Articles
THE DISEASE SUPPRESSIVENESS OF LIGHT-COLOURED SPHAGNUM PEAT AND BIOCONTROL OF PLANT DISEASES WITH STREPTOMYCES SP.
The suppressing effect was regaived, when new peat was added to disinfected peat.
The most common microbes in the peat were bacteria, Streptomyces spp., followed by fungi, Penicillium spp., Mortierella spp. and Trichoderma viride.
The effect of spore suspension and powder, prepared by fermentation and freeze-drying of Streptomyces griseoviridis to control plant diseases was tested.
Damping-off caused by Alternaria fungi was controlled by seed dressing with Streptomyces as effectively as by chemical seed dressing with thiram.
Dressing the cucumber seeds reduced the proportion of poor-quality seedlings and the mortality rate of seedlings.
Spraying the preparate on the surface of the peat substrate increased the average yield of cucumber.
The largest annual yield increases were 9 – 12%. Treating the peat surface decreased the disease incidence of Fusarium wilt of carnation, cyclamen and gerbera.
Several isolates of Streptomyces species obtained suppressed fungal growth on agar and produced a heptaene polyene antibiotic.
There was a significant difference in the antibiotic production between suppressive and nonsuppressive isolates.
Heptaene polyene was determined in peat treated with Streptomyces sp.