What are dead spots on foliage called?

The correct term for dead spots on foliage is "leaf spot." Leaf spots refer to specific areas of discoloration or necrosis on leaves, which can appear as small, round, or irregularly shaped spots that may be brown, black, or various other colors depending on the cause. These spots can arise from various factors such as fungal or bacterial infections, physical damage, or environmental stressors.

Leaf spots are significant because they can indicate underlying issues with the plant's health, potentially leading to further decline if not managed properly. Understanding the terminology is key for arborists and horticulturists when diagnosing plant issues and determining appropriate treatment methods.

The other options describe related but distinct phenomena. Leaf lesions typically refer to damaged or dead tissue caused by pathogens, injury, or disease. Leaf blight is a term used to describe a more extensive necrosis affecting larger areas of leaves, often resulting in leaf drop. Foliage decay encompasses general deterioration of foliage, which may involve factors beyond just the localized dead spots referred to as leaf spots. Understanding these variations helps in recognizing the specific symptoms and the nature of the problems affecting plant health.