Location: Crop Improvement and Protection Research
Project Number: 5305-43000-004-04
Start Date: Jun 30, 2014
End Date: Sep 30, 2014
Oxygenated phosphine fumigation and nitric oxide fumigation will be studied as methyl bromide alternatives for postharvest insect control on fresh fruit and vegetables, phytosanitary barriers facing U.S. exported fresh commodities on overseas markets. Insects used in this project will include codling moth (Cydia pomonella), light brown apple moth (Epiphyas postvittana) (LBAM), western flower thrips (Frankliniella occidentalis), lettuce aphid (Nasonovia ribisnigri), and leafminer (Liriomyza langei). Codling moth and LBAM are currently reared in the APHIS-PPQ-CPHST lab in Salinas, CA and will be used in this project. Western flower thrips and lettuce aphid are currently reared in our laboratory/greenhouse cultures. The leafminer will be collected from infested lettuce leaves from the field for testing. For oxygenated phosphine fumigation, insects will be fumigated with 500-2000 ppm phosphine under 50-60% O2 at 1-5°C for different durations to develop an effective treatment for a specific insect. The treatment will be tested on host commodities along with the pest to verify its efficacy and determine its potential impact on product quality. For nitric oxide fumigation, insects will be fumigated with 0.5-2.0% nitric oxide under nitrogen atmosphere with =50 ppm O2 at 1-5°C for different durations to determine effective treatments. Identified treatments will be tested on host commodities to determine safety on product quality. For nitric oxide fumigation of fresh products, fumigation chambers will be flushed with nitrogen to reduce nitric oxide level before terminating the treatment to prevent potential injury to products by nitrogen diuoxide from reaction of nitric oxide with oxygen. Codling moth eggs and larvae at different instars on artificial diet and in infested apples will be subjected to oxygenated phosphine fumigation treatments and nitric oxide fumigation treatments to identify most tolerant life stages and develop effective treatments for the most tolerant life stage(s). The selected fumigation treatments will be further evaluated for potential impact on apple quality in larger chamber fumigations. An effective oxygenated phosphine fumigation treatment has been developed for control of LBAM eggs. Under the current project, oxygenated phosphine fumigation for control of LBAM eggs will be evaluated for safety to cut-flowers. LBAM will also be studied for responses to nitric oxide fumigations and treatments will be developed for eggs and other life stages. Once effective treatments are identified, they will be evaluated for safety to quality of fresh commodities including lettuce, cut-flowers, and fruit. Nitric oxide fumigation treatment for western flower thrips will be developed and tested on different fresh commodities including lettuce, broccoli, strawberries, apple, and orange for safety to product quality. Nitric oxide fumigation for lettuce aphid and leafminer pupae will also be developed and tested on lettuce to verify efficacy and determine its safety to lettuce quality.