GROWTH, YIELD, AND FRUIT-QUALITY OF NUCELLAR FROST MARSH GRAPEFRUIT ON 15 ROOTSTOCKS IN CYPRUS

Tree growth, yield, and fruit quality of nucellar 'Frost Marsh Seedless' grapefruit (Citrus paradisi Macf.) on 15 rootstocks were evaluated under Cyprus conditions. Over the 9-year production period, trees on Palestine sweet lime, the group of rough lemon, and Citrus volkameriana Pasq. were more productive per unit of tree size, and their cumulative yields per tree were significantly higher than those of trees on sour orange, which is the standard rootstock commercially used in Cyprus. Rootstocks affected fruit size and weight, rind thickness, juice content, total soluble solids concentration (SSC), and total acids, but the differences were not large enough to affect the market value of the fruit. On the basis of the results of this trial and because sour orange is highly susceptible to tristeza, the C. volkameriana and rough lemon group, which are tolerant to tristeza, should be included in further trial plantings as a potential commercial rootstock.