In-package use ofMuscodor albusvolatile-generating sachets and modified atmosphere liners for decay control in organic table grapes under commercial conditions

Abstract

Introduction . In-package biofumigation with the volatile-producing fungus Muscodor albus was tested to control fungal decay in organic table grapes stored at a commercial packinghouse. Materials and methods . Sachets containing two different amounts of activated M. albus culture were inserted into shipping boxes containing approximately 4.5 kg of ‘Thompson Seedless’ or ‘Red Seedless’ table grapes. The volatiles were contained inside the boxes either by wrapping pallets of the boxes externally with plastic film after pre-cooling (pallet wrapping) or by using a modified atmosphere liner inside each box. Decay incidence was evaluated after 7 weeks of storage at 0 °C. Results . The M. albus sachets reduced decay incidence among ‘Red Seedless’ table grapes in both wrapped pallets and boxes with liners. In this cultivar, the modified atmosphere liner alone reduced decay incidence by about 70% and the M. albus treatment in the liner further reduced decay incidence, regardless of the amount of M. albus used. The combination of the M. albus sachet and the modified atmosphere liner proved to be the most effective decay control treatment. Decay incidence was lower among ‘Thompson Seedless’ table grapes and a significant decay control was only observed after the grapes had been allowed to warm up after storage with the 50-g rates applied inside the liner. No adverse effects were associated with the treatment or the liners. Discussion . Based on our results, biofumigation with M. albus sachets is compatible with the commercial handling of organic table grapes and could provide significant improvement in their shelf life.