Evaluation of yield, earliness and head characteristics of bull variant plants of the globe artichoke varieties "blanca de tudela" and "violet de provence" at murcia (Campo de Cartagena, se Spain)

Thirty pairs of contiguous artichoke plants were selected in a commercial field of variety Blanca de Tudela one of each pair being of the normal type and the other bull type. When the production characteristics of both types were compared, the former yielded the equivalent of 20.98 t ha-1, while bull yielded the equivalent of 14.98 t ha-1. The normal type began production an average of 28 days earlier. However, it was clear that many of the heads had been removed before they could be monitored and only in eleven pairs of plants could the total production be reliably assessed. In these pairs, the yield was the equivalent of 23.74 and 18.00 t ha-1, respectively, for normal type and bull type, the former initiating production 21 days earlier on average. The characteristics of both types also differed in other respects; bull heads being heavier, of greater diameter, shorter and with a receptacle that was heavier (although not necessarily showing a higher percentage of receptacle weight). A study carried out with plants of the variety "Violet de Provence" pointed to similar differences between a normal type and a bull type.