Growth retardants in the cultivation of Chrysanthemum × grandiflorum (Ramat.) Kitam. ‘Leticia Time Yellow’

The objective of the presented experiment was the showing of the possibility of replacing daminozide, contained in the preparation B-Nine 85 SP, by metconazole, contained in Caramba 60 SL preparation, in pot cultivation of pot chrysanthemum ‘Leticia Time Yellow’. Experiment was carried out in three cycles: in the spring, beginning 10 April; in the summer, beginning 11 June; and in the autumn, beginning 13 August, 2007. The metconazole contained in the Caramba 60 SL preparation was able to impede the growth of ‘Leticia Time Yellow’ chrysanthemum as effectively as the daminozide contained in the B-Nine 85 SP preparation. However, the effectiveness of metconazole depended on its concentration and on the dose of the preparation, on the number of treatments and on the growing term in the plastic tunnel. In the summer term of cultivation, the effect of metconazole applied only once in a concentration of 300 mg dm^-3 was comparable with the effectiveness of daminozide applied twice in a concentration of 2,550 mg dm^-3, and in the autumn cultivation, the effectiveness was even higher. In addition, no retardation of flowering was recorded, either in relation to the plants sprayed with daminozide or in relation to the control plants not sprayed with any retardant.