Question

Red ring disease of coconut palm is caused by:

• A. Bursaphelenchus/ Radinaphelenchus cocophilus
• B. Aphelenchus avenae
• C. Ditylenchus dipsaci
• D. Bursaphelenchus bicaudatus

Hint:

Red Ring Disease of coconut palm = Radinaphelenchus cocophilus (or Bursaphelenchus cocophilus).
Vector = South American Palm Weevil (Rhynchophorus palmarum).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Red ring disease is a lethal disease of coconut and oil palms, particularly prevalent in Central and South America.
It is caused by a plant-parasitic nematode that is vectored by an insect.

Step 2: Detailed Explanation:
The causal agent of Red Ring Disease is the nematode Radinaphelenchus cocophilus (also classified under Bursaphelenchus cocophilus).
The nematode is transmitted primarily by the South American palm weevil, Rhynchophorus palmarum.
Inside the palm trunk, the nematode infestation leads to a characteristic reddish-brown ring visible in cross-sections of the stem.

Step 3: Final Answer:
Therefore, the correct option is (A).