Whitefly Trouble

This was originally posted from Dave Palmer in Manatee County.

This email was forwarded from Dr. Lance Osborne.

Based on early reports, 2011 may be another challenging year for whitefly management,with whitefly detections reported in several parts of the country.
Growers are reminded that in 2005, SAF helped USDA to convene the Ad Hoc Whitefly Task Force, made up of state and federal regulators, representatives of the ornamentals, cotton and vegetable industries, and leading scientists. That Task Force developed a comprehensive and effective whitefly management program, with specific spraying recommendations for whitefly control.

The continued success of the Whitefly Management Program depends in large part upon you: the ornamentals grower.

The program has been successful – but it will only work if growers are using it!
What should commercial growers be doing?

1. Weekly scouting is essential! Use sticky cards to monitor adults, and check the undersides of leaves to monitor the immature population. Visual inspections, sticky cards, and product performance-scouting are all necessary. Don’t let the whiteflies get ahead of you, or your treatment options will be more limited. Don’t wait until shipment to find out you have whiteflies!

2. Study and implement the “Management Program for Whiteflies on Propagated Ornamentals.” Click on any of the following websites:

The management program is based on the best scientific data and is updated to include new testing results and new products as they become available.

3. Do not rely on just one or two effective products. Rotate, rotate, rotate, with different modes of action, to decrease the potential for developing resistance. A resistant B-biotype can be just as bad as a Q-biotype! Or, if you are using a product that only kills the B-biotypes and have a mixed population, you will end up with more Q-biotypes, harder to control. Growers should also time product applications to meet label recommendations for the current life stage present. If neonicotinoids are applied too early in the crop cycle and/or heavy irrigation has occurred, the active ingredient residual may not last or may be leached out before the end of the crop cycle.

4. If you have control problems: Contact your propagator, your local extension agent or university expert. Knowing which biotype you are dealing with will help you choose the most effective control products: Q-biotype and some B-biotype whiteflies are resistant to certain products and will not be effectively controlled unless you use the correct program. So follow the Whitefly Management Program, and please get your whiteflies biotyped. The biotyping process is fast, free, and information will be kept absolutely confidential. The Whitefly Management Program provides the contact address to which samples may be sent for biotyping.

5. Practice good sanitation BETWEEN crop cycles. Whitefly management does not end once you ship. It is very important not to develop a resistant whitefly population develop within your nursery or greenhouse, and then cycle it from crop to crop! So make every effort to eradicate residual populations after shipment. It’s important for your vegetable, cotton, or peanut-producing neighbors – and it’s important for your future crop years. Letting whiteflies – and especially difficult-to-manage populations of either biotype – survive within your greenhouse or nursery is just a headache, and maybe a disaster, waiting to happen.

6. Inspect incoming shipments, and isolate if necessary. Ornamentals propagators are cooperating with the Task Force-developed program, so you should not be receiving undue numbers of whiteflies. Zero-tolerance is NOT the goal for anyone, so you may see a whitefly or two when your shipments arrive. That’s normal, and means that your propagator or rooting station is probably following good management practices. But if you see many whiteflies on incoming shipments, keep those plants separate from your other crops until they have been treated. And inform your propagator or rooting station.
7. Watch your neighbors’ fields. If you’re near cotton, peanut or vegetable fields (and especially if you are in a part of the country that has been hot and dry over the summer), you may see whiteflies migrate to your greenhouse at the end of their season. Obviously, you don’t want to be contributing whiteflies to their fields, either!


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