1983 Volume 52 Issue 3 Pages 286-293
Muskmelons (Cucumis melo L.) were grown in diluted sea water from transplanting to harvest in order to determine the salt tolerance at 3 growth stages-stage I (transplanting to pollination), stage II (pollination to fruit net development) and stage III (fruit net development to harvest). Treatment solutions contained 0, 250, 500, 750 and 1, 000ppm Cl in sand and soil cultures, and 0, 1, 000, 2, 000, 3, 000 and 4, 000ppm Cl in nutrient solution culture. Whole plant dry weight and fruit fresh weight at harvest decreased with increasing sea water concentrations in all cultures. The increment in growth at stages II and III was less at higher sea water concentrations. Growth was reduced more in sand than in soil culture. Slightly visible salt injury symptoms appeared at stages II and III at 1, 000ppm Cl in sand culture and at the beginning of stage I at 3, 000 and 4, 000ppm Cl in solution culture. Cl and Na increased, while SO4 and osmotic potential decreased in leaves at the end of stage III in all cultures as sea water concentrations increased. Cl and Na in leaves tended to be higher in sand than in soil culture at all stages. Cl was especially high at stage I. More accumulation of Cl and/or Na in leaves at stage I in sand than in soil culture may be one of the causes for greater growth suppression in sand culture.