How A South Carolina Grower Tackles Nematodes Head On
⋅ BY CASSIDY NEMEC ⋅
ASSOCIATE EDITOR
Jason Waltz farms cotton in St. Matthews, South Carolina. He recently worked with Clemson University and Deltapine on a nematode study. In the study, they tested nematode-resistant varieties versus Telone-applied fields versus a control with nothing. After two years of data, Waltz is growing all nematode-resistant cotton on his farm today.
The Farm
Waltz, a Deltapine New Product Evaluator grower since 2006, farms cotton, corn, peanuts and soybeans across his South Carolina farming operation southeast of Columbia.
The soil textures on Waltz’s farm include Orangeburg loamy sand, Faceville fine sandy loam and Lucy sand. The average pH over all his soils is 6.7.
Dr. John Mueller, Clemson Extension row crop pathologist, said reniform nematodes tend to prefer more of the loamy soil that has more color to it, whereas the root-knot nematodes steer toward the sandier fields and soils.
Waltz said he had tried every nematicide one could think of prior to this study. “You name it, we’ve done it,” he said. “Long story short, I knew we had a problem.”
He commented that his common varieties at the time were DP 2038 and DP 2055, which he would pair with the in-furrow nematicide, Telone, before seeing DP 2141NR come up in the Class of ’21 NPE varieties. The variety stood out to him, and he wanted to do an extensive plot the next year.
The Study
Dr. Mueller noted DP 2141NR’s resistance qualities to both reniform and root-knot nematodes. He took samples of nematodes to obtain numbers and weights throughout the study’s duration.
Mueller said that, for root-knot nematode-infested fields, it not only controls the nematodes in the current year but also helps knock down numbers for the next year.
In Waltz’s on-farm trial, the following combinations were tested in a reniform-infested field:
⇒ DP 2055:
■ Five pounds of AgLogic and zero gallons of Telone.
■ Five pounds of AgLogic and three gallons of Telone.
⇒ DP 2141:
■ Five pounds of AgLogic and zero gallons of Telone.
■ Five pounds of AgLogic and three gallons of Telone.
DP 2141NR B3XF is a mid- to full-maturity Bollgard 3 XtendFlex variety known for its root-knot and reniform nematode-resistant qualities, and DP 2055 B3XF is a full-maturity Bollgard 3 XtendFlex variety.
“We were looking at high root-knot and reniform nematode populations on that field,” Waltz said. “We applied Telone on 100% of our cotton acres because of high nematode pressure in our sandy soils. In 2021, we planted DP 2055 with and without Telone, and I planted DP 2141NR B3XF with and without Telone side by side.”
Each combination was harvested in six-row, 2,067-foot-long strips, equaling out to 0.901 acres a piece.
The study was a strip trial in around an 83-acre field in Fort Motte, South Carolina. They dug roots for each combination in the plot at different times throughout the season. Mueller pulled nematode samples at the cotyledon stage, but populations were not that high due to it being very dry at the start of the season.
Waltz noted there was still a noticeable difference in plant health and could tell something was wrong with the plant health in the DP 2055 rows without Telone at this stage.
Waltz commented on DP 2141NR being a powerhouse cotton variety that is very vegetative and absorbs nutrients in an efficient manner — so much so that he lowered his fertilizer rate by 10% last season.
“I say it’s not a variety; it’s an animal.”
The Results
The nematode count results at both five weeks and harvest for the four scenarios planted showed stark differences between DP 2055 and DP 2141NR.
The harvest counts for reniform nematodes showed the following numbers of reniform nematodes per 100cm3 soil:
⇒ DP 2055 with Telone = 1,342.
⇒ DP 2055 without Telone = 2,055.
⇒ DP 2141NR with Telone = 142.
⇒ DP 2141NR without Telone = 572.
When looking at the harvest numbers, Waltz said he almost fell out of his chair. “We were decreasing our nematode population in the 2141.”
“The Telone did work on top, as we knew it would, but if you just compare the varieties, 2141 is just not supporting infection and reproduction by the reniform, which is exactly what you want,” Mueller said.
He also noted the bump in yield between the two tested varieties. “If you had 2141 versus 2055, you’re looking at a 300-pound yield increase [with 2141].
“That’s a big deal,” Waltz said.
He was able to pick a whole field of DP 2141NR with no Telone applied and still make 1,300 pounds.
Seeing the results of this large field study, Waltz decided to plant all DP 2141NR moving forward.
“What I saw was so strong, and data doesn’t lie. We have a cotton variety that’s going to revolutionize the nematode problem we have in cotton.”
“It tells me that DP 2141NR has very good resistance to nematode, and it is actually suppressing nematodes whereas we did not see that with Telone on DP 2055. It helped, but DP 2141NR actually reduces the populations. And you cannot tell much of a difference between DP 2141NR with Telone and without Telone. On DP 2055, you can tell there is a major difference in plant health.”
The 2022 cotton season brought Waltz several challenges from Mother Nature, but he did not let that stop him or his 2022 crop.
“We had two weeks of bad rain in September, had a lot of boll rot, had a hurricane come through, and I’m still set to average over 1,100 pounds to the acre on 1,600 acres this year,” he said. “It’s been phenomenal.”
Even with the obstacles that came, Waltz still managed to be a High Yield Award winner as part of NPE with DP 2349NR. This is another nematode-resistant variety from Deltapine’s new Class of ’23 varieties that Waltz harvested at 1,380 pounds per acre.
“It’s what we’ve needed forever,” Dr. Mueller said in reference to the nematode-resistant varieties. “Hopefully, this is just the beginning.”