Cotton – Southeast – Multiple Pests Demand Attention As July Starts – AgFax

©Debra L Ferguson Stock Photography

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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

Aphids continue to build. The fungus is starting to show in parts of our coverage area, but the question is whether populations will crash before growers are pushed into spraying.

Stink bugs – likely heavy this season. Some areas have more greens, others more browns. Make treatment choices based on species and pay close attention to the sliding scale for stink bug thresholds.

Drought and hail have compounded a tough start. In at least one part of Alabama, farmers lost about 500 acres to hail. More growers across the Southeast are now praying for that “liquid sunshine” to find their crops.

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CROP REPORTS

Ron Smith, Auburn Extension Entomologist:

“Four pests are pressuring us and that’s likely going to continue another week or so, then we’ll add worms to the mix. The list includes aphids, spider mites, plant bugs and stink bugs. The highest pressure is in central and south Alabama.

“Aphids continue building and growers don’t want aphid stress on top of the drought stress.  I haven’t heard or seen any aphid fungus yet, so we could be from one to two weeks from that happening, maybe longer.

“Spider mites are blowing up in some fields. Immature plant bugs are hatching from eggs deposited in June, and we’re picking them up in all the fields. Stink bugs are sitting there just waiting for a bloom to drop off so they can get after those small bolls.

“We do have beautiful fields of cotton, but we have more fields with uneven plants and spotty stands. It’s not a good start and it’s not getting much better. We’re living off scattered thunderstorms, which means most fields are left out. All we can hang our hat on right now is what these varieties can do if we get into a good rainfall pattern.”

Phillip Roberts, Extension Entomologist, Tifton, Georgia:

“The hot topic is aphids. Numbers continue to increase in many parts of the state. We’re seeing fields that are heavily infested and we are treating aphids where warranted. We don’t normally treat aphids.

“The good news is the fungus started crashing aphid populations in the southernmost part of Georgia – south of Tifton – on June 29. A few days later we started seeing fields clean up because of this naturally occurring fungus.

“Historically, the fungus moves north and east. Growers who are deciding whether to treat aphids need to keep in touch with their network to find out where the fungus is. Gray, fuzzy aphid cadavers indicate the fungus. Once you start seeing the fungus in a field, there’s no need to treat because you can expect aphids to crash within a week.

“That said, keep watching this cotton. It may still be 7 or 10 days before the fungus gets to parts of Georgia. Pay special attention to seedling cotton. Heavy populations of aphids that stress seedlings may delay maturity, which we do not need on late-planted cotton. We can remove that aphid stress.

“We’ve seen fields covered up with aphids. But that’s not the case in 100% of our fields. We are seeing fields with honey dew from the top to the bottom of the plant. On the other hand, we have fields that are relatively clean. That’s why we look at every field and make field-by-field decisions.”

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

“It’s dry here – very dry. Our cotton is all the way from 5 true leaves to early bloom.

“We have a few aphids and a few more stink bugs than normal, and we’ll have to treat stink bugs in a week or so. It seems like we have a few more green stink bugs than we normally expect. Once we start getting a decent boll load, we’ll need to remove them.

“We need rain, liquid sunshine. We’re supposed to get rain at the end of the week, and we can recover if we do.”

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

“We have plenty of aphids now and we’re still waiting for the aphid fungus to materialize. That fungal organism has been less predictable than it used to be. Growers should hold off treating aphids as long as they can. Whether to treat a field is a judgement call between the consultant and grower.

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“If your cotton is irrigated and you’ve kept drought stress off of it, you might be able to wait for the fungus. If the field is dryland, under drought stress and still has good yield potential, then spraying and relieving that stress might be in order. Research indicates that aphid sprays rarely pay for themselves, so I’m always hesitant to recommend treatment. However, because the fungus is much less predictable and reliable, it is difficult to argue with spraying heavy and uniform aphid populations, especially on young, struggling cotton.

“Pretty soon, we will spray for stink bugs and if the aphids are still hanging around, you can go with a pre-mix of neonics and pyrethroids or tankmix the two to get the aphids and the stink bugs.

“Anecdotal evidence shows bollworm pressure may be a little lighter than usual. Pheromone trap captures have been low. Between that and not seeing them at high numbers in corn, I think cotton growers in our area might have an easier year than usual with bollworm. On the other hand, stink bug numbers will likely be high this season, based on what we are observing in corn.”

Larry Walker, Walker Cotton Technical Services, Flintville, Tennessee:

“A few of our cotton fields began blooming in the last week of June. That part of the crop has had a second shot of Pix and plants responded well. In places, we do have 5- to 8-leaf cotton intermingled with 10- and 12-leaf cotton, and we’ll have to use a compromised rate of Pix on those fields.

“With the showers and rains in low fields, weeds grew bigger than we’d like and those needed to be cleaned up last week. That cotton now looks much better this week. The Engenia post application cleaned up pigweeds and we also included a Dual or Outlook spray. That’s kept things manageable and I don’t think we’ll have to come back with Liberty.

“We made our top-dress fertilizer application and treated plant bugs in places where cotton was at 10 to 12 nodes. Plant bugs hit threshold at the end of last week, and treatments seem to have worked well.”

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

“In cotton, the biggest issues so far are stink bugs and aphids. Stink bug pressure is above average. We already are going back with a second stink bug application in fields at threshold. Stink bugs are the worst around corn, and we’re seeing more brown stink bugs, which are harder to control.

