A field experiment was conducted during 2011 and 2012 seasons to evaluate the effect of cyanobacterial foliar application with different levels of chemical fertilizers (25%, 50% and 100% of the recommended dose of NPK fertilizer) on the growth characters, macro-elements content, essential oil percentage, yield and composition, total phenol content, total flavonoid content as well as the antioxidant activity of marjoram (Origanum majorana L.) plant. The cyanobacteria (Blue green algae) belonging to the strain Spirulina platensis were used as a foliar spray at four concentrations (0, 4.5, 7.5 and 10 g/l). The obtained results revealed that the application of cyanobacteria combined with 50 or 100% of the recommended dose of NPK fertilizer improved growth characters, chemical constituents and essential oil composition than the other treatments. So, using cyanobacterial foliar spray with 50% of the recommended dose of NPK fertilizer could provide a high quality product with reduced harmful agrochemicals and eliminate environmental pollution.

Irrigation water use management is one of the most important factors of agricultural sustainability. Therefore, an experiment was conducted at the Experimental Farm of Arab El- Awammer Research, Station, Assiut, Egypt. during the two successive growing seasons of 2017/2018 and 2018/2019, to study the foliar application with different concentrations of Moringa leaves extract (control (zero), 2 and 4%) under different levels of deficit irrigation (60, 80% and 100% ETc). The results showed that, all evaluated parameters of black cumin plant (height, number branch, number of capsules /plant, weight of seeds (gm)/ plant and weight of seeds (kg)/fed.) significantly decreased with increasing water stress, inversely water stress increased significantly unsaturated fatty acids percentage (linoleic, oleic acids, Eicosadienoic acid). Economic productivity of irrigation water and IWUE, were significantly increased at 60% ETc compared to 80 and 100% ETc. The mean values of all studied characters were significantly increased as the moringa extract concentration increased in both seasons. While the highest mean values of fixed oil, total protein and total carbohydrate were obtained with100% and 80% water interacted with the highest moringa extract applied level (4%). The combination of full irrigation and 4% MLE gave the highest values of most previous parameters; additionally insignificant differences were noticed between full irrigation and moderate stress treatments with the same concentration. Therefore, it could be recommended by foliar application of 4% MLE with 80% Etc irrigation water for obtaining higher yield and quality of black cumin.

Crown gall is one of the most hazardous diseases for nurseries of stone fruit plants. Biological control of crown gall caused by Agrobacterium tumefaciens using Agrobacterium radiobacter K84 is more comparatively effective in disease control compared to chemical means. In the present work, the distinguished components of essential oils of caraway (Carum carvi L.) were carvone (79.38157%) and limonene (18.78265%), and those for thyme (Thymus vulgaris L.) were identified as thymol (14.79336%), 1,8-Cineol (14.45795%), borneol (13.22024%), β-caryophyllene (10.86938%) and bornyl acetate (5.08278%). The inhibition zone produced by the antagonist A. radiobacter against A. tumefaciens 27AS_ Pp4 was 11.8 mm in diameter, whereas it was 10.2 and 11.0 mm in caraway and thyme essential oils, respectively. The minimal inhibitory concentration (MIC) of essential oils against A. tumefaciens 27AS_Pp4 was 12.8 μl/ml of both caraway and thyme as compared with the minimal bactericidal concentration (MBC) being 25.6 and 12.8 μl/ml for caraway and thyme, respectively. When A. tumefaciens 27AS Pp4 was treated with caraway and thyme, the crystal violet uptake was increased. No disease syndromes were observed on apricot (Prunus armeniaca L.) seedlings inoculated with the pathogen A. tumefaciens 27AS_Pp4 and the antagonist A. radiobacter. Moreover, a significant decrease in the number of galls was observed in caraway and thyme essential oil treatments compared to the positive control. The fresh and dry weight of galls per plant confirmed the effectiveness of caraway and thyme treatments. The treatment of caraway essential oil showed a significant decrease in the fresh weight of shoots and roots compared to both positive and negative controls and A. radiobacter treatments. No significant differences in the fresh weight of shoots and roots in thyme oil treatment compared to negative control and A. radiobacter. Determination of the dry weight of shoots and roots comparatively confirmed these results. On the other hand, the essential oil of caraway showed a significant decrease in plant length compared to thyme, A. radiobacter, and positive and negative control treatments. In the case of thyme oil, the length of the plant has increased significantly compared to the negative control, with no significant difference between thyme oil and A. radiobacter treatments. These results suggest that the essential oils of caraway and thyme have a reasonable potential for controlling crown gall disease. Consideration should be given to the potential effect of the essential oil of caraway on plant growth. Further work with different horticulture seedling nurseries is needed.

This study aimed to examine the influence of Aloe vera gel at different concentrations as growth enhancer on Eucalyptus citriodora, Hook micropropagation. The experiments were conducted from April 1 st 2019 until January 15 th , 2020 at Plant Tissue Culture Laboratory of Prof. Dr. Abd El-Fatah H. Belal, Fac. Environ. Agric. Sci., Arish Univ. The obtained results presented that, soaking Eucalyptus citriodora explants on (Clorox) ® solution at 20% (v/v) for 20 minutes recorded the highest survival percentage of explants (87.33%) on establishment stage. Furthermore, addition of BA at 1 mg l-1 in combination with NAA at 0.1 mg l-1 recorded the highest shoot number/explant, shoot length (cm) and leaf number/shoot (7.33, 4.66 and 9.50, respectively) on multiplication. Also, the maximum shoot number/explant, shoot length (cm) and leaf number/shoot (9.33, 7.00 and 11.50, respectively) were achieved with addition of Aloe vera gel at 20 m l-1. Moreover, Murashige Skoog (MS) medium with IBA addition at 1.0 mg l-1 recorded the maximum growth of Eucalyptus citriodora during rooting stage. i.e., shoot number/explant, shoot length (cm), leaf number/shoot, rooting percentage, root number/explant and root length (cm) (3.44, 8.13, 12.86, 99, 3.27 and 5.07, respectively). Finally, rooted shoots were highly successful (above 80%) on soil mixture contains peatmoss and sand at a rate of (1:1, v:v).