Suppressive effects of a polymer sodium silicate solution on powdery mildew and root rot diseases of miniature rose

Sodium silicate was dissolved in water in either a monomer form or polymer form; the effects of both forms of sodium silicate aqueous solution on rose powdery mildew and root rot diseases of miniature rose were examined. Both forms of sodium silicate aqueous solution were applied to the roots of the miniature rose. Potassium silicate aqueous solution was used as a control and was compared to the effect of sodium silicate aqueous solution. The polymer sodium silicate aqueous solution was the most effective treatment against both powdery mildew and root rot diseases. Moreover, no inhibition effects of silicate solutions were observed in vitro on Pythium helicoides, the causal pathogen of rose root rot disease. The silicon contents in the roots of the miniature rose treated with polymer sodium silicate were significantly greater than that in plants treated with monomer sodium silicate. In conclusion, the suppressive effects of sodium silicate in the polymer form were confirmed against powdery mildew and root rot diseases of the miniature rose.   Key words: Podosphaera pannosa, Pythium helicoides, miniature rose, polymer and monomer sodium silicate.