Why is it important to avoid using esters in high temperatures?

Avoiding the use of esters in high temperatures is particularly important because they can vapor drift and potentially harm desirable plants in the vicinity. During warmer conditions, esters can volatilize more readily, which means they can evaporate into a gaseous form more quickly. This volatility increases the likelihood that the herbicide may drift on air currents to unintended areas, where they can damage sensitive plants.

Understanding the behavior of esters in different temperatures is crucial for effective pest management; their use requires careful consideration of environmental conditions to minimize the risk of non-target plant injury. The other options presented do not directly relate to the key issue of vapor drift and the impacts of temperature on ester volatility, making them less relevant in this context.