THE STUDIES ON THE EFFECT OF POTTING AND OMEGA GRAFTING IN RELATION TO DIFFERENT TIME ON GRAFT TAKING PERCENTS OF SOME STANDARD WALNUT VARIETIES

The main objective was to determine the most suitable time for omega-bench-grafting of c.v. Yalova-1, Yalova-2, Yalova-3, Yalova-4, Kap-6, Sebin, and Bilecik on 1 year-old rootstock of c.v. Balaban (Juglans regia L.) being 1.5–2 cm in diameter.

The three grafting times employed were at the beginning of January, February, and March. Having grafted, the plants were moved to a room that had a constant temperature (26°C) and relative humidity (80%) for 3 weeks. Subsequently the temperature was reduced down to 18°C within 1 week. Then the plants were potted in black polyethylene tubes (35x40 cm) containing soil:peat:sand mixture (2:1:1:) and kept in a greenhouse until May. Finally they were transferred to a semi-shaded structure to grow up to November.

At the end of the experiment a significant difference was determined between the times for graft taking percentage. The maximum taking was obtained in March (80%), while 50% in February and 20% in January. Also a great variation was observed among the varieties, 82% in Yalova-1, 59% in Bilecik, 57% in Yalova-4, 57% in Sebin, 56% in Yalova-3, 45% in Yalova-2, and 41% in Kap-6. The mean taking percentage of 4 years showed similar tendency.