A COMPENDIUM OF TROPICAL PLANT DISEASES AND DISORDERS
ALGAL LEAF SPOTS
SYMPTOMS
Circular to oblong leaf spots with or without a yellow or reddish border (halo) Signs of yellow to reddish orange sporulation on the leaf spot surface ( C. verescens ) C. parasiticus causes brown leaf spots with a red border andorange tufts of spores on the underside (resembling rust)
Algal leaf spots caused by Cephaleuros species are often mistaken for rust, powdery mildew, various leaf spots, and a bacterial canker. This resulted in some of the cases misleadingly named “red rust”. Cephaleuros virescens appears to be the most common and widespread species in the genus, but diseases caused by C. parasiticus are more severe and damaging to the plant.
FAVORABLE CONDITIONS
Poor air circulation
Warm temperatures typical of summer months
High relative humidity
ALGAE LEAF SPOT
ALGAE LEAF SPOT OF GUAV
ALGAE LEAF SPOT SPORULATIN
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BROWN SPOT WITH RED HALO
REDDISH ORANGE SPORULATION
BROWN SPOT
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