Monty Kahle still has ultra-narrow-row (UNR) cotton in his rotational plans. He's just not 100% sold on it.

Even though yields can be 10% or higher than conventional 30"-row yields, drought and late-season weed pressure have sometimes made ultra-narrow-row cotton more trouble than it was worth for the Braman, OK, grower.

Kahle is among many growers who have added UNR to their cotton programs the past few years. Their reason was to increase yields and quality and get by with less cost for cultivation and herbicide needs.

Growers are trying to reduce production and harvest costs by planting 7½-10" rows as opposed to 30", 38" or 40" rows, says Bill Molin, USDA-ARS plant physiologist in Stoneville, MS. His research results, and those of other USDA and university crop scientists, have shown some positive results that growers like Kahle can consider when deciding whether to stay with or switch from UNR.

Kahle added UNR production to his already new cotton program in the late 1990s. He was once strictly a wheat, corn and sorghum producer until cotton became a profitable alternative crop around 1995. It was so attractive that he joined several other northern Oklahoma producers to build a 50,000-bale-capacity gin.

“We are no-till farmers for cotton and soybeans,” says Kahle, who farms with his father Elston and brother Dennis. “We leave the previous year's stalks or stubble to help preserve water and prevent problems from blowing.”

Kahle added UNR to their cotton program after seeing positive results elsewhere. He saw an opportunity to enhance yields and enjoy a more uniform harvest using a broadcast stripper harvester.

The crop is planted using a Deere 1810 Air Seeder as well as MaxEmerge Plus planters. Roundup Ready stacked gene varieties are used. “We have seen at least a 10%, or 40-50 lbs/acre better yield from the UNR dryland cotton, and even more for irrigated,” he says. “That type of production really looks good.”

For the 2002 crop, Kahle no-tilled wheat into standing cotton stalks. “We killed (terminated) the wheat in April, then no-tilled cotton into the wheat residue and cotton stalks,” he says. “We saw three benefits: lower weed pressure, no blowing sand and dirt, and reduced soil erosion during heavy spring rains.”

He admits there are other factors that can sometimes take away from the benefits of UNR. For one, a more dense plant population is needed for narrow rows, or about 80,000 plants per acre. “That's up to $10-12 more in seed costs,” says Kahle.

Two straight years of dry growing conditions took away any possible UNR yield advantages. Also, because narrow-row fields can't be cultivated or chemically treated with hooded sprayers, there can be excess weed or plant pressure as harvest approaches.

“The weed pressure is not too bad on dryland UNR cotton,” he says. “But for irrigated, the weeds can be a problem (since Roundup applications must stop at the fifth leaf stage).”

Kahle hopes to see more advanced over-the-top herbicide programs that allow for later-season weed control.

Defoliation helps harvest, but poor weed control does not make for an easy harvest, he says.

The finger blades in his CenCorp 20' broadcast stripper header can become clogged by the excessive plant growth. “We have to make sure the fingers are spaced from ⅜" to ½" to hopefully prevent clogging,” he says. “Any excessive foliage hurts your grade at the gin.”

USDA's Molin is in the middle of a 10-year research project on UNR- vs. conventional-spaced cotton. “We're working toward developing crop and weed management systems that will establish criteria for growing UNR cotton in the Delta,” he says.

“With UNR cotton, a farmer can plant more rows and potentially harvest more cotton per acre. We hope that planting rows closer together will help crowd out weeds, reducing the need for mid-season herbicide applications.” However, he adds, “Judicious use of pre-emergence and postemergence herbicides will be necessary in order to keep the UNR crop clean.”

In his field studies, Molin looks at several popular commercial cotton varieties grown using both wide and ultra-narrow rows. He then evaluates various weed-control programs. Results show that UNR cotton is comparable in yield to conventional cotton.

He also looks at key fiber characteristics of UNR and conventional cotton. Fiber characteristics are more favorable in conventional cotton, where fibers are longer and less tangled. But by improving crop management and harvesting techniques, Molin says UNR cotton quality should also improve.

In previous UNR studies by Wayne Reeves, an ARS agronomist in Auburn, AL, conservation tillage using either a wheat or a black oat cover crop produced up to a 60% higher yield for UNR over conventional cotton.

“We feel that merging the UNR system with modern conservation technologies and using cover crops can reduce crop production inputs, conserve soil and moisture and improve yields,” says Reeves.

Kahle is expanding his overall crop production to include soybeans doublecropped after wheat, followed by cotton for two years. And he is hopeful the future is good for UNR because of the pluses he has seen with it.

“If there is sufficient weed control, we feel it will work well for us,” he says.