What is a common lawn disease and its primary cause?

The correct answer highlights that dollar spot is caused by the fungus Sclerotinia homoeocarpa, which is a well-documented fact in turf management. Dollar spot is a prevalent lawn disease characterized by small, round, bleached spots that can quickly spread across the lawn if left unmanaged. Sclerotinia homoeocarpa thrives under conditions of high humidity, prolonged leaf wetness, and can be exacerbated by low nitrogen levels in the soil.

Identifying the specific fungal pathogen responsible for dollar spot is crucial for effective management and treatment strategies. This knowledge guides turf managers in selecting appropriate fungicides and cultural practices to mitigate the disease's impact on the lawn.

The other options reference diseases and causes that do not accurately describe the primary factors behind the mentioned conditions. While brown patch is indeed a common disease, it is primarily caused by a different fungal pathogen, not by insects. Rust disease results from specific fungi, primarily affected by environmental and cultural conditions rather than soil deficiencies alone. Leaf spot can occur due to various factors, including environmental stress and diseases, but excessive mowing is not the sole cause. Understanding the true causes enables better prevention and treatment of lawn diseases.