Plant density of sage (Salvia officinalis L.), 30.000, 40.000, 50.000, and 60.000 plants per hectare and three doses of nitrogen fertilizer N0 = without N, N1 = 100 kg N/ha, and N2 = 200 kg N/ha were tested in the field experiment. The trial was carried out in Pančevo locality, (south Banat region) in the period 1998 - 1999 year. Soil type was humoglay, pH(KCl) = 5.7, humus = 3.5%, available P = 120 ppm, K = 380 ppm, 48% clay, 46% silt, 6% sand. Sage variety named "Primorska" was used in experiment. Nursery plants were planting at the beginning of April 1998. Sage was growth as a perennial crop.
Two cuts per year were attained in both experimental years. The average yield in the first year was 14.939 kg/ha of fresh matter (F.M), wherein 38.6% in first cut, and 61.4% in second one was attained. In the total fresh matter the dry leaves deal with 21.7%, the dry stalk with 9.8%.
The yield of FM in the first year varied from 12.780 kg/ha (at 30.000 p/ha) to 17.023 kg/ha FM (at 60.000 p/ha). Statistically significant increment was reached at plant density of 40.-, 50.-, and 60.000 p/ha comparing with 30.000 p/ha, and at 60.000 comparing with 30.-, 40.- and 50.000 p/ha. Statistically significant difference in the yield between plant density 40.000, and 50.000 p/ha in first year was not obtained. The total annual yield in the second year was as follows: at plant density 30.000 p/ha = 23.789 kg/ha, at 40.000 p/ha = 28.862 kg/ha, at 50.000 p/ha = 32.026 kg/ha, at 60.000 p/ha = 37.156 kg/ha FM, with statistically significant differences between all plant densities.
Fertilizing with nitrogen (N) did not influence on the yield of sage in first experimental year, when it was 14.408 - 15251 - 15.158 kg/ha FM at N0 - N1 - N2, respectively, but in the second year the yield at N2 (32.324) was significantly higher than at N0 (28.277 kg/ha FM).
Concerning interaction of two tested factors, in the first year the lowest yield was attained at 30.000 x N0 combination (12.016 kg/ha), and the highest at 60.000 x N1 combination (17.861 kg/ha FM). The lowest yield in the second year was at 30.000 x N0 combination (21.059 kg/ha), and the highest at 60.000 x N2 combination (40.085 kg/ha FM).
The essential oil content in dry leaves of sage at different plant densities varied from 1.60 to 1.69% in firs cut, and from 0.92-1.09% in second cut, in the first year of investigation. Significant differences in the essential oil content between different plant densities and different nitrogen doses was not obtained in first year.
Key words: Salvia officinalis L., cultivation, plant density, nitrogen fertiliziation, yield, essential oil content