EFFECTS OF VARIOUS ROOTSTOCKS ON THE GROWTH OF '0900 ZIRAAT' SWEET CHERRY

'0900 Ziraat' is the main export sweet cherry variety of Turkey. An experiment was started in 2000 to study the effects of dwarfing rootstocks such as Gisela 5 (Prunus cerasus x P. canescens), MaxMa 14 (P. mahaleb x P. avium), Weiroot 158 (P. cerasus), and SL 64 (P. mahaleb) on this variety. Mazzard (P. avium) seedling and F12/1 clonal rootstocks were used as controls. The trees were drip-irrigated. At the time of planting (spring, 2000) and at the end of the growing season, trunk diameters were measured. In winter 2000-01, shoot lengths and stem heights also were measured. Flower bud density and other phenological observations were recorded.
Preliminary results revealed the seasonal diameter growth of '0900 Ziraat' to be 6.3 mm on MaxMa 14, and 3.1 mm on Gisela 5, mazzard seedling and SL 64. Shoot growth of '0900 Ziraat'/Gisela 5 was very weak. Scion flower buds formed on Gisela 5 and SL 64, while there was either no or very few flower buds on Weiroot 158, MaxMa 14 and mazzard. Gisela 5 induced good precocious fruit set on the pollinizers ‘Stark Gold’ and ‘B. Gaucher’, but fruit set on ‘0900 Ziraat’ was very low even though bloom density was as high or higher than for the pollinizers.