This study, carried out in Almeria (Spain), evaluates the performance of 'Clausellina' mandarin on four rootstocks: Carrizo citrange [Citrus sinensis (L.) Osb. x Poncirus trifoliata (L.) Raft C. volkameriana Ten. and Pasq.; and, the two new hybrids 'C-13' (C. depressa Hay. x P trifoliata) obtained at the University of California Citrus Research Center and '020326' [Troyer citrange (C. sinensis x P trifoliata) x Cleopatra mandarin] obtained at the Instituto Valenciano de Investigaciones Agrarias in Valencia (Spain). Soil was sandy, with pH>8 and electric conductivity below 4.5 mmhos cm(-1) in the saturation extract. Yield was weighed during the first nine harvests, fruit quality was determined in the 5(th) and 9(th) harvests and tree size was evaluated annually from 3 to 11 years after planting. Trees on C. volkameriana rootstock were biggest and produced the highest yield, followed by trees on Carrizo citrange. Trees on the C-13 hybrid selection were most efficient in yield m(-3) of canopy volume. There were few differences between rootstocks in terms of fruit quality
