**2. Disinfection of stems**

The leaves must be removed from the stems, after which the stems are disinfected for a few seconds into alcohol 70–96%, followed by a few minutes in a solution of sodium hyperchlorite 10%. After disinfection, rinse with sterile water (distilled water).

#### **3. The first in vitro culture**

The cuttings are cut into pieces including an axillary bud. They are then placed in the culture medium, with the base pushed into the medium. The test tube must be closed. After 4 days, the bud could start to grow into a stem.

Throughout the in vitro development stages (Steps 3 and 4), only 1 medium type is used. The Murashige and Skoog growing medium contain a wide range of nutrients including the auxin hormone that induces root development. Consequently, the use of this growing medium during stages 3 and 4 leads to the production of seedlings [15]. The composition of the culture medium


#### **4. Multiplication**

Seedlings produced in Step 3 are cut into pieces with an axillary bud and leaf. These individual pieces are placed in a new tube medium, with the bud just above the nutrient medium. This multiplication step can be repeated every 4 weeks, resulting, on average, in 5 new vitro-plants from a single initial vitro-plant.

#### **5. Acclimatization**

After the desired number of vitro-plants is produced, they must be fortified for later uses in greenhouses, under shelters or in fields. For acclimatization, the vitroplants are planted in small pots containing the soil, then the temperature is reduced from 2023 to 18°C in the greenhouse.

If the micro-tubers are produced directly in a greenhouse, the vitro-plants have no interest in being fortified (physiological maturity), they can be used as such.
