Field experiments were conducted during the two successive seasons of 2019/2020 and 2020/2021 at Mallawi Research Station, El-Minia Governorate, Egypt, aiming to minimize rates of mineral nitrogen fertilizer application at garlic production Egaseed 1 cultivar (Eg1). Mineral nitrogen fertilizer was used with three levels (50, 75 and 100% of the recommended dose of N). Four kinds of bio-fertilization (Control, Minia-azotien 3.0 L. fed^-1, Spirolina plantlets 4.0 g.L^-1, and 3.0 L./fed. of Minia-azotein + 4.0 g.L^-1 of Spirolina plantlets) for studying its effects on yield and quality of garlic.The experiment was laid out through a split-plot randomized complete block design (RCBD) with three replications, where the three rates of mineral nitrogen supply occupied the main plots. The bio-fertilization treatments were distributed at random in the sub-plots. The mineral nitrogen rates differ significantly in their effects on garlic growth parameters and yield. The best rate for obtaining these characters' highest values was 100% of the recommended dose.
Regarding the biofertilizer effects, the Spirolina plantlets treatment showed the best results to improve either growth parameter or yield and quality of garlic compared with Minia-azotien at uninoculated plants. The interaction effects between mineral and biofertilizer treatment results showed that the best treatment was 100% mineral nitrogen + 4.0 g.L-1 of Spirolina plantlets to obtain better growth and garlic's highest yield and quality. In comparison, the lowest treatment was 50% mineral and un-inoculated plants.