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Georgia Dealing With Whitefly Problem

Whiteflies in Georgia? Yes, it’s true. The scourge of the Southwest can invade Southeast cotton fields as well.

Especially last year. Hot, dry conditions throughout the South led to high populations of whiteflies, especially where vegetables were nearby.

“I don’t want anyone to think I’m blaming the vegetable growers, but it’s true that vegetables are a primary host for whiteflies,” says Phil Roberts, Georgia Extension entomologist. “We see them more in Georgia than elsewhere in the South.”

So far, the problem is a localized one, says Roberts. “It’s mostly only in south-central Georgia.”

That could change, though.

“Whiteflies tend to be a problem when there are vegetable farms in the area,” explains Wayne Brown, technical sales representative for Nichino America. “Growers in the Southeast region are always looking for higher-value crops, and vegetables are one such crop.”

Control Strategies Exist

The primary controls for whiteflies are adulticides like Thimet and endosulfan, or insect growth regulators like Knack and Courier.

Roberts prefers the latter, by far.

“The growth regulators are target-specific and much less harmful to beneficial insects,” he explains. “And beneficial insects are an important part of whitefly control. Whiteflies multiply so rapidly that if you come in with a broad-spectrum chemical, you’ll be chasing whiteflies all season.”

Doyle Singleton is an independent crop consultant based in Pelham, Ga., who consults on more than 10,000 acres of cotton and vegetables. In addition, his farmer has 350 acres of cotton.

“The main thing is that if whiteflies get ahead of you, there’s nothing you can do,” says Singleton. “You can knock them back, but that’s about it. That’s what I like about Courier. It controls the nymphs and keeps them from going to adults. Courier gets into the plants and stays there while the plant grows.”

Singleton knew of Courier from his work with vegetables. In 2007, most of his clients were able to get through the season with a single application of Courier insect growth regulator.

“With 60-cent cotton, growers didn’t want to come back again, so most went with just a single application, and it held its own,” reports Singleton.

His father’s yield goal is two bales an acre on double-cropped cotton, “and we achieved that,” says Singleton. “But I saw a lot of 650-pound cotton in the area – yield losses of 100, 150, even 250 pounds where growers let whiteflies get away from them.”

Difficult Decision

It’s a hard call for producers, says Matt Joiner, sales representative with UAP in Albany, Ga.

“If it rains, cotton can grow out of the damage caused by whiteflies, so a lot of growers wait, hoping it will rain,” explains Joiner.

“But these IGRs have to go on early. If you’re too late, that becomes a wasted application. Then you’re stuck with a harsh chemistry, and you could end up treating multiple times.”

One thing to keep in mind is to always rotate between insecticides.

“Vegetable growers are the first to get hit with whiteflies, and what they use on their crops will affect what cotton growers do,” notes Joiner.

Nichino contributed information for this article.

Tips To Control Whitefly Outbreaks

• Be aware of vegetable farms.

• Check on host environments.

• Use insect growth regulators early.

• Avoid broad spectrum spraying.

• Don’t kill beneficial insects.

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