Flowering dynamics of peach-leaved bellflower (Campanula persicifolia L.) 'alba' treated with bioregulators, grown in an unheated plastic tunnel and in field

Abstract

The effect of BA, GA₃ and BA+GA₃ on flowering of peach-leaved bellflower (Campanula persicifolia L.) 'Alba', grown in an unheated plastic tunnel or in open field, was investigated. Bioregulators at the following applications: 0, 100, 200, 400 mg x dm^-3, were applied foliarly twice. It has been found that the cultivation of peach-leaved bellflower in an unheated plastic tunnel accelerates flowering of plants by about 2 - 3 weeks, compared to open field cultivation, in the first and second year of flowering of plants. It is advisable to apply gibberellic acid at a concentration of 400 mg x dm^-3 in plastic tunnel cultivation of bellflower and at a concentration of 200 mg x dm^-3 in field cultivation, since this treatment accelerates flowering by 2 - 9 days. It is recommended that gibberellic acid should be applied at a concentration of 400 mg x dm^-3, which extends the flowering period of peach-leaved bellflower grown in a plastic tunnel by 6 - 13 days. When peach-leaved bellflower is grown in an unheated plastic tunnel, full flowering is predicted to occur in the first or second week from the beginning of flowering of plants. When bellflower is grown in open field, full bloom of inflorescences is expected in the second week of flowering of plants. Irrespective of the type of substance applied in both years of cultivation, in the unheated plastic tunnel the largest amount of inflorescences was ready for cutting in the first decade of June, and in the field in the second decade of June.