A hydroponic culture experiment was carried out during two successive seasons (2017 and
2018) on two years old grapevines cv. Flame seedless (Vitis vinifera L.) aimed to study the effect of
Mycorrhiza, Azospirillum and Azotobacter treatments on growth, leaf chemical composition and cation
equilibrium of Flame Seedless grapevines own rooted cuttings. The plants were two years old at the start of
the experiment. The experiment was conducted under controlled conditions in Laboratory, with temperature
fixed at 25 ± 3C°, relative humidity between 75–85% and 14-hours light exposure. Three microorganisms
commonly used in biofertilization, namely: Arbuscular Mycorrhiza, Azospirillum brasilense, and
Azotobacter chrococcum were used as biofertilizers. Standard nutrient solution, adapted with grapevines
needs, reported by Morard 1995 and Ibrahim (2001) was prepared and used in this experiment. The Flame
seedless own rooted cuttings exhibited high growth parameters as a result to biofertilization than those
untreated cuttings. However, the higher values of shoot length, number of leaves/shoots, leaf area,
chlorophyll contents and growth ratio at nutrient solutions was obtained from the seedlings treated with the
three micro-organisms in combination. The chemical analysis of mature leaves and roots indicated that the
own rooted cuttings received Mycrrohiza showed significantly higher ratio of P, K, Mg and Fe than other
bio-fertilizers treatments. On the other hand, the Azotobacter treatments exhibited higher levels of N and Zn
contents. Significant differences were observed between the two cultivars in Ca contents. However, the
lowest N. P, K, Mg, Fe and Zn values were obtained from control treatment.