Nitric oxide fumigation for postharvest pest control on lettuce

Authors: YANG, XIANGBING - University Of California; Liu, Yong Biao

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2018
Publication Date: 6/19/2018
Citation: Yang, X., Liu, Y.-B. 2018. Nitric oxide fumigation for postharvest pest control on lettuce. Pest Management Science. https://doi.org/10.1002/ps.5123.
DOI: https://doi.org/10.1002/ps.5123

Interpretive Summary: U.S. lettuce export to Japan and Taiwan faces phytosanitary barriers due to the presence of lettuce aphid and western flower thips, which are common lettuce pests. Nitric oxide is a new fumigant discovered in a USDA laboratory in Salinas, California and has potential to be a safe and effective alternative fumigant for postharvest pest control on fresh products. In the current study, small-scale nitric oxide fumigations were conducted to determine effective treatments and large-scale fumigations were conducted to confirm the efficacy against the two pests and to determine safety to postharvest quality of commercially packed lettuce. Complete control of lettuce aphid was achieved in 3, 8, and 16 h fumigations with 2.0%, 1.0%, and 0.5% nitric oxide, respectively, at 2°C in small-scale tests. Complete control of both lettuce aphid and western flower thrips was achieved in a 16 h fumigation with 0.5% NO at 2°C in large-scale tests. The fumigation treatment had no negative effects on lettuce quality 14 days after treatment. The study demonstrated that nitric oxide fumigation has potential to be an alternative treatment to methyl bromide for postharvest pest control on harvested lettuce.

Technical Abstract: The lettuce aphid, Nasonovia ribisnigri, and western flower thips, Frankliniella occidentalis, are common pests of lettuce (Lactuca sativa L.) in U.S., but are quarantine pests in Asia markets, and, therefore, require treatments on lettuce exported to Japan and Taiwan, respectively. Nitric oxide is a newly discovered fumigant for postharvest pest control that has been demonstrated safe to fresh fruit and vegetables. In this study, small-scale nitric oxide fumigations were conducted to determine effective treatments and large-scale confirmatory tests were conducted to determine the efficacy against the two pests and safety to postharvest quality of commercially packed lettuce. In small-scale experiments, complete control of N. ribisnigri was achieved in 3, 8, and 16 h fumigations with 2.0%, 1.0%, and 0.5% NO, respectively, at 2°C on both iceberg and romaine lettuce. In a large-scale experiment, complete control of both N. ribisnigri and F. occidentalis was achieved in a 16 h fumigation with 0.5% NO at 2°C. The fumigation treatment had no effect on either external or internal postharvest quality of lettuce 14 days after treatment. The study suggests that NO fumigation has potential to be an alternative treatment to methyl bromide for postharvest pest control on harvested lettuce.