What is phytotoxicity and how can it be avoided?

• A. Plant injury caused by pesticide exposure; avoid by following label rates, timing, and compatibility testing.
• B. A beneficial effect of pesticides that improves plant growth; achieved by using high label rates.
• C. The process of pesticide degradation in soil; avoided by watering after application.
• D. Injury to beneficial insects caused by drift; avoided by applying at night.

Answer: (A)

Phytotoxicity is plant injury caused by pesticide exposure. It happens when a chemical meant to target pests ends up harming the crop, showing up as symptoms like leaf burn, yellowing, spotting, stunted growth, or distorted development. The best way to avoid it is to follow label instructions exactly: use the correct rate for the specific crop, apply at the recommended growth stage and timing, and consider compatibility when mixing products. Performing compatibility testing (jar tests) before tank-mixing helps ensure the combination won’t injure the plant. Calibrate equipment so you’re applying the intended amount, minimize drift by choosing proper nozzle types and application conditions, and avoid spraying under stressed conditions (hot, dry, or stressed plants) that make injury more likely. If a crop is particularly sensitive, or if a mixture raises red flags in testing, choose an alternative product or adjust the plan. The other options describe different issues—either a mistaken idea of a beneficial effect, a process like degradation in soil, or injury to non-target organisms from drift—which are not what phytotoxicity means.