Insect treatment decisions are still being made. But an increasing portion of the crop is past the point that insects matter. In some cases, cotton was so stressed by heat and drought that it came to an early end. But even some irrigated cotton or fields that caught better rain are hitting termination.
Defoliation could start soon in some dryland fields that missed sustaining showers. Boll rot and hard lock are becoming factors in areas in the lower Southeast that started receiving rain.
Stink bugs are still a primary focus in parts of the lower Southeast, but another large corn earworm (CEW) flight is underway in the upper Atlantic Southeast. Some treatments could be needed in still-green fields with vulnerable bolls. Loopers and fall armyworms also are building in some cotton.
Corn earworms are posing a larger threat to soybeans than in cotton in certain areas. Virginia has been dealing with a continuous, heavy wave of egg laying in flowering beans. This week, Virginia Extension Entomologist Ames Herbert said that treatment recommendations for CEW in soybeans now include a full rate of pyrethroid tankmixed with a half-pound of Orthene. The combination has been widely adopted in the Midsouth this season to deal with similar CEW pressure. "We still have other treatment options," Herbert told us Tuesday. "But this is one more tool that we can consider."
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Phillip Roberts, Extension Entomologist, Tifton, Ga.: "We’re still in a normal pattern, with stink bugs the predominate insect being treated. Corn earworms and fall armyworms are still scattered around. We’re finding a few loopers here and there, along with a few spider mites and whitefly. No loopers are being treated in cotton, just reported. A small percentage of our cotton is being released in terms of insects, something less than 10%. We’ve had scattered storms, with decent coverage. It’s helping our late cotton fill out some bolls, but I’m afraid we’ll also get into regrowth issues in dryland cotton that made a crop and then quit when it got dry."
Jack Bacheler, North Carolina Extension Cotton Entomologist: "We’re trying to decide when to stop the scouting season in some fields that cut out a couple of weeks ago. We have a lot of cotton bolled up from the bottom to the top. Unfortunately, there isn’t a lot of space between that bottom boll and the top one. Some of this cotton probably didn’t need scouting 10 days ago. We’ll have some tricky defoliation decisions because cotton started opening early, but we still have potential for regrowth. Overall, we’ve had more fields this year sprayed for bollworms than average. For stink bugs, it’s been more like a normal year. Cotton that is green and carrying vulnerable fruit could still come under worm pressure. The corn earworm moth flight is at least into the central part of the state and could be in the rest of the state this week. It’s been heavy. In one trap last week in Scotland County in the southern part of the state, we caught 1,300 moths in 2 nights. That’s the highest I can remember in a long time. We tend to think of our last effective bloom date as August 20, but that varies, depending on location. Protecting that last potential fruit will be further complicated by the fact that a lot of cotton and even some full-season soybeans are no longer attractive to moths. So, they’ll concentrate in these last green fields. We had a field tour this week in Bertie County, and Keith Edmisten (Extension Cotton Specialist) said that he saw some cotton that could have been defoliated that day. That doesn’t represent a lot of acres, but some fields have reached that point."
John Burleson, Consultant, Swan Quarter, N.C.: "We’re checking for any worm escapes and are finding a few. But the crop is so mature that we’ll probably just let them eat. We treated about 150 acres of WideStrike for worms, but that’s been all we’ve had to deal with lately. Overall, the crop is pretty far along, and some defoliation will be done next month. Some cotton west of here is earlier because it’s been so dry in those areas. But we’ve gotten more rain, and our crop is still pretty lush. Since August 6, we’ve gotten 10 inches of rain in areas. That caused a little shedding, but cotton still looks great."
Jeremy Greene, Clemson University Cotton Entomologist, Blackville, S.C.: "Our corn earworm (CEW) traps here at the station were full again over the weekend, so we know that moths remain active, at least in this part of the state. We still have some cotton and soybeans with life left in them, so folks will have to deal with CEW a while longer. I was in some really late cotton last week that was covered up with eggs. Some Bollgard acreage in the south part of the state has been treated for fall armyworms (FAW). A consultant also said that FAW were running 4% to 5% infested plants in some Bollgard II. Our threshold is 10%, and this week we’ll probably have some fields hitting it. If folks haven’t sprayed in the last 10 to 14 days for stink bugs, they need to check. Despite having a lot of heat units and an early crop, stink bugs still have time to cause damage. We’re getting more rain today (8/16) after rain over the weekend. We were getting dry again, but now we’re mostly in good shape for moisture. Temperatures have at least gone down, which helps as long as it doesn’t trigger a lot of shed in the top of plants."
