AgFax: MidSouth Cotton
By Laykyn Rainbolt and Owen Taylor
AgFax
Plant bugs are the main player this week. More treatments have cranked up as the insects move into cotton from corn and wild hosts. Heaviest pressure tends to be where cotton adjoins corn. In extreme cases, three or even four plant bug applications have been made.
Aphids are around and even building in some cotton. The aphid fungus is mostly occurring in spots.
Bollworm moths are in the air and people are finding eggs, but activity continues to run behind schedule across a big part of our coverage area.
Hank Jones, RHJ Ag Services, Winnsboro, Louisiana
“About 75% of my cotton acres are in the second or third week of bloom (as of 7/13). The cotton looks very good, with a nice fruit set, and we have had some very well-timed rains. We’re into the second week of bloom and haven’t irrigated any cotton yet. We still have a long way to go, but the crop has great potential.
“We are starting bollworm sprays this week in our dual-gene cotton. This isn’t a tremendous egg lay yet, but moths are depositing eggs low in the plant. It’s not uncommon to find larvae in the bloom tags this time of the year. The moth flight is certainly kicking off, and we are just in the early stages of it.
“In May-planted cotton adjoining corn, we have been battling terrible and consistent plant bug migrations for the last two weeks. These are maybe the worst plant bug numbers I’ve fought in the last 4 or 5 years. In extreme cases, some areas have been treated 3 or 4 times for plant bugs. However, pressure subsides greatly the farther from corn the cotton is.
“Fortunately, no spider mite issues have developed this year.
“Growers are starting to spray a lot of redbanded stink bugs (RBSB) in soybeans. We’re at about 75% threshold (7/13) in places, and we’ve been riding a bunch of sub-threshold RBSB populations for 14 to 17 days. It’s time to clean them up because we are starting to see a few immatures. Small numbers of southern green and a couple of brown stink bugs are in the mix, but we’re mainly spraying RBSB.
“We are picking up some target spot in beans. With all the rain over the last two weeks, I’m not surprised. Plants developed dense canopies, so things are staying wet underneath. We likely will be spraying those beans soon. Target spot isn’t a disease to take lightly.
“This might be one of the best corn crops I have ever checked. I found some early March corn in black layer over the past few days, and we’re probably done watering 75% of our corn acres. In places, northern corn leaf blight developed, and we’ve sprayed certain fields twice.”
Harold Lambert, Independent Consultant, Ventress, Louisiana
“We’re in the third week of bloom on the oldest cotton, and the younger cotton is just starting to bloom (as of 7/13). Square retention is really good, although we’ve had two spells of heavy rain in the past couple of weeks, and our oldest cotton is starting to shed a lot of small bolls. The hot nights are not helping boll retention, of course.
“A few applications have gone out for plant bugs, but the numbers aren’t extreme like we’re used to seeing.
“We are looking pretty hard for bollworms on double-gene cotton, but the egg laying has not been terrible so far. I’ve had to treat very few acres, and there’s basically none in most counts, although that could change at any time. I’m mainly finding them down in the plant on dried bloom tags but not in the terminals. Maybe that’s because it’s so hot.
“A lot of my corn is at black layer, and the rest is close behind. We are in dry-down mode, and the high heat is helping with that, but moisture is still way too high to harvest right now. We should be harvesting in 2.5 weeks.
“The oldest soybeans are at R6. Several of those fields have been treated twice for stink bugs, and the majority of them have been treated at least once, which is normal. Redbanded stink bugs have been late showing up, which I think validated how well we handled them near the end of last season. We had no winter kill at all. When combined with counts of other species, we were over threshold in a lot of fields.
“We have been following our standard fungicide procedure, starting when beans reach R3. Our youngest beans are still around V8 to V10.
“Aerial blight has only been an issue in a few fields that have a history of it. So far, defoliating caterpillars are staying really light.
“By this point in July, it’s not uncommon to have bollworm pressure in certain soybean fields, but we haven’t seen that happening so far.”
Sebe Brown, Louisiana Extension Field Crops Entomologist
“Plant bugs are really picking up across the state. It’s hot and dry and the corn is starting to dry down, so we’re finding this influx of plant bugs from corn into cotton. Much of the cotton is into the second or third week of bloom, so it has plenty of blooms for plant bugs to go to.
“In places, guys are having trouble gaining control. We’re also seeing a combination of plant bug damage and physiological shed from a week of cloudy weather. We do have sunlight and heat units this week, and that should continue at least 7 days (from 7/15). All that will help.
“No spider mite concerns are turning up, and I think that gets back to a good deal of Liberty herbicide being applied both pre- and post-emerge. In places, that likely did a number on mites before the cotton even emerged.
“Aphids are starting to resurge. Rains kind of beat them down, but they’re coming back with these hot, dry conditions. The aphid fungus moved through in places but it hasn’t been widespread. Aphids are definitely out there but not at super-serious levels, and plant bug applications also are taking them out.
“The expected bollworm moth flight really hasn’t materialized to any degree. In normal hotspots, eggs are barely reaching threshold on dual-gene cotton. Trap numbers are picking up, but you have to scout hard to find eggs, and damage isn’t there yet. Worms still have time to materialize but the moth flight and egg lay are a little delayed this year.
“In soybeans, threecornered alfalfa hoppers are starting to blow up in places. Stink bug numbers are picking up, too. We’re seeing surges in stink bug numbers as you go farther north. Another chunk of soybeans will hit R5, and that triggers stink bug movement. We’re finding a mix of redbanded stink bugs, greens, southern greens and browns, but the majority are redbanded.
“A little rumble has started about soybean loopers in soybeans in far south Louisiana. That’s early for us. But the way this year has gone, I’m not surprised. Numbers aren’t huge yet but are picking up.”