How to treat Pythium blight in lawns? Detailed control methods

Pythium blight occurs commonly in all regions nationwide and can infect all turfgrasses, such as cool-season bluegrass, Kentucky bluegrass, and so on. Among them, cool-season turfgrasses suffer the most severe damage. So, how do you treat Pythium blight in lawns?

1. How do you treat Pythium blight in lawns?

You can appropriately spray protective fungicides and monopotassium phosphate, once every 7-10 days, to improve the lawn's disease resistance and provide a preventive effect. If infection has already occurred, you can use a 64% Sandofan wettable powder 400-fold solution spray, spray carbendazim 500-800 fold or thiophanate-methyl 1000 fold to drench the diseased areas.

2. The harm caused by Pythium blight in lawns

It generally develops from May to September. When the disease occurs, the leaves have no obvious spots; affected plants generally wilt downward from the leaf tips or wilt upward from the leaf sheaths in a water-soaked manner. The lesions are blue-gray, sometimes with a reddish-brown tinge. When humidity is high, they turn dark green and rot, and obvious mycelium can be seen on the plants, which feels greasy to the touch. The dead grass patches are circular or horseshoe-shaped. In severe cases, large areas of lawn wilt and die, and the rotting material sticks to the soil surface. Such dead grass areas are often distributed in low-lying, damp sections of the lawn, and sometimes appear in long strips along the mower's operating route.

Pythium has strong adaptability. It can not only infect and cause damage in cold, wet environments, but also run rampant and spread when the weather is hot, rapidly destroying the lawn. When the daytime maximum temperature is above 30°C, the nighttime minimum is above 20°C, and the atmospheric relative humidity is above 90% and lasts for more than 14 h, Pythium blight in lawns is very likely to be triggered. When the area is low-lying and waterlogged, the soil is poor, the organic matter content is low, aeration is poor, phosphorus and potassium fertilizers are lacking, and nitrogen fertilizer is used excessively, the disease is severe.

Pythium blight is a disease that causes relatively great harm to lawns. Prevention and control should be the main approach. If infection occurs, do not worry; simply use chemical agents promptly to eliminate it.