الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 176 |  |  |
| | | from | 176 | | |
Abstract
This study seeks mainly to achieve the following objectives: 1- Identify new sources of safe and inexpensive allelopathic compound and antioxidant of natural origin. 2- To Investigate the effect of applied antioxidants (ascorbic acid (AsA), salicylic acid (SA), humic acid (HA), chitosan (CH), seaweeds extract (SWE), olive oil (OO), ginger oil (GO) and Plant water extract prepared from the shoot and root systems of corn and peanut) on growth, essential oil productivity and some biochemical constituents to mitigate or alleviate the harmful effect of drought stress condition on dragonhead and moringa plants. The study has reached a number of results, most important of which are: Experiment 1: Growth:Results also showed that applied treatments were significantly increased all previously growth characters of dragonhead plants (plant height, shoot weight, fresh and dry weight of leaves, number of leaves, number of branches, fresh weight of flowers) in both seasons. It could be show that humic acid (HA) and ginger oil (GO) were the most effective in this respect. Photosynthetic pigments: Different applied treatments increased photosynthetic pigments content in the leaves of dragonhead during the growing seasons. Moreover, ginger oil was the most effective in this respect. Essential oil productivity: Drought stress treatments ( irrigation every 25, 30 and 35 days) increased leaves and seed oil percentage of dragonhead plants during 2015 season. Moreover high drought stress level (irrigation every 30 days) was the most effective in increasing oil percentage in both leaves and seed of dragonhead plants. Endogenous non-enzymatic Antioxidants content: The data show that irrigation intervals treatments and applied antioxidants as well as their interactions slightly increased all endogenous non-enzymatic antioxidants contents such as total phenol, proline and ascorbic in leaves of dragonhead plants during the growing season. It could be show that all applied antioxidants promoted the synthesis and accumulation of endogenous non-enzymatic antioxidants under drought stress levels treatments (irrigation every 25, 30 and 35 days). Humic acid (HA), ginger oil (GO) and seaweeds extract (SWE) every 35days were most effective in this respect. Experiment 2: Growth: Applied treatments were significantly increased all growth parameters of moringa plants throughout the experimental periods during the two growing seasons. It could be show that humic acid (HA), seaweeds extract (SWE) were the most effective in this respect. Photosynthetic pigments: Different applied treatments increased photosynthetic pigments content in the leaves of moringa during the growing season. Moreover, ginger oil treatment was the most effective in this respect. Ca2+ and Fe contents: Antioxidants humic acid (HA) treatment was the most effective in this respect. Total carbohydrates :Different applied treatments increased total carbohydrates content in the leaves of moringa during the growing season. Moreover, chitosan treatment was the most effective in this respect. Endogenous non-enzymatic Antioxidants content: Irrigation Intervals treatments and applied antioxidants as well as their interactions slightly increased all endogenous non-enzymatic antioxidants contents such as total phenol, proline and ascorbic in leaves of moringa plants during the growing season. It could be show that all applied antioxidants promoted the synthesis and accumulation of endogenous non-enzymatic antioxidants under drought stress levels treatments (irrigation every 60 and 90 days). Humic acid (HA)and irrigation every 90 days were most effective in this respect.