Cotton – Southeast – Limited Defoliation At Hand, Rains Restore Balance – AgFax

Photo: Clemson University Public Service and Agriculture

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Pam Caraway, Contributing Editor

Owen Taylor, Editor

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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

Defoliation is at hand in a few dryland fields in the lower Southeast.

Rainy weather has shifted the crop’s equilibrium through parts of the Southeast. In particular, dryland fields needed moisture, and several of our contacts said that cotton and peanuts looked better.

Rain also will suppress silverleaf whiteflies in areas where they’ve built. Thunderstorms won’t eliminate the insect, but the rain may hold back the insect enough that applications won’t be needed in fields with slight populations.

All the moisture, on the other hand, will encourage disease development.

Stinkbug pressure continues to be mostly light, our contacts continue reporting.

Hurricane Laura started in the Gulf of Mexico and came ashore early this morning at Lake Charles, Louisiana. Since then, it has been moving through east Texas and western Louisiana. That seems to be a long way off, but weather models do show it shifting into an easterly track at some point, with remnants reaching the Atlantic Ocean. Whether the storm has any influence on the Southeast’s weather remains to be seen.

 

LAST 2020 ISSUE

This issue wraps up our 18-week publishing season for 2020 – and the 23rd year that these reports have been available to ag folks in the Southeast.

Our thanks to:

The crop advisors and Extension personnel who take time to provide the field-level reports that go into each issue. We are grateful to them for their patience, insight and willingness to share information with the broader community.

The Southeast Cotton Team of Amvac Chemical Corporation for once again sponsoring the reports you’ve received each week. In these uncertain times, Amvac’s participation has been a bright point of encouragement for our staff. The next time you see someone from Amvac, be sure to thank him or her for making this coverage possible.

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CROP REPORTS

Wes Briggs, Briggs Crop Services, Inc., Bainbridge, Georgia

“We have some active pockets of silverleaf whiteflies (SLWF) between here and the Alabama line, and they are especially building near cucumber fields. The rain helped, but we started seeing them again today (8/26) after two days of sunshine.

“About 75% of our acres have been sprayed once for SLWF and maybe a third of that has been sprayed twice. We have some older cotton – about 20% of our acres – that hasn’t been sprayed at all. We saw a resurgence in an area last week, although it wasn’t bad. We will make a second spray on a lot of cotton next week. Fortunately, SLWF hasn’t exploded on us. We learned a lot from 2017, so we were a little earlier spraying this time.

“Last week, it looked like corn earworms might blow up, but we’re just seeing issues in isolated fields.

“We have some hardlock and boll rot in cotton that’s 100 days or older. We need our fields to dry out. Tuesday and Wednesday (8/25 and 8/26) were the first two days of sunshine in about 10 days. If Mother Nature cooperates by giving us some sunshine between now and about September 15, we’ll be ahead of the curve.

“Yield potential still looks very good in our irrigated cotton. We are mindful that Hurricane Michael hit on October 10 in 2018, so we still have risk and we still have a long way to go.

“About 5% of the peanut crop is ready to dig, and we may be able to start digging this weekend if it doesn’t rain more. Peanuts look good. We’re seeing late leaf spot and a little bit of white mold. But given the hot and humid conditions we’ve had, I feel like we’ve done an excellent job controlling both diseases. Fields that are under a good fungicide program with timely treatments every 13 to 14 days look really good.

“We’re careful about what we do on peanuts this time of the year.  If we put a half-inch of water on irrigated peanuts and it rains an inch three days later, we can have trouble getting back in the field to make a timely treatment.

“Our Group IV soybeans look pretty good, and our late soybeans are going into R1. All of our soybeans have had two applications for worms. Beans were clean this week, but we’ll probably move into another flight before long. We’re seeing a little bit of frogeye and southern blight, but nothing critical. Plenty of soybean rust developed in the area, but we’re not seeing any in our beans. All of the soybeans had a fungicide application, so we’re holding that at bay.”

