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Injured Clearfield rice hybrids across Mid-South

In late April and early May, the calls came in a trickle. The producer complaints Bob Scott heard were similar: after the first of two required Newpath herbicide applications, fields of Clearfield hybrid rice were severely stunted, had yellowing leaves or simply died. By late May, says the Arkansas Extension weed specialist, “the situation broke wide open.”

“Now, I’m getting calls from all over on injured Clearfield hybrid rice. I’m in a quandary over some of this injury because we’ve done variety testing on these hybrids and they were nearly as tolerant as CL 161 and CL 131. There were no red flags on any injury possibilities like what’s being seen now. The hybrids were much more tolerant than the early Clearfield varieties.”

The problems aren’t only in Arkansas. According to Extension specialists, researchers, consultants and producers spoken to for this story, injured Clearfield hybrids — mostly CL XL8 and, to a lesser extent, CL XP730 — are being seen from south Louisiana into the Missouri Bootheel.

“I’m running up to 400 miles a day doing nothing but checking banged up hybrid fields,” says Ford Baldwin with Practical Weed Consultants in Austin, Ark., and Delta Farm Press contributor. “I’m looking at some fields of sprayed XL8 that are so bad it wouldn’t be any worse to have sprayed Newpath on a conventional variety. That’s saying something. All the fields aren’t that bad, but plenty are.”

Knots in stomachs

Chuck Wilson, Arkansas Extension rice specialist, has walked and gotten calls on injured hybrid fields from northern Arkansas counties “all the way down to Desha County — one county north of the Louisiana border. The problem is widespread and has left farmers in a major dilemma.

“We’re telling farmers to nurse these fields and hope they turn around. It’s been so cold I’ve been hesitant to tell anyone to flush. But now that warmer weather is here it may be time for that.”

This season, there’s more injury on the Clearfield hybrids than Steve Linscombe has seen in the past. “We know the hybrids aren’t quite as tolerant as CL 131 and CL 161,” says the rice breeder who works at LSU’s Crowley Rice Research Station. “That means a bit more injury on them compared to the Clearfield varieties isn’t a big surprise. But the damage is more extensive on the hybrids than we’ve ever seen.”

There’s not a good explanation for the problems, he says. “Cool, cloudy wet conditions like we’ve had for the last couple of weeks tend to lead to more injury. But even before that, when temperatures were a bit warmer than normal, we were seeing quite a bit of injury on the hybrids.”

Even so, Linscombe expects most of the injured fields he’s seen — “and I’ve looked at a bunch” — to turn around and have decent stands.

Most of the rice in the Mid-South was planted in a shorter than normal timeframe, says Jim Thompson, director of seed marketing for RiceTec, the company responsible for the Clearfield hybrids. Thompson points out recent Extension newsletters on many crops suffering from the recent cold snap.

Hybrid rice, he says, “was at a very vulnerable stage when the cold weather hit. And the cold hung around much longer than a normal ‘blackberry winter’ would. In some areas, it lasted for the better part of three weeks.

“It isn’t just rice that’s been affected. I was down in south Arkansas last week. There was some fairly extensive replanting of some cotton there.”

Thompson, citing extreme concern for “each customer,” says all injured fields have had, or will have, individual management recommendations by RiceTec reps. Records will be maintained during the growing season and yield records will be maintained after harvest, as well.

Hybrid seed production process “is imperfect,” says Thompson. “We expect to see a low percentage of plant deaths every year. With well over 400 new hybrid customers just this year, we’ve received more calls than in the past. That wasn’t unexpected.

“Bottom line: our goal, as it always has been, is for each customer to not only (remain) a RiceTec customer next year but to increase his/her percentage of hybrid rice. To achieve this goal we’ve committed ourselves to a level of customer support that, to my knowledge, is unsurpassed in the industry.”

But despite assurances, consternation remains high.

