Collar blight is a plant disease caused by a fungal pathogen. The word "collar" refers to the area near the base of a plant stem, and "blight" means a rapid and severe wilting of leaves and stems. The spelling of "collar blight" in IPA phonetic transcription is /ˈkɒlə/ /blʌɪt/. The first syllable is pronounced with the "oh" sound as in "hot," the second syllable has a short "uh" sound, and "blight" is pronounced with a long "i" sound as in "eye."
Collar blight is a plant disease that affects the lower part of a plant's stem or trunk, specifically the collar area where the stem meets the roots. It is caused by fungal or bacterial pathogens, which infiltrate the plant tissues and lead to the development of symptoms such as decay, rot, and discoloration. The term "collar blight" is commonly used in the context of woody plants, including trees, shrubs, and vines.
The disease usually starts with the invasion of the pathogen through wounds or damaged tissues in the collar region. Once inside the plant, the pathogens multiply and spread, causing the affected area to become weakened and compromised. Symptoms of collar blight include the presence of cankers, which are localized dead areas on the plant's stem, often accompanied by a dark or discolored appearance. As the disease progresses, the cankers may expand and become sunken or cracked. In severe cases, collar blight can lead to the death of the plant.
The management of collar blight involves several preventive measures, such as maintaining proper sanitation practices in gardens or orchards, including the removal of diseased plant debris. Additionally, promoting good plant health through regular pruning, fertilization, and irrigation can help reduce the risk of infection. In cases where collar blight is already present, affected plant parts should be pruned and destroyed to prevent further spread of the disease. Some cases may require the application of fungicides or bactericides to control the pathogen's growth.