Abstract. It was found that soaking of freesia ‘Versailles’ corms in solution of chitosan before planting increased the coefficients of corm weight and corm number increase, irrespective of the molecular weight of chitosan. Treating of corms with chitosan decreased the occurrence of Fusarium spp. on offspring corms of freesia.

The evaluation of influence of chitosan on yield
and healthiness of freesia ‘Versailles’ corms

Summary

In the years 2004 and 2005 experiments were carried out in a plastic tunnel, evaluating the influence of chitosan on yield and healthiness of the offspring corms of freesia ‘Versailles’. Before planting corms were soaked for 20 minutes in 0.2% solutions of chitosan of molecular weight: 0 (control), 2000, 2500, 3000, 3500, 5000, 6500, 50 000, 124 000, 500 000, 970 000 g·mol^-1.

It was found that treating of corms with solution of chitosan increased the coefficient of corm weight increase and the coefficient of corm number increase. Value of the reproduction coefficient depended on the molecular weight of chitosan. Significant extension of offspring corms weight increase was in the objects where chitosan of molecular weight 6500 g·mol^-1 (2004) and 970 000 g·mol^-1 (2005) was used in comparison with the control object. Significant extension of offspring corms number increase was in the objects where chitosan of molecular weight 3500, 6500, 124 000 g·mol^-1 (2004) and 5000 g·mol^-1 (2005) was used.

Mycological investigation directly after corms digging indicated the occurence of Fusarium spp. only in the control object, while did not indicate it in all the objects where chitosan was used.