Ornamental and Turf Pesticide Applicators Practice Exam

Large patch disease in turfgrass, caused primarily by the fungus Rhizoctonia solani, typically manifests as round, brown patches in the lawn. These patches can vary in size but are most often seen in a circular formation, which is a key feature of the disease. As the disease progresses, the outer edges of these patches may appear yellow, while the interiors remain brown or dead. This transition can sometimes create the appearance of yellow areas adjacent to the brown patches, but the distinctive round patches themselves remain the primary symptom to identify.

The other choices do not accurately describe the symptoms associated with large patch disease. Irregular yellow spots may suggest other issues, such as nutrient deficiency or other foliar diseases. Small white bleached spots could indicate different types of damage, possibly from environmental stress or pest activity. Fungal growth on leaves is a general symptom that could relate to various fungal diseases but does not specifically point to large patch disease, which is primarily characterized by its patchy appearance in the turf.