Effect of ethephon and girdling treatments on quantity and quality characteristics of Vitis vinifera L. cv. Rishbaba Qermez

Berry skin color is one of the most important characteristics of grapes that determine quality of red and black grape cultivars. It has been shown that the anthocyanin accumulation is influenced by many factors. To study the effect of girdling and ethephon (0, 150 and 300 mg/L) treatments in veraison stage on berry coloring and quantity and quality attributes of 'Rishbaba Qermez' cultivar this research was conducted as Factorial experiment based on RCBD in Urmia region on 25 years bi lateral trained vines. At harvest time the total soluble solids (TSS), titrable acidity (TA), pH, berry and bunch weight, berry firmness and shatter, amount of total phenol and antioxidant and skin berry color were evaluated. Both girdling and ethephon improved amount of TSS but reduced the TA. Berry and bunch weight was increased in girdling vine whereas ethephon didn’t have significant effect on them. At harvest time, the shatter rate in girdled vine was less than control but ethephon treatments increased shatter and reduced the berry flash firmness. Both treatments increased the amount of phenol and antioxidant composition in berry. The highest amount of total phenol was recorded in vines that treated with girdling and ethephon at veraison stage. Red berry skin color was improved by applying ethephon and girdling in veraison stage.