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

Abstract

a b s t r a c tThe 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 SO 2 pad; (iii) cold storage at 0 • and inoculated with Botrytis cinerea suspension; (iv) cold storage at 0 • C with SO 2 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 SO 2 treatment. A good control of gray mold could be achieved on 'BRS Vitoria' table grapes by sulfur dioxide during storage without affecting fruit quality.

Cold Storage and Biocontrol Agents to Extend the Storage Period of ‘BRS Isis’ Seedless Table Grapes

“…Moreover, for 'BRS Vitoria' table grapes inoculated under similar conditions, the gray mold incidence observed was higher than 40% [10]. Thus, the incidence values can change according to cultivar, storage time, temperature, and packing conditions.…”

“…Thus, the incidence values can change according to cultivar, storage time, temperature, and packing conditions. Nevertheless, these authors achieved gray mold control in table grape cultivars using salt strategies, such as potassium bicarbonate [18,19] and sulfur dioxide releasing pads [10].…”

“…In subtropical areas, grape harvest can occur during high favorable conditions for the development of postharvest fungal diseases, which can limit the long-distance transportation of fresh grapes [8][9][10]. Among fungal diseases, gray mold, caused by Botrytis cinerea Pers.…”

“…In addition, preharvest fungicide applications are not always effective in preventing and controlling gray mold infections during long-term storage. Their efficacy is strictly related to the timing of application [15], and for safety reasons, their application is no longer allowed in many countries [10].…”

“…For example, treatments with salt solutions such as potassium bicarbonate have been recommended for inhibiting gray mold in 'Italia' and 'Benitaka' table grapes [18,19], as well as cold storage combined with sulfur dioxide (SO 2 ) [10,[20][21][22][23].…”