Effect of spraying potassium silicate, boron and vitamin C on levels of antioxidant enzymes and phytohormones in the black French grape Vitis vinifera L.

Abstract

  The research was conducted in one of the private orchards in Al-Musayyib District, Babylon province, Iraq for the seasons 2020 and 2021 to study the effect of spraying with potassium silicate, boron and vitamin C on levels of peroxidases and catalase enzymes and the phytohormones gibberellin (GA₃) and indole acetic acid (IAA) in the black French grapevine The experiment was conducted according to a randomized complete block design (RCBD) as a factorial experiment, and the means were compared using the least significant difference at the probability level of 0.05 to test the significant differences(L.S.D.). The results showed that spraying with potassium silicate at a concentration of 500 mg. l ^-1 with boron and ascorbic acid, both at a concentration of 50 mg.l ^-1, resulted in a significant increase in the levels of peroxidase, catalylase, indole acetic acid and gibberellin in French black grape leaves, which gave (40.62 and 40.65) unit.100 g ^-1, (0.093 and 0.091) unit.g^-1 protein, (65.28 and 66.02 μmol.g^-1 fresh weight and (32.14 and 32.74) μmol g^-1 fresh weight for the first and second seasons, respectively, which was significantly superior to most of the interactions. These levels of the two enzymes and hormones studied are among the appropriate levels for the grape plant to exercise its physiological activity and carry out vital processes.