Cold steel sometimes best on weeds

Most of the time, herbicide-resistant cotton does an excellent job of weed control for cotton producer Brad Cobb. But sometimes, nothing works better or is cheaper than cold, hard steel.

Cobb farms nearly 10,000 acres of cotton, all Roundup Ready/Bt cotton varieties, around Tunica, Miss., with his son, Bradford, and daughter, Lee. Like many cotton producers today, he's trying to cut costs through reducing tillage and watching inputs. And like many cotton producers these days, it's a work in progress.

“I'm still not sure what's the best way to do things,” Cobb says. “I've kind of come to the conclusion that minimum-till works best for me.”

One reason is that Cobb has found no reliable chemical alternative for wild sweet potato vine (also known as big root morningglory) and red vines. “The glyphosate is just not going to get them. You have to get them by some kind of mechanical means to give your crop a head start. You're just not going to make a crop where those vines are heavy.”

And there are times when cold steel is just plain cheaper than glyphosate, according to Cobb. “People say they can burn down cheaper than they can go across the field with a tractor and a cultivator. I take issue with that. I have to have the tractors and I have the men.”

Cobb's lineup of 225-hp tractors pulling 40-foot implements at 5 to 6.5 mph makes a good case. “We can get across a tremendous amount of land,” Cobb said.

For Cobb, cotton profit is cotton yield. “I am blessed with good soil. Volume helps. My philosophy is to keep the expenses as low as possible without impacting yield. I do everything I can to maximize yield within reason.”

At harvest, Cobb applies Def and Prep and where regrowth may be a problem, he may substitute Dropp for Def. “We try to get the crop out as quickly as possible. We're going at breakneck speeds to beat any adverse weather. We try to keep real good harvesting machinery and keep everything in tip-top shape,” said Cobb, who runs six John Deere 9976 six-row harvesters.

Cobb cuts stalks as quickly as possible behind the pickers. “I like to run a subsoiler on every dryland acre every year and irrigate every other year. We are beginning to look at a Paratill, which goes up and down the row instead of at a 45-degree angle. Based on one year of experience, I like it.”

Cobb says the subsoiling is the key to keeping yields up in a dry year. “In a wet year, there really won't be any difference. But you have to prepare for the average year. And the average year around here is a dry July and August.”

Cobb uses a lot of mixed fertilizer, mostly potash, which he will put out before he subsoils in the fall. “I feel like the rains can work that potash down into the cracks and down into the root zone.”

On the sandier soil, the producer will put out the potash right around burndown.

The land is not touched until after the first of the year. “Sometime around March 1, when we begin to see some vegetation, we do a burndown. Around March 15, we will run a middle buster with anhydrous knives.

“The anhydrous is much cheaper than other sources of nitrogen and we do 12 rows at a time, so it goes pretty quickly. Most of the time, we follow that with a roller to flatten out the top of the beds.

“As a bonus, if conditions are right, the middle buster will do a fairly good job of cleaning the beds and that will take the place of a second burndown.”

At planting, Cobb looks for inexpensive but effective approaches to getting cotton up and growing. “Where I part company with the second burndown concept is that some of my land, especially the sandier soils, seems to support running a harrow lightly in front of a planter.

“It doesn't cost near what the burndown herbicide costs,” he said. “Harrows are cheap to buy and economical to run. One 12-row tumbling harrow will stay ahead of two 12-row planters. We've saved a good deal of money just by not automatically going to that second burndown.”

Cobb carefully considers any in-furrow treatments. “You can save $20 an acre by eliminating a lot of them.” Instead, he prefers to wait until conditions are optimum before planting. It doesn't hurt to have excess planting capacity, six 12-row planters.

“With a good forecast, I might start planting on April 20. Normally, I like to start the last week of April. But if I could plant every acre the first week of May, if would be just fine.”

Three or four years ago, Cobb raised all conventional cotton varieties. “But the weed spectrum has changed so quickly and so dramatically for me. Until four years ago, I had never seen a Palmer pigweed, which the yellow herbicides and even Staple didn't seem to have any effect on.”

Cobb still doesn't know how the weed, as well as infestations of sicklepod, got a foothold on the farm. “But now it's spread to most of my land. It went from no problem to a major problem in three to four years. And glyphosate is the only product that will control it.”

That forced Cobb into going to 100 percent Roundup Ready cotton and today “those weeds are no longer causing a major problem. I am still struggling with morningglories and nutsedge, which glyphosate is a little weak on. I'm amazed at how weeds are able to adapt.”

Going with Roundup Ready cotton didn't mean giving up the plow, Cobb stresses. “After the cotton comes up to a stand, I'll go with glyphosate in a band over the top of the cotton and cultivate the middles. That's simply for cost savings. Due to the vines, I pretty much have to plow anyway, so why not plow the middles and spray the band?”

Ten days later, he will either go over the top with glyphosate again, or spray it underneath, depending on the weeds and the size of the cotton. “The important thing is to time your application for the toughest weed that you have to kill. For me that's morningglories.”

There may be one more post-directed application of glyphosate, “then I like to switch off to Caparol or Bladex.”

There are two additional areas where Cobb would like to cut expenses, but there's not a lot he can do about one of them.

Cobb explained that budworm/bollworm pressure is traditionally light in the north Delta, making the use of Bollgard cotton “real iffy. Every once in a while, worms will show up.”

Cobb must have Roundup Ready cotton varieties for Palmer pigweed and sicklepod, but says that for him the “Roundup Ready-only varieties don't yield as well as the stacked varieties.”

Paying a $32 per acre cost for a technology he doesn't need doesn't sit well with a producer so motivated to cut costs.

“If I could get a high-yielding Roundup Ready variety without getting the Bollgard, I'd be tempted to put it on a large percentage of my acreage. And if I didn't have the sicklepod and Palmer pigweed problems, I'd go back to conventional varieties.”

Until then, his cotton varieties are Sure-Grow 501 BR and Paymaster 1218 BG/RR, which he believes are two of the better-yielding transgenics in north Mississippi.

Cobb has more control cutting costs in another arena, efficiency. The producer is now talking to a major equipment company about doing some testing on 18-row equipment. “I told them I would be most happy to be the first to try it. It's going to have to go that way. You have to make more with less in this low price/high cost environment.”

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