in two successive seasons; 1998 and 1999. The trace elements used in this experiment were Zn, B and Mo. Zn or B used at the rates of 0, 25, 50 or 100 ppm, while Mo at 0, 5, 10 or 20 ppm. The plants were treated with the microelements as foliar spray on April 22 nd , July 7 th and October 23 rd. The obtained results can be summarized as follows: Spraying the plants with B at 100 ppm resulted in the greatest plant height and number of branches/plant as well as oil percentage in herb and leaves and N, K and B content in the herb. It increased herb and leaves fresh and dry weight/plant, oil yield of herb and leaves/plant as well as total carbohydrates, chlorophylls (a, b and total), carotenoids, P, Zn and Mo contents in the herb. Treating the plants with B at 50 ppm increased the vegetative growth, leaves and herb oil % and oil yield/plant, chlorophylls a, b and total, carotenoids, total carbohydrates content, N, Zn, B and Mo in the herb. Using B at 25 ppm led to an increase in the vegetative growth, oil% and yield in leaves and herb/plant, chlorophylls a, b and total, carotenoids, total carbohydrates content, Zn, B and Mo in the herb. However, it decreased P% in both seasons, compared to control plants. Supplying the plants with Zn at 50 ppm resulted in the highest P% in the herb. It increased the vegetative growth as well as oil% and oil yield in herb and leaves/plant. It increased chlorophylls a, b and total, carotenoids, total carbohydrates content, N, P, Zn, B and Mo in the herb, compared to control plants. Application of Zn at 25 ppm resulted in an increase in plant height, oil% in the leaves, oil yield in leaves and herb/plant, total carbohydrates, chlorophylls a, b and total, K%, Zn, B and Mo content in the herb. However, it decreased herb and leaves fresh and dry weight/plant in comparison Spraying the plants with Mo at 5 ppm caused an increase in plant height, leaves and herb fresh and dry weights/plant, as well as oil% and yield of leaves and herb/plant, chlorophylls (a, b and total), carotenoids, Zn and B contents. However, P and K% in both seasons were decreased compared with control plants. Treating the plants with Mo at 20 ppm decreased all vegetative characteristics and the chemical determinations, except chlorophylls (a, b and total), carotenoids, Zn, B, and Mo contents which were increased compared to untreated plants.

during the two successive seasons of 2004 and 2005 to study the effect of compost, bio-fertilizer and yeast on growth , oil production and chemical composition of Origanum syriacum L. cv. Sinaicum (Boiss). The plants were fertilized with compost at the rates 5, 10 and 20 m 3 /feddan, bio-fertilizer (Azotobacter chroococcum, Azospirillum sp., Bacillus cirulans and Bacillus megaterium var. phosphaticum) and active dry yeast at the concentrations of 0, 5 and 10 g /L. The results showed that compost application at 10 and 20 m 3 /feddan enhanced number of branches, herb fresh and dry weights, oil percentage, oil yield / plant and chemical composition (N, P, K and total carbohydrates percentage) of oregano plants. Compost at 10 m 3 /feddan was the most effective treatment followed by 20m 3 / feddan. Active dry yeast, at 5 or 10 g /L led to a significant increment in vegetative growth parameters, oil percentage and oil yield / plant, as well as chemical composition (N, P , K and total carbohydrates percentage). Yeast at 5 g /L was the most effective treatment in most cases. Whereas Yeast at 10 g / L was the most effective treatment on oil percentage. Bio-fertilizer led to a significant increase in number of branches, fresh and dry weights / plant, oil percentage, oil yield/ plant, and chemical composition (N, P, K and total carbohydrates percentages) in both two seasons. Interaction had a significant effect on all parameters. Compost at 10 or 20 m 3 / feddan plus bio-fertilizer plus active dry yeast at 5 or 10 g /L gave the highest values of vegetative growth parameters, oil percentage, oil yield / plant and N, P , K and total carbohydrates percentage.

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.