What can lead to phytotoxicity due to pesticide carryover?

The correct answer highlights the impact of planting a sensitive rotational crop before the recommended waiting interval as a significant factor that can lead to phytotoxicity due to pesticide carryover. When pesticides are applied to a field, they may persist in the soil for varying periods depending on their chemical composition, environmental conditions, and application rates. If a crop that is particularly sensitive to the residual effects of those pesticides is planted too soon, it may absorb harmful levels of the chemical, resulting in injury or death to the plant.

This scenario emphasizes the importance of adhering to specified waiting periods provided on pesticide labels, which are designed to mitigate the risk of such effects by allowing sufficient time for the chemical residues to degrade. Understanding these intervals is crucial for ensuring the health of subsequent crops and effectively managing residues in the soil.

Other factors mentioned, while potentially relevant to pesticide use and plant health, do not specifically relate to the concept of carryover leading to phytotoxicity. Thus, the timing of planting sensitive crops in relation to pesticide application is a critical aspect of avoiding phytotoxic effects.