The effect of gibberellic acid GA3 on morphological features of artichoke (Cynara scolumus L.)

An artichoke is a commonly cultivated vegetable in the Mediterranean region. It is cultivated for an undeveloped flower head. Because of high thermal requirements in Poland the artichoke is cultivated as an annual plant. In the years 2009-2011 the research on the influence of gibberelic acid (GA 3 ) on yielding and morphology of artichoke plants was conducted. In order to establish the optimal date of spraying and development stage of plants GA 3 was used in 2 different variants: spraying done once at the stage of 8 leaves, spraying done twice at the stages of 8+12 leaves, in comparison to the control (without use of GA 3 ). Plants which were sprayed with gibberellic acid once or twice formed inflorescences up to 45 days earlier in comparison to control plants. Plants treated with GA 3 were shorter, formed less leaves in rosettes, leaves had blades of smaller length and width and shoots at the base were thicker in comparison to control plants. Plants sprayed with GA 3 formed less floral heads on inflorescence shoots but they characterized with higher mean weight in comparison to plants not treated with the gibberellic acid. Plants sprayed once gave higher yield of heads by 0.4 kg ∙ plant -1 in comparison to control plants and plants sprayed twice