When Ford Baldwin first went to work with the University of Arkansas nearly 30 years ago, Roy Smith was the USDA weed scientist researcher at the Rice Research and Extension Center in Stuttgart. One of Smith's career goals was seeing some kind of technology for red rice control in dry-seeded rice.
“I was kind of the same way,” says Baldwin. “Being able to control red rice in drill-seeded rice has been one of the milestones out in front of us.”
Today, Baldwin is a partner with his wife, Tomilea Baldwin, in their business Practical Weed Consultants, based in Austin, Ark. And today, rice growers have the Clearfield technology to control red rice in rice.
“I think the Clearfield-Newpath system is excellent technology for controlling red rice and many other weeds,” Baldwin says. “The rice varieties with this technology are good choices for growers. While they are good yielders, they're still not quite up there yet with top-yielding conventional varieties like Wells, Francis or Cocodrie.
“However, you also have to factor in the cost from red rice, even in fields with light infestations There's either a cost this year or there will be a cost two or three years down the road.”
With Clearfield rice, growers apply Newpath herbicide in the imidazolinone-tolerant rice varieties. Clearfield rice varieties were discovered at Louisiana State University. LSU AgCenter and BASF, the manufacturer of Newpath herbicide, are jointly developing the technology. While Clearfield varieties feature the unique characteristics of Newpath tolerance, they are traditional-type varieties and should be managed accordingly.
For the 2003 season, growers can choose from three Clearfield rice varieties from Horizon Ag: CL121, CL141 and new CL161. “The CL121 and CL161 are better-suited for Arkansas production than the CL141,” Baldwin says.
“These varieties obviously yield well enough to plant in a severe red rice infestation, but they're also good enough to consider long-term in fields with lighter infestations, especially CL161. It's a higher yielder, but what I really like about CL161 is its enhanced Newpath tolerance. Therefore, you can be more flexible in the kind of weed control programs that you use with it, compared to CL121 or CL141. I think that in itself gives CL161 a big advantage.”
Sequential Newpath applications control many key weeds, including red rice, barnyardgrass, fall panicum, yellow nutsedge, crabgrass, rice flatsedge, broadleaf signal grass and smartweed. Newpath also suppresses sprangletop.
“When the Clearfield-Newpath system is working properly, the only escaped weeds should be coffeebean, indigo, and eclipta,” Baldwin says. “Newpath is a pretty broad-spectrum herbicide. When growers go to the CL161, they probably will use two postemergence Newpath applications.
“When you go total post, you don't get quite as good control of some weeds. Growers will probably be more pleased with their weed control if they also put something like Command down first. But overall, the Clearfield-Newpath system is broad-spectrum technology.”
Baldwin says there's no question that using the Clearfield technology in fields with severe red rice infestations pays in year one. “That's a no brainer,” he adds. “What everybody is trying to do is figure out where that threshold is; that is, how much red rice do you have to have before the technology will pay in year one?”
Baldwin's philosophy is that the technology pays even in some fields with scattered red rice infestations. The payback might not occur in year one, but it may prevent the red rice problem from escalating into a severe problem in year three or four.
“There are two ways to use the technology,” he explains. “Growers can plant it in heavy infestations where they are depending on getting maximum returns in year one. They also can clean up the red rice on a farm-wide basis, which requires planting Clearfield rice in all fields from scattered infestations on up, but the payoff may be two to four years down the road.
“I believe in stopping red rice in its tracks. Where you have a real heavy red rice infestation, you can grow Clearfield rice and then Roundup Ready soybeans. However, when you rotate back to rice, you will have some red rice in that field. If you don't plant it to Clearfield rice, there will still be some red rice there and you could lose ground again. Whereas if you plant Clearfield rice in a light to moderately-infested field, and then rotate to Roundup Ready soybeans, there's a good chance that by year three when you go back to rice, that field will be red rice free.”
Baldwin notes that many growers are caught in an economic situation where they do not feel they can afford to look two to three years down the road. “They're strictly concerned about next year,” he says. “This is unfortunate because if we misuse the technology, we'll lose it. I have seen that first-hand through my wife's out-crossing research. When you have red rice escapes in the field, the out-crossing potential exists.
“It's similar to our experience with herbicide-resistant weeds of other types. Once you document resistance in a given field, it's already in a whole lot more fields than that. That's the reason that I hate to see the technology only used in those severely infested fields where a grower feels he can't grow rice without it. If he just uses it there, and lets his scattered infestations get worse, then basically he's going to chase red rice around the farm, and the out-crossing will eventually get him.”
BASF's product stewardship programs help address this potential problem. For example, growers must attend and complete a Clearfield rice grower certification seminar in order to purchase Clearfield rice seed.
“Clearfield rice is a good choice for growers,” Baldwin says. “There are some good varieties now, and even better ones are coming. It would be nice if the Liberty Link rice and/or Roundup Ready rice had come along at the same time because rotating the chemistries will give us a better out-crossing management.
“However, that won't happen in the near future. So Clearfield is the present red rice control technology that we have in rice. It's such a good tool that it's going to be a real challenge to keep it sustainable with out-crossing management.”