Nursery production of rooted offshoots of globe artichoke (Cynara scolymus L.)

Different experiments were carried out to study the rooting of artichoke offshoots in alveolate trays in relation to offshoot size, plant density. and substrate type, respectively. The trials were carried out in the autumn 2000 and 2001, utilising offshoots of cultivar 'Terom' cultivated in Florence area. In the first experiment, offshoots of different size were used: diameter 1-2 cm, length 15 or 20 cm; diameter 2-3 cm, length 15 or 20 cm. The results showed that offshoot diameter is less important than length in influencing rooting; 87% rooting was achieved with 20 cm long offshoots, and only 57% with 15 cm long offshoots. In the second experiment. two plant densities were tested: 240 or 360 plants m(-2) (40 alveolus or 60 alveolus trays, respectively). No effect was observed on rooting percentage, while offshoot survival decreased (-10%) at the higher plant density, due to disease problems. The substrates tested in the third experiment were pumice, sphagnum peat, coconut fibre and some mixtures. Their effect on offshoot rooting and survival was correlated with water capacity; advantages derived from the use of peat (75% rooting and 57% survival) in comparison with pumice (65% rooting and 52% survival).