 

Ron Smith, Extension Entomologist, Auburn University

“All late-April and early-May cotton has matured out the top and is no longer susceptible to insect injury. In later planted cotton, which is mostly in the southern part of the state, silverleaf whitefly (SLWF) is slowly spreading. We are still watching for stinkbugs and possibly spider mites. Rainy weather this week will help reduce spider mites and SLWF populations. 

“Worms are heating up in soybeans. Moth traps are filling with high numbers of soybean loopers statewide. Also, fieldmen report high numbers of moths in the southern part of the state.

“We continue to hear of damaging numbers of redbanded stinkbugs in several areas. We also are seeing a high number of corn earworm moths, which could be a problem in soybeans. Corn earworms prefer pods, but they will eat the blooms off the soybean crop.

“In the Tennessee Valley, we hope to get rain – but no wind – on our beans planted behind wheat.”

 

Phillip Roberts, Extension Entomologist, Tifton, Georgia

“Silverleaf whiteflies (SLWF) continue to spread out of our core area. We must manage whiteflies until every leaf has dropped from the plant. So, defoliate in a timely manner and pick that cotton as soon as possible. That’s important for a lot of reasons just in terms of yield and fiber quality. The quicker we get leaves off the plant the sooner we eliminate the possibility of whiteflies impacting quality.

“Beyond that we eliminate that field of cotton as a source of building the overall whitely population. Eliminating the food source helps us keep them from moving to other cotton that’s not quite ready to harvest. Timely defoliation also reduces the population that can move to vegetables.

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“Whether we grow cotton or vegetables, we all need to do our part to manage the overall population of whiteflies. In Georgia, we grow crops 12 months a year that give whiteflies a place to reproduce and build populations. When we harvest a field, we need to eliminate that crop – whatever it is – as a source for building populations.

“We can’t let up on SLWF management just because it’s raining. Where they are entrenched, the rain will suppress adult whiteflies, but it won’t make them go away. The rain simply gives us a break for a few days until the immatures turn into adults. For those fringe areas with lighter populations, the rain may be enough to help us win this race to the finish line.

“For cotton growers, the pressure this year is nowhere like the outbreak of 2017. Our growers have done an excellent job of managing SLWF. Their proactive approach helped us avoid a lot of what we saw in 2017. When we work together, we all benefit.

“Conserving beneficial insect populations helped – and was easier to do this year because stinkbug numbers have mostly been low, which helped us reduce sprays. We’re fortunate to have the opportunity to use natural controls.

“We are addressing corn earworm on scattered fields. It’s important to scout.

“It’s raining almost every day, and that’s helping some of our dryland cotton. But we’re also starting to detect a little boll rot. We’re at the point where this rain helps cotton in places but hurts it in others. Overall, we have an above-average crop and hopefully we’ll wrap it up soon.”

  

John Burleson, Consultant, Swan Quarter, North Carolina

“Our cotton is about done. The crop is anywhere from cutout to 5 nodes above white bloom. We have a little time left to protect that younger cotton, but we’re not finding much pest pressure.

“In general, we saw lighter stinkbug pressure and more plant bugs than normal this year. We knew we had a late crop, so we tried to protect it. This cotton really made a 180-degree turn. Although we didn’t have blooms by the Fourth of July, once it started going it didn’t stop. We have potential for a great crop.

“Recent rains will help fill out cotton and soybean. Our soybeans range from R3 to nearly ready to harvest. We have hot pockets of corn earworm and soybean loopers. In a few places, we’re finding heavy stinkbug pressure. None of the insect pressure is widespread.

“Corn harvest is underway. We had a hard start with a rough spring. So far, the crop seems to range from below average to average. But it’s still a little early to know how it will turn out.”

 

Jeremy Greene, Clemson University Entomologist, Blackville, South Carolina

“It’s been raining almost every day. Although these storms have been scattered, most of the state is wet.

“This wet weather is releasing moths from pupal chambers underground, including bollworms and tobacco budworms. When soil remains moist for a long period, that likely encourages them to emerge. 

