Question

For the management of rice root-knot nematode Meloidogyne graminicola, which of the following methods are more popular

• A. Switching to a direct seeded rice system
• B. Soil solarization
• C. Seed and seedling treatment with chemical pesticides
• D. Biological control agents

Hint:

Direct-seeded rice (DSR) increases root-knot nematode problems due to the lack of early-season flooding.
Targeted chemical seed and seedling treatments are highly valued by resource-constrained farmers because they are inexpensive and easy to apply.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The rice root-knot nematode, Meloidogyne graminicola, is a major pest of rice, particularly in nurseries and well-drained upland or direct-seeded rice systems.
Managing this pest in economically constrained rice-growing regions requires practical, cost-effective methods that protect the crop during its early, vulnerable growth stages.

Step 2: Detailed Explanation:
Let us evaluate the practical application of the listed management options:
- Switching to a direct-seeded rice (DSR) system: DSR actually worsens M. graminicola infestations.
Because DSR fields are not continuously flooded during the early vegetative stages, the soil remains aerated, which creates ideal conditions for the nematode to infect rice roots.
Continuous flooding is a traditional cultural control method used to suppress this nematode, making option (A) incorrect.
- Soil solarization: While highly effective in nursery beds, solarization is labor-intensive and costly over large fields, limiting its widespread popularity.
- Biological control agents: These are useful in integrated programs, but they can produce inconsistent results under varying field conditions, making them less popular as standalone solutions.
- Seed and seedling treatments: These are highly practical, targeted, and cost-effective methods used by rice farmers.
Treating seeds with systemic chemicals (such as carbofuran, benfuracarb, or newer seed-treatment nematicides) or dipping seedling roots in a nematicidal solution before transplanting protects the young plants during their critical early growth stages.
This targeted application uses less chemical active ingredient per hectare than soil broadcast treatments, reducing cost and environmental impact while protecting the nursery and transplanted crop.
Therefore, seed and seedling treatments are the most popular and widely recommended practical management methods.

Step 3: Final Answer:
The most popular and cost-effective management practice for Meloidogyne graminicola in rice is seed and seedling treatment with chemical pesticides.