Which practice reduces the risk of contamination by applying pesticides only when absolutely necessary?

• A. Applying pesticides only when absolutely necessary and using techniques that minimize leaching or runoff.
• B. Applying pesticides broadly to ensure complete coverage.
• C. Spraying during rainfall to wash pesticides onto ground.
• D. Relying on high-concentration formulations to reduce application time.

Answer: (A)

The main idea here is applying pesticides only when necessary and using methods that keep the chemical from moving beyond the target area. This approach reduces the amount used and minimizes the chances of contamination to soil, water, and non-target organisms by limiting over-application and choosing application techniques that curb leaching, runoff, and drift. When you apply only as needed and use tactics such as proper calibration, appropriate timing (avoiding rain or irrigation that can wash or move the product), and drift-reducing equipment, you lower environmental exposure and protect water quality.

Why this option fits best: it combines restraint with careful application methods to minimize environmental movement of pesticides, directly addressing contamination risk.

Why the other options don’t fit: applying broadly increases the total amount released into the environment, raising contamination risk; spraying during rainfall promotes runoff and leaching, spreading pesticides to unintended areas; using high-concentration formulations to reduce application time can still lead to over-application and higher local residues, potentially increasing toxicity and environmental impact.