“My trap counts are spiking again this week, and the counts are the highest they’ve been in three years. This flight isn’t likely to impact our early-planted cotton. We could see some top-crop issues in cotton that was planted on time, but we don’t expect anything significant. However, carefully watch late-planted cotton.

“Stinkbugs are the insect I’m most worried about, and they are easy to find on bolls in cotton fields. The stinkbug complex will do well in this moist environment. The eggs hatch better, plus growers can’t get in the field to spray because it’s so wet. That could be an issue in both cotton and soybean.

“In soybeans, also watch closely for tobacco budworms and podworms. We’re also seeing soybean loopers, which is a critical defoliating pest to clean up early. According to a call today (8/25), velvetbean caterpillar (VBC) may be coming in soon. If they reach threshold, I’m going to put out an insecticide trial. We are hoping the resistant migrant VBC population that came through last year was an anomaly.”

 

Brandon Phillips, Phillips Ag Services, LLC, Fitzgerald, Georgia

“When this rain moves out, we’ll start defoliating dryland cotton. About 10% of our dryland cotton is ready for defoliation with a yield potential between 500 to 700 lbs/acre. Most of our irrigated cotton looks strong – as good as last year or better. We’ll see how that holds.

“This time last year things started turning dry, and we picked every boll that opened. This year, though, we already have boll rot, so we could lose 50 to 250 lbs/acre of yield from that.

“In addition to boll rot, target spot is showing up. In fields where we had a history of target spot – about 10% of our acreage – we were proactive with a fungicide application.

“We are battling silverleaf whiteflies (SLWF) in fields that are in the fifth or sixth week of bloom. They’re expensive to treat, and we’ve been fighting them for about two weeks now. When SLWF show up in the historical areas, they’re usually here about a week later. That didn’t happen this year, but that’s likely because we were managing for beneficial insect populations and we were able to hold off on stinkbug sprays early in the season.

“Dr. (Phillip) Roberts said we were doing something right and should keep doing it. On dryland acres, we’re worried about regrowth attracting SLWF. With cotton prices so low, it’s hard to justify a whitefly spray on one-bale cotton.

“We sprayed about 60% to 70% of our cotton once for stinkbugs. Stinkbugs just never materialized at the level we usually expect.

“In peanuts, our main focus right now is white mold and leaf spot. We moved to a 10-day fungicide schedule when the weather pattern shifted to hot and wet. We started finding white mold three or four weeks ago, and now leaf spot is showing up. These rainy, cloudy conditions are perfect for leaf spot. My growers have done a good job of being on time with fungicides.

“Tomato spotted wilt virus (TSWV) started early in skippy stands and never slowed down.

“About 200 acres that were planted April 10 will be dug in 2 weeks, which puts them at 145 days after planting”

“Most everybody added something to the tank for worms when they made the last two fungicide applications. We primarily are seeing velvetbean caterpillars, but the mix also includes loopers, rednecked peanut worms and corn earworms.

“Remnants of lesser cornstalk borers are still present, but the rain has sent them packing. Threecornered alfalfa hopper numbers are increasing. We pay attention to them when they start girdling the stems and determine how much girdling is taking place.

“As far as insects, it’s been a normal year.”

  

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

“With widespread rain over the last week or so, the majority of our cotton looks better. We are in a huge bollworm flight, but this is the fourth generation, and they historically reach about first instar and then peter out. Of course, this is 2020, so we could see something different.

“We passed our last effective bloom date. Given the late crop, some growers are hoping to harvest blooms this week, but that’s a risky proposition. We do still have plant bugs around. Growers likely don’t need to worry about plant bugs hitting squares, but we do need to protect small bolls.

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“Plenty is going on in soybean. We are seeing stinkbugs build, and we expect heavy pressure in soybeans, even though we didn’t have heavy stinkbug pressure in corn or cotton. But that’s changing in soybeans.

“We also confirmed a fungus growth in soybeans that is rotting some pods. This is highly unusual, and we think stinkbugs transmitted the virus into the pod.

“We are still treating corn earworms and starting to see soybean loopers. They are early, so if our usual flush develops next week, we will also have a heavy soybean looper year.”

