Pythium spp, a water mould that mainly affects young, weak plants.
Pythium spp. (Pythium spp.) This water mould (Oomycetes) can affect plants via spores and fungal threads. Pythium occurs in young, weak and damaged roots (seedlings!) at the boundary of soil and air.
Pythium can also affect grass: pythium blight. There is then a dark gray, greasy layer on the grass and the roots die.
Control
Remove infested plants.
Prevention
Pythium is most common in weakened plants. Pythium likes a warm and humid environment such as a greenhouse. Not too much water, good aeration and healthy plant material help prevent pythium. There are plant strengtheners on the market that make fungus-based plants more resilient. The same is done by a biofungicide based on the bacterium Streptomyces griseovirides: it colonizes the root of the plant before pythium, among others, can settle itself on the roots.
