Effects of diurnal irrigation on some physiological and biochemical factors of four Iranian grapevine cultivars

In order to investigate the effects of diurnal irrigation on pigments and biochemical components of four grapevine cultivars (Yaghooti-e-Ghermez, Askari, Sahebi and Keshmeshi-e-Sefid) an experiment with 5 irrigation treatments (3, 6, 9, 12 and 15 days interval) in 4 replications was done in greenhouse in 2012. The results of this experiment showed that diurnal irrigation affected on physiological and biochemical factors of grapevine cultivars. The amount of chlorophyll a, b and total chlorophyll in four cultivars were reduced with increasing diurnal irrigation, and maximum reduction was observed in 15 days interval irrigation in four cultivars. The maximum and the minimum of chlorophyll a, b, total chlorophyll and carotenoids content were observed in ‘Sahebi’ at 6 days interval irrigation and ‘Askari’ at 15 days respectively. Total soluble sugars, Phenolic compounds and proline contents of leaves in all cultivars increased and leaf relative water content decreased with increasing diurnal irrigation. The maximum leaf relative water content and proline was observed in Sahebi cultivar and the minimum was in Yaghooti-e-Ghermez and Askari cultivars. Based on the results of this study it seems that Sahebi cultivar had more tolerant to increasing diurnal irrigation in compare to Yaghooti-e-Ghermez, Askari and Keshmeshi-e-Sefid cultivars.