الفهرس 
REVIEW OF LITERATURE
Effect of nitrogen on yield and oilOnly 14 pages are availabe for public view
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Abstract
Two pot experiments were carried out in the experimental farm of Faculty of Agric., Ain Shams University during 2010/2011 and 2011/2012 seasons. This study was conducted to apply natural sources of nutrition (Azolla and compost) and different methods of addition with a reduction of mineral nitrogen fertilizer and its effect on vegetative growth, the yield of flower heads, total macronutrients (NPK), nitrate and nitrite contents, total phenolic, antioxidant activity and the volatile oil content and composition of chamomile flower heads. The result obtained revealed that significant increase was achieved with dry Azolla (DA) in growth characters and number of flower heads/plant above the rest treatments. Meanwhile, the same treatment stimulated total NPK percentage in the chamomile shoot against the control in both seasons. On the other hand, DA gained the highest total phenolic content, antioxidant activity, essential oil percentage and the percentage of total azulene and α-bisabolol and its oxides in chamomile inflorescences extract against the control and the reverse was true for nitrate and nitrite contents. Positive response was achieved with compost+Azolla treatments in growth characters, number of flower heads/plant and total NPK percentage in the chamomile shoot against the same treatments without compost. On the other hand, reduction of nitrate and nitrite contents was recorded with compost treatments. Meanwhile, the same treatments stimulated total phenolic content, antioxidant activity and essential oil percentage and its composition against mineral fertilization in both seasons. Dry Azolla treatment was the most efficient one in increasing the yield production with increment in active substances under sandy soil.