By J.T. Smith
Progressive Farmer Contributing Editor
Some weeds just seem to "show up" in some growing seasons more than others. Devil's claw was widespread in many 2013 crop fields, especially across the vast Texas Rolling Plains. With large leaves and big, sharp claw-like seedpods (hence the name), devil's claw doesn't need a lot of encouragement.
"The reason it is so hard to control devil's claw is that the weeds will come up even when there's almost no detectable moisture," said Darrell Cross, a diversified producer from Ovalo, Texas.
European colonists believed devil's claw could treat arthritis. The plant's large tuberous roots are still grown as a medicinal herbal supplement. For Cross, the weed is merely a pain. Even in this arid growing region, devil's claw can flourish quickly, rob precious moisture and choke out cotton plants, causing a substantial loss in yield.
Cross operates Cross Family Farms with his son, Cody. Sticking to a strict rotation program of cotton, wheat and grain sorghum, and carefully fitting herbicides to weed situations generally keeps their fields clean.
However, in otherwise clean cotton in 2013, devil's claw emerged quickly. They zapped the weed with glyphosate, opting to use Roundup PowerMAX herbicide rather than generic glyphosate. Good control came with a 30-fluid-ounce rate -- about 25% more than normal but still within labeled rates.
Robert Pritz, Texas A&M AgriLife Extension Service agent based in Abilene, said many growers dealt with devil's claw in 2013 but were able to control it if they sprayed early.
"What I've heard to be successful more than anything are two treatments with Roundup Ultra, one early at about 4 to 8 inches, and a second application after that," he said. "I wouldn't say you'd achieve total control, but at least 80% control if you use two treatments."
This annual broadleaf weed thrives on soil disturbance, such as plowing. Devil's claw has seeds that may last in the soil for many years before they germinate in late spring or early summer. The seedpods look a lot like okra before they turn black. The weed is also commonly found in cattle lots or pastures.
Cross chose Huskie herbicide to deal with devil's claw in sorghum. He said it was the perfect fit with a sorghum and wheat crop rotation.
Preplant-incorporated (PPI) herbicide isn't an option to control devil's claw emergence. "Because devil's claw is an oilseed weed -- just like cotton, itself -- the PPI yellow herbicides won't touch it," Cross noted.
Texas A&M AgriLife Extension recommends that when used with a tank mix of atrazine, Huskie is especially effective and should typically be applied in sorghum at 13 to 16 fluid ounces per acre.
Typically, the Cross farming operations have been about 80% dryland farming. After an extended drought in 2011 and 2012 in Texas, none of the irrigation wells would supply water for the 2013 growing season.
"So we haven't been able to irrigate in a year and a half," Cross lamented. They were thrilled when timely rains returned in 2013 to deliver some of the best cotton yields in years. The bad news is devil's claw also took off rapidly with the better rainfall.
The father-and-son team know both crop and chemical rotation is important to any weed-control strategy. With devil's claw, they also know the key is to get it before it turns ugly.
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