Orchid rust: Uredoapidendrum

The sporophore (O) and rusty sporophore (I) were not seen. The summer spore pile (11) was born on both sides of the upper or lower part of the leaf, showing a reddish edge, brown macular eminence, and finally ruptured the epidermis, while the teliospore pile (dish) was not seen.

(1) harm: Uredo epidendrum is a rare rust fungus in orchids. The host kings of orchids have been found to be Oncidrum cavendishianum, Diacrium, Bilamellatum,Epidendrumnocturnum, E. venosum, Ionopsis sp,Laelia sp,Rodriguezia sp, and TrignodiumSemamix.

(2) symptoms: this rust occurs only on leaves. The typical symptom is the production of protruding brown spore piles, usually with reddish edges. The symptoms first appear on the back of the leaves. With the development of the disease, spore piles are produced on both sides of the leaf epidermis. When the spore pile matures, its color changes from brown to purple-black.

(3) Control methods: destroy all diseased plants and apply protective fungicides to all susceptible species of orchid plants, such as thiram, at a dosage of 800 times, once every 7 days.

Liu Zhongjian