PRELIMINARY PERFORMANCE OF 7-YEAR-OLD 'VALENCIA' ORANGE TREES ON 21 ROOTSTOCKS

A study of fruit production, fruit quality, and tree size of 'Valencia' sweet orange {Citrus sinensis {L.) Os· beck) trees on 21 rootstocks was conducted from 1974 to 1981. Fruit yields and pounds solids per tree were highest on Carrizo and Yuma citranges {C. sinensis X Poncirus tri­ fo\iata (L.) Raf.), rough lemon 807, and Volkamer lemon {C. limon (L.) Burm. f.) rootstocks. The largest trees were on Carrizo and Yuma citranges, rough lemon, rough lemon 807, sour orange No. 2, (C. aurantium L.), sour orange 839, and Volkamer lemon rootstocks. Trees on Argentina and Pomeroy trifoliate orange {P. trifoliata), Norton citrange (C. sinensis X P. trifoliata), and sour orange hybrid 895 pro· duced fruit with the highest total soluble solids. The major citrus cultivar grown througho~t the world is 'Valencia' orange. Rootstock-related diseases and constantly changing cultural practices emphasize the im­ portance of rootstock selection. Research on citrus root­ stocks is time-consuming and a continuing process, be­ cause results can vary from area to area due to climate, soil, disease, and cultural practices. This report presents information on the performance of 'Valencia' orange on 21 rootstocks 7 years after planting.