by AgFax Media LLC, AgFax.com
Worms continue to build in places. Bollworms are the main player in soybeans, but soybean loopers have required treatments, as well. A mix of other worms and caterpillars are turning up, as well.
The redbanded stink bug (RBSB) has now expanded its range across Alabama’s southerly counties. Treatments also have been made in Arkansas and Mississippi, which aren’t normally in the insect’s range. For a clear idea about how destructive RBSB can be, see comments by Louisiana consultant Blaine Viator.
Bean leaf beetle numbers continue to pick up in some areas. In places, kudzu bugs are succumbing to a fungal infection.
Decidedly wetter weather has moved into parts of the South, delaying corn harvest and holding growers back from applying desiccants on early planted soybeans.
LOUISIANA CROP REPORTS
Sebe Brown, Northeast Louisiana Region Extension Entomologist:
“We’re kind of all over the place with weather. It rained 2 inches on Saturday at Winnsboro but only 0.2 of an inch at St. Joe. After tomorrow (8/10), the forecast calls for a solid chance for several days. Growers have been cutting corn as fast as they can. A few guys decided to hold off on desiccation shots on soybeans because they wouldn’t have time to harvest before the next rainy pattern sets in.
“A few soybean fields have been sprayed for loopers. I’m not hearing about any locations specifically at threshold yet, but if a big storm starts pushing air up from the gulf, soybean loopers could colonize pretty fast. Stink bugs persist, and redbanded have made a big push. Some growers have exhausted their seasonal use limit of acephate and bifenthrin. We’re scaring up a few corn earworm (CEW) moths in lush R1 to R3 plants that haven’t canopied yet.”
Hank Jones, C&J Ag Consulting, Pioneer, Louisiana:
“It’s rained enough that we need a drier pattern so we can move into corn harvest and give beans a chance to dry down. Along the Interstate 20 corridor it rained 7 to 10 inches last week where storms were training through. At our farm in West Carroll Parish we’ve gotten close to 4.8 inches in the last 10 days. In Tensas Parish it’s ranged from 2 to 6 inches. We’ve been able to get in about a week’s worth of corn harvesting. Most guys cut a good bit of dryland corn. But once they got into the irrigated fields the moisture was high enough that they pulled back.
“Considering corn prices right now, nobody wants to cut wet corn and then dry it down. Dryland corn yields are up from last year – 140 to 160 bu/acre on the better dirt. Irrigated corn looks better than it did last year. I am hearing some yield variations by variety where northern corn leaf blight hammered corn in a couple of fields.
“The rain also held us up from applying Gramoxone on beans last week. This appears to be the best soybean crop I’ve ever checked. A lot of fields will average 70 bu/acre. Overall, this is the lowest amount of disease in soybeans that I can remember. Insect pressure has been normal. Last week I did pull the trigger on loopers across several thousand acres. The first 10 days of August tends to be our looper season.
“We have another chance for rain later this week, and the biggest headache is trying to time those expensive looper sprays. We need 3 to 4 hours for the material to get into the leaf. But with this weather pattern, we’ve flown on a treatment at noon with clear skies and then had a torrential rain pop up 2 hours later.”
Harold Lambert, Independent Consultant, Innis, Louisiana:
“Corn harvest is going on, although rain has held some folks back. Rainfall has generally been spotty in the last 10 days – ranging from 1 to 3 inches. Sunday night (8/7) I think everybody in my area received an additional half-inch to 2.5 inches.
“Some of our early-planted MG4 soybeans have been harvested, and those fields will be planted in sugarcane. None of my other beans are ready for a harvest aid. We’re treating stink bugs, mainly redbanded, and they’re easy to find in many fields. Some of our later beans have a tall, dense canopy, and they’re hard to even walk through. So measuring stink bug infestations with a sweep net is difficult, at best.
“Soybean loopers have been around but are only a threat in isolated areas. Velvetbean caterpillars are more abundant than we’ve seen in a number of years. Some of this hot, hot weather has at least moderated their feeding rate. But as their development accelerates, I do expect that they will be hitting later beans with tender foliage.”
Blaine Viator, Certified Independent Agricultural Consultant, Plattenville, Louisiana:
“We had no winter down here, so we’ve been finding a lot of everything in soybeans. Plus, it’s rained and rained. Our average annual rainfall is about 65 inches, and we’re on track to exceed the average by quite a lot. The rain has disrupted everything – planting, fertilizer applications and treatments for pests and diseases.
“We’ve had an ongoing battle with insects. Redbanded stink bugs (RBSB) started out a little low, and we had other stink bugs in the picture before the redbanded finally displaced them. We’ll have to fight redbanded almost to harvest in a lot of the early-planted soybeans, the ones that we’ll follow with sugarcane. Depending on the area, we’ve treated redbanded 1 to 3 times, and in places we’ll likely make a fourth treatment before it’s over. All of those applications are based on economic RBSB thresholds, too.
“You’ve got to stay on top of redbanded. In one small field we picked up a threshold, but it was too wet that week for the grower to treat, and the field was in a location that couldn’t be sprayed by air. In the second week the farmer was really busy planting sugarcane and couldn’t stop to spray. In the third week when he finally was able to spray, a big thunderstorm developed.
“By the fourth week, the field was a loss – just bushes with nothing viable in the way of soybeans – and the farmer ended up shredding what was left. Fortunately, it was a very small field, but it does show what can happen. That was an extreme situation, of course, but in cases where people couldn’t make timely treatments we’ve occasionally seen 30% to 40% yield losses
“When RBSB hit hard, they also alter the plant’s physiology, so the plants won’t dry down, and harvest aids won’t solve the problem. Between the damaged beans and all the green stems going into the combine, no grain elevator will take them.
“In terms of worms, we’ve mostly been dealing with soybean and cabbage loopers. Treatments for redbanded would have taken care of nearly anything else out there. Because soybean loopers aren’t susceptible to materials we’d apply for redbanded, we’ve had to fall back on a larvicides for them.
“With all this wet weather, disease has been very pronounced. As is usually the case, we’re dealing with cercospora. Frogeye also has been extremely heavy in places. One grower applied a fungicide, not knowing he was having problems on part of the boom, so we ended up with an untreated check, you might say. The frogeye damage was unbelievable where no fungicide went out. Soybean rust isn’t much of an issue this year, probably because we’ve been covering everything with fungicides for other things.”