Interaction of gibberellic acid, potassium nitrate and role of pollen sources on physicobiochemical traits of grape

In table grapes including female Siah-e-Samarghandi, cluster morphology and berry size are very important. However, there are some problems in production of these grapes such as shot berries and low berry which result in reducing yield and marketing. Shot berry disorder is a major problem of Siah-e-Samarghandi cultivar. So, interaction of GA₃ at the rate of 0, 30, 60 and 90 mgL^-1 and KNO₃ at the rate of 0 and 1.5% in open and controlled pollination conditions on Siah-e-Samarghandi was conducted. Also, in another experiment the effect of pollen sources (Siah-e-Shiraz, Askari, Rotabi, Rishbaba and Aatabaki cultivars) on pollination of Siah-e-Samarghandi was evaluated. Results showed that pollens of other cultivars increased quantity characteristics of Siah-e-Samarghandi berries and clusters except for Atabaki cultivar. In general, GA₃ at 30 mgL^-1 along with KNO₃ at 1.5% had the greatest positive effect on quality and quantity characteristics of berries and cluster.