Cotton – Southeast – Thrips Surge In Places, Triggering Second Sprays – AgFax

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Owen Taylor, Editor
Questions, comments, complaints? My door is always open.

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Here is this week’s issue of AgFax Southeast Cotton, sponsored by
the Southern Cotton Team of AMVAC Chemical Corporation

OVERVIEW

Hot, dry weather has settled over much of our coverage area, and rain is needed on a wide basis.

Thrips have surged in more places over the last week. In some cases, a second foliar application has been made or at least is being considered. See comments by Dominic Reisig and Ron Smith.

Grasshoppers are getting attention in certain areas.

Spider mites have become evident in at least some cotton in south Alabama. With hot and dry conditions, plus acephate treatments for thrips, mites could gain an opening.

Cotton planting has nearly wrapped up through a big portion of the Southeast, although our contacts say that farmers have had to do more replanting or spot planting than usual.

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CROP REPORTS

John Burleson, Consultant, Swan Quarter, North Carolina:

“We’re gone dry but I’ll take that over all the rain and flooding that folks in the Midwest are dealing with. We have cotton now at 4 to 6 leaves. Acephate went out with the first herbicide.

“We also have cotton that hasn’t emerged yet. Some has been laying in the ground for 7 days (from 5/27) and we’re finding stand issues on both ends of Hyde County, although stands are pretty good in the middle of the county. All the varieties seem to be emerging a little weaker this year. I’m hearing about some replanting in the area but I only have one farmer who replanted a small number of acres.

“Corn ranges from about V9 to V11 and a lot of leaves are rolling up in the afternoon. Highs will be in the upper 90s every day this week, with 99 in the forecast for Thursday. I’m seeing a lot of discoloration in the corn where it’s not taking up nutrients. We’re 70% done with bean planting and they don’t look that bad.

“We’re dry now after a very, very wet winter – from one extreme to the other. There’s at least some chance of afternoon showers this week.”

Brad Smith, Nutrien Ag Solutions, Selma, Alabama:

“We’re probably 90% finished with cotton planting – the first time – but we’re looking at more replanting than normal. About 2.5 weeks ago (from 5/27) we had a huge rain. That was followed by another rain the next day, which packed the ground and put us in these replant situations.

“Probably 60% of our cotton is up and, fortunately, it looks really good. I just drove by some of our oldest cotton and it’s probably at 5 or 6 true leaves. We do need a rain in the next 4 to 5 days. The high yesterday was 98 and I’m guessing it hit 98 today, too. Strangely, the humidity levels are lower than what we would expect. It’s hot but it’s a drier heat.

“We’re finding a few thrips and about 20% of our acres have been or will be sprayed for them, based on what I know right now. I understand, though, that areas south of here are dealing with a considerable number of thrips.

“Our soybeans range from hand-width high to still being planted. Bean acres will probably be down 30% from a year ago. Corn looks good but the heat and dry conditions are a concern. So far, I haven’t seen anything wilting in the daylight. What irrigated corn we have is being watered. By the end of the week we’ll likely see some tassels.”

Jack Royal, Royal’s Agricultural Consulting Co., Inc., Leary, Georgia:

“We’ve been dry and hot. Temperatures have been in the mid-90s to just over 100 for at least the last 10 days – and the forecast says that will continue for the rest of this week.

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“Most of my growers have planted 90% of their cotton, if not a little more, and they’re watering up most of the last of that. In our older cotton, we’re starting some herbicides – Roundup and Staple and in some fields it’s dicamba and Roundup.

“Most of my growers went with AgLogic, the aldicarb soil insecticide, and that made a big difference in the way cotton came up. Thrips haven’t jumped on it and plants look pretty fair. In a few places, growers didn’t use the material and thrips have developed in that cotton.

“We’re also about 90% finished with peanut planting or maybe a little further along. Where we have irrigation, we’ll wrap up cotton and peanut planting in short order.

“Corn looks super. It loves sunshine, and those plants have had it in abundance. With this heat, we’re having to keep the pivots running. Most of our corn is either in tassel or heading towards it. We’re having to treat much of the corn crop for brown stink bugs at tassel or just ahead ot tassel.

“If we can keep the water going and maybe get rain this weekend, we could be set up for a very good corn crop. No disease is showing up to speak of. Very little northern corn leaf blight is present and I’ve found no rust whatsoever.”

Aaron Cato, Entomologist-Post Doctoral, Auburn University:

“In checking thrips trials today (5/28) at Prattville, spider mites weren’t hard to find. We were seeing them all across the thrips trial and also in bollworm trials. Scattered mite injury was evident and mites were present on the underside of leaves.

“With dry and hot weather right now, conditions are very conducive to mite propagation. Acephate treatments for thrips also can give spider mites an opening, so we need to watch for them, especially if two thrips applications go out. Given a chance, mites will spread and defoliate leaves.

“It’s tricky to know when or whether to treat in this early situation. Mississippi State’s research indicates that you can expect some level of yield loss if spider mites cause injury for 14 days. If you’re finding mites spread across the field with active colonies, they will only get worse in this heat and with thrips application.

“If you receive rain, it’s not 100% certain that you will get rid of them. Bottom line: check and be prepared to treat if necessary. Go with abamectin. It’s economical and it may be the only thing your distributor has in stock.

