What is in this article?:
- Beetle threatens California Navel exports to Korea
- No crystal ball
- Farm tactics and fumigation
- The California citrus industry is working to keep Fuller rose beetle eggs out of Navel orange shipments exported next year to Korea.
Jim Cranney, California Citrus Quality Council president, works to find ways to keep Fuller rose beetle eggs from hitchhiking in California Navel orange shipments to Korea.
Farm tactics and fumigation
Another insecticidal possibility is under review by Beth Grafton-Cardwell, director of the Lindcove Research and Extension Center, Exeter, Calif. Grafton-Cardwell has determined that the products Sevin, Actara, and Kryocide provide fairly good, but not a perfect kill of the FRB.
In combination with skirt pruning and trunk treatments, the foliar treatments could be used to kill adults which find a way onto the foliage.
Additionally, Cranney says some of the more effective foliar pesticides lack maximum residue levels (MRLs) for product use in some global markets. He says gaining MRLs for insecticides is a very time-consuming process.
Morse and Grafton-Cardwell have written a detailed FRB article which will appear in the March-April issue of Citrograph magazine, published by the California Citrus Research Board.
Treatment beyond the farm includes the possible use of postharvest fumigation gas (other than methyl bromide) at citrus packinghouses packing Navels for the Korean market.
According to Cranney, one fumigant option explored by Elizabeth Mitcham, director, UC Davis Postharvest Technology Center, Davis, is the active ingredient ethyl formate (trade name Vapormate).
Cranney says ethyl formate kills about 85 percent of FRB eggs. The CCQC is seeking full registration of the product which could be approved by this fall.
Spencer Walse of USDA-ARS in Parlier, Calif., is conducting research on the active ingredient phosphine, a relatively toxic fumigant which Cranney says would likely be used in a fumigation chamber or with a dedicated tarping system.
Overall, Cranney says FRB control could be achieved through a combination of on-farm tactics and fumigation, but this will depend on population levels in individual groves and whether the fumigants can be registered in time for use next season.
Nearly all of the available options for FRB control are new tactics so the industry has very little experience on how the products will work under field conditions.
Cranney says the CCQC is also concerned about the cost of these measures.
“We have a set of tools, when used in combination, can probably do the job,” the citrus leader said. “The industry faces a huge learning curve. The challenge over the next few years is to determine which products are the best tools for the job and how to use them.”
The next step is for the California citrus industry to execute the plan.
“I am optimistic that Fuller rose beetle egg control efforts will keep California Navel orange trade flowing with Korea, but it will require more costs and efforts to get there,” Cranney concluded.
The University of California will conduct a Fuller rose beetle field day April 22 at the Lindcove Center from 1 to 3 p.m. For more information, call (559) 592-2408.
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