Ron Smith, Alabama Extension Entomologist: "Rainfall has been scattered statewide, and most cotton is beyond the point that it would benefit from rain, anyway. An extremely heavy tobacco budworm (TBW) moth flight and egg lay was observed on cotton in Seminole County, Georgia, on August 11, but only our late-planted conventional cotton would be at risk. It’s worth noting, though, that TBW are infesting soybeans in sizable numbers in some southern locations. A reminder: the Wiregrass REC is this Friday, August 20, starting at 8:30 a.m."
Rome Ethredge, Seminole County, Georgia, Extension Coordinator: "Caterpillars are giving us some problems, but stink bugs are the main pest right now. We’re on the second treatment on some fields. Bollgard II and Widestrike are helping with caterpillars. Some dryland cotton that cut out early will probably be defoliated in a week or so. The irrigated cotton that’s opening seems to be moving pretty quickly, which isn’t surprising, since we’re 200 heat units ahead of normal. We’re wet in spots, and since the weekend we’ve gotten anywhere from 2 inches to 2 tenths."
Ames Herbert, Virginia Extension Entomologist: "We’re getting reports about loopers in cotton in North Carolina. The Bollgard II and WideStrike are effective on loopers and, if anything, the WideStrike may be a littler better. We’re finding some corn earworm (CEW) escapes in Bollgard II and WideStrike varieties. The amount of damage can vary by variety, based on what we’ve seen in the last 2 years. Generally, it’s 2% to 5% damage, with up to 10% in some cases. When we start sampling this week, I’ll be surprised if that’s not what we find. Treatments should have been triggered in some cotton a while back, and I think most people will be okay. The worms that did slip through were likely affected by the plant’s toxin, so they were more susceptible, perhaps, to a pyrethroid application. We’re approaching that point in the third week of August when anything that hasn’t been set probably won’t be worth protecting. But in some fields we could be dealing with worms into mid September."
Charlie Burmester, Extension Cotton Agronomist, Belle Mina, Ala.: "Most of the moth flight is over, and I don’t know of anyone treating anything in cotton right now. It was a fairly light year in terms of pest pressure. On conventional cotton plots, we got by with 2 worm treatments. It’s hot and dry. We’re still getting rain, but it’s isolated, just helping small areas. Some cotton probably could be defoliated right now. I’m seeing fields that are 60% open. It happened so quickly that a lot of people aren’t ready in terms of equipment, and the gins probably aren’t ready, either. By the end of the month we should see some defoliation starting.”
Mark Mitchell, Mitchell Ag Consulting, Inc., Bainbridge, Ga.: "We’re getting a bunch of rain that we don’t need on cotton and are finding plenty of boll rot and hard lock. The rain has been variable, and boll rot is not a problem in every field. But we’ve gotten up to 3 inches of rain in the last 7 days on some irrigated cotton, and that’s going to take a toll on the bottom crop. Along with losing those bolls, we have about 5 to 6 fewer nodes on these newer varieties that we did with DPL 555. That means we don’t have that later top crop coming to replace what we’ve lost on the bottom. Plants also have aborted quite a bit of fruit with this weather. We’ve got some dryland that would be close to being ready for defoliation. But at this point, timing will depend on the weather. And if it does continue raining, we stand to lose a lot more lower bolls in irrigated fields and older cotton. We’re still spraying different bug species, trying to protect the top crop. We’re finding various combinations of green and brown stink bugs and leaffooted and clouded plant bugs. We’re taking some damage but are trying to address the bugs as they hit economic levels. We’re not finding tremendous worm pressure in the Bollgard II. Most of my 555 has had Diamond at some point, and it’s holding worms to sub-threshold levels."
Johnny Parker, Agronomist, Commonwealth Gin, Windsor, Va.: "Most of the crop in our region is reaching a very mature status. I would estimate that our crop is about two weeks ahead of average, and some fields already have a significant number of open bolls and are advancing rapidly. The primary characteristic of the cotton crop in our area is that the harvestable bolls are on about 4 to 6 nodes. Most of the fields have a very limited top crop due to dry weather. We know that bolls are mature when they are within 4 nodes above the highest cracked boll. So, some of these short plants with low yield potential will be ready to defoliate with only about 40% of the bolls open. As the cotton matures, we are going to see regrowth increase dramatically. There already is a good amount of regrowth in fields that are fully mature and in areas that have had a good bit of rain over the last 3 weeks. If regrowth started in late July, it should have some larger squares that could have a chance, but August regrowth has no value."