Leaf spots that are generally round, uniformly distributed over the leaf, and have a sharp margin between healthy and affected tissue are typical of:

The appearance of leaf spots that are round, uniformly distributed, and exhibit a sharp margin between healthy and affected tissue is a characteristic feature of chemical spray injury spots. When pesticides or herbicides are applied improperly, or when the plant is sensitive to the chemical used, it can lead to distinct leaf damage that is noticeably segmented from healthy tissue. This sharp demarcation helps distinguish this type of injury from other issues affecting foliage.

In contrast, fungal leaf spots often display more irregular shapes and varying sizes, and they may not maintain a sharp boundary with healthy tissue, as the infection progresses gradually. Bacterial leaf spots can show water-soaked areas that may eventually turn dark but usually do not present a sharp margin. Powdery mildew does not typically cause leaf spots in the same manner; instead, it creates a dusty, white coating on leaves rather than discrete spots.

Recognizing the specific symptoms of each stressor or disease is crucial for appropriate diagnosis and management, therefore understanding the characteristics of chemical spray injury is important in pesticide safety and plant health management.