It has been an odd year for cotton production in Alabama, but “odd” in a good way, says Auburn University Extension cotton specialist Dale Monks.
“Usually, at about this time of year, we're talking about moisture shortages, cut-outs and what we'll need to finish out the crop. But rainfall has made all the difference this year,” said Monks during the recent East Alabama Cotton Tour.
Alabama's cotton crop, for the most part, is delayed this year, he adds. “From what I've seen, the earlier planted cotton has looked much stronger than the later planted cotton. It all depends on the development of the root system and how much rain the plant has received,” he says.
Wet weather conditions have created a large cotton plant with — in many cases — an under-developed root system, says Monks. “We have a large plant that needs moisture for the remainder of the season. A week of dry weather will cause some plant wilting after just a few days. It's not a big cause for concern because there's nothing we can do about it. The root systems just can't support that type of plant structure without rainfall for the remainder of the season,” he says.
North Alabama's Tennessee Valley received heavy rainfall early in the season, says Monks, causing some corn to be drowned and some cotton not to be planted.
“Cherokee County normally has 22,000 to 24,000 acres of cotton, and those growers planted only about 9,000 acres this year. They have about one-third of their normal crop because of early rainfall.
“We've seen a decrease in cotton acres statewide in Alabama this year, going from 600,000 acres last year to about 560,000 acres this year. Part of that is due to poor planting conditions early in the season,” he says.
Warm temperatures in late July and August have created fields of healthy, green and growing stands of cotton, says Monks. “In every field, we have strong areas and weak areas. In the weaker areas where water has stood, we have short, yellow cotton,” he says.
Alabama cotton producers won't see record-breaking high yields this year, but they also shouldn't have a short crop, he says.
“In general, cotton appears to be running about two weeks behind normal.”
Heavy rainfall during the early part of the season means that fertilizer and chemicals were re-applied in many Alabama fields.
“Growers in Alabama's Wiregrass region, in the southeast part of the state, should have one of their best crops in several years. North Alabama has a reasonably good crop, although it's running a little late. Growers in central and south Alabama should have good crops. In southwest Alabama, near the Gulf Coast, there are some fields that'll make two bales and others that'll be turned loose. Baldwin and Mobile counties received about 40 inches of rain over a three-month period.”
Cotton growers in central and south Alabama saw a gradual movement this year of plant bugs into their cotton crops, says Extension Entomologist Ron Smith.
“It was primarily the tarnished plant bug, and we never saw a sharp peak that required spraying. But eventually, as we moved into July, a lot of our fields had enough plant bugs to damage the cotton,” says Smith. “In central Alabama, a lot of the population switched over clouded plant bugs in July. The tarnished plant bug population played out, even in unsprayed fields.”
The clouded plant bug, he explains, is a larger, more robust insect, and it customarily is a late-season pest. “We associated the clouded plant bug more with boll feeding. We've done research on a fairly high population of plant bugs, and we believe the clouded plant bugs are more difficult to kill,” he says.
A large number of brown stink bugs survived the winter, says Smith, and most of the stink bugs found in fields in early July were of the brown species. As corn began to dry down, green stink bugs entered the system, he adds.
“Right now, we're seeing a mixture of brown and green stink bugs,” said Smith in August. “We make a distinction between the two because the brown stink bug is more difficult to kill. Most pyrethroids don't do a very good job on that pest. We've had to go with a phosphate such as Bidrin to kill brown stink bugs.”
Stink bugs don't necessarily cycle out, says the entomologist, because adults live for more than 30 days. “Most stink bugs now in the field will be there until the cotton matures out. If you have damaging numbers, and you hope they'll cycle out, just know that it won't happen. They'll be there pretty much for the remainder of the season.”
There actually is more than one species of brown stink bug, says Smith. “Some have pointed spines on their shoulders — we've always said these were beneficial stink bugs. But to be safe this year, I'm not sure we should count them as beneficials. We probably should count all stink bugs as damaging pests. There primarily is one species of green stink bug that damages cotton.”
It has been a relatively “light” worm year in Alabama cotton, with the exception of isolated areas, he says.
“Up until about mid-July, we were seeing tobacco budworms, which meant that the new chemistry was required to do a good job of control.
“In Prattville in central Alabama, we had a heavy moth flight at about the middle part of July, and the egg laying continued for about 14 days. They all were bollworms, so we did a good job of controlling them with pyrethroids. Anything we see for the remainder of the season will be a mixture of both species.”
A mixture of bollworms and budworms requires new chemistry or at least a tank-mixture of new chemistry, says Smith. The Double-Threat product, with a mixture of the pyrethroid Capture and the new chemistry Tracer, is a good choice for late-season control, he says.
“Capture is good on stink bugs, and it's the one pyrethroid that does work on brown stink bugs. It's a good choice when we're trying to guess the population late in the season. There probably are other products you can mix yourself.”
There aren't many beneficial insects left in some Alabama cotton fields, says Smith. “Every field presents a different situation. I can't say, in general terms, what'll be needed for the remainder of the season. There's always a chance we'll see some fall armyworms, and we also could see some soybean loopers before the end of the year.”