“We are finding a few silverleaf whitefly in cotton next to vegetables, and we are urging growers to destroy vegetables as soon as they’re done with them. Silverleaf whitefly is probably the most expensive insect that we have in Georgia. It’s a $15 to $20 an acre treatment every time we go over them.

“In peanuts, we have moderate to light worm pressure, predominately cutworm. We haven’t treated for them yet. We are starting to pick up hopper burn from leafhoppers, but we haven’t found anything at treatable levels.

“Tomato spotted wilt virus is at average levels and we’re not seeing any white mold, but we’ve been on a two-week fungicide schedule and haven’t been late.  With the Fourth of July holiday, that spray schedule could be disrupted. We need to say on top of it because conditions are just right for white mold.”

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

“The bright side is that the plant bug situation looks to be a little better, which is good because we’re going to be spraying bollworms in a month. With that in mind, we sure don’t want to be spraying broad-spectrum insecticides now.

“Stink bug numbers seem to be heavy. But there’s still no reason to treat cotton for stink bugs until we have bolls.

“Corn earworms appear to be everywhere in corn. They were inconsistent last year but this year we’re steadily finding 60% to 70% infestation in non-Bt corn.

 “This is pretty good caterpillar weather. We recommend scouting eggs on older cotton varieties and scouting larvae on the cotton that has the Vip trait.

“We have good insecticides to spray stink bug and bollworm, so we’re not in a pickle, but folks definitely need to scout so we’re not caught unaware.”

Eddie McGriff, Regional Extension Agronomist, Northeast Alabama:

“Hail damage right now is our number one concern. About 1,000 acres of cotton were severely damaged by hail and about 500 acres were a total loss.

“Plant bugs are increasing. While they’re getting above threshold, plant bugs haven’t really done much damage yet. Scout each field and make decisions on a field-by-field basis. We don’t want to treat if we don’t have to and we don’t want to flare spider mites, either.

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“Peanuts are blooming and beginning to peg. I’ve seen fields that were almost lapped in the middle, so peanuts are really doing well.”

Ethan Carter, Regional Crop IPM, Marianna, Florida:

“We’re getting just enough rain to keep the crops going.

“We do have plenty of stink bugs. I’m seeing them more in corn than cotton. Southern greens are the most prevalent. We’re finding a brown every fifth or sixth one. Cotton will be their next best friend. As these flowers start turning into bolls, stink bugs will be all over the cotton.

“We were seeing crown rot early on in peanuts, but not too many insects. Our conditions have been perfect for early-season white mold, but I haven’t found white mold yet. With peanuts lapping, the microclimate will be perfect, so fungal disease will come in soon. I’ll continue to look for white mold.”

Steve Bullard, CCA, BCT Gin Co., Quitman, Georgia:

“We have aphids and spider mites at treatable levels. The spider mites are kind of a shocker –this is early for us. Other than that, we’re applying plant grown regulators.

“We made an excellent peanut crop in our area last year. If we can stay on track, it looks like we can do it again this year. We haven’t had any white mold – yet. I’m sure it’s coming, but everybody is on a good spray program.”

Sally Taylor, Virginia Tech Extension Entomologist, Tidewater REC:

“Plant bug pressure is spotty. It’s been light in most Virginia counties, although we’ve certainly found fields with heavy pressure. To help with scouting, growers can pick up free beat sheets at the Tidewater station. Also, cotton scouting clinics will be hosted in multiple locations in July, so check with your local ANR agent or the Tidewater station for dates and times in your county.

“I’m really cautious about putting out insecticides in any crop unless we scout. We don’t want to create problems with secondary pests. A mild winter in Virginia has contributed to large populations of aphids and other insect pests. It pays to treat at recommended thresholds, so don’t hesitate to deal with known problems in your fields.

“In corn, we’re sampling for stink bugs but not seeing consistently heavy pressure. Once corn is past R1, our thresholds increase to 25%. When scouting, check the borders first. If they’re not on any of the borders, I feel safe that they’re not going to be in the center of the field. If you find them on any border, they can make it to the middle.

“In peanuts, be aware of the weather forecast if planning to apply Lorsban. If it’s not going to rain within 10 days after application, Lorsban may flare spider mites and will not be effective against southern corn rootworm.”

ALSO OF NOTE
20160514-cotton-seedling-emergence-024-watermarked-150x150%5B1%5D.jpg
Ultimately, many (if not most) fields that were planted between May 26 and June 3 had to be replanted.
cotton-picker-08312014-facebook-600111-150x150%5B1%5D.jpg
We don’t yet know the extent of that but it could be enough to mean that acres actually intended to be planted were more than the March 13.78 number?
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The peanut field conditions have gone from hot and dry in early June to a mix of wet and dry at the end of the month across much of Florida’s peanut production area 
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Plant bug populations have been spotty, and lower overall than this time last year. 10% or fewer of Virginia fields need insecticide applications this week. Unfortunately, a much higher percentage will end up treated.
squaring_cotton_irrigation_pivots_university_of_georgia1-150x150%5B1%5D.jpg
Now that cotton is growing again, we need to control vegetative growth in order for the plant to allocate resources toward the fruiting structures on the plant.
aphid-cotton-insect-150x150%5B1%5D.jpg
In certain instances, treatments are warranted, and those are usually very bad situations with too much stress on the plant.
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Once cotton blooms for a couple weeks, monitoring square retention becomes a less reliable way to make treatment decisions, as does the sweep net.
cotton-rows-DF-300_29-57-150x150%5B1%5D.jpg
Some of this cotton is ready for nourishment, some of it just needs time to grow up and some of it needs a little Pix to keep it from getting wild.

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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