1/3 in peanuts,” he says. “And we’re on a two year rotation with our peanuts. That’s where the nematode-tolerant varieties fit into my program – in the second year of my cotton rotation, we try to put in a variety that will withstand the nematode pressure.

 

“The first year a particular field is in cotton, we expect the nematodes will be suppressed from the peanut rotation the year prior,” Cochran says. “So we’ll grow one year of whatever cotton variety we want to plant there, regardless of the nematode resistance. Then the second year is when we try to put in a nematode tolerant cotton variety in the field.”

 

Of course, a key to that system working was the development of high-yielding varieties that also happened to feature nematode resistance.

 

Raising the Yield Bar

 

Mercifully, a staple of Deltapine variety advancement, the company’s representatives say, is that the new varieties must yield on par with, or better than, their existing offerings. So the nematode resistant varieties the company developed also featured improvements in yield potential.

 

“These nematode varieties were moving along in the research and they were coming up with varieties that were nematode resistant that would still yield and grade,” Cochran says. “So we opted to use these nematode varieties to help control our problem.”

 

Much of Cochran’s farm is dryland acreage, so he is always on the lookout for a variety that will yield well in occasionally stressful irrigation conditions. When planting dryland cotton behind peanuts, a scenario where he doesn’t expect to encounter high nematode populations, he turns to DP 1555 B2RF – “a good high yielding variety” he says. The result has been that Cochran has had to raise his expectations for what he could accomplish on dryland.