5th International Walnut Symposium, Sorrento, İtalya, 9 - 13 Kasım 2004, ss.313-317
Walnut seedlings were bench grafted with scion of some walnut cultivars and selections, and planted in plastic bags. 12 of grafted plants were put in plastic boxes and placed in greenhouse. Hot callusing cables were lined next to the graft unions between bags and covered with growth medium of 5-7cm thickness leaving the bud at the top of scion uncovered to keep graft unions moist and the temperature constant. Graft unions were heated at 25 degrees C for 33 days. The greenhouse was heated when air temperature decreased below 10 degrees C. Growth medium was removed after power cut. The average graft take was 11.5% higher in the second year (92.4%). The percent graft take ranged between 76.4% (Sebin and Bilecik) and 88.9% (Yalova-3) in the first year and between 80.6% (Topak) and 100% (Yalova-1) in the second year. In addition, mass production of walnuts with about 20.000 grafts was tested in nursery conditions. The average graft take was 82%. Hot callusing cable is now routinely used to enhance callus formation and about 20.000 grafted plants/year are produced in the nursery. This technique is a valuable tool in areas where winter and late spring frosts limit the walnut propagation.