Evaluation of sulfur dioxide-generating pads and modified atmosphere packaging for control of postharvest diseases in blueberries
Postharvest diseases are a limiting factor of storage and shelf life of blueberries. Gray mold caused by Botrytis cinerea is one of the most important postharvest diseases in blueberries grown in California. In this study, we evaluated the effects of sulfur dioxide (SO2)-generating pads (designated as Dual or Slow release pads) alone or in combination with modified atmosphere packaging (MAP) on gray mold and other diseases and fruit quality. Freshly harvested fruit were placed in clamshells in cardboard boxes. In each box, 6 clamshells in which one single fruit pre-inoculated with B. cinerea was placed in the center of the clamshell were used to evaluate the treatment effects on the fruit-to-fruit spread of gray mold, and the remaining 6 clamshells without pre-inoculated berries were used to examine natural infection. All clamshells together in each box were then wrapped with either a regular liner or MAP bag. There were three replicates for each pad and bag combination. Fruit were stored at 1°C for 5 weeks. On the fruit treated with the Dual pad, no gray mold was observed on the inoculated fruit, thus there was no spread of gray mold. Although gray mold developed on the inoculated fruit treated with Slow pad or MAP bag alone, gray mold spread was significantly reduced compared to the control. Incidence of decayed fruit was significantly reduced with either Dual or Slow pad, especially in combination with MAP bag, compared to the control. However, more than 25% of blueberries treated with Dual pad exhibited bleaching due to SO2 injuries. Our results suggested that the combination of Slow release pad and MAP bag is a promising method for control of fruit decay while maintaining blueberry fruit quality during storage.
Saito, S. and Xiao, C.L. (2017). Evaluation of sulfur dioxide-generating pads and modified atmosphere packaging for control of postharvest diseases in blueberries. Acta Hortic. 1180, 123-128
blueberry, postharvest diseases, sulfur dioxide, modified atmosphere packaging, Botrytis cinerea