Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: 10/20/2005
Publication Date: 11/20/2005
Citation: Liu, Y. 2005. Ultralow oxygen treatment for postharvest insect control on lettuce and broccoli. Proceeding of 2005 International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. Oct 31-Nov. 3, 2005, San Diego, CA. Page 90.
Interpretive Summary: Results from controlled atmosphere studies on postharvest control of lettuce aphid on iceberg lettuce and western flower thrips on broccoli were reported. Lettuce aphid was successfully controlled on iceberg lettuce without injury to lettuce quality using ultralow oxygen treatment with oxygen levels of 0.015-0.025% without injury to lettuce quality. At even lower oxygen levels, thrips was successfully controlled on broccoli without any negative effects on broccoli quality or shelf-life. The ultralow oxygen treatments are promising in controlling lettuce aphid on lettuce and in controlling western flower thrips on broccoli.
Technical Abstract: Controlled atmosphere treatment with ultralow oxygen (ultralow oxygen treatment or ULO treatment) was studied to develop an alternative treatment to the current practice of chemical fumigation with methyl bromide. Lettuce aphid, western flower thrips, and leafminer, Liriomyza langei, were tested under different oxygen levels and temperatures for various durations. Lettuce aphid was most susceptible among the three insects to ULO treatment. Leafminer flies were more tolerant to ULO treatment than lettuce aphid or thrips. Lettuce aphid can be controlled successfully without negative impact on lettuce quality. Thrips can also be controlled on broccoli without any negative effects on broccoli quality. Ultra-low oxygen treatment for control of thrips had minor effects on lettuce quality in the form of low oxygen injury or carbon dioxide injury to heart leaves and research is continuing to determine safe ultra-low oxygen treatment for thrips control on lettuce.