Control of Botrytis mold of the new seedless grape ‘BRS Vitoria’ during cold storage

• The incidence of gray mold on ‘BRS Vitoria’ table grape was investigated.
• The experiments were carried out in and during out of season.
• A good reduction of gray mold was achieved with SO2 during cold storage.
• Grape physicochemical variables were not negatively affected with SO2 treatment.

The objective of this work was to evaluate the incidence of gray mold of the new seedless table grape ‘BRS Vitoria’ grown under subtropical conditions, during the cold storage. Grape bunches were obtained from a commercial field trained on overhead trellis and located at Marialva, state of Parana (PR) (South Brazil). The trials were conducted on two consecutive seasons, regular and out of season crops of 2013. Grapes were subjected to the following treatments in a cold chamber: (i) cold storage at 0° (control); (ii) cold storage at 0 °C with SO2 pad; (iii) cold storage at 0° and inoculated with Botrytis cinerea suspension; (iv) cold storage at 0 °C with SO2 pad and inoculated with B. cinerea suspension. The randomized design was used as statistical model with four treatments and five replicates, with 20 bunches per plot. The incidence of gray mold on grapes was evaluated at 30 days after the beginning of cold storage and at 7 days at room temperature after the end of cold storage. Grape physicochemical variables, such as bunch mass, berry firmness, bunch mass loss, skin color, soluble solids (SS), titratable acidity (TA) and SS/TA were evaluated at the beginning and 30 days after the period of cold storage. The results of this study showed that a good reduction of gray mold was achieved by SO2 during cold storage and shelf life periods. Also, bunch mass, berry firmness, mass loss, color, SS, TA and SS/TA of the grape tested was not negatively affected by SO2 treatment. A good control of gray mold could be achieved on ‘BRS Vitoria’ table grapes by sulfur dioxide during storage without affecting fruit quality.