Growth, yield and fruit quality of 'Shamouti' orange on fourteen rootstocks in Cyprus

Tree size, yield, yield efficiency and fruit quality of nucellar 'Shamouti' orange (C. sinensis L. Osbeck) on 14 rootstocks have been evaluated under Cyprus conditions. Over the nine-year production period, Volkamer lemon (C. volkameriana Ten. and Pasq.) and Morton citrange [C. sinensis cv. Washington navel x P. trifoliata (L.) Raf.] were the most productive, and cumulative yields of trees on these rootstocks were significantly higher than those of trees on sour orange (C. aurantium L.), the rootstock commercially used in Cyprus. Yields from trees on Red rough lemon, rough lemon (C. jambhiri Lush.), and Rangpur (C. limonia Osb.) were next in order, followed by those on Palestine sweet lime (C. limettioides Tan.), C. amblycarpa Oshse (Nasnaran), sour orange, Yuma citrange and Estes rough lemon. Trees on Troyer citrange and C. taiwanica Tan. Shim. (Nansho - daidai) were the least productive. Rootstocks affected fruit size and weight, rind thickness, juice content, Brix and total acids. On the basis of the results of this trial, and because sour orange is highly susceptible to tristeza, Volkamer lemon, Morton citrange, C. ambycarpa, Swingle citrumelo [C. paradisi Macf. x P. trifoliata] and Carrizo citrange, which are tolerant to tristeza, appear to be the most promising rootstocks and should be included in further trial plantings. (C) 1999 Elsevier Science B.V. All rights reserved.