Cotton – Midsouth – Coping In An Out-Of-Sync Season – AgFax

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

OVERVIEW

More optimism. Much of the Midsouth cotton crop has hit bloom and the mood among people in the field has noticeably perked up in the past several weeks.

Still, the season is largely out of sync. Normally by now, bollworms are turning up in cotton in the southern portion of our coverage area, but the expected flight hasn’t kicked into gear on any wide basis. Along with that, uneven stands are complicating plant growth regulator timing.

Aphids and plant bugs remain a problem in places.

In soybeans, redbanded stink bugs continue to build through much of the lower Midsouth. Kudzu bugs are showing up in parts of Tennessee.

Producers with grain sorghum are being warned to closely watch for sugarcane aphids. Numbers are taking off in places.

CROP REPORTS

Angus Catchot, Mississippi Extension Entomologist: 

“This is typically the week when we’re getting into our big bollworm flight. So far, though, nothing heavy has materialized. Of course, that can and may change over the next 7 to 10 days. Worm eggs are sporadic where they are being found. I think this delay has to do with our corn being planted a little later, and it appears the flight is about a week behind.

“Plant bugs are extremely light in areas that are normally hot spots. But in other locations, they’re tough, and some of that is likely due to proximity to corn. We’re still dealing with aphids across a large geography. There’s no real confirmation of the aphid fungus but we’re within the period when I’d expect populations to begin crashing.

“In soybeans, redbanded stink bugs (RBSB) have been treated in a little pocket around Jackson. As we move into pod-fill, I expect more RBSB reports. This year, we actually have a lot of kudzu bugs in soybeans. We’re not overly concerned but treatments have gone out in 2 or 3 spots, mainly smaller hill fields. It seems they’re moving out of kudzu.

“In the last few days, several people called about sugarcane aphids in grain sorghum, and aphid numbers have really increased in our own trials. We don’t have a lot of grain sorghum this year. But where we do, pay attention because the numbers are spiking.”

Gus Lorenz, Arkansas Extension IPM Specialist: 

“Plant bugs are moving from corn and into cotton at a pretty good pace. We have a lot of late corn and tassels are turning brown on plenty of it. So, more and more migration is under way. Plus, it’s getting dry in spots, so weeds around field edges are beginning to dry up and plant bugs are shifting out of that, too.

“Thankfully, no issues with control. A lot of people are now transitioning to acephate, Diamond and Bidrin. Transform is going out in places to knock out plant bugs and gain that complementary control on aphids.

“In the southern part of the state – Desha, Drew, Chicot and Ashley Counties – we’ve been kicking up more moths and seeing pretty good egg lays. Those egg lays are upwards of 25% in many cases – one out of four plants has eggs, which is the threshold. We’re not seeing that in every field but it seems to be happening where cotton has been blooming for 10 to 14 days.

“I think this bollworm flight will roll across a good portion of the cotton-growing region. But it’s definitely started in the southeast part of the state. We can expect it to at least move up to Interstate 40, I think.

“More bollworms also are turning up in soybeans. Even up in the Arkansas River Valley the number is about 4 to 5 per 25 sweeps.

“More redbanded stink bugs (RBSB) are apparent in the southern part of the state, although they’re not at treatment levels yet. But more and more folks have been finding them, and treatments have been going out just across the line in Louisiana. With this late soybean crop, I have no doubt that we’ll have to deal with RBSB, especially in the southern tier of counties. When you find ‘em, get ready to act. In no time at all, they’ll build from just a few to full-blown treatment levels. Redbanded stink bugs can sneak up on you.

“Sugarcane aphids are now all over the state’s grain sorghum. We don’t have many acres of it this year but sugarcane aphids seem to have found all of it and they are blowing up.”

Hank Jones, RHJ Ag Services, Pioneer, Louisiana: 

“Half of my cotton acres are well into bloom. Plant bug numbers haven’t subsided and we still have hot spots. However, cotton aphids have been the major issue in northeast Louisiana for the last couple of weeks — probably the worst I’ve seen in 20 years. Even where we spray for them, they show up again 3 or 4 days later. The parasitoids have done a pretty good job.

“I’m not kicking up bollworm moths yet.

“We do need water in spots. But after a very long spring, cotton is shaping up. We’ve battled to get it to this point and it’s now cleaned up. Overall, my attitude about the crop has improved.

“Yesterday, I gave my first recommendation this year for a redbanded stink bug (RBSB) treatment in soybeans, and they’re steadily showing up. Some of the older soybeans are at R-4 and are carrying all 3 of the major species of stink bugs and the numbers are rising. RBSBs are showing up even north of Interstate 20. By and large, a lot of greens and browns are moving out of corn into soybeans. I’m even picking up brown stink bugs in cotton.

