What is a sign of pesticide over-application in plants?

Leaf burn or wilting is a clear indication of pesticide over-application in plants. When plants are exposed to excessive pesticide amounts, the chemicals can cause damage to their sensitive tissues. Symptoms of this damage often manifest as leaf burn, where the leaf edges may turn brown and dry out, or the leaves may begin to wilt, losing turgor pressure and appearing limp. This physiological stress occurs because the high concentration of active ingredients in the pesticide can disrupt the plant's natural functions, leading to cellular damage.

While leaf discoloration or yellowing, stunted growth, and increased pest activity can also be symptoms related to plant health, they may arise from various causes not necessarily linked to pesticide over-application. For example, leaf discoloration could indicate other issues like nutrient deficiency, while stunted growth might be caused by poor soil conditions or inadequate watering. Increased pest activity may suggest that the pesticide application was ineffective or that the pests have developed resistance. Therefore, leaf burn or wilting specifically highlights the detrimental effects of applying too much pesticide, making it the most direct sign of over-application.