Toxicity symptoms and tolerance of strawberry to salinity in the irrigation water

Symptom characteristics and tolerance to different types of salinity in the irrigation water on strawberry (Fragaria x ananassa Duch.) cultivars was studied in soil pot experiments. The responses of the cultivars 'Douglas' and 'Toro' were compared when they were irrigated with water containing either 0, 6, 12, 18 or 24 meq l(-1) NaCl or with water containing either 0, 6, 12, 18 or 24 meg l(-1) NaHCO3. In another experiment, the cultivar 'Douglas' was irrigated with water containing either 0, 6, 12 or 18 meq l(-1) NaCl; 0, 6, 12 or 18 meq l(-1) KCl, or 0, 6, 12 or 18 meq l(-1) Na2SO4. The overall results indicate that Na2SO4 and NaHCO3 do not provoke immediate harmful effects on strawberry whereas the chlorinated waters (NaCl and KCl) cause phytotoxicity. Thus the leaf scorch is basically due to the increase in the foliar Cl- concentration. The hydric stress derived from the electrical conductivity of the saturated soil extract (EC,) is an adverse factor which contributes to the development of lesions on the leaves. When considering the incidence and evolution of leaf scorch, 'Toro' is more tolerant to salinity. II can be calculated that if the leaf Cl- concentration is less than 1% and the EC less than 2 dS m(-1), no toxic symptoms are produced in the leaves of the cultivars of strawberry under study. (C) 1997 Elsevier Science B.V.