Articles
ECTOMYCORRHIZAL INOCULATION OF AVENUE TREES IN PARIS
It consists of inoculating seedlings in the nursery with mycelia of ectomycorrhizal fungi selected for their better performance, compared to the resident symbionts at the planting site, for stimulating tree growth.
It is an energy-saving and environment-friendly alternative to soil tilling, chemical fertilizers and pesticides for improving the early growth of forest plantations.
The French Ministry of Environment, the City of Paris and the National Institute for Agricultural Research (INRA) have been collaborating for several years to test the possibility of adapting controlled mycorrhization to urban trees.
A first set of experiments was done with silver lime (Tilia tomentosa) and inoculation at planting with three ectomycorrhizal fungi: Laccaria laccata, Paxillus involutus and Cenococcum geophilum. In spite of irregular colonization of the roots by the introduced symbionts, tree growth was significantly stimulated in the three fungal treatments and yellowing of leaves in autumn was delayed.
These promising results led to another series of experiments with Turkish hazel (Corylus colurna) and a wider range of fungal strains, some of them specially isolated from this tree species.
Two inoculation alternatives are compared: at the last transplanting in the nursery or at outplanting in Paris.
In addition, special attention is given to competitive interactions between resident and introduced fungal strains by using DNA fingerprinting.