Effect of water and salt stress on the growth and chemical composition of peganum harmala L. under Ras Sudr Conditions

A field experiment was carried out in Ras Sudr Research Station, Desert Research Center, at South Sinai Governorate, Egypt, during two successive growing seasons, vis. 2007 and 2008 to study thee effect of three irrigation intervals (10, 20 and 30 days), two levels of saline water (3000 and 7000 ppm) and their interaction on the growth and chemical composition of Peganum harmala L. plants. Growth measurements were taken at 2 (first cut), 4 (second cut) and 6 (third cut) months after transplanting; while the chemical composition was determined after 6 months. The results could be summarized as follows: Prolonging the irrigation interval from 10 to 30 days depressed significantly plant height, fresh and dry weight / plant in the first, second and third cuts. Percentage of crude protein, total ash, potassium, total flavonoids and water-insoluble ash % in plant tissues decreased by increasing irrigation intervals from 10 to 30 days. In contrast, total carbohydrates, crude fiber, total lipids, total tannins, total alkaloids, sodium content and acid-insoluble ash % increased by increasing irrigation intervals up to 30 days. Irrigation with saline water had a dwarfing effect on Peganum harmala plants. There was a significant reduction in plant height, fresh and dry weight / plant at the 2, 4 and 6 months from transplanting. On the other hand, there was a decrease in the crude protein, total ash, total flavonoids, potassium. content and water-insoluble ash % with increasing salinity levels of irrigation water, while the total carbohydrates, crude fiber, total lipids, total alkaloids, sodium content and acid-insoluble ash % increased by increasing salinity level from 3000 to 7000 ppm. The tallest plants and the heaviest fresh and dry weights / plant, as well as the highest crude protein and potassium content were obtained when plants were irrigated with 3000 ppm saline water every 10 days.