Abstract
The effect of tuber dressing and plant spraying with Polyversum (B.A.S. Pythium oligandrum) and Biochikol 020 PC (B.A.S. chitosan) bio-preparations on the infestation of potatoe tubers by Streptomyces spp. was studied during the 2005-2007 years. The Vitavax 2000 FS (B.A.S. karboxin and thiuram) was used as a standard fungicide.
The results received from field experiments indicate that, during all years of study these preparations significantly reduced tubers infestation by Streptomyces spp. The Polyversum bio-preparation, which was applied to tuber dressing and sprayed on plants four times during vegetation period, showed the best protective effect against Streptomyces spp.