Thielaviopsis or black root rot
July 7, 2015
Root and stem rots
Pathogen
Thielaviopsis basicola.
Hosts include
Digitalis, Gaillardia, Geranium, Lathyrus, Lupinus, Pachysandra, Phlox and Viola.
Symptoms
Stunting, yellowing and plant death. Symptoms are often mistaken for nutrient deficiency symptoms.
Spread
Thielaviopsis basicola produces spores that can persist for long periods of time in soil or on infested pots and equipment.
Reusing contaminated equipment is a common source of disease. Fungus gnats and shore flies can vector spores.
Management
Do not reuse plug trays, flats or pots for susceptible crops. Keep good records of the production areas where there have been problems with T. basicola. Avoid growing susceptible crops in these areas for several years. Fungicide drenches should be used to protect very susceptible plants from infection.
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