“All of my corn is well into dent and we’re probably looking at one more irrigation. Even the May-planted corn looks very nice. But other corn fields aren’t looking so good after that tough spring. Southern rust is evident in places but it isn’t something I’m spraying.”

Scott Stewart, Extension Entomologist, Jackson, Tennessee: 

“Plant bug numbers are beginning to pick up, although it’s nothing crazy. A lot of cotton is blooming and plant bugs are simply moving along with it.

“Nothing is going on with bollworms. We usually don’t expect a flight until the last week of July and I hope that’s the schedule this year, too.

“With bollworms in cotton, treatment timing is usually more important than the rate. In dual-gene cotton, our threshold is 20% eggs. If you catch that egg-lay in a timely manner, you can get away with a 7-ounce shot of Besiege or a 14-ounce of Prevathon. If you’re late and chasing worms in the canopy, you need to step up the rate to either a 10-ounce shot of Besiege or a 20-ounce shot of Prevathon.

“We’re pulling pipe and aren’t watering corn anymore. Guys are waiting it out until they can get in and harvest.

“On soybeans, redbanded stink bugs (RBSB) are our number one pest and guys are spraying all over the state. No crazy-high numbers are being reported but I’m hearing that RBSB are moving into Arkansas and Mississippi. Here, they’re spraying stink bugs from R-3 to R-7. The earliest soybeans will probably be desiccated after the big tropical storm that’s in the forecast for this weekend. If we didn’t have all this rain coming, they’d already be desiccating soybeans in south Louisiana.”

Herbert Jones Jr., Ind. Consultant, Leland, Mississippi: 

“Our cotton is anywhere from 2-leaf all the way to blooming, and that started this week. We’re still spraying in the young cotton for thrips and aphids. I’d say 50% to 60% of our cotton is at 11 to 13 nodes and we’ve sprayed it once with Transform plus Diamond for plant bugs. It’s holding good fruit.

“Our older cotton that’s at 16 to 17 nodes also has only been sprayed once. This week, I’m going back to spray the cotton next to corn to take out more plant bugs. The bollworms just haven’t shown up yet. I’ve found a few eggs but that’s it.

“We’ve been getting showers in some places but 10 miles away it’s almost dry. We’re not watering anything and don’t expect to for about 10 days.

“I can count 4 to 6 stink bugs per 25 sweeps in soybeans. They aren’t quite at threshold and most of them are immatures. I’m picking up a few loopers and green cloverworms but not enough to be a concern.

“We’re watering corn where needed just to fill it out. In places, it’s rained enough that we haven’t had to water all year. It’s still green and lush and the plant bugs haven’t left yet.”

Harold Lambert, Independent Consultant, Innis, Louisiana: 

“Most of our cotton is in the second week of bloom. Some cotton needs rain, some doesn’t. In certain fields, we’ve had trouble applying plant growth regulators, although that’s not unusual down here.

“Except in cotton that’s very close to corn, plant bug numbers are below expectations. Most of our treatments have been on acres adjacent to corn, and control has been good where weather didn’t delay applications.

“By now, I expected more bollworm eggs in cotton. But I’m flushing very few moths, even though I’ve expected them since early July. Yesterday, bollworms showed up in some 2-gene cotton and several fields will receive Prevathon based on the 20% egg threshold.

“Aphids have been spotty, although some late-planted cotton had to be treated. Most of our plant bug treatments have been with Transform plus Diamond but we’ve also applied Bidrin plus Diamond in places. Everything has worked well.

“Weeds have not been an issue. We were able to get our sprays out when needed, and layby applications have nearly wrapped up. We were wet for a while, which delayed spraying, but we’ve been dry for about a week and that let us catch up.

“We have early MG IV soybeans planted on ground that’ll go into sugarcane next month. They’re around R-5.3 and some of those acres have been treated for stink bugs. So, far, the caterpillar complex is very quiet in soybeans.”

Tyler Sandlin, Extension Crop Specialist, North Alabama, Belle Mina:

“This is a tale of two crops. The cotton that was planted at the end of April and into the first 10 or 12 days of May looks good. Nearly everything planted after that is kind of rough. Herbicides aren’t working well and we’ve gone too long without rain.

“On the other hand, pest pressure is as light as I’ve seen it in several years – across all the crops. I don’t know of anything that’s been sprayed twice. Hopefully, insect pressure will remain light.

“What we need most of all is rain.”