This study investigated the growth characteristics of Euonymus japonicus, Hedera helix, and Peperomia puteolata treated with different calcium chloride (CaCl₂) concentrations to evaluate salt tolerance limits in hydroculture cultivation. Six concent...
This study investigated the growth characteristics of Euonymus japonicus, Hedera helix, and Peperomia puteolata treated with different calcium chloride (CaCl₂) concentrations to evaluate salt tolerance limits in hydroculture cultivation. Six concentrations of CaCl₂ (0, 1, 2, 5, 10, and 15 g·L<SUP>-1</SUP> referred to as Cont., C1, C2, C5, C10, and C15) were applied to solution grownplant species. The survival rate, growth index, plant height, plant width, leaf width, leaf length, number of leaves, and relative chlorophyll contents were measured at monthly intervals. Euonymus japonicus, Hedera helix, and Peperomia puteolata survived up to C2, C5, and C10 at each CaCl₂ concentration. The Euonymus japonicus was higher in the C1 treatment than in the Cont. for most growth characteristics. Hedera helix had the highest leaf width, leaf length, and number of leaves in the Cont., a significant difference was observed compared with the C1 treatment. The chlorophyll content did not differ significantly between the C5 and Cont. treatments. The leaf width and length of Peperomia puteolata were greater in the C2 and C1 treatments than in the Cont., whereas the number of leaves and chlorophyll content were the highest in C5. Dry weight analysis revealed that Euonymus japonicus, Hedera helix, and Peperomia puteolata were the lowest in the Cont. treatments. Euonymus japonicus was 74% in C15, and Hedera helix, and Peperomia puteolata were analyzed at approximately 37%- 50% and 9%-14%, respectively, regardless of the concentration in the CaCl₂ treatment groups. In indoor hydroponic cultivation, the salt tolerance limit concentrations of Euonymus japonicus, Hedera helix, and Peperomia puteolata are 2, 5, and 10 g·L<SUP>-1</SUP>, respectively, indicating that hydroculture management techniques should be applied at higher concentrations.