Effect of head position and climatic conditions on seed yield of globe artichoke (Cynara cardunculus L. var. scolyinus (L.) Fiori), cv. Imperial Star

The effect of head position on seed yield was studied on 56 at random taken plants grown in an open-air plot near Zaragoza (Spain) which contained around 150 'Imperial Star' globe artichoke plants. When plants started bolting, primary heads were cut away to favour the development of the remaining heads, Flowering started by mid-May and finished at the end of June. During this period, the week in which flowering started was recorded for 77 secondary, 56 tertiary and 60 quaternary randomly chosen heads. During flowering and seed setting, rainfall and temperatures were recorded. Harvested seeds were classified into viable and non-viable for each of the 193 heads. No significant interaction was found between the week of flowering and head position (secondary, tertiary or quaternary). Seed yield was higher on quaternary and tertiary than on secondary heads. The best seed setting period, the first fortnight of June was associated with absence of rain. In all cases, seed yield was low. (C) 2002 Elsevier Science B.V. All rights reserved.