MORPHOLOGICAL TRAITS, DECORATIVE VALUE AND YIELD OF CORMS OF FREESIA (Freesia Eckl. ex Klatt) DEPENDING ON THE APPLIED CHITOSAN

In terms of turnover value on the global wholesale flower markets, freesia has been for many years in the top ten of cut flowers. Achieving high quality inflorescences in a cultivation center without cooling the sub-strate is a huge challenge for the producers. The study was conducted in the years 2010–2012, during the summer-autumn season in an unheated foil tunnel. The material consisted of prepared daughter corms of ‘Summer Beach’ variety. Chitosan of 8 000 g∙dm-3 molecular weight was used in the research. Chitosan ap-plication methods (watering or spraying), its concentration (0.0; 0.2 or 0.4%), and application frequency (every 7 or 14 days) were compared experimentally. During the experiment, the number of days from the beginning of sprouting until the end of flowering was determined, and the vegetative and generative organs were evaluated. The yield of daughter corms was assessed after the end of the cultivation. High tempera-tures prevalent in the time of generative organ formation prolonged the flowering period of ‘Summer Beach’ freesia but the inflorescences were typical and characteristic of the variety. The effect of chitosan depended also on the temperature during the cultivation. Irrespective of chitosan application method, its concentration and frequency of treatment, its presence delayed freesia heading at higher temperatures and accelerated the process at lower temperatures. Chitosan caused an increase in freesia height, number of generated shoots and leaves and leaf greenness index. It positively affected the quality of the resulting in-florescences. However, this effect was concentration and application dependent. Moreover, chitosan in-creased the ratio of daughter corm formation and total ratio of corm number and mass, and reduced the ratio of daughter corm mass gain.