Georgia Pesticide Applicators Practice Exam

What symptom indicates the presence of bacterial leaf spots on plants?

1. Yellowing of leaves

2. Water-soaked spots with yellow halo

3. Wilting of leaves

4. Brown leaf edges

The correct answer is: Water-soaked spots with yellow halo

The presence of bacterial leaf spots on plants is typically indicated by water-soaked spots accompanied by a yellow halo. These water-soaked lesions arise when bacteria infect the plant, causing localized damage to the leaf tissue. As the disease progresses, the affected areas often expand and may develop a distinct yellow coloration around the edges. This "halo" effect is a common characteristic of bacterial infections, differentiating them from other plant issues that might have similar symptoms but do not present this specific water-soaked appearance. In contrast, yellowing of leaves might suggest nutrient deficiency or other physiological issues, while wilting can indicate a lack of water or root problems, and brown leaf edges may signify environmental stress or low humidity. Each of these symptoms has its own distinct causes and is not specific to bacterial leaf spots, highlighting the importance of recognizing the specific symptom of water-soaked spots with a yellow halo associated with bacterial infections.