Mycorrhizal Douglas-fir plants by LACCARIA bicolor S238N under license and control of INRA.

Douglas-fir Pseudotsuga douglasii mycorrhiza Laccaria bicolor S238N

These plants are inoculated with the ectomycorrhizal fungus  LACCARIA bicolor S238N  selected by the INRA Center of Nancy. Research was conducted by INRA in partnership with ROBIN Pépinières and a colleague. After several years of trials, this collaboration resulted in a commercial production. This allows us to offer plants that are more efficient in planting than traditional natural mycorrhizal plants. The figure below shows the results obtained for more than ten years by INRA in a network of comparative plantations.

10-year-old Douglas trees (examples from the INRA experimental planting network (Invert the 2 color squares and the legend under the graph)

License and control logo of INRA

License and control of INRA

The control carried out in our nursery by the INRA guarantees a good level of mycorrhization by the inoculated strain, according to strict specifications. LACCARIA bicolor S238N is a strain coming from the natural area of ​​Douglas in the north-west of the States United.

It is therefore particularly adapted to this species and stimulates its initial growth for at least ten years. The control is indicated by a vintage and numbered label placed on each box of plants

The saving of a release is a realistic goal given the experimental results of INRA.

Mycorrhizae are fragile organs, sensitive to external conditions. The mycorrhization is very fragile and disappears quickly in contact with the air. The  ROBIN ANTI-CHIGNON® bucket  allows the development of a beautiful root system, and protects the mycorhization from contaminants.

The bucket preserves the root system and intact mycorrhizae until the time of planting, thus retaining all the benefits of controlled mycorrhiza- tion. As the test results show, plants inoculated with the strain LACCARIA bicolor S238N should be placed on soils. acids: pH (water) optimum soil 5 to 5.5. These plants should not be installed on grassy soils.


Mycorrhizae is formed by the fungus LACCARIA bicolor S238N with a Douglas root. Mycorrhizae are mixed root-mushroom organs. They are the seat of a symbiosis, that is to say an association with mutual benefit: The tree provides sugars to the mushroomThe mushroom in return, carries water and minerals to the root, while protecting against certain pathogens and producing growth regulators.Mycorrhizal fungi are numerous, but some, such as  LACCARIA bicolor S238N , are more successful than others in stimulating tree growth.

Mycorrhizal s238N® Douglas-fir root with Laccaria bicolor s238N®

Coforêt site in Ronno (69).  Douglas-fir (Pseudotsuga douglasii) HIGH PERFORMANCE® mycorrhizal with Laccaria Bicolor S238N, plantation ROBIN ANTI CHIGNON® RODET R200 cm, aged one year height 15 cm and over, photo taken 2 years and a half after planting average height of plants 150 to 180 cm, recovery rate 99%, only one release was made