Growth of cucumber fruit as affected by the addition of NaCl to nutrient solution

Effects of adding NaCl to a nutrient solution of cucumber (Cucumis sativus L. cv. Asomidori) plants at 10 leaves stage on the fruit growth were studied in solution culture. Non-destructive growth analyses of individual fruits until marketable size (20 cm long) were repeated for 3 to 4 weeks after the treatment. NaCl had marked effects on the relative growth rate (RGR) based on volume depending on NaCl concentration and the growing season. Thirty mM NaCl had little effect on fruit RGR, whereas 100 mM NaCl caused necrosis, In the spring experiments, 50 mM and 60 mM NaCl caused a decrease in RGR with high variablility among fruits. In the autumn experiments, 60 mM NaCl did not decrease RGR when fruit temperature was not controlled, but it did when fruits were kept at 20 degrees C or 30 degrees C. Sixty mM NaCl is suggested to be the threshold for normal fruit growth, at which other environmental factors seem to interact with the treatment.