Effect of Planting Distances on the Growth, Yield, Essential Oil Productivity and Chemical Composition of Rosemary (Rosmarinus Officinalis, L.) Plant.

Abstract

in two successive seasons; 1998 and1999. The aim of this study was to investigate the effect of planting distances on the growth, yield, essential oil productivity and chemical composition of Rosmarinus officinalis, L. plant. The plants of this experiment were cultivated at a distance of 20, 30, 40, 60 or 80 cm between them in the row and 30 cm between the rows. All the plants of this experiment were fertilized with nitrogen (N) at 150 kg, phosphorus (P 2 O 5) at 50 kg and potassium (K 2 O) at 30 kg/fad. Nitrogen was added in the form of ammonium nitrate (33.5% N), while phosphorus was applied as calcium superphosphate (15.5% P 2 O 5) and potassium as potassium sulfate (48% K 2 O). The obtained results can be summarized as follows: Growing rosemary plants at 20 cm apart resulted in the tallest plants, while, increasing the distance from 20 to 80 cm decreased steadily plant height. Cultivation at 80 cm between the plants in the row increased the number of branches, fresh and dry weights of herb as well as leaves/plant. Also, the plants which grew at this distance had the highest oil percentages and oil yield in their fresh herb and leaves per plant. Whereas increasing planting distances from 20 to 80 cm increased photosynthetic pigments (chlorophylls a, b and total, as well as carotenoids), total carbohydrates, nitrogen, phosphorus and potassium percentages in the herb in the two seasons. As a general trend, it is very clear that the highest values of all previous parameters were resulted in cultivation at the widest distance (80 cm between the plants in the row). Whereas the lowest values of all previous characters were produced from cultivation at the narrow distance (20 cm between the plants in the in the two seasons.