Effects of Controlled Mycorrhization on Production of Jacaranda mimosifolia D.Don

Growth and mineral absorption of ornamental woody plant such as Jacaranda mimosifolia D. Don., in gnotoxenic conditions out of a mycorrhization by a commercial inoculum containing Glomus irregulare were studied. Used Jacaranda plants are one- year old, they were first grown, in 10/12cm caliber pots then in 16/18cm caliber pots for 6 months in a sterile substrate consisting of 2/3 commercial peat and 1/3 sand. Four treatments, achieved three times, were processed. Apart from the control, two other treatments consisted of the addition of commercial inoculum containing Glomus irregulare to the culture substrate, at a rate of 62.5 mg / plant for the first and 100 mg / plant for the second. These quantities respectively correspond to 100 propagules / plant and 160 propagules / plant. The fourth treatment is illustrated by the incorporation of 4g/plant of OSMOCOT EXACT standard-Scotts fertilizer; 15 + 9 + 12 (+2.5), into the substrate. Mycorrhization rate of inoculated plants by 100mg/plant dose reached 43.21% while it only reached 21.48% for those that received 62.5mg/plant. Colonization remains at the beginning of installation presenting essentially mycorrhizal hyphae structures. Mycorrhization significantly improves nitrogen, phosphorus and potassium nutrition of Jacaranda . This result in a stimulation of plant growth Level of mycorrhization by 21.48%, and achieve gains of aerial dry biomass of about 45.5% and root volume of about 46.29%. When the level of mycorrhization is equal to 43.21%, these gains correspond to, respectively, 59.1% and 67.28%. Fertilization provides for gains of 29.58% in aerial dry biomass and 9.69% in plants height. It has no effect on roots volume.