Influence of post-véraison water deficit on berries yield and quality of three table grape cultivars

Abstract

In order to investigate the effect of regulated deficient irrigation (RDI) on some quantitative and qualitative characteristics of the three commercial grapevine cultivars (i.e. Keshmeshi, Sahebi and Sharabi), an experiment was set in split plot arranged in an RCBD design with three replications. In this experiment, irrigation treatments including 100 (as control), 80%, 60% and 40% crop evapotranspiration (ETc) were implemented in a period between onset of berries color change (véraison) to harvest of fruits. At the end of experimental period, some traits such as berry weight, berry length, berry diameter and cluster weight as well as some fruit quality traits such as total soluble solids (TSS), titratable acidity (TA), flavonoids, anthocyanin, total phenol, and total antioxidant capacity were measured. The results of this experiment revealed that effect of RDI at different levels on yield, berry and cluster weight, berry length and diameter, TSS, TA, anthocyanin, phenol, and flavonoid was significant. Also, there was no significant difference between control and 80% ETc in terms of yield, berry diameter, TSS, and TA; and these treatment enhanced total phenol, anthocyanin and antioxidant activity in the three cultivars. In both years of experiment, RDI remarkably enhanced anthocyanin, flavonoids, antioxidant activity and phenolic concentration. Overall, the results indicated that 80% ETc might be sufficient to gain adequate yield in Keshmeshi, Sahebi and Sharabi without undermining the quality of fruit.