To determine which method is not involved in the process of separation of grains from stalks, husks, chaff, and bran, we will analyze each option provided in the question.
### Step-by-Step Solution:
1. **Understand the Methods**: The question presents four methods: sieving, hand picking, binoying, and threshing. We need to evaluate each method to see if it can separate grains from the unwanted parts.
2. **Evaluate Sieving**:
- **Definition**: Sieving is a technique that separates particles based on size.
- **Application**: In this method, grains can be separated from husks and other larger particles because they pass through a sieve while larger particles remain.
- **Conclusion**: Sieving is involved in the separation process.
3. **Evaluate Hand Picking**:
- **Definition**: Hand picking is a manual method where larger unwanted particles are removed by hand.
- **Application**: This method can effectively remove larger stones and dust but struggles with smaller particles like fine husk or bran.
- **Conclusion**: Hand picking is not effective for separating grains from stalks, husks, and bran, especially smaller particles. Thus, this method is likely the answer.
4. **Evaluate Binoying**:
- **Definition**: Binoying involves throwing the mixture into the air so that the wind can blow away lighter particles.
- **Application**: This method effectively separates lighter husks from heavier grains.
- **Conclusion**: Binoying is involved in the separation process.
5. **Evaluate Threshing**:
- **Definition**: Threshing is the process of loosening the edible part of the grain from the straw to which it is attached.
- **Application**: This method is specifically designed to separate grains from their stalks.
- **Conclusion**: Threshing is involved in the separation process.
6. **Final Decision**:
- Based on the evaluations, the method that is not involved in the separation of grains from stalks, husks, chaff, and bran is **hand picking**.
### Answer:
The method that is not involved in the process of separation of grains from stalks, husks, chaff, and bran is **hand picking** (Option 2).
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