What is in this article?:
- Upper Southeast cotton growers brace for thrips invasion
- New product not available
- Expensive materials
• The major variable on how much damage thrips cause is largely dependent on the weather and the size and timing of thrips flights into cotton fields.
• In terms of yield differential, Herbert says over the past 10 years thrips-related yield loss in Virginia has averaged about 380 pounds of lint per acre.
• In North Carolina, average losses are about half that amount.
NORTH CAROLINA State University Entomologist Jack Bacheler discusses thrips management.
New product not available
A new aldicarb product (Meymik), which is nearly identical to Temik, has been cleared for use by the EPA, but will not be available to farmers for the 2012 thrips season.
Reportedly, work is well under way on a new production facility for Meymik production in Georgia. However, under the best of scenarios, the new Temik-like product won’t be available to growers until the 2013 season for cotton.
North Carolina State Entomologist and thrips fighter Jack Bacheler says there is still lots to learn from Memik, even when it gets to the market place.
“It is supposed to be very similar to Temik, but little is known about the possible costs, flowability and efficacy of Meymik. Additionally, the successful re-registration of aldicarb (a carbamate), the active ingredient, by the EPA in 2014 or 2015 season is not a given,” Bacheler points out.
Seed treatments are a must for starters, but alone these products have not proven to be adequate to manage thrips in most years.
The good news may be that all the nicotinoid seed treatments, with or without additional insecticide and nematode combinations in the seed treatment, essentially work the same.
The bad news is the same as the good news. Growers will likely get what they pay for with these seed treatments, but years of research in North Carolina and Virginia indicate they are not enough to manage heavy infestations of thrips.
With Temik, growers got the added benefit of managing nematodes. Nematode damage often mimics thrips damage and vice-versa. Seed treatments with nematicides have not been adequate in fields with heavy nematode pressure.
“The Holy Grail of seed treatments would be a high rate (or new active ingredient) of an insecticide on cotton seed that would remain active for 4-5 weeks. In many cases, the 3 weeks of seed treatment activity from current seed treatments seems to come up short by only a week or two.
So far, with the exception of a few testimonies to the contrary, this seemingly simple answer to short-lived seed treatment activity has defied the best efforts of major seed companies, consultants and university scientists,” Bacheler says.
He adds that foliar insecticides following seed treatments remain an important component of the thrips arsenal for North Carolina and Virginia growers. “We and others have confirmed that the combination of Orthene following a seed treatment greatly increases the odds of having to treat later for cotton aphids and spider mites,” Bacheler cautions.