THE VEGETATIVE PROPAGATION OF THE ARGAN TREE (ARGANIA SPINOSA L. SKEELS) BY GRAFTING

Grafting is a promising method for the vegetative propagation of the argan tree (Argania spinosa L. Skeels), a species endemic to Morocco that is of major ecological, economic and social interest. The objective of this study is to optimise the grafting process by studying the effect of young rootstocks on grafting success. The trial was conducted using three types of four-week-old rootstocks: PG without cotyledonary leaves, PG with a single cotyledonary leaf and PG with two cotyledonary leaves, and two types of graft: summit graft (GS) and intercalary graft (GI), from two different genotypes, the Souhayl variety already inscribed in the official catalogue of the National Office for Food Safety (ONSSA) under registration number DCSP/SHV/CM/LP/501, and a clone currently undergoing registration. Grafting was carried out under aseptic conditions, and the plants were cultured in an incubator for 21 days at 21°C, with relative humidity of 90-94% and light intensity of 200 to 1000 lux. The results obtained show that the first buds break as early as the tenth day after grafting, particularly in intercalary grafts. It appears that the bud break rate varies significantly depending on the rootstock, reaching 100% in PG with two cotyledon leaves, compared to 88% and 55% respectively for those with one or no cotyledon leaves in the Souhayl variety, when using intercalary grafting. The highest wilting rate (55.55%) was observed in the top grafts of the Souhayl variety, while that of the intercalary grafts did not exceed (33.33%). Fungal attacks, although limited, affected up to 22.22% of grafted plants of variety Souhayl. After acclimatisation carried out in a glass greenhouse, the survival rate of grafted plants reached 100% in both varieties, confirming good post-grafting recovery. The longitudinal growth of grafted plants placed in a glass greenhouse was more pronounced in the GS (Clone)/2F combination (63%), while the average number of branches was higher in the intercalary grafts 1.6 and 1.5 respectively in the Souhayl variety (GI/1F) and the clone (GI/2F).