Correct Option
The correct option isCultivation of resistant varieties
Explanation
Sustainable pest management focuses on reducing reliance on synthetic chemicals. One primary strategy is Host Plant Resistance (HPR), which involves modifying the plant's genetic constitution-through conventional breeding or biotechnological methods (such as developing transgenic organisms)-to create inherent resistance against specific pests.
Option Analysis:
- Application of organophosphates Application of organophosphates: Incorrect. This refers to the use of synthetic chemical pesticides. It is not considered eco-friendly due to high toxicity, residue problems, and adverse effects on non-target organisms. Furthermore, it is an external application, not a modification of the plant.
- Cultivation of resistant varieties Cultivation of resistant varieties: Correct. This method relies on plant modification (genetic improvement) to introduce traits that repel or tolerate pests. For example, the development of Bt crops (transgenic) incorporates bacterial genes to produce proteins toxic to specific insects. This is an eco-friendly approach as it drastically reduces the need for chemical sprays.
- Deep summer ploughing Deep summer ploughing: Incorrect. This is a cultural method of pest control where the soil is turned to expose resting stages of pests (pupae) to extreme heat and predatory birds. While eco-friendly, it involves soil management rather than plant modification.
- Chemical seed treatment Chemical seed treatment: Incorrect. This involves coating seeds with insecticides or fungicides to protect them during germination. It relies on chemical agents and does not involve modifying the plant's inherent traits.
Key Takeaway:
The cultivation of resistant varieties utilizes genetic modification or breeding to enhance a plant's internal defense mechanisms, offering an environmentally safe alternative to chemical pesticides.