Which of the following is NOT a factor that may contribute to pesticide phytotoxicity?

• A. Plant condition
• B. Environmental conditions
• C. Soil properties
• D. Weather forecast

Answer: (D)

Phytotoxicity from pesticides depends on conditions that the plant and chemical actually experience during exposure. Plant condition matters because stressed or damaged plants are often more vulnerable to injury from pesticides. Environmental conditions at the time of application—like temperature, humidity, sunlight, and wind—affect how quickly the product dries, moves, and is absorbed or degraded, influencing the amount that reaches the plant. Soil properties such as texture, organic matter, pH, and soil moisture alter pesticide availability, movement toward roots or leaves, and how long the chemical remains active. Weather forecast, while useful for planning, is not a direct factor in causing phytotoxicity because it is just a prediction of future conditions, not the actual conditions that determine the pesticide’s impact. The actual weather during and after application drives whether phytotoxic effects occur.