Throughout Texas, cotton growers can finally solve the costly problem of cotton root rot, thanks to the U.S. Environmental Protection Agency’s Section 18 emergency exemption allowing use of Topguard Fungicide.
Left uncontrolled, cotton root rot causes direct yield losses of as much as $30 million per year, reports the Texas A&M University AgriLIFE Extension Service. The economic impact is so severe that the EPA stepped in, at the request of the cotton industry, to approve Topguard in 2012 and again this year.
From regions throughout Texas, growers found success with Topguard in 2012 and plan to repeat their programs this year.
“We have struggled with root rot for many years. There are some fields you couldn’t plant to cotton,” says Austin Clary, of Uvalde. He says, the ability to use Topguard “is right up there with eradication of the boll weevil.”
In 2012, Clary applied Topguard to cotton under center pivot and in-furrow irrigation. Previously, root rot would damage 70 percent to 80 percent of his crop. After applying Topguard, there was almost no disease. Under center pivot, his yields averaged more than four bales to the acre. “That’s very good,” notes the grower.
Clary used the recommended T-band application to apply Topguard in 2012. On his furrow-irrigated fields, Topguard control was good, but not as complete as on the center pivot fields. “There are still some things to be figured out,” Clary observes. On all of his fields, Topguard reduced cotton root rot.
To fine-tune Topguard’s performance on furrow-irrigated, drip-irrigated and dryland cotton, this year growers can use a recommended modified in-furrow application. Texas A&M University research confirms it provides even more effective root rot control for cotton grown under these systems.
According to Cheminova, maker of Topguard, the modified in-furrow technique uses a seed firmer with a Y-split tube to apply Topguard to the furrow walls, which minimizes the direct contact with the seed.
“We are learning how to get Topguard out where it provides the best coverage,” says Jon Whatley, a dryland grower in San Patricio County. He applied Topguard in areas where root rot, left untreated, typically kills about 35 percent of the crop. With Topguard, only about 2% of the crop was affected by root rot, he calculates.
“We need to spread our risk and Topguard provides growers the opportunity to get into a better rotation,” Whatley observes. “It will make some farms a little more profitable. Our goal is to identify problem areas and use Topguard with precision application equipment. In this day and age, with the cost of production, we can’t afford to have any holes in our program.”
After reading about Topguard in Texas A&M University research trials, Mark Sugarek, of Beeville, was eager to try it. He applied Topguard in a field where root rot has historically killed 90% of the cotton, complicating harvest with dead plants and less full cotton bolls. In 2012, after applying Topguard, Sugarek harvested better, cleaner cotton—and, he notes, his harvest was much easier. “Topguard worked. I would spend the money on it again and try it elsewhere in a heartbeat,” Sugarek attests.
John Perryman, near Waco, treated 600 cotton acres. “Normally, root rot would kill big areas in the field. After treating it last year, we had just a sprinkling of dead stalks mixed in with green stalks. I was surprised at how much the fungicide helped because we have been fighting root rot here since way before I began farming,” Perryman notes.
He added that harvest was easier after using Topguard because there were not as many dead stalks of cotton to jam the stripper.
Crop consultant Mark Nemec of MJN Consulting Service in Hewitt, says Blackland growers have found it almost impossible to grow cotton in some fields due to root rot. With Topguard, growers may now be able to plant in these areas and take better advantage of crop rotations.
Last year, two of Nemec’s dryland growers applied Topguard. One treated all of his acres. “It wasn’t 100 percent perfect, but the field was much improved over the past year,” states Nemec.
The second grower treated a field where he knew there was root rot on one side, but didn’t think there was root rot on the other side. He applied Topguard to the side known to have the problem—it stayed green. The other side, where he didn’t treat—and didn’t think he had a root rot problem—had a lot of dead cotton, relates Nemec.
Information provided by Cheminova.