Farming these days seems to be about the latest technology — GPS satellites driving tractors while the operator relaxes, soil monitors that precisely measure moisture — so why are cotton producers pulling weeds by hand?

The short answer is: because they have to.

Palmer amaranth, a pigweed variety that has developed resistance to nearly anything cotton growers can throw at it, is less of a problem now due to extensive control efforts. But experts estimate it will take several more years to effectively control the pest.

“I saw about four or five plants in a cotton field and I went out and pulled them up,” Colquitt County farmer Louie Perry said Friday. “That’s a sure way to kill it. Our fields are relatively clean of it. All around people are doing a much better job with this.”

Stanley Culpepper, a University of Georgia extension weed scientist, is encouraging cotton growers to pull the weeds by hand as the start of the 2011 fight against Glyphosate-resistant Palmer amaranth.

“A great sign of our aggressiveness was evident this past week with numerous hand weeding crews in full force across the state,” Culpepper said in a recent cotton update. “Growers utilizing these hand weeding crews will benefit greatly as we try to get the upper hand.”

Female plants can produce 400,000 seeds each — five plants can create 2 million, Culpepper said.

Colquitt County extension agent Scott Brown said some fields have been “horror stories” this year, but overall there has been an improvement over the past two years.

“For the most part our growers have done a good job,” he said. “It’s still an ongoing battle and it’s still the biggest issue in cotton in terms of production.”

There are chemicals that control the weed early in the season, but once a Palmer amaranth plant reaches four or five inches in height nothing except pulling by hand will work, Brown said. Pulling the weeds before female plants produce seeds this year is the best protection.

“This particular weed apparently develops resistance very fast, (with) wholesale resistance to multiple chemicals,” he said. “We’ve got to do everything we can to help these products to keep on working, or we won’t have anything.”