“The consultants and farmers I’ve spoken with have knots in their stomachs,” says Baldwin. “They’ve got $150-per-bag seed and have already put out $16 to $20 worth of Newpath. They’re locked into a Clearfield system. It’s getting too late to replant rice, so they’re looking at yield losses if they do replant. They can still make a crop at this late date but it won’t yield what it once would have.”

“I was rolling this around in my mind while I was trying to go to sleep last night,” says Scott. “I just can’t figure out what’s going on. We did (hybrid) trials properly and told everyone they’re almost as tolerant as the regular Clearfield varieties. I walk fields and receive pictures showing injury and I think, ‘It just doesn’t look like the seed we tested. We saw nothing this bad.’”

Tolerance questions

While not wanting to “chuck rocks” at anyone, Ronnie Helms, who does research, consults and farms with G&H Associates in Stuttgart, Ark., has been uncomfortable with the Clearfield hybrids for a while.

“I hope what I’ve seen is a complete anomaly… but two years ago, I initiated some studies with CL XL8. We did some high rates of Newpath to check the tolerance levels. Bottom line: we saw some big yield reductions in XL8 from higher rates.

“What scared me in the XL8 studies I did two years ago — and then repeated last year — was the second application was often more injurious than the first.”

It is “obvious” to Helms that the Clearfield hybrids don’t have the tolerance of 131 or 161. Why is it obvious? “Because growers can’t afford to put the hybrids on the levees so they’ll plant 131 there. After spraying Newpath, I’m seeing fields that are hurt badly while the levees are fine.”

It’s typical for Newpath to “sit” on the hybrids a little while, says Baldwin. Until this year, he “figured the pattern was we’d have a few injured fields and that was just the nature of the beast. This year is entirely different. Whether it’s due to a prolonged cool, wet period, I don’t know.

“In some cases, the injury is well past what I think a lot of farmers are willing to put up with… These hybrids just don’t have enough tolerance. That’s a cold, hard fact.”

Like Linscombe, Baldwin believes much of the rice will recover and that “may salve a lot of wounds. But there’s added expense in it. Many farmers will have to flush a couple of times, perhaps with fertilizer. Even if these varieties come back and make normal yield, he’s put in extra expense, time and worry.”

Key questions

What about replanting and the second application of Newpath? The stewardship agreements signed by farmers make the second shots mandatory.

Without the second application “red rice control will be iffy and that leads to all the usual threats of outcrossing and resistance,” says Scott. “This is a messy situation brewing.”

“I’d make very sure I had healthy rice before putting (the second shot) out,” says Linscombe. “You don’t want to stress rice that’s already stressed.”

Wilson says he’d be “very cautious with the second Newpath application. I’d delay that as long as possible. It certainly doesn’t need to be sprayed while rice is still sick.”

Some replanting has already occurred. But Linscombe says planting studies show that, in most cases, replanting rice this late in the season isn’t wise. Having a thin stand planted early is usually better than having a full stand planted late.

“We’re almost into June — it’s late. As far as a threshold, it’s difficult to nail down. If I had two or three plants per square foot and they’re fairly uniform, I’d keep it. They tiller well and I’ve done very well with extremely thin stands before. Regardless of where I was in the Mid-South, at this stage I’d be very cautious about replanting.”

At this point, there’s no point in “bashing RiceTec,” says Baldwin. “Whatever’s done is done. We’ve got to get the crop through this in the best manner possible. Any recommendation changes can wait until fall.

“I’m a big fan of hybrids. Truth is, it’s in its infancy and yet they already have varieties that will yield with — or outyield — conventional varieties. If they continue to improve the technology, there’s potential for quicker breakthroughs than there is in a conventional breeding program. We need both.”

The best thing farmers can do now is manage the injured fields for optimum tillering.

“It’s getting dry enough that fields need to be flushed,” says Baldwin. “We think that’s the right thing to do. If it isn’t done, the rice will die from drought stress anyway.”


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