**3.1 Mother plants**

The mother plant material is derived from apical meristems that are first grown in tissue culture; the emerging seedlings are then tested for virus infection while grown in an insect-free core greenhouse. In a second stage, all the 'core plants' undergo a tight supervision by the breeders to guarantee its genetic identity and cleanliness, in a "true to type" process, before further propagated in a foundation greenhouse to produce clean mother plants. After 2–3 months of cold treatment, the bare-rooted mother plants are rooted in 7–7–8 cm pots and then distributed among farmers for the last propagation step. For propagation, plugged mother plants are transferred in late April to a hung coir channel system at a planting density of a single mother plant per 1 m row length, at height of 2 m above ground, and at 1.5 m distance between rows, thus providing maximum light interception and aeration throughout the propagation process. Coconut fibers packed in 1 m long growbags are the preferred growth medium. The mother plants are planted on top of the growbag and after a short rooting period, they start producing runners. Crowning joints of the runners are planted, while still attached to the mother plant, in empty holes between mother plants along the growbags. After rooting, these buds produce secondary runners that fall as curtains on both sides of the hung growbags. On early September, 100–150 daughter plants per meter-row, depending on the cultivar, are selected and retrieved from these secondary runners. During the propagation period, water is supplied at 4–6 mm day−1 using 1.6 l h−1 emitters, five emitters per 1 m dripline length. The irrigation water is of a high quality (desalinated water), fortified with a liquid composite NPK fertilizer Mor 4:2.5:6 (ICL, Israel) plus calcium and magnesium at 1 and 0.5%, respectively, and at a fertilizer concentration of 60–120 ppm N. Fertigation is operated four times a day, which can be raised up to 6 pulses a day under heat wave events.
