## 3 Results
At the same time, the transpiration rate was higher in the zeolite treatment and in the EM treatment compared with the control under normal conditions. Administration of NaCl contributed to an increase in the transpiration rate in all treatments, but was not associated with significant differences between treatments. In addition, the subtreatment in which plants were sprayed with algal extract in the presence of salinity (III) showed similar transpiration rates in all treatments, which were also not significantly different from the corresponding subtreatments in which plants were given NaCl only (II). The control subtreatment in which the plants had ceramic powder applied in the presence of salinity (IV) showed a significantly higher transpiration rate compared with the normal conditions subtreatment (I), but a similar difference was not found in the other two treatments (Figure 1c). As far as the concentration of internal CO2 is concerned, there were no significant differences among the treatments in normal conditions and between normal and saline conditions in all treatments. The implementation of seaweed extract under salinity (III) had a positive effect on the internal CO2 concentration in all treatments, while the application of ceramic powder (IV) was associated with a significantly lower concentration of CO2 compared with normal conditions in zeolite treatment (Figure 1d). In general, proline concentration ranged at a similar statistical level among the plants of all treatments in normal conditions, although the plants in the EM treatment had the lower concentration (Table 2). The administration of NaCl alone (II) led to a decrease in proline concentration in the control treatment, while in the other two treatments proline concentration in the presence of salinity increased. In fact, the corresponding subtreatment (II) in the EM treatment demonstrated a statistically significantly higher concentration of proline compared with all the subtreatments of control or zeolite treatment. In the  
Figure 1: (**a**) Photosynthesis rate, (**b**) stomatal conductance, (**c**) transpiration rate, and (**d**) internal CO2 concentration in leaves of the apple plants. All the values are averages of four replications \(\pm\) standard error. The different letters in the same column show statistically significant differences among the twelve subtreatments according to the Duncan test (\(p\leq 0.05\)) with the larger values corresponding to the letter “a”. I: no NaCl, II: NaCl 50 mM, III: NaCl 50 mM + seaweed extract spraying, IV: NaCl 50 mM + ceramic powder spraying. EM treatment included compost addition. subtreatments in which either seaweed extract or ceramic powder solution was applied to the plants (III or IV), an increase in proline concentration was observed in the control, but in the zeolite and EM treatments, a decrease in proline concentration was found in the aforementioned subtreatments. However, the plants of the effective microorganisms treatment, when sprayed with algal solution with simultaneous salt administration, showed a higher proline concentration compared with the corresponding subtreatments of the other treatments. The concentration of carbohydrates in leaves did not display significant differences among the treatments (Table 2). The carbohydrate concentration was heightened in the presence of salt (II) in the control treatment but it was diminished in the respective subtreatment when zeolite was implemented as a substrate additive. On the contrary, the combination of compost and microorganisms led to consistent carbohydrate concentrations in both normal and saline conditions. Moreover, the spraying with the algal extract (III) provoked shrinkage to the carbohydrate content of leaves, while the ceramic powder spray solution (IV) resulted in higher values, compared with the application of seaweed solution, in all cases.