Effect of Grafting Time, Antioxidant and Plant Growth Regulators on Minigrafting in Walnut (Juglans regia L.)

One of the most important factors in successful grafting of woody plants is inhibition of oxidation of phenolic substances which results in formation of suitable callus between rootstock and scion. For this reason، the effect of antioxidant (PVP)، auxin (IBA) and cytokinin (BA) in four different times (early January، February، March and early May) on walnut minigrafting was investigated. Results showed that the most suitable time for minigrafting is February with 83. 24% grafting success. Grafting success and scion growth in antioxidant concentrations was significantly different from control. Among antioxidant and hormone treatments the combination of 50 mg l-1 IBA and 80 mg l-1 BA with 83. 94% grafting success and minimum grafting duration (21 days) was the superior treatment. Antioxidant treatments also required the minimum grafting duration. In conclusion، 50 mg l-1 and 80 mg l-1 of BA in February is recommended for improving walnut minigrafting process.