الفهرس 
Introduction
I : Effect of BiofertilizationOnly 14 pages are availabe for public view
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Abstract
The present study consisted of two field experiments, and carried out during the two successive seasons, 2003/2004 and 2004/2005. The first experiment aimed to investigate the response of vegetative growth, yield components, essential oil and chemical composition of caraway, Carum carvi plants grown in sandy soil under drip irrigation system to three biofertilizers (biogein, phosphorein and their mixture), as well as, four levels of NP mineral fertilization treatments. While the second experiment was executed to explore the effects of antioxidants (ascorbic and salicylic acids) at various concentrations as foliar spray treatments on vegetative growth, yield components, essential oil and chemical composition of caraway, Carum carvi plants which grown in sandy soil under drip irrigation system.
The most important results could be summarized as follows:
First experiment:
I- Effects of biofertilization:
Vegetative growth traits:
All biofertilization treatments (biogein, phosphorein and their mixture) gave significant promotion on different vegetative growth characters, i.e. plant height, stem diameter, branch number and herb dry weight/plant. The tallest plants and highest number of branches were obtained with the mixture and biogein treatments, whereas, the thickest stems with heaviest herb dry weights were produced by biogein and mixture treatments.
Yield and yield components:
Biofertilization treatments (biogein, phosphorein and their mixture) significantly increased number of umbels/plant and weight of 1000 fruits, as well as, fruits yield per plant and per feddan. The heaviest weight of 1000 fruits and the largest fruits yield per plant and per feddan were obtained as a result of mixture, phosphorein and biogein treatments respectively, while the highest number of umbels/plant was obtained due to biogein treatment.
Essential oil determinations:
Essential oil percentage and oil yield per plant and per feddan of caraway plants were significantly augmented with all biofertilization treatments (biogein, phosphorein and their mixture). The maximum values of essential oil percentage and yield per plant and per feddan were produced in descending order as a result of mixture, phosphorein and biogein treatments.
Photosynthetic pigments:
The contents of photosynthetic pigments in the fresh leaves of caraway plants were enhanced due to biofertilization treatments (biogein, phosphorein and their mixture). The highest content of chlorophyll a was obtained with biogein and mixture treatments, while the contents of chlorophyll b and carotenoids were produced from plants treated with mixture and phosphorein treatments.
Nitrogen and Phosphorus percentage:
all biofertilization treatments (biogein, phosphorein and their mixture) stimulated N and P percentages in dry herb of caraway plants. The highest percentage of N was obtained with mixture treatment, whereas, the highest percentage of P produced by using phosphorein and mixture treatments.
II- Effects of chemical NP fertilization:
Vegetative growth traits:
Supplying caraway, Carum carvi plants with 25, 50 or 75 % of the recommended mineral NP fertilization dose led to significant reduction on plant height, stem diameter, branch number and herb dry weight/plant compared to control treatment (full dose) which produced the tallest plants with thickest stems having more branches and heaviest herb dry weights.
Yield and yield components:
Number of umbels/plant, weight of 1000 fruits and fruits yield per plant and per feddan were significantly decreased when caraway plants were fertilized with 25,050 or 75 % of the recommended mineral NP fertilization dose. The highest number of umbels/plant, heaviest weight of 1000 fruits and the maximum fruits yield per plant and per feddan were obtained from control plants which received the full dose of recommended mineral NP fertilization.
Essential oil determinations:
Essential oil percentage and yield per plant and per feddan of caraway plants were significantly decreased due to the application of 25, 50 or 75 % of the recommended mineral NP fertilization dose. Whereas, the plants, which supplied by full dose gave the maximum values of all essential oil determinations.
Photosynthetic pigments:
All mineral NP fertilization treatments (25, 50 or 75 % of the recommended NP mineral fertilization dose) resulted in a significant reduction on the contents of the three photosynthetic pigments (chlorophyll a, b and carotenoids) in the fresh leaves of caraway plants in comparison with check treatment (full dose), which gave the highest contents of these substances.