 

Eddie McGriff, Regional Extension Agronomist, Northeast Alabama

“We’re into the dog days of summer. The biggest thing we need to be scouting for in cotton and soybeans is stinkbugs. Stinkbugs seem to be lighter than usual, which may be because corn was planted later and so it’s later drying down. However, don’t forget about stinkbugs because the level of pressure still could change. They are commonly our most damaging pest.

“As long as we don’t get any wind and heavy rain from the storms this week (Marco and Laura), we’ll be fine. It’s always that wind and heavy rain combination that gets you.

“Next thing we’re thinking about is harvesting corn and making pre-harvest decisions on cotton. Everything is going to break loose at one time. We will start harvesting corn, then begin defoliating cotton in September.”

 

Jennifer Bearden, Extension Agricultural Agent, Okaloosa County, Florida

“Everything is looking pretty good. We have some whiteflies at low levels, but nothing we need to treat. We’re just going to watch them. A little boll rot is going on in the bottom of the canopy, and that situation won’t improve with the rain. We had a sunny, breezy day on Tuesday (8/25), but this week is likely a bust for us in the field. We expect rain for the next several days and we had 2 to 3 inches on Monday.

“We’re harvesting green peanuts for boiling. We don’t have a lot of insects. Most of my growers are on solid fungicide spray programs and they’re looking pretty good. This wasn’t the year to go with a weak spray program or miss a spray.”

 

Sally Taylor, Virginia Tech Extension Entomologist, Tidewater REC

“Blacklight captures of corn earworms remain high in southeast Virginia. Continue to scout soybeans that have flowers and susceptible pods.

“Several kinds of caterpillars are out there, including soybean loopers and green cloverworms, and both defoliators are turning up in places in large numbers. Only spray for them when the defoliation threshold is reached. That’s 15% until pod fill.

“Pyrethroids do not kill soybean loopers and can flair populations by killing natural enemies. Also, no single insecticide kills loopers and stinkbugs, so make informed product decisions. If you need help with that, contact me or ask for guidance from your local Extension agent or your retailer.

“On the positive side, stinkbug pressure is low this year, and you may only need to spray for worms – or, hopefully, not at all.

“Pay attention to soybean plants that are breaking at or near the soil level. If you find lodged beans, look for a girdle or callus on the stem. That is threecornered alfalfa hopper injury. It occurred very early in the season and cannot be mitigated now. Please reach out to my program if you are finding a large number of injured plants. They will be more apparent in thinner stands. To plan for 2021, we want to know how much of Virginia has been affected by this pest.

“We are also finding high rootworm injury in peanut, likely from late maturing plants. Remember that widespread injury in sandier soils is relatively rare and the only strategy for this pest is knowing your risk and preventatively applying insecticides when justified.

ALSO OF NOTE

Dicamba Ban – 12 Crop Consultants Outline Potential “Plan B” Strategies For 2021

Georgia: Cotton and Peanut Research Virtual Field Day, Sept. 9   8-27

Cotton – Midsouth – Waiting For Defoliation, Waiting For The Hurricane – AgFax   8-27

Cotton – Southwest – Yields and Crop Status, So Far – AgFax   8-26

North Carolina Cotton: Weed Management Benefits of Cover Crops – Video   8-26

Alabama Cotton, Soybeans: Don’t Stop Scouting for Insects   8-25

West Alabama: Corn Harvest Underway, Caterpillars in Peanuts, Crops in Need of Rain   8-25

Alabama Cotton, Peanuts: Plan Fungicide Applications Ahead of Hurricane Landfall   8-25

Alabama: Cotton Leaf Roll Dwarf Virus – 4 Thoughts   8-25

Shurley on Cotton: A Run We’ve Waited For   8-25

Alabama Cotton: Defoliation Considerations – Video   8-25

Cotton: Preventing Plastic Contamination when Handling Modules   8-25

Virginia Peanuts: Maturity Running Much Later Than Last Year   8-27

North Carolina Soybeans: How Do I Manage Stink Bugs? – Video   8-27

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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