Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 3, 2008
Publication Date: March 20, 2008
Citation: Liu, Y. 2008. Ultralow oxygen treatment for postharvest control of western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae), on iceberg lettuce. II. Pre-treatment on lettuce tolerance and sequential controlled atmosphere. Postharvest Biology and Technology. 49:135–139. Interpretive Summary: Pre-treatment storage was demonstrated to increase tolerance of iceberg lettuce to ultralow oxygen (ULO) treatment for postharvest pest control. Lettuce pre-stored for 7 days at low temperature under normal atmosphere or under controlled atmosphere (CA) tolerated 2 day ULO treatment at 10 C for control of western flower thrips. Fresh lettuce without pre-storage, however, sustained significant injury to heartleaves by the ULO treatment. A sequential combination of CA storage and ULO treatment was demonstrated to safe and effective in controlling western flower thrips and lettuce aphid on iceberg lettuce.
Technical Abstract: Pre-stored iceberg lettuce under normal atmosphere and controlled atmosphere (CA) with about 3% oxygen at low temperature for one week was compared with fresh lettuce for their response to 2-day ultralow oxygen (ULO) treatment at 10 degrees C for control of western flower thrips. For both atmospheric treatments, pre-stored lettuce tolerated ULO treatment while over 30% of fresh lettuce sustained minor injury to heartleaves. Therefore, pre-storage at low temperature enhanced tolerance of lettuce to insecticidal ULO treatment. A sequential CA storage and ULO treatment was demonstrated to be effective against western flower thrips and lettuce aphid and safe to all seven lettuce cultivars tested. The study resulted in a safe and effective CA and ULO combination treatment for postharvest insect control on lettuce.