“The caveat is that spraying mites in late May or early June may mean you lose efficacy with abamectin if you have to spray again. Mites probably aren’t gaining resistance to abamectin, as such, but they can build localized tolerance. In Arkansas evaluations with multiple sprays, a third application of abamectin didn’t work at all.”

Dominic Reisig, NCSU Extension Specialist, Entomology, Plymouth, North Carolina:

“It’s all thrips all the time, and the situation has gotten worse over the last week. A few spots received showers and isolated areas look good, but cotton is mostly sitting in dust and thrips are banging it up.

“Any weed hosts have dried down, and that dispersed thrips and exacerbated the expected peak in cotton. I’m fielding a lot of calls about whether to respray for thrips after already making an acephate application 8 to 10 days ago (from 5/28). Thrips are still jumping on those plants and dinging them up pretty badly.

“It’s hard to say what to do, quite frankly. I’ve been here 10 years and have never seen it get this hot this early. I made that statement to a veteran crop consultant who said that this is his 30th season and he’s also never seen this kind of heat this soon.

“People are asking whether to increase rates on a second spray. Going with higher rates of acephate can be problematic and could bring on spider mites. With thrips, timing is more important than rates, I think.

“I’m also being asked if any of this is due to resistance. We did send samples to Scott Stewart at the University of Tennessee for resistance testing and his group reported that both acephate and Radiant should work, so this doesn’t appear to be a resistance issue. To some extent, dry weather worked against plants taking up seed treatments, and that’s a factor, too.

 “We swept some daisy fleabane in northeastern North Carolina and found a pile of immature plant bugs and some adults, so that’s the next thing to worry about.

“The next 3 days will be very hot. The predicted peak will be on Thursday at 99.”

Phillip Roberts, Extension Entomologist, Tifton, Georgia:

“Any cotton planted in April is at least close to pinhead square. I was in some cotton today (5/28) planted on April 25 that was squaring. So, be mindful about the need to start scouting for plant bugs and monitoring retention. Right now, that would be just a small percentage of our acres.

“Growers are trying to finish planting. It’s dry, and we haven’t had a rain in 18 to 20 days, plus it’s hot.

“Toward the end of last week, I began receiving a few more calls about thrips. I think we’ve had a big flush of them moving from other hosts as they dried down and people began noticing a bit more injury last week in cotton. A little spraying is being done, but thrips shouldn’t be an issue past that.

“Where people have been timely with foliar sprays, plants look so much better. We promote making that treatment decision at first true leaf. With seed treatments, you begin seeing breakthroughs about 14 days after planting. You still have some activity from the seed treatment, but a foliar spray would be necessary if you find moderate to high thrips pressure.

“With thrips, it’s better to be on the early side, and that spray at the first leaf synchronizes with a lot of our normal production practices, like herbicides. With thrips, this is a good time to evaluate how your at-planting program worked, and take notes for reference next year. Don’t just make mental notes. Write it down and put it someplace where you can find it next year.

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“We’re starting to pick up a few aphids but it’s almost June 1, which is normal timing for them to appear. I was in a field yesterday with hot spots, which is to be expected. I’m getting an occasional report about grasshoppers but they’ve mostly slowed down.”

Ron Smith, Alabama Extension Entomologist:

“Over the last 10 days (from 5/28), all the calls have been about thrips. In areas that dried up the quickest in the southern part of the state, thrips came off wild host plants right away and overwhelmed cotton.

“This is some of the heaviest thrips pressure I’ve seen in the last 10 years. In places, acephate went out and 6 days later people are deciding whether to treat again. In our thrips trial, cotton planted on April 17 is at the ninth true leaf and has pinhead squares, and that makes it some of the oldest cotton in the state. Normally at the fifth true leaf we can forget about thrips, but that’s not the case this year.

“We have fields that clearly needed a second treatment at about the fifth true leaf. In places, we have cotton at the fifth true leaf and not a single leaf has unfolded – the thrips pressure is that intense. In the worst-case scenarios, some growers tried to economize and went without a seed treatment. This was not the year to do that.”

Jeremy Greene, Clemson University Entomologist, Blackville, South Carolina:

“It’s hot, it’s dry and cotton that is up and has a good root system may be able to hang on. But, we really, really need some water to fall from the sky.

“Calls about grasshoppers continue. With grasshoppers, killing them tends to get back to dosage. The larger the grasshopper, the more active ingredient you’ll need to knock it out. We have several species of grasshoppers – some small, some large. Grasshoppers thrive in hot, dry conditions, so it’s not surprising that plenty of them are out there now.

“I’m getting feedback about volunteer peanuts in cotton and whether that is causing some of these issues with grasshoppers, since those peanuts are a host for whatever is out there. When you spray Liberty and kill the peanuts, grasshoppers will move into the cotton.

“Should you add something for grasshoppers when you apply that herbicide? That’s a tough question. You need to base that decision on closely scouting the field and determining what those peanuts might be holding. I’m not a weed scientist but my understanding is that Liberty is pretty hot and you have to be careful what you might tank mix with it. Check the label at the very least but also seek guidance from people who regularly deal with herbicide tank mixing.”

AgFax Southeast Cotton is published by AgFax Media LLC
Owen Taylor, Editorial Director.
 
Working-Copy%5B1%5D.jpgThis weekly report is distributed during the cotton production season. It is available to United States residents engaged in cotton farming, field scouting and other qualifying ag professions. Mailing address: 142 Westlake Drive, Brandon, MS 39047. Office: 601-992-9488.
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