INFLUENCE OF ROOTSTOCKS ON ORLANDO TANGELO LEAF ELEMENTAL CONCENTRATION

The influence of 10 rootstocks on leaf elemental concentrations and their relationship with yield, tree growth, leaf fresh weight and dry matter of 'Orlando' tangelo (C. paradisi Macf. x C. reticulata Blanco) was studied under the arid climate of southwestern Arizona. 'Orlando' tangelo trees on Carrizo citrange [(C. sinensis (L.) Osbeck x Poncirus trifoliata (L.) Raf.], Yuma citrange (P. trifoliata x C. sinensis), Taiwanica (C. taiwanica) and Volkamer lemon (C. limon Burm f.) had larger canopy and higher yield than the trees on Savage citrange (P. trifoliata x C. sinensis), Ichang pummelo (C. ichangensis hyb.) and Palestine sweet lime (C. limettoides Tan.). Leaves of trees on Carrizo citrange were heavier but those on Savage citrange had higher percent dry matter than those on other rootstocks. Trees on macrophylla (Alemow) (C. macrophylla Wester) had significantly higher leaf N and Mn while those on Carrizo, Yuma and Savage citranges had lower leaf N than the trees on other rootstocks. Trees on Volkamer lemon, rough lemon (C. jambhiri Lush), macrophylla and Palestine sweet lime had low leaf K but high leaf Mg. 'Orlando' trees on Carrizo citrange had the highest leaf Mg and Cu but the lowest leaf Mn. Considering mineral (elemental) uptake efficiency, tree growth and/or yield, Carrizo citrange, Volkamer lemon, Yuma citrange, rough lemon and Taiwanica are desirable for 'Orlando' tangelo under the arid conditions and sandy soils of the southwest United States. Macrophylla could only be used for a short term planting, while Savage citrange, Batangas mandarin (C. reticulata Blanco), Ichang pummelo and Palestine sweet lime are not recommended for planting under the arid conditions similar to those of this experiment.