Nitrogen and Phosphorus percentage:
The percentages of N and P in the dry herb of caraway plants were significantly reduced as a result of the use of 25, 50 or 75 % of the recommended mineral NP fertilization dose. While, control plants which received the full dose of mineral NP fertilization gave the highest percentages of N and P in the dry herb.
III- Effects of the interaction between bio and chemical fertilization:
Vegetative growth traits:
All vegetative growth traits namely, plant height, stem diameter, branch number and herb dry weight/plant of caraway plants were significantly affected by the interaction treatments in the two experimental seasons. Supplying caraway plants with 100 % of the recommended mineral NP fertilization dose in combination with biogein, phosphorein or the mixture of both biofertilizers increased, all vegetative growth parameters compared to control treatment. In this concern, fertilizing caraway plants with 75 % of the recommended dose of mineral NP fertilization in combination with biogein or the mixture of biogein + phosphorein had gave a beneficial effect on the vegetative growth aspects.
Yield and yield components:
Generally, number of umbels/plant, weight of 1000 fruits and fruits yield per plant and per feddan of caraway plants were augmented due to fertilization with 100 % of the recommended mineral NP fertilization dose with the mixture or phosphorein and biogein, followed by 75 % of the recommended dose of mineral NP fertilization in combination with the mixture or biogein and phosphorein.
Essential oil determinations:
Application of 100 % of the recommended mineral NP fertilization dose in combination with biogein, phosphorein or the mixture of both biofertilizers significantly enhanced essential oil percentage in the fruits, as will as, oil yield per plant and per feddan of caraway plants. In the second place came the treatment of fertilization with 75 % of the recommended mineral NP fertilization dose combined with the mixture of biogein + phosphorein which improved all essential oil determinations.
Photosynthetic pigments:
The most effective interaction treatments which gave the highest contents of the three pigments were, in descending order, 100 % of mineral NP fertilization dose + biogein, 100 % of mineral NP fertilization dose + the mixture of biogein and phosphorein, 75 % of mineral NP fertilization dose + biogein or the mixture of biogein and phosphorein.
Nitrogen and Phosphorus percentage:
Plants received 100 % of the recommended mineral NP fertilization dose in combination with biogein, phosphorein or their mixture had the highest N and P percentages, followed by the plants which supplied by 75 % of the recommended mineral NP fertilization dose combined with any one of biofertilization treatments.
Second experiment:
Effect of antioxidants:
Vegetative growth traits:
All ascorbic and salicylic acid concentrations (100, 200 and 300 ppm) were significant for vegetative growth parameters (plant height, stem diameter, branch number and herb dry weight/plant) of caraway, Carum carvi plants. Ascorbic acid at 100 ppm gave the highest values of these aspects, followed by salicylic acid at 100 ppm and ascorbic acid at 200 ppm.
Yield and yield components:
The number of umbels, weight of 1000 fruits and fruits yield per plant and per feddan of caraway plants were significantly affected by ascorbic and salicylic acid treatments. The highest number of umbels/plant, heaviest weight of 1000 fruits and the largest fruits yield per plant and per feddan were produced with the application of ascorbic acid at 200 ppm or 100 ppm of both ascorbic and salicylic acids in the two experimental seasons.
Essential oil determinations:
Ascorbic and salicylic acid treatments had a noticeable influence on all essential oil determinations of caraway plants. The maximum essential oil percentage was produced as a result of ascorbic acid at 200 ppm followed by salicylic acid at 100 ppm. Whereas, the highest values regarding essential oil yield per plant and per feddan were obtained with ascorbic acid at 200 ppm followed by ascorbic acid at 100 ppm then salicylic acid at 100 ppm.
Photosynthetic pigments:
Spraying caraway plants with the different concentrations of ascorbic and salicylic acids led to increase or decrease in three photosynthetic pigments contents. The highest contents of chlorophyll a were produced due to 100 ppm of both ascorbic and salicylic acids. While, ascorbic acid at 200 ppm gave the highest contents of chlorophyll b and carotenoids.