Back to top

Pansy – Crown rot (Myrothecium)

Pansy – Crown rot (Myrothecium)
Pansy – Crown rot (Myrothecium)

Myrothecium Leaf Spot, flower blight, and crown rot caused by Myrothecium roridum is widely distributed and affects a wide range of hosts, causing leaf spots and sometimes stem cankers, particularly at the soil line. The pathogen is a common, soil-dwelling organism that only attacks susceptible hosts under favorable environmental conditions or when hosts are under stress. Myrothecium infections tend to develop at wounds such as those at the base of cuttings, or at leaf edges and tips. The disease is favored by abundant moisture and high relative humidity which may occur during propagation under mist. During propagation, this disease may cause defoliation and extensive loss of cuttings.Careful sanitation, minimizing the duration of leaf wetness, and avoiding unnecessary wounds will minimize damage. The promotion of rapid wound periderm formation (warm temperatures) after cuttings have been taken and the application of fungicides on stock plants and cuttings of highly susceptible species will help manage Myrothecium diseases. Apply chlorothalonil (Daconil,Echo) or thiophanate-methyl (Cleary’s 3336F) at 7-14 day intervals as needed.

Pansy - Crown Rot (Myrothecium)
Pansy - Crown Rot (Myrothecium)
Pansy - Crown Rot (Myrothecium)