Original article Effect of vegetative propagation on field performance up to age 8 of hybrid larch (Larix x eurolepis) clones

Summary — More than 100 clones of hybrid larch (Larix x eurolepis) have been vegetatively propa-gated by stem cuttings and their behaviour under field conditions been examined in 2 clonal tests up to age 8 and 10 yr. Rooting rate was high (87%) but very variable from clone to clone. Transfer of rooted cuttings from greenhouse to the nursery remained a serious problem. No correlation between ortet vigour (total height at age 2 yr) and rooting ability could be found. Rooted cuttings behaved mostly like seedlings for both growth traits and stem form, at least when taken from young ortets (2 yr old). Age (2 compared to 16 yr) of donor plants seemed to have long-lasting effects (up to age 10 yr) on further growth of ramets. The genetic composition evolution of a fictive multiclonal variety was simulated up to age 8 yr. No major change in the representation of the component clones could be observed. Larix x eurolepis / vegetative propagation / stem cutting / clonal test / hybrid larch Résumé — Comportement en forêt à 8 ans de clones de mélèze hybride (Larix x eurolepis) multipliés par voie végétative. Une centaine de clones (expérience 1) et 21 autres clones (expé-rience 2) de mélèze hybride ont été multipliés végétativement par bouturage horticole et installés à Eclache (Puy-de-Dôme) et à Peyrat-Le-Château (Haute-Vienne). Le comportement des clones e