The effect of different vine training systems on the shelf life of Vitis vinifera cv. Bidane Sefid.

In this study, the effect of vine training system and storage time were evaluated on some grape characteristics, such as berry contamination percentage, berry shedding percentage, berry browning rate, titratable acidity, soluble solids, total phenol and the activity of peroxidase, polyphenol oxidase and phenylalanine ammonia -lyase enzymes, in order to maintain the quality of grape during storage time. Factorial experiment was conducted based on completely randomized design with two factors of vine training system (Khazandeh, pergola and cordon) and storage time (zero, 20, 40 and 60 days after storage) with three replications during 2018 -2019. After transferring the fruits to the cold storage with temperature of +4 ◦C, relative humidity of 85 -90% and storage for two months, some characteristics of grape were examined on different days after storage. The results showed that the level of contamination of the berry increased over time, and during the storage period, the lowest level of contamination (13.706%) was related to the cordon training system. Also, after 60 days of storage, the lowest percentage of berry drop (27.535%) was observed in the fruits harvested from the cordon training system. The amount of berry browning after 60 days of storage was significantly higher than other times. The highest amount of TSS (26.182 degrees Brix) was related to the Khazandeh training system in 40 days after storage, however, a significant decrease in the value of this index was observed during 60 days after storage. The results showed that the amount of phenol increased until the end of the storage period, and the maximum amount of phenol in all three training systems was significantly higher than other days in 60 days after storage. The level of peroxidase enzyme activity in the Khazandeh training system reached its highest level at 20 days after storage, while in the other two training systems, it was significantly higher than the other days at 40 days after storage. Also, the activity of polyphenol oxidase enzyme reached its maximum level in 40 days after storage in Khazandeh and pergola training systems and then decreased. While in cordon training system, the highest activity of this enzyme was observed after 60 days of storage. The activity of phenylalanine ammonia -lyase enzyme increased during the storage period, and 60 days after storage, the highest activity of this enzyme was related to the pergola training system. In general, the results showed that the cordon training system had the best effect in maintaining the characteristics of grape during the storage period compared to other training methods. [ABSTRACT FROM AUTHOR]