Pythium Blight: Causes, Prevention, and Treatment

 

What is Pythium Blight?

Pythium Blight is a widespread fungal infection that wreaks havoc on well-kept turf grass. The lawn fungus responsible for this infection, also known as Pythium Root Rot, may damage a number of grass species across the United States. Pythium Blight damage occurs in the northern states throughout the summer months and in the southern states from early fall to late spring.

Pythium Blight occurs unexpectedly during hot, humid weather and is frequent in the wettest locations and surface drainage patterns. This lawn disease is most damaging to young grass and plants and is hardly ever seen in household lawns. Pythium Blight symptoms include quickly developing, dark, oily circular patches reaching 3/4 to 2 inches in diameter. Pythium Blight generates cotton-like clumps that can unite to form bigger patches. The affected parts of your lawn may appear brown to orange in color.

Signs and Symptoms of Pythium Blight

You must be sure you’re fighting with Pythium Blight and not something else. Here are several clear indications of Pythium Blight.

• Pythium blight is frequently caused by Pythium fungus species, including Pythium aphanidermaturm, Pythium graminicola, Pythium ultimum, and Pythium vanterpoolii.
• During hot, humid conditions, it is a severe disease of cool-season turfgrasses.
• The disease first shows as orange-colored patches on short-cut turf such as bentgrass, putting greens, or fairways. The patches are usually 1 to 3 inches across.
• If humidity levels remain high, a fluffy white pile of mycelium may form. This is sometimes referred to as the “cottony blight” stage of development.
• If the conditions stay suitable, the spots may become larger in a short period of time.
• How to Prevent and Treat Pythium Blight
• Excessive thatch must be removed.
• Don’t overfertilize the lawn with nitrogen.
• Encourage enough light penetration into the grass canopy.
• Increase air circulation to help the lawn dry faster.
• When creating a new location, make sure there are adequate surface and drainage channels.
• Watering young plantings should be avoided, as should watering late in the day.

Chemical Control of Pythium Blight

The easiest method to combat Pythium Blight is to establish surroundings that promote healthy grass. Not only will this make your lawn unsuitable for Pythium Blight development, but it will also reduce your chance of significant damage if the grass infection progresses.

Because of the disease’s tendency for fast spread, high-value regions and sensitive grasses should be safeguarded with a preventative fungicide treatment. When circumstances are favorable for Pythium blight development, applications should be begun when night temperatures regularly reach 65°F for cool-season grass and repeated at 14 to 21-day intervals as recommended on the fungicide label.

Proper watering is the most important element of treating this disease, especially during periods of high overnight temperatures. Overwatering should be avoided; only irrigate to a depth of 4 to 6 inches when absolutely required. Avoid mowing soggy grass or applying large amounts of nitrogen during hot, humid weather. Reduce shade to improve soil aeration and water drainage. New established grass from seed should be timed to coincide with periods when the environment is not conducive to the disease’s growth.