The modern technique in the field of crop variety improvement is known as ________

Explanation

**Step-by-Step Solution:**

1. **Understanding Crop Variety Improvement**: The question asks about modern techniques used to improve crop varieties. This involves methods that enhance the traits of plants for better yield, disease resistance, or other desirable characteristics.

2. **Identifying Modern Techniques**: One of the most significant modern techniques in crop improvement is genetic engineering. This technique allows scientists to manipulate the genetic material of plants to achieve specific traits.

3. **Explaining Genetic Engineering**: Genetic engineering involves altering the DNA of a plant to introduce new traits or enhance existing ones. This can include inserting genes from other organisms to provide new characteristics, such as pest resistance or improved nutritional content.

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