Question

For a crop having a maximum permissible limit for off-types 0.2%, the minimum number of plants required for conducting the GOT is-

• A. 800
• B. 1600
• C. 2000
• D. 2400

Hint:

The required sample size for a Grow-Out Test is inversely proportional to the off-type limit: 0.1% requires 4000 plants, 0.2% requires 2000 plants, and 0.5% requires 800 plants.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The Grow-Out Test (GOT) is a field test used to determine the genetic purity of a seed lot by observing morphological characteristics of plants grown under controlled field conditions.
The sample size required for a reliable test depends on the maximum permissible limit of off-types specified for that crop.

Step 2: Detailed Explanation:
To achieve statistical confidence in genetic purity assessments, the size of the plant population grown in the field must be large enough to detect off-types at the designated threshold.
According to international and national seed certification guidelines (including ISTA and Indian standards), the relationship between the maximum permissible limit of off-types and the minimum sample size for the Grow-Out Test is standardized:
- For a crop with a maximum permissible off-type limit of 0.10%, the minimum required population size is 4000 plants.
- For a crop with a maximum permissible off-type limit of 0.20%, the minimum required population size is 2000 plants.
- For a crop with a maximum permissible off-type limit of 0.50%, the minimum required population size is 800 plants.
Since the crop under consideration has a maximum permissible limit of 0.2% off-types, a minimum of 2000 plants must be raised and evaluated in the field to yield statistically valid results.

Step 3: Final Answer:
Thus, the minimum number of plants required for conducting the GOT under these conditions is 2000.