Cotton – Southeast – Plenty Of Insects, Limited Spraying (So Far) – AgFax

Cotton insecticide spraying. ©Debra L Ferguson

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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

Tarnished plant bugs are triggering localized treatments in parts of our coverage area. In places, numbers are running on the light side, but counts are maybe trending up a bit in locations where they normally aren’t a factor. People are on the lookout for stinkbugs, too.

Bollworm moth flights are underway.

Aphids are apparent on a wide basis, but no one seems to be treating them, at least based on this week’s reports. The aphid fungus is turning up in certain areas.

Whitefly treatments have been necessary in Georgia in areas where the pest tends to develop every year, but people in the field are beginning to find at least a few whitefly outside of their historic range.

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CROP REPORTS

Ron Smith, Extension Entomologist, Auburn University

“We are at the point when we have to decide whether to protect beneficial insect populations or protect bolls. The majority of our cotton in south Alabama is in the last week of the plant bug window. Next week will mark the third week of bloom, which is the first week of the stinkbug window.

“At this point, we need to clean up plant bugs and stinkbugs with a hard chemical. We like beneficials, but they can only carry us to about the third week of bloom in the Southeast. Again, we need to protect bolls.

“A heavy bollworm moth flight developed in southeast Alabama last week, and it’s in southwest Alabama and the Florida Panhandle this week. Check our two-gene cotton for escaped worms and determine the level of escapes.

“We’re growing a significant amount of two-gene cotton because of one popular, high-yielding variety. Southeast farmers choose the high yield over the three-gene technology because escaped worms have not been a major problem. We had pressure from escaped worms in 2017, but worm pressure was low to nonexistent in 2018 and 2019.

“Aphids are losing the battle to the fungus in some fields. We can’t predict when the fungus will occur in the others. We do know that aphids don’t significantly impact yield, so we are better off focusing on tarnished plant bugs and stinkbugs.

“Spider mites are flaring again after just a few days of hot weather. We are making treatment decisions in southeast Alabama again.”

 

Jeremy Greene, Clemson University Entomologist, Blackville, South Carolina

“Tarnished plant bugs are showing up in cotton at lower levels post-bloom than we found them in the pre-bloom period. We made 3,200 sweeps this week in South Carolina fields. The only field close to threshold was at 6.5 tarnished plant bugs per 100 sweeps, which is still below the threshold of 8 per 100 sweeps.

“Even in that field, square retention was higher than 90%, and the threshold is 80%. We didn’t find any dirty blooms. In our area, tarnished plant bugs tend to leave cotton. In the Midsouth, they keep building.

“The fungus is starting to take out some of our aphids. Aphid populations are declining in certain areas but are still building in other fields. Aphids are good food for building our predator populations, and predator insect populations are high.

“We don’t need to treat aphids. A 9-trial aphid study across the Southeast in 2019 showed treatment had no impact on yield. We are watching for the cotton leafroll dwarf virus, but we have seen fewer symptoms so far this year.

“We found a few pest stinkbugs this week, but in certain fields we saw more predatory stink bugs that were likely feeding on the lady beetle larvae that have been eating aphids. We have a robust population of beneficial insects, and we hope they are still here and hungry when bollworms and stinkbugs show up.

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“In soybean, kudzu bugs are building, and I have seen a few green cloverworms, soybean loopers and stinkbugs. Everything else is at low levels. Hold off treating a little longer so we can catch everything at once.”

 

Phillip Roberts, Extension Entomologist, Tifton, Georgia

“Aphids are crashing hard south and west of Tifton. The fungus is not in the eastern part of the state, but hopefully it’s on the way. In nearly all cases, we need to wait for the fungus to control aphids for us.

“Unless the aphids are causing significant stress, we don’t recommend treating them. We simply can’t demonstrate a consistent yield response from spraying aphids.

“Spiders mites are showing up, but only scattered fields are being treated. Spot treating is an option if it’s a localized infestation. For at least the immediate forecast, we are hot and dry, and that favors spider mites.

“We are on the front end of a corn earworm flight. This is right on time. Scout all cotton, regardless of technology. Bt cotton is not immune to corn earworm. If we see eggs and larvae, we want to give technology the chance to work. But if the larvae size up, we need to be ready to act quickly.

“About half of the cotton is setting bolls. Make sure stinkbug management is a priority. This week, I’ve heard mixed reports on stinkbugs, ranging from low to moderate pressure. The only way to know what to do is to scout. We only want to spray for stinkbugs when they are at threshold or higher. Conserve those beneficial insects.

“One of the main reasons to conserve beneficial insects is whiteflies. We are treating some fields for whiteflies in the core area. It’s so important to be on time with your initial insecticide spray. Treatable acres are in the core areas now, but scouts are picking up low populations in distant areas.

“The question is how far will they spread? Who knows? All we can do is make sure all of Georgia is on alert and looking for whiteflies. Just knowing they are there is important, because they should influence every treatment decision you make from here on out.”

