Argan (Argania spinosa (L.) Skeels) Seed Germination Under Some Pretreatments of Thermal Shocks

Aim of study: The objective of this study was to optimize the germination of A. spinosa seeds after different physical pretreatments by thermal shock to establish a simple, effective, and less expensive procedure. Area of study: The study was conducted in the laboratory on seeds from four regions of Morocco (Aoulouz, Essaouira, Sidi Bou Othmane, and Boulaouane). Material and methods: The seeds were dried and stored. Before the launching of the experimental protocol, they were dehulled and applied each their pre-treatment for the four provenances. The pretreatment used are the following. C: control without thermal shock, HC1: freezing, HC2: hot water, HC3: freezing + hot water. Main results: The results showed that the onset of germination of argan seeds subjected to pretreatment HC3 was reduced by 2 days on mean compared to seeds that were subjected to pretreatment (C). The application of the cold or hot pretreatment allowed us to reach up to 82% of the final percentage of germination. However, the combination of two pretreatments allowed us to reach up to 100% of the final germination percentage. Highlights: Freezing combined with hot water significantly improved the germination of A. spinosa seeds. This pretreatment could be recommended in the nursery for practitioners.