Evaluation of rootstocks for 'Clementine' mandarin in Cyprus

Tree size, yield, yield efficiency, fruit quality and leaf nutrient levels of 'Clementine' mandarin (Citrus clementina Hort. ex Tan.) on 12 rootstocks were evaluated under Cyprus conditions. Cumulative yield over I I years of production was highest on rough lemon (C jambhiri Lush.), followed by that on Volkamer lemon (C. volkameriana Ten. and Pasq.), Yuma and Carrizo citranges (C sinensis cv. Washington navel x Poncirus trifolia (L.) Raf.), sour orange (C aurantium L.), Rangpur lime (C limonia Obs.), Palestine sweet lime (C limettioides Tan.) and Estes rough lemon, although there were no significant differences among these rootstocks. Cumulative yields on Troyer citrange and Swingle citrumelo (C. paradisi Macf. x P. trifoliata) were next in order, followed by those on C. taiwanica Tan. Shim. and C, amblycarpa Oshse (Nasnaran). The largest trees were on sour orange and the smallest on Estes rough let-non and Palestine sweet lime. Yield efficiency was the highest on Estes rough let-non and lowest on C. amblycarpa. However, no rootstock induced significantly lower yield efficiency than that induced by sour orange. Rootstock affected fruit size and weight, rind thickness, juice content, brix and brix:acid ratio, but not total acids. Leaf analysis of 12 elements showed significant differences among rootstocks in the concentration of only Mg, Mn, Cu and B. At present in Cyprus, sour orange is the most commonly used rootstock for the commercial cultivation of 'Clementine' mandarin but it is highly susceptible to tristeza. The results showed that Carrizo citrange and Volkamer lemon were very promising as alternative rootstocks. (C) 2002 Elsevier Science B.V. All rights reserved.