Black rot on orchids is caused by Pythium and Phytophthora species. Black rot targets a variety of orchids but Cattleya orchids are especially susceptible
In mature plants, the disease can strike at any leaves, pseudobulbs or roots, but often starts in new leaves or growing leads, and progresses downward through the plant until reaching the roots..
Black rot shows up as dark blackish spots or lesions on the affected plant part. The black spot or spots enlarge rapidly and can spread throughout the plant. If allowed to reach the crown of a monopodial orchid, the rot will kill the plant. Affected leaves may turn yellow around the infected area, and the lesions themselves will be soft and exude water when pressure is applied.
Treatment-
-Isolate
-cut affected area ,remove whole leaf or pseudobulb if necessary
-seal with cinnamon or fungicide
prevention-
-Dont use unsterile gardening tools,avoid reusing media or pots
-Avoid water logging in grow area
-Good air circulation
-if any plant is grossly affected better to throw it than risking contamination in other plants
Link of AOS article on Black rot
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My videos on cattleya orchid care are all under this playlist ..Have a look
• Cattleyas
20 июн 2021
