Submitted to: Journal of Asia-Pacific Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 14, 2012
Publication Date: February 22, 2012
Citation: Liu, Y-B. 2012. Ultralow oxygen treatment for control of western flower thrips, frankliniella occidentalis (thysanoptera: thripidae), on harvested table grapes. Journal of Asia-Pacific Entomology. 15:269-271. Interpretive Summary: Organic table grapes exported from U.S. to Taiwan are currently fumigated with methyl bromide to control western flower thrips, a quarantined pest there. The fumigation treatment is not compatible with organic products and fumigated organic table grapes can no longer command market values of organic products. Methyl bromide fumigation is also expensive because it is being phased out globally. The practice causes economic harm to U.S. grape growers as well as dissatisfies consumers who prefer organic products. There is no alternative treatment exist. In this study, western flower thrips and table grapes were subjected to ultralow oxygen (ULO) treatments at about 3°C. Thrips was successfully controlled with a 3-day ULO treatment with <0.01 ppm oxygen, and the treatment did not have any negative impact on grape quality. The ULO treatment has a potential to be developed and used to control western flower thrips on exported table grapes.
Technical Abstract: Western flower thrips, Frankliniella occidentalis (Pergande), is a common pest on grapes and other fresh commodities in the United States, but a quarantined pest in Taiwan. Methyl bromide fumigation has been used to control the thrips on U.S. exported fresh commodities, including organic table grapes. In this study, ultralow oxygen (ULO) treatments with <0.01 ppm oxygen was studied to develop an alternative treatment for thrips control. ULO treatments of 1, 2, and 3 days at 3.3°C were tested for control of western flower thrips and the 3 day ULO treatment achieved complete control of the thrips. The 3-day treatment was also applied to table grapes of Thompson seedless and Flame seedless varieties and grape quality was evaluated two weeks after the treatment. The ULO treatment had no negative impact on table grape quality. There were no significant differences in overall grape quality or percentage of premium quality berries between the ULO treatment and the control. The results indicated that the ULO treatment was effective and safe to control western flower thrips on table grapes and should be developed for commercial use.