## 3 Results  
Results of the experiment have demonstrated a significant effect of various spacing of stevia plants on their growth, biometric measurements, yield and chemical composition of stevia plants. Selected stevia plants cultivated in the study are illustrated in Figure 1.  
Figure 3: Contribution of various parts of the stevia plants (leaves, shoots and plant waste: dried and damaged leaves and shoots) in the total yield of stevia grown in the spacing of 50 cm \(\times\) 30 cm. Figure 2: Weight of the stevia plants grown in different spacings. Data are given as means (\(n=27\)) with standard deviation. Small letters show homogenous groups in the measurement of weight of the stevia plants (Tukey test, \(\alpha=0.05\)), capital letters show homogenous groups in the measurement of weight of the leaves from the stevia plants (Tukey test, \(\alpha=0.05\)), Greek letters show homogenous groups in the measurement of weight of the shoots from the stevia plants (Tukey test, \(\alpha=0.05\)). Analysis of biometric measurements (Table 3) conducted in July did not reveal any significant differences among stevia plants grown in different spacings. However, measurements taken in September indicated that the height of the plants and number of leaves on the lowest lateral shoot were still similar across all spacing variations, but the width and number of shoots on a single plant were lower in stevia plants grown in spacings of 45 cm \(\times\) 25 cm and 30 cm \(\times\) 30 cm. Figure 4: Contribution of various parts of the stevia plants (leaves, shoots and plant waste: dried and damaged leaves and shoots) in the total yield of stevia grown in the spacing of 45 cm \(\times\) 25 cm. Figure 5: Contribution of various parts of the stevia plants (leaves, shoots and plant waste: dried and damaged leaves and shoots) in the total yield of stevia grown in the spacing of 30 cm \(\times\) 30 cm. Results of the analysis of elements and nitrates in the stevia leaves are shown in Table 4.  
Stevia plants grown in the spacing of 30 cm \(\times\) 30 cm exhibited the lowest concentration of nitrate ions in July (1003.1 mg\(\cdot\)kg\({}^{-1}\) f.m.) and in September (1073 mg\(\cdot\)kg\({}^{-1}\) f.m.). In contrast, stevia plants grown in spacings of 50 cm \(\times\) 30 cm and 45 cm \(\times\) 25 cm were characterized with a similar concentration of nitrate ions in July (1360.99 and 1343.82 mg\(\cdot\)kg\({}^{-1}\) f.m., respectively), but the concentration was higher in September for the stevia plants grown in the spacing of 50 cm \(\times\) 30 cm (1856.18 mg\(\cdot\)kg\({}^{-1}\) f.m.). In July, the concentration of phosphorus was similar across all analysed samples (ranging from 117.50 to 134.58 mg\(\cdot\)100 g\({}^{-1}\) d.m.). However, in September, phosphorus concentration was highest in stevia plants grown in the spacing of 50 cm \(\times\) 30 cm (234.17 mg\(\cdot\)100 g\({}^{-1}\) d.m.) and lowest in those grown in the spacing of 30 cm \(\times\) 30 cm (155.69 mg\(\cdot\)100 g\({}^{-1}\) d.m.). Potassium concentration was greater in the samples harvested in September. Stevia grown at 50 cm \(\times\) 30 cm spacing exhibited a higher concentration of potassium compared to other spacings. Calcium content was similar across all samples in September (835.31-888.18 mg\(\cdot\)100 g\({}^{-1}\) d.m. ), while in July, the highest calcium concentration was detected in plants grown in the spacing of 50 cm \(\times\) 30 cm and 45 cm \(\times\) 25 cm (836.11-841.67 mg\(\cdot\)100 g\({}^{-1}\) d.m.). Stevia plants grown in the spacing of 30 cm \(\times\) 30 cm had the lowest concentration of magnesium in July (143.89 mg\(\cdot\)100 g\({}^{-1}\) d.m.) and in September (156.94 mg\(\cdot\)100 g\({}^{-1}\) d.m.). The highest magnesium concentrations were found in plants grown in 45 cm \(\times\) 25 cm and 50 cm \(\times\) 30 cm spacings (166.11-168.89 mg\(\cdot\)100 g\({}^{-1}\) d.m. in July and 172.22-176.39 mg\(\cdot\)100 g\({}^{-1}\) d.m. in September).