Question

Teak rust is caused by _________.

• A. Puccinia sp.
• B. Olivea sp.
• C. Melampsora sp.
• D. Ralstonia sp.

Hint:

- Teak rust = Olivea tectonae.
- Poplar rust = Melampsora medusae.
- Cereal rusts = Puccinia species.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Teak (Tectona grandis) is a highly valuable hardwood timber species.
It is susceptible to several fungal pathogens that affect its leaves, reducing photosynthetic efficiency and overall growth.

Step 2: Detailed Explanation:
- Teak rust is a prominent foliar disease characterized by the appearance of orange-to-brown pustules on the lower surface of teak leaves, leading to premature defoliation.
- The causal organism of teak rust is the biotrophic rust fungus belonging to the genus Olivea, specifically Olivea tectonae (formerly classified under the family Chaconiaceae).
- Let us evaluate the other options for comparison:
- Puccinia sp. causes rust in cereal crops (such as wheat rust caused by Puccinia graminis) and many grasses.
- Melampsora sp. causes rust in forest trees like poplar and willow.
- Ralstonia sp. is a bacterial genus responsible for bacterial wilt (such as *Ralstonia solanacearum* in solanaceous crops), not a rust fungus.

Step 3: Final Answer:
Teak rust is caused by Olivea sp. (Option B).