الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
This research was aimed to isolate local strains of cyanobacteria and select the most efficient ones, then applicate them, their extracts and compost tea for evaluation effectiveness of theses bio-organic fertilizers on wheat plant growth. It could be overviewed of the most important results as the following, eighteen cyanobacterial isolates were collected from soil samples at various locations from governorates of Kafr El-Sheikh and El-Dakahlia. Cultural and morphological characterizations were performed to identify these isolates. Heterocyst-forming cyanobacteria were Anabaena sp., Nostoc sp., Oscillatoria sp. and chroococcus sp. Where, Nostoc sp. and Anabaena sp. isolates were represented at high frequency in the two isolated areas. The less frequency of occurrence in this study were Oscillatoria sp., chroococcus sp., Phormidium sp., Pseudoanabaena sp. At level of species, the isolates were identified as Nostoc calcicola, Anabaena oryzae, Anabaena cylindrical, Nostoc pruniforme, Anabaena variabilis, Anabaena qelatinicola, Phormidium foveolarum, Pseudanabaena qaleata, chroococcus minor, Oscillatoria brevis. Bioactivity of cyanobacterial strains were studied in vitro through assess their growth and ability of fixing nitrogen as well nitrogenase activity and plant growth promoting agent indole acetic acid . Results of both Nostoc calicola D and Anabaena cylindrica D were recorded as the most active nitrogenase activity, indole acetic acid production. Therefore, these two strains of cyanobacteria were chosen for applying as it is and their extracts in bio-organic farming experiment. Then, a pots experiment was carried out in the greenhouse during the winter season of (2018) to study the effectiveness of biological and organic fertilization amended with less doses of mineral nitrogen on the growth and yield of Wheat plant. The experiment was arranged as a completely randomized design in 39 treatments with three replicates. The treatments were as following: 3 treatments with mineral N2 doses only (100, 75, 50%); 6 treatments with biological treatments in two groups amended with 75 or 50% mineral nitrogen [Anabaena (A), Nostoc (N), A+N]; 14 treatments with organic fertilizers only either single or mixture in two groups amended with 75 or 50% mineral nitrogen [compost tea (T), Anabaena extract (AE), Nostoc extract (NE), T+AE, T+NE, AE+NE, T+AE+NE) and 16 treatments with biological and organic fertilizers in two groups amended with 75 or 50% mineral nitrogen (T+A, T+N, T+A+N, AE+N, NE+A, T+AE+N. T+NE+A. T+A+N+AE+NE). Data indicated that total bacterial counts of rhizosphere soil samples recorded highest value with full dose of mineral nitrogen at 60 days, while it reduced with mineral nitrogen consumption, then treatments of compost tea + Anabaena, compost tea + Nostoc and compost tea + Anabaena + Nostoc + their extracts in the presence of 75%N gave highest total bacterial counts as well N2-fixing cyanobacterial contents. Vegetative growth parameters of Wheat plant were measured (plant height, fresh, dry weight of shoot, number of leaves and tiller/plant) after 60, 90 and 120 days. The maximum growth values were appeared with the application of C75TA (75 % N + compost tea + A. cylindrica), C75TN (75% N + compost tea + N. calicola) and with C75TNANEAE (75 % N + compost tea + N. calicola + A. cylindrica + their extracts) after 60, 90 and 120 days. While the lowest values was recorded with the C50 (50% N). Root characteristics represented by root length and fresh and dry weight were followed during growth stages after 60, 90 and 120 days from planting. Data showed that the highest mean value of root length and dry weight were observed with the treatment of C75TA (75% N + compost tea + A. cylindrica), C75TN (75% N + compost tea + N. calicola) and C75TNANEAE (75% N + compost tea + N. calicola + A. cylindrica and their extracts) after 120 days while the lowest value recorded with C50 (50% N). In addition, data of the pigments content (chlorophyll A, chlorophyll B and carotenoids) of wheat leaves revealed that the lowest values recorded with treatment of C50 (50% N) as control, while, the highest mean values of the pigments content observed with combinations of Compost tea with Nostoc (TN), Anabaena (TA) and their extracts (TNANEAE) in the presence of 75%N (C75). Data of nutritional status of plant (at 60, 90 and 120 day) also affected by nitrogen mineralization with compost tea, N. calicola, A. cylindrica and their extracts. It was found that all treatments significantly affected in N, P and K percent in roots and shoots. The highest mean values of N, P, K were obtained with the treatment of C75TNANEAE (N 75 % + compost tea + N. calicola, A. cylindrica and their extracts) which recorded 2.93, 3.48 and 2.55% for N, 0.34, 0.30 and 0.18% for P and 1.72, 2.39 and 1.65% for K after 60, 90 and 120 days. While the lowest values recorded with treatment of C50 (50% N). Finally, the most important measurements that reflect the effectiveness of biological and organic treatments on Wheat plant are the yield parameters as weight of 100 g, weight of straw, weight of spike and number of grain/spike. Significant differences among bio-fertilization, organic and N-fertilization were appeared. Among all the treatments, the maximum mean values mostly recorded with combinations of compost tea + cyanobacteria + their extracts supplemented with 75% of N-fertilization dose while the lowest value was obtained with C50 (50% N). Through this conclusion, it can be recommended for conducting research on a larger scale in the cultivation of wheat plant or other important crops, using biological and organic fertilization represented in mixture of cyanobacteria, their extracts, and compost tea to soil supplemented with less dose of mineral nitrogen fertilizer as an attempt to reduce the use of mineral fertilizer and subsequently increment soil fertility and reduce the cost as well environment pollution.