Effects of citrus rootstocks on growth, yield and fruit quality of Navelate orange

Abstract

The aim was to study the performance of Navelate sweet orange on five rootstocks: Carrizo citrange [Citrus sinensis (L.) Osb. x Poncirus trifoliata (L.) Raf.]; Cleopatra mandarin (C. reshni Hort. ex Tan.); C. volkameriana Ten. & Pasq. and two new hybrids C-13 (C. depressa Hay. x P trifoliata) developed at the University of California Citrus Research Center and 020326 [Troyer citrange (C. sinensis x P trifoliata) x Cleopatra mandarin] developed at the Instituto Valenciano de Investigaciones Agrarias in Valencia, Spain. The investigation was conducted in Almeria, Spain. The soil was sandy, with pH>8 and electric conductivity in the saturation extract below 4.5 mmhos cm(-1). The design was a complete-block with randomised single-tree plots and eight replications. Tree spacing was 4.5 m x 4 m. Yield was recorded during the first nine harvests, fruit quality was determined for the 50(th), 6(th) and 9(th) harvests and tree size was evaluated 11 years after planting. Trees on C. volkameriana rootstock produced the highest yield and largest fruits. Trees on the C-13 hybrid selection were the most yield-efficient on a canopy volume basis, and had fruit with the highest soluble solid content, but there were few differences between rootstocks for the latter parameter. Cleopatra mandarin and 020326 induced the lowest individual fruit weight and diameter.