This spring, Yazoo City, Miss., cotton producer Rob Coker will plant a herbicide-resistant crop in his Bt refuge, just like he's done for the last four years. But this time, the crop will be tolerant to something other than glyphosate.

Not that Coker has anything against glyphosate. In fact, he'll plant around 2,700 acres of his 3,000 cotton acres in Roundup Ready varieties, 2,400 acres in stacked varieties with Roundup Ready and around 300 acres in Roundup Ready-only lines.

But half of his refuge acres will be planted in Liberty Link cotton, which will be introduced in the Cotton Belt this coming season. Liberty Link cotton varieties are resistance to Ignite (glufosinate).

Coker, who farms in a family partnership, has some high expectations of the technology and the genetics associated with it. “I think (the Liberty Link system) is better on morningglory and hemp sesbania, which is a weakness in the Roundup Ready system,” Coker said. “Also, we've been in a Roundup Ready system for four years now. I'm hoping that as we get more varieties and more availability, we can flip flop the (two herbicide-resistant systems) for resistance management.”

Liberty Link cotton will be available for 2004 in four picker varieties, FM 981LL, FM 966LL, FM 958 LL, FM 832 LL, and one stripper variety, FM 5035 LL. Coker will plant 300 refuge acres this year in FM 966 LL. He's grown the conventional version of the variety and another FiberMax brand, FM 960. “I've been happy with both those varieties for yield and vigor.”

Stacked varieties on the farm will include FM 960 BR, FM 800 BR, ST 5599 BR and DP 555 BG/RR. Coker's tillage program is one-third conventional, one-third reduced till, and one-third no-till.

For all cotton varieties, “we'll plant using a good fungicide seed treatment, plus 4 to 5 pounds of Temik. We'll put a light shot of a pyrethroid behind the planter. We'll either burn down before or after the planter. We'll use some Ignite and Roundup for burndown. Where we have horseweed, Ignite might make a better burndown material.

“On our Roundup Ready cotton varieties, we'll put a shot of Roundup out by the fifth true leaf. With Ignite, we may change that approach and wait a little longer. But we are not going to let the weeds compete with the crop.”

Both first shots will be made over-the-top.

Coker will wait 10 to 14 days and make an underneath or post-directed application of Roundup in Roundup Ready cotton and Ignite in Liberty Link cotton. “Hopefully, that comes around pinhead square,” said Coker, who will work out the timing with his entomologist, Mike Sartor. “We'll give it a shot of Trimax on a band for plant bugs.”

The underneath shot with Ignite is primarily to attain better coverage, according to Coker. “You can go overhead with Ignite up until 70 days before harvest. But we're piggybacking some insecticide applications that we can band using our layby rig, so spraying underneath seems to be a better way to do it.”

At layby, Coker will let the weed spectrum decide what he will tank mix with Direx. But again, the bottom line is to never let weeds compete with cotton.

This winter Coker met with Jim Stanard, Bayer CropScience technical service representative, to discuss how he would manage the Liberty Link system. “There are not a whole lot of changes with equipment and how we go about it,” Coker said.

“We've dealt with it having Roundup Ready cotton and conventional cotton. You just have to do a good job — the right tips, the right pressure and making sure you have some buffer zones.”

Bayer recommends that Ignite be applied with a minimum of 15 gallons of water applied with flat fan tips. Ignite's maximum exposure is 80 ounces per season, according to Stanard. The use rate per application is 32 ounces to 40 ounces.

Coker plans to plant his Liberty Link crop “where I won't have a lot of exposure to other crops. But I always tell my drivers to assume that any adjacent field is not transgenic.”

The bottom line for growers and applicators is simply that Ignite cannot be sprayed on Roundup Ready cotton. Neither can Roundup-brand herbicides be sprayed on Liberty Link cotton. Just to be sure, Bayer CropScience will supply 5-foot flags to stick in each corner of a field which designates the field as a Liberty Link field.

Ignite is also labeled for hooded applications in conventional and Roundup Ready cotton, noted Bayer CropScience sales representative Steve North. “If a farmer has a severe morningglory problem, Ignite will take care of it in the middles.”

Coker believes that new transgenic technologies are definitely making cotton production easier. “We used to mix two or three chemicals a week, plow around once a week. We had two insecticides and two herbicides in a tank.”

More options also mean more stability in pricing. And the genetics are finally starting to come around, too. “We're on the verge of getting back to where we were in 1991, and we were going forward with cotton genetics. For a while, our varieties weren't any better than they were in 1991, they were just transgenic.”

Cotton yields on the farm — which is about 20 percent irrigated — average around 975 pounds on two-thirds of the farm, according to Coker. “The other third, I'd rather not talk about. It was a place I picked up late and it had some problems. It's a project.”

Coker is hoping for yields approaching 1,200 pounds for FM 966 LL, which is planted on some of his best ground. But only time will tell how well the technology and genetics turn out.

“This is new technology that I haven't seen on my farm. I'm excited about it. I fully expect it to be successful,” he said. “But then again, we're going to have to evaluate it during the season.”


e-mail: erobinson@primediabusiness.com