A 3 X 3 factorial experiment was conducted during two successive growing seasons 2011 and 2012 at the Expt. Farm, Medicinal and Aromatic Plants, Fac. of Pharmacy, Cairo Univ. to evaluate to what extant active dry yeast, whey and their interaction treatments affect growth and volatile oil production of rosemary plant. The 3 tested activated dry yeast levels (0, 4, and 8 g yeast/ liter) were foliar sprayed; while the 3 tested levels of whey (0, 10, and 20 cm3/ L.) were soil drenched. Each of yeast and whey were applied monthly tell the experiment ended.
Generally, plant growth expressed as: plant height, branches number/ plant and fresh and dry weights/ plant were significantly increased under the effect of active dry yeast or whey applications, each alone. Gradual increases in the abovementioned parameters were recorded as the tested levels of yeast or whey were increased up to the highest level of each. This was confirmed during the two cuts. Also, yeast or whey applications increased herb yield/ fad and oil % and oil yield/ plant and/ fad.
More enhancements were noticed when spraying active dry yeast interacted with whey soil drenching. The highest stimulate effects on growth and essential oil production were, generally, recorded when the highest yeast level (8 g/ L) interacted with the highest whey level (20 cm3/ L).
For the main components of produced volatile oil, most interaction treatments between yeast and whey levels increased 1- 8 cineol %. While, spraying yeast at 8 g/ L alone or interacted with 10 or 20 cm3 whey/ L increased Linalool %. Camphor % was increased only under the effect of 8 g yeast/ L + 10 or 20 cm3 whey/ L interaction treatment.