Nitric oxide fumigation for control of western flower thrips and its safety to postharvest quality of fresh fruit and vegetables

Abstract

Nitric oxide fumigation under ultralow oxygen conditions was studied for controlling western flower thrips and effects on postharvest quality of fresh fruit and vegetables. Four hour fumigation with 1.0% nitric oxide at 2°C and 3h fumigation with 2.0% nitric oxide at 5°C achieved complete control of the thrips. The 4h treatment was tested on 10 fresh fruit and vegetables including lettuce, broccoli, pepper, squash, tomato, apple, lemon, orange, peach, and pear. When the treatment was terminated by flushing with nitrogen to dilute nitric oxide before exposing the products to ambient air, the treatment had no negative impact on quality of the products. When the treatment was terminated by flushing with air to allow nitric oxide to reacts with oxygen in the air to form nitrogen dioxide, the treatment caused injuries to the majority of the fresh products. Fresh products with thick and robust skins were more tolerant than those with thin and delicate skins to nitric oxide fumigation. The 4h fumigation with 1.0% nitric oxide of strawberries at 2°C had positive impact on strawberry quality with enhanced firmness, brighter and richer color than the controls. The study demonstrated efficacy of nitric oxide fumigation in controlling western flower thrips, safety to fresh commodities, and benefits to postharvest quality of strawberries.