Advances in postharvest pest control on perishable commodities using ultralow oxygen treatment and low temperature phosphine funigation

Authors: Liu, Yong Biao

Submitted to: Controlled Atmosphere & Fumigation in Stored Products International Conference
Publication Type: Proceedings
Publication Acceptance Date: 7/15/2008
Publication Date: 9/1/2008
Citation: Liu, Y. Advances in postharvest pest control on perishable commodities using ultralow oxygen treatment and low temperature phosphine fumigation. Proceedings of 8th International Conference on Controlled Atmosphere and Fumigation in Stored Products, Sept. 21-26, 2008, Chengdu, China.

Interpretive Summary: There is an increasing need for developing methyl bromide alternatives for postharvest pest control on perishable commodities. In the last several years, advances have been made in ultralow oxygen (ULO) treatment and low temperature phoshine flower thrips and black widow spiders on lettuce, broccoli, and table grapes. However, there are also challenges in preventing injury by ULO treatment. Low temperature phosphine fumigation treatment was also successfully developed for control of western flower thrips on lettuce, broccoli, asparagus, and strawberries. Control of lettuce aphid and leafminer using low temperature phosphine fumigation was also achieved on lettuce. A commerical scale trial of low temperature phosphine was conducted successfully to control western flower thrips in a feefer container. These progresses indicated that ULO treatment is promising for controlling specific pests on selective commodities. Low temperature phosphine fumigation also has potential to be used on fresh commodities for postharvest pest control.

Technical Abstract: Recent research in postharvest pest control on fresh fruits and vegetables for export to markets have resulted in promising ultralow oxygen (ULO) treatments and low temperature phosphine fumigation treatments for a variety of pests on different commodities. Lettuce aphid (Nasonovia ribisnigri), western flower thrips (frankliniella occidentalis), and black widow spiders (Latrodectus hesperus) were successfully controlled on head lettuce, broccoli, and table grapes repsectively without negative impact on product quality. Tolerance of lettuce to ULO treatment varied among cultivars and was also affected by pre-treatment storage. One weekstorage under normal or CA conditions prevented injury to lettuce by the subsequent ULO treatment for control of western flower thrips. In general, shorter treatment at higher temperature had less impact on lettuce quality as compared with longer treatment at lower temperature for control of western flower thrips. Low temperature fumigation with diluted pure phosphine gas was effective for control of western flower thrips on lettuce, broccoli, asparagus, and strawberries without negative effects on product quality. A successful commercial trial in a refrigerated reefer container also demonstrated the efficacy of low temperature phosphine fumigation for control of the thrips and its safety to the postharvest quality of all products. Complete control of lettuce aphid and leafminer (Liromyza langei Frick) were also achieved with low temperature phosphine fumigation without negative effects on lettuce quality. These advances provided promising controlled atmosphere and fumigation treatments for commercial development. The ULO treatment als has potential to be used for postharvest pest control on organic products and facilitate international trade of organically produced agricultural commodities.