Study of self-pollination and capitula characteristics in globe artichoke (Cynara cardunculus var. scolymus Hayek L.) under different irrigation regimes

In order to estimate the drought effects on capitula characteristics and self-pollination of globe artichoke (<em>Cynara cardunculus</em> var. <em>scolymus</em> Hayek L.), the randomized complete block design was carried out with three irrigation regimes (20 %, 50 % and 80 % depletion of soil available water) and six replicates. The artichoke is mostly open-pollinated, however, after covering the buds and isolation of flowers to prevent cross pollination, 1.79 % self-pollination was observed and this amount was not affected by different irrigation regimes. In stress conditions (50 % and 80 % water depletion) as well as non-stress condition (20 % water depletion), plants with respectively one and two medium capitula and without small capitula had most relative frequencies in the population and drought stress increased these relative frequencies by reducing the number of medium and small capitula in plants. In addition, Capitula size and dry weight were significantly affected by water stress. Water shortage induced severe decrease in length and dry weight of all capitula including large, medium and small, although capitula width was less affected by water deficit and only slight decline in medium (12.5 %) and small capitula (23.7 %) was observed under severe stress condition.