The use of vented clamshells has become popular in the packaging of grapes for local and international markets. The aim of this study is to evaluate the postharvest preservation of ‘Benitaka’ table grapes individually packaged in vented clamshells using different types of SO₂-generating pads and perforated plastic liners during cold storage. A completely randomized design with four replications in a two-factor arrangement with an additional treatment [(4 × 3) + 1] was used. The trials were carried out under two situations: Artificial or natural infections with Botrytis cinerea, which is the causal agent of gray mold on table grapes. The incidence of gray mold, shattered berries, and stem browning were evaluated at 30 and 45 days of cold storage at 1 ± 1 °C and 3 days of shelf-life at 22 ± 1 °C after the period of cold storage. Mass loss and berry firmness were also examined at the end of the cold storage period. The use of dual-release SO₂-generating pads containing 5 or 8 g of a.i. and slow-release pads with 7 g of a.i. was effective in controlling the incidence of gray mold in grapes packaged in vented clamshells and kept under cold storage for up to 45 days. Under these storage conditions, perforated plastic liners with 0.3% ventilation area or micro-perforated liners with 1.0% ventilation area reduced the percentage of mass loss and shattered berries.

The objective of this work was to evaluate the effect of ethephon and of abscisic acid (ABA) application timing on the color of 'Rubi' Table grape. Eight treatments were evaluated: control, without application; ethephon 500 mg L‑1 applied seven days after veraison (7 DAV); and two concentrations of ABA (200 and 400 mg L‑1) arranged with three application timings at 7 DAV, at 15 days before harvest (DBH), and at 7 DAV + 15 DBH. ABA does not modify physical‑chemical characteristics of the cluster and improves the color of grapes, especially when applied twice (7 DAV + 15 DBH) at the concentration of 400 mg L‑1.

The objective of this work was to evaluate the effect of (S)-cis-abscisic acid (S-ABA) application at different ripening stages, in increasing phenolic compounds and color of berry and juice of 'Isabel' grape (Vitis labrusca). The evaluated treatments were: control, without S-ABA application; 400 mg L^-1S-ABA applied 7 days before veraison (DBV) + 400 mg L^-1S-ABA at 35 days after first application (DAFA); 400 mg L^-1S-ABA applied at veraison (V) + 400 mg L^-1S-ABA at 35 DAFA; and 400 mg L^-1S-ABA applied 7 days after veraison (DAV) + 400 mg L^-1S-ABA at 35 DAFA. There was no difference among treatments regarding the physical characteristics of berries and clusters, as well as total polyphenols in berry and juice. However, there was an increase in total anthocyanins in berry and juice with S-ABA application. Colorimetric variables indicated the increase in color of berry treated with S-ABA. Juices produced from grapes treated with S-ABA were more appreciated by tasters. The treatments with 400 mg L^-1S-ABA applied 7 days before, during, or 7 days after veraison, combined with an additional application 35 days after the first one, increment total anthocyanin concentration and color of berry and juice of 'Isabel' grape, with better juice acceptance, without affecting total polyphenol concentration.

In colored table grapes, the anthocyanin contents are inhibited by the high temperature during ripening and berries suffer a lack of skin color, thus affecting their market value. In order to overcome this issue, a research study was planned to evaluate the influence of (S)-cis-abscisic acid (S-ABA) on rates of anthocyanin accumulation in table grapes when applied at different timings of ripening, and to quantify the gradual increase of berry color. The study was conducted in a commercial vineyard of ‘Benitaka’ table grapes (Vitis vinifera L.), grown under double annual cropping system in a subtropical area. The trials were carried out during two consecutive seasons (i.e., summer season of 2015 and off-season of 2016). The treatments used for the experiments contained 400 mg L⁻¹ S-ABA applied at different timings of veraison (the onset of ripening), as follows: control (with no application); at pre-veraison (PRV); at veraison (V); and at post-veraison (POV). For all S-ABA treatments, a second application was performed 10 days after the first application. Berries were analyzed for weekly and daily anthocyanin accumulations, weekly and daily color index development (CIRG), total soluble solids (TSS) content, titratable acidity (TA), and maturation index (TSS/TA). Grapes subjected to exogenous application of S-ABA at any time of veraison, especially at PRV or at V, significantly increased the anthocyanin accumulation as well as berry color index development. Other chemical properties of grapes (i.e., TSS, TA, and TSS/TA evolution) were not affected by the use of S-ABA and followed a predictable pattern in relation to days of berries ripening.

The development and evaluation of new cultivars of seedless grapes (Vitis spp.) with good yield and adapted to different edaphoclimatic conditions are essential to increase the competitiveness of the productive system. The present work had the objective to characterize the phenology and the yield of the new hybrid seedless grape ‘BRS Melodia’, grown in an annual double cropping system in a subtropical region. The evaluations were carried out during the 2013 summer cropping period and the 2014 off-season cropping period in a commercial area located in Marialva, PR, Brazil. The ‘BRS Melodia’ scions were grafted onto ‘IAC 766 Campinas’ rootstocks, trained in an overhead trellis system spaced at 2.5 × 2.5 m. In both seasons, the duration in days of the main phenological phases of the vines, as well as their thermal demand and their physicochemical and productive characteristics were evaluated. The ‘BRS Melodia’ seedless grapevines presented a cycle of 138 days and yield of 23.85 tons.ha⁻¹ in the summer season, and 121 days and yield of 19.4 tons.ha⁻¹ in the off-season crop. The soluble solids, titratable acidity, and maturation index were 15.1 °Brix, 0.5% tartaric acid and 28.5, respectively, in the summer season and 15.4 °Brix, 0.6% tartaric acid and 25.6 in the off-season crop, indicating a possibility of cultivate this new hybrid seedless grape under an annual double cropping system in subtropical conditions.