Yield and mineral composition of 'Verna' lemon trees as affected by salinity and rootstock combination.

Effects of salinity on fruit yield during 1985-87 and leaf mineral composition during 1986/ 1987 were studied in a field experiment with lemon trees cv. Verna on either macrophylla (C. macrophylla Wester) rootstock or with a sanguina orange interstock on ‘Cleopatra’ mandarin (C. reticulata Blanco) and sour orange (C. aurantium L.) rootstocks. Trees were irrigated with four different kinds of water having Cl~ concentrations that ranged from 6 to 42 mol m-3. Fruit yield was progressively decreased by salinity in all treatments, but the effect was influenced by the specific rootstock combination. Chloride concentrations in leaves from the combinations where sanguina orange interstock was present were significantly lower than those from the Citrus macrophyllal'Verndi’ lemon combination. Data on the accumulation of other nutrients in relation to the specific rootstock combination, sampling date and saline treatment are also presented. The importance of each effect depended on the nutrient considered.