Which of the following methods in not used for crop improvement?

Options

A. Inbreeding
B. Introduction
C. Hybridization
D. Mutations

Answer

To determine which method is not used for crop improvement among the options provided (breeding, introduction, hybridization, mutation), we can analyze each method step by step.

### Step-by-Step Solution:

1. **Understanding Breeding**:
- Breeding involves the mating of closely related individuals to enhance desirable traits in crops. It can lead to the expression of recessive traits and may not always improve crop quality. However, it is still a method used in crop improvement.

**Hint**: Breeding is a common method that can sometimes lead to undesirable traits.

2. **Understanding Introduction**:
- Introduction refers to the process of bringing new genetic material into a breeding program. This can enhance genetic diversity and improve traits in crops. It is a recognized method for crop improvement.

**Hint**: Introduction increases genetic diversity, which can be beneficial for crop improvement.

3. **Understanding Hybridization**:
- Hybridization is the crossing of two different varieties or species to produce offspring with desirable traits. This method is widely used in crop improvement to enhance yield, disease resistance, and other beneficial characteristics.

**Hint**: Hybridization combines traits from different plants to create improved varieties.

4. **Understanding Mutation**:
- Mutation involves inducing changes in the genetic material of plants to create new traits. This method can lead to the development of new varieties with improved characteristics and is also used in crop improvement.

**Hint**: Mutation can create new traits that may be beneficial for crop improvement.

5. **Conclusion**:
- Among the options provided, breeding is the method that is not primarily used for crop improvement due to its potential to express undesirable traits. Therefore, the answer to the question is **breeding**.

### Final Answer:
The method that is not used for crop improvement is **breeding**.