Red Rust of tea
Cephaleuros parasiticus
Red rust, also known as red blight or Hemileia vastatrix, is a devastating fungal disease that primarily affects tea (Camellia sinensis) plants. This disease can lead to significant economic losses in tea-producing regions. Here is a description of red rust of tea:
Symptoms: Red rust disease primarily affects the leaves of tea plants, and the symptoms can vary in appearance as the disease progresses. Key symptoms include:
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Rusty Pustules: The most characteristic symptom of red rust is the presence of rusty or reddish-brown pustules on the undersides of tea leaves. These pustules are actually masses of fungal spores and can give the leaves a speckled or spotted appearance.
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Yellowing of Leaves: Infected leaves may exhibit yellowing or chlorosis, particularly in areas surrounding the pustules. This yellowing is often a result of the fungal infection interfering with the plant's ability to photosynthesize.
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Leaf Curling and Necrosis: As the disease progresses, infected leaves may curl and eventually become necrotic (dead), leading to defoliation.
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Reduced Quality and Yield: Severe infestations of red rust can significantly reduce the quality and yield of tea leaves. Infected leaves are often not suitable for processing into tea products.
Disease Cycle: The life cycle of the red rust fungus involves several stages:
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Infection: The fungus primarily spreads through windborne spores. When these spores land on tea leaves and conditions are favorable (high humidity and moderate temperatures), they germinate and penetrate the leaf tissue.
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Sporulation: Once inside the plant, the fungus forms the characteristic rust-colored pustules on the undersides of leaves. These pustules release new spores, which can be carried by the wind to infect other tea plants.
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Overwintering: In some regions, the fungus can overwinter in infected plant tissues or on fallen leaves.
Environmental Conditions: Red rust thrives in conditions of high humidity, moderate temperatures, and rainfall. It is most active during the wet season when these conditions are met.
