Question

Red rust of tea is due to
A. Rhizopus
B. Puccinia
C. Cephaleuros parasiticus Karst
D. Phytophthora

Answer 1

Hint: Red rust of tea is caused by algae and is the only algal disease of tea. It affects the growth and yield of tea. In this an orange brown color powder appears on the infected plant’s leaves and stems. It is caused by aerophilic and filamentous green algae.

Complete answer:
Red rust of tea is the only algal disease of tea plants. It is marked by the formation of orange brown color powder on the leaves of the infected plant. It is caused by algae Cephaleuros parasiticus Karst. Cephaleuros is a genus of parasitic thalloid green algae comprising approximately 14 species. Its common name is red rust.
Red rust is a disease of economic importance which results in wilted leaves, dieback of branches and contortion of fruits. This pathogen is widely distributed in tropics and subtropical regions.
The symptoms of this disease are as follows-
> Orange-brown color velvety spots appear on the leaves.
> The spots are 2-4 mm in diameter.
> These spots merge together and slowly cover the whole plant eventually destroying it.
> Sporangia are formed on these spots giving them a furry look.
> The older the infection gets the more these spots become greyish in color.
> The spores of algae are spread either airborne, or water borne. These algal spots are mostly present on the upper surface of the leaves.

Therefore, the correct answer to this question is option ’C’- Cephaleuros parasiticus Karst.

Note: Red rust is not only a disease of tea plants. It also affects other plants like litchi, guava, mango. Cephaleuros is a parasitic algae most commonly seen in hot and humid climates. For treatment of algal leaf spot copper fungicide is used.