RANKING THE SALT TOLERANCE OF CITRUS ROOTSTOCKS BY JUICE ANALYSIS

High correlations were found between juice and leaf chloride (Cl) contents in a wide range of citrus cultivars, which included lemon (Citrus limon L.), orange (Citrus sinensis L.), grapefruit (Citrus paradisi Macf.) and mandarins (Citrus reticulata, Citrus temple Hort ex Tan. and C. reticulata × C. paradisi) on different rootstocks, irrigated with different quality waters. Juice Cl analysis has proven to be a good tool for assessing the salinity response of diverse rootstocks and the effect of cultural practices on Cl uptake by the trees. Juice, rather than leaf analysis, has the advantages of providing a larger and more uniform sample, and preventing sample contamination by contact with saline irrigation water. Cl uptake and transport into the leaves and fruit of the scion was increased by trifoliate orange (Poncirus trifoliata L.) and 'Troyer' citrange (C. sinensis × P. trifoliata), even when irrigated with mildly saline water. Under high salinity, Cl accumulation in grapefruit and orange trees was low on Cleopatra mandarin (Citrus reshnii Hort ex Tan.) and sour orange (Citrus aurantium L.), while it was increased on rough lemon (Citrus jambhiri Lush.). © 1990.