Thielaviopsis in pansy

In September, the Central Maryland Research and Education Center received pansies infected with the fungus Thielaviopsis basicola, the pathogen that causes black root rot.

Infected plants were severely stunted, and the roots were blackened due to the numerous black spores produced by the fungus.

Sanitation is important in controlling this disease, starting with clean growing media, plant material, pots, and flats. The pathogen is favored by alkaline (high) pH and can be kept in check by keeping the pH of the growing media at or below 5.6. Discard infected plants and remove plant debris and infested soil.

Fungicide applications will not cure affected plants, but will protect healthy plants from infection. A soil drench application of a fungicide such as Cleary’s 3336, Medallion or Terraguard will help protect roots from infection.

For more, Stanton Gill