Few diseases are as destructive as Phymatotrichum root rot, which can attack and kill over 2,000 species of plants. Fortunately, with its affinity for hot, dry climates and calcareous, slightly alkaline clay soil, this root rot is limited to certain regions. In the Southwest United States, the disease can cause significant damage to fruit crops, such as sweet cherry trees. Continue reading for more cherry cotton rot info.
What is Cherry Phymatotrichum Rot?
Cherry root rot, also known as cherry cotton root rot, cherry phymatotrichum root rot, or simply cotton root rot, is caused by the fungal organism Phymatotrichum omnivorum. This disease is soil borne and spread by water, root contact, transplants or infected tools.
Infected plants will have rotted or decaying root structures, with visible brown to bronze colored woolly strands of fungus. A cherry tree with root rot will develop yellowing or browning foliage, starting with the plant crown and working down the tree. Then, suddenly, the cherry tree foliage will wilt and drop. Developing fruit will also drop. Within three days of infection, a cherry tree may die from phymatotrichum cotton root rot.
By the time the symptoms of cotton root rot on a cherry are visible, the plant’s roots will have been severely rotted away. Once the disease is present in the soil, susceptible plants should not be planted in the area. Depending on conditions, the disease can spread in the soil, infecting other areas by stowing away on transplants or garden tools.
Inspect transplants and do not plant them if they look questionable. Also, keep your gardening tools properly sanitized to avoid the spread of diseases.
Treating Cotton Root Rot on Cherry Trees
In studies, fungicides and soil fumigation have not been successful in treating cotton root rot on cherry or other plants. However, plant breeders have developed newer varieties of plants that show resistance to this devastating disease.
Crop rotations of three or more years with resistant plants, such as grasses, can help control the spread of phymatotrichum root rot. As can deeply tilling infected soils.
Amending the soil to reduce the chalk and clay, and also to improve moisture retention, will help prevent the growth of phymatotrichum. Mixing in garden gypsum, compost, humus and other organic materials can help correct the soil imbalances in which these fungal diseases thrive.