Influence of extract of tutsan (hypericum perforatum l) on cause of fusarium root decay in beet (fusarium oxysporum)

The studies were conducted in the laboratory of plant protection at Konstantin Preslavski University of Shumen in 2015. Under in vitro conditions the influence of 7 concentrations of aqueous extract of tutsan leaves (Hypericum perforatum L.) on growth and aggressiveness of isolates of fusarium root decay in beet (Fusarium oxysporum) was investigated. The contents of the extract of the tutsan in a concentration 10,15 and 20 ml/l nutrition media increases as the growth of mycelium, as the aggressiveness of the pathogen. The content of the extract of tutsan in a concentration 10 ml/l nutrition media inhibits spore-formation of the agent during the period from 24h to 72h.