Castor bean (Ricinus communis L.) is an oleaginous plant having multiple uses on the artisanal level and in the chemical industry. With the aim of determining the extent of this biofertilization, the effect of this biofertilizer is studied in the local field (Ndoutourou) in the locality of Bini-Dang (Adamaoua, Cameroon). The experimentation is led by the University of Ngaoundere campus, following a completely randomized block design, with six treatments (0, 5, 10, 15, 20 and 25 g of mycorrhiza per seed hole), repeated three times. The germination rates and survival of the seedlings, the parameters of growth (the size and number leaves), diameter of the stem, dry biomass of seedlings, number of fruits by ears, number of ears by plants, mycorrhization rate of root and seed yield are evaluated. The amounts of mycorrhiza significantly increased (p <0.05) the productivity of castor bean compared to the control. In a general way, the seedlings of castor resulting from the plots to have received 5, 10, 15, 20 and 25 g of mycorrhiza do not show a significant difference in the germination rate, survival, size, and number of leaves, diameter of the stem, dry biomass, and number of fruits, mycorrhizal rate of roots and seed yield. Looking at the results obtained from our work, the amount of 5 g represents the minimum quantity of mycorrhiza which would ensure optimal productivity of castor s in the field. The seedlings of castor resulting from the plots enriched with this quantity by mycorrhiza have the biomass of 27.23 ± 4.66 g in flowering and a seed yield of 29.39 Kg / ha in 175 days after sowing. This ratio is the largest of 25.96 and 33.85% compared to the control.