Most phytotoxicity to non-target plants is the result of ________.

• A. Runoff
• B. Drift
• C. Leaching
• D. Fracking

Answer: (B)

Spray drift is the main way non-target plants take phytotoxic hits from a pesticide application. When a spray is released, some droplets don’t land where intended but are carried by air currents to nearby vegetation. If those droplets deposit on leaves or stems, they can cause visible injury such as stippling, scorch, or chlorosis on plants you didn’t mean to treat. The extent of drift depends on factors like how small the droplets are, how high the spray is released, wind speed and direction, temperature, and the type of nozzle and pressure used. This direct transfer of active ingredient to nearby plants is why drift is the most common cause of phytotoxicity outside the target area.

Runoff involves pesticide movement with surface water into fields or waterways, which can affect other environments but typically causes problems through water and soil movement rather than direct foliar injury from airborne spray. Leaching is the downward movement through soil toward roots, which can affect plants in the soil profile but isn’t the typical route for immediate non-target foliar phytotoxicity from an applied spray. Fracking is unrelated to pesticide phytotoxicity.