What causes St. Augustine Decline (SAD)?

St. Augustine Decline (SAD) is primarily caused by a virus. Specifically, the virus responsible for SAD is known to affect St. Augustinegrass, leading to symptoms such as yellowing, wilting, and overall decline of the grass quality. This viral infection compromises the plant's ability to photosynthesize effectively, resulting in poor health and often leading to the eventual death of the grass if not managed properly.

Understanding the nature of viral infections in plants is important, as they can spread quickly and are often difficult to control compared to other issues such as pests or nutrient deficiencies. Management requires a combination of strategies, including the use of resistant grass varieties and proper cultural practices.

Other options, while they can affect grass health, do not specifically cause the distinct symptoms and decline associated with SAD. For instance, pest infestations may damage the grass but typically do not produce the same viral effects, and nutrient deficiencies might lead to general poor growth but do not manifest in the particular decline seen with viral infections.