Comparison between nitrogen biofertilizers source (blue green algae and bacteria) on growth of date palm plantlets (Phoenix dactylifera ‘Malacabe’) during acclimatization stage

The acclimatization phase is the most important stage in the protocol of date palm micro-propagation because if not optimized, the whole process will be in efficient. Factors affecting the successful production of free-living date palm, including length of plantlets, number of leaves, strength of root system, humidity of the growing environment, and composition of the soil have been studied. Bio-fertilizers such as cyanobacteria and bacteria considered which have efficient potential to enhance the vegetative growth, chemical composition in leaves and improved nutrients uptake were evaluated. The purpose of this study was to investigate the influence of either mixture of bacteria (Azospirillum lipoferum, Azotobacter chroococcum and Paenibacillus polymyxa) or mixture of cyano bacteria (Nostoc muscorum and Anabaena oryzae) and the combination between the mixture of bacteria and cyano bacteria in presence of two levels of ammonium nitrate (33.5% (as nitrogen source), 50 and 75% of recommended dose) on growth, Soil biological activity and chemical composition of date palm plants during acclimatization stage. Experimental results indicated that all bio-fertilizer (blue green algea and bacteria) significantly increased plant height (cm), number of leaves, leaf width (cm), indole (mg g^‑1 fw) and chlorophyll a, b and c (mg g^‑1 fw) contents in both seasons, with the superiority of mixture between (Nostoc muscorum+ Anabaena oryzae + Azotobacter chroococcum + Azospirillum lipoferum + Paenibacillus polymyxa + 75% N, which gave in general, the high means in plant height (cm), number of leaves plant^‑1 and leaf width (cm). A similar trend was also gained concerning the content of indoles, chlorophylla, activity of dehydrogenase, nitogenase and carbons content compared to the control and other treatment. So, It may be recommended to use a mixture of Nostoc muscorum + Anabaena oryzae + Azotobacter chroococcum + Azospirillum lipoferum + Paenibacillus polymyxa + 75% to enhance the vegetative growth, increase soil biological activity such as dehydrogenase, CO₂ and nitrogenase activity and chemical composition in leaves during acclimatization stage.