PITHIUM
Pythium is a plant parasite of the mushroom family.Fungi live in the soil and on infected leaves year-round, obtaining the nutrients they need from the lawn.
During the cooler periods of the season, the fungi grow slowly and generally do not infect the foliage.
Some species cause roots to rot during cold, rainy periods.
When temperatures become warm and humid, fungi grow extremely quickly, causing infection and discoloration of the lawn within hours.
Pythium grows mainly on poorly draining soils with a pH greater than 7.0 and with a high concentration of nitrogen.
HOW TO RECOGNIZE PYTHIUM
Symptoms of Pythium include:
HOW TO TREAT PYTHIUM
Pythium is very difficult to treat as it grows rapidly.
The best defense is good lawn care with appropriate techniques that promote healthy growth.
These techniques include:
Symptoms of Pythium include:
- Initial symptoms appear as small, reddish-brown spots ranging in size from 3 to 15 cm, with a sticky or greasy texture that quickly increases in size. If temperatures and humidity remain high, the spots can merge together, and large areas of turf can become infected within hours.
- During humid periods, such as early morning, waterlogged leaves collapse together and turn into a purplish-gray or cottony-white mass called mycelium. As the grass dries, the mycelium disappears and the damaged leaves turn brown.
HOW TO TREAT PYTHIUM
Pythium is very difficult to treat as it grows rapidly.
The best defense is good lawn care with appropriate techniques that promote healthy growth.
These techniques include:
- Reduce shade and increase air circulation by pruning trees that obscure your lawn.
- Correct any drainage problems in your lawn, as this is the primary cause of Pythium spread. Proper aeration helps alleviate soil compaction and improves water absorption and air circulation at the root zone.
- Water infrequently and abundantly, making sure that your lawn receives the right amount of water each week.
- Avoid watering or mowing during the active disease period. Disease spores can be spread by lawnmowers or simply by walking across the lawn.
- Avoid watering and mowing at night. This keeps the leaves wet and creates favorable conditions for the spread of spores. Water early in the morning so that the plant's leaves dry by sunset.
- Provide the right amount of fertilizer. Excessive nitrogen can promote the growth of Pythium.