Performance of 'Nova' mandarin on eleven rootstocks in Cyprus

Tree size, yield, yield efficiency, fruit quality and leaf nutrients of 'No va' mandarin (Citrus reticulata Blanco x (C. paradisi Macf. x C. reticulata )) on 11 rootstocks were evaluated under Cyprus conditions. Cumulative yiel d over the 11-year production period was highest on Palestine sweet lime ro otstock (C. limettioides Tan.), followed by that on rough lemon (C. jambhir i Lush.), sour orange (C. aurantium L.), Volkamer lemon (C. volkameriana Te n. and Pasq.) and Estes rough lemon, although there were no significant dif ferences among these rootstocks. Cumulative yields on Carrizo and Yuma citr anges (C. sinensis cv. Washington navel x Poncirus trifoliata (L.) Raf.) we re next in order, followed by those on Rangpur (C. limonia Obs.), C. taiwan ica, Troyer citrange and Swingle citrumelo (C. paradisi Macf. x P. trifolia ta). The largest trees were on sour orange, rough lemon and Palestine sweet lime, and the smallest on Yuma and Carrizo citranges, Swingle citrumelo an d Rangpur. Yield efficiency was highest on Carrizo citrange, whereas other rootstocks had similar yield efficiencies. Rootstock affected fruit size an d weight, rind thickness, juice content, Brix, total acids and Brix:acid ra tio. Leaf analysis showed significant differences among rootstocks in the c oncentration of 10 out of 12 elements. Overall, results so for showed that Carrizo citrange and Volkamer lemon are the most promising for replacing th e sour orange rootstocks which is used commercially in Cyprus but which is highly susceptible to tristeza. (C) 2000 Elsevier Science B.V. All rights r eserved.