Question

Given below are two statements:
Statement (I): Barley is used as barrier plant around cauliflower to reduce the incidence of aphids and cauliflower mosaic viruses.
Statement (II): Hydrophobic neem oil (70%) effectively controls the mango anthracnose disease.

• A. Both Statement (I) and Statement (II) are correct
• B. Both Statement (I) and Statement (II) are incorrect
• C. Statement (I) is correct but Statement (II) is incorrect
• D. Statement (I) is incorrect but Statement (II) is correct

Hint:

Barrier crops work best for "Non-persistent" viruses because the insect "cleans" its mouthparts on the wrong plant.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Cultural and botanical control methods are vital components of Integrated Pest Management (IPM).
Barrier crops act as physical or biological shields, while botanical oils provide eco-friendly pathogen suppression.
Detailed Explanation:
Analysis of Statement (I):
Aphids transmit many viruses (like Cauliflower Mosaic Virus) in a non-persistent manner.
If an aphid lands on a non-host barrier plant (like Barley) before reaching the main crop (Cauliflower), it probes the barrier plant.
During this "test probe," the virus particles on its stylet are cleaned off or "lost."
By the time the aphid moves to the cauliflower, it is no longer infectious.
Research has shown that tall barrier crops like barley effectively reduce virus incidence in vegetable crops.
Hence, Statement (I) is correct.
Analysis of Statement (II):
Neem oil contains various bioactive compounds (azadirachtin, salannin, etc.) that have both insecticidal and antifungal properties.
Hydrophobic extracts of neem oil have been specifically tested against Colletotrichum gloeosporioides.
Studies indicate that a 70% concentration or high-purity formulations can inhibit fungal spore germination and mycelial growth, helping manage mango anthracnose.
Hence, Statement (II) is correct.

Step 2: Final Answer:
Both statements are scientifically recognized practices.