 

Scott Graham, Extension Entomologist, Auburn University

“Tarnished plant bugs overall seem lighter than usual in north Alabama where cotton isn’t quite at bloom. Square retention looks good, and we are not catching any plant bugs in sweeps.

“The bollworm flight kicked off in south Alabama right on time last week. Bollworm trap counts in north Alabama were still low this week. We generally expect the bollworm flight to arrive in north Alabama in the first week of August.

“In soybeans, west Alabama farmers sprayed a couple thousand acres for redbanded stinkbugs (RBSB). The populations aren’t high, but you don’t want to play catchup with RBSB.”

 

Sally Taylor, Virginia Tech Extension Entomologist, Tidewater REC

“We’ve found a few more plant bugs in cotton this week. We are still a bit out ahead of bloom. The majority of our cotton acres will move into true bloom in the next two weeks. Scout for plant bugs after the second week of bloom using a black beat cloth. Stop by the station or give me a call if you need a beat cloth. We provide them for free thanks to generous industry supporters.,

“We are sampling for western corn rootworm in our traditional continuous corn area on the west side of the state. We again are seeing low pressure. We believe wet springs in recent years are causing high mortality.

“One precaution for peanut and cotton farmers in dry areas across the state is don’t mow. Mowing can flare spider mites. We also need to consider spider mites any time we make insect treatment decisions. Our peanut farmers are smart IPM practitioners. They’ve been doing this a long time.”

 

Chad Savery, Anchor Ag Solutions LLC, Fairhope, Alabama

“Aphid numbers are way down, even in untreated fields. We are seeing symptoms of cotton leafroll dwarf virus sporadically in a small percentage of fields.

“On about half our cotton acreage, we put out preventive fungicides for target spot prior to canopy closure. So far, we haven’t seen any target spot in treated or untreated fields.

“Spider mites haven’t reached treatment level, probably because we have had a lot of rain. Because of that rain, we are putting out tons of plant growth regulator.

“We are at the third week of bloom on our oldest cotton and we’re randomly finding stinkbugs. We started seeing bollworm moths this week. We treated tarnished plant bugs, and they appear to have been zeroed out, at least for now.”

 

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

“Everything is still running smoothly. We’re seeing scattered tarnished plant bugs, nothing heavy, and we are spraying a few fields. Most of our cotton is in the first or second week of bloom, so we are scouting for stinkbugs, and we expect to reach threshold next week.

“We are closely watching the two-gene cotton. We expect the bollworm flight to pick up next week. Most of our cotton is three-gene and it’s clean.

“Rain is boosting growth, so we are applying PGR. We’re trying to complete layby and make our last herbicide shot. Our fields are pretty clean. We applied most of our dicamba early.

“Peanut insect pressure is light. We’re on a good fungicide program. We start spraying at about 36 days old. So far, we’ve been pretty clean as long as we’ve stayed on schedule. You can find a little tomato spotted wilt virus (TSWV) in all of our fields. We have a couple of fields where the stands are adequate, but a little skippier than I’d like, and we have a little more TSWV in those.”

 

David Butcher, NC Ag Service, Inc., Pantego, North Carolina

“Cotton development is still a little behind, but it’s catching up some. The weather is finally starting to warm up. The most mature cotton we have is just beginning to flower. The majority isn’t quite there.

“We are seeing aphids and a few plant bugs. We don’t want to do a lot of spraying unless we absolutely must. With this delayed crop, we’re going to be more protective than usual because we don’t have time to make up for any mistakes.

“Corn is just starting to silk or tassel and it looks good. We have low stink bug pressure and aren’t seeing any disease.

“Our earliest planted soybeans are flowering. We are seeing a few stinkbugs, and we eventually will need to spray some.

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“We are hoping for rain today (7/13) Now that it’s getting hot, we need regular rain. Some areas of the state are dry. While we have good moisture right now, we can’t go long without a rain.”

  

Richard Davis, Davis Ag Consulting, Montgomery, Alabama

“We are setting up for a good crop if this rain continues.

“Cotton maturity varies from pre-bloom to the fourth week of bloom. Our fruit set is great. We are finishing our layby herbicide applications and everything looks clean.

“We treated tarnished plant bugs earlier, but we are not spraying anymore. The aphid fungus hasn’t shown up, but we hope to see it next week. We are kicking up a few bollworm moths, but we haven’t seen any eggs or larvae.”

 

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

“Most of the action is in cotton right now. We’re spraying tarnished plant bugs. Although populations are still spotty, they are spreading across a larger area. We are seeing them where we expect to in the northeast. But they are also showing up in the southeast, where they aren’t often seen.

“Our recommendation is to hold off on broad-spectrum insecticides until you have to use them. If you have to take out plant bugs, take them out. But pay attention to what you use to treat.

“It is important to scout within the field, especially given the heavy replant situation this year. Rank and variable growth complicates treatment decisions. We need to make a decision based on the whole field.

“Some soybean fields were hit at seedling stage by threecornered alfalfa hoppers, and that damage is starting to show up now.

P“Corn is our nursery crop for the bollworms. It looks like we have plenty of them breaking through corn. But a lot can happen between now and when they move to cotton and soybeans.”

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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