St. Augustine Decline (SAD) is a viral disease of St. Augustine grass and centipedegrass caused by the panicum mosaic virus. Initial symptoms appear as a mild chlorotic mottling or stippling of leaf blades. Infected leaves turn yellow in appearance, resembling nutrient deficiency symptoms. Severely affected turfgrasses become less vigorous and begin to thin and eventually die. The virus is mechanically transmitted and can be brought into a lawn if infected sod is purchased or can be spread through contaminated mowing and mechanical equipment. There is no cure. Cultural practices that promote vigorous turf growth help minimize some of the virus’s effects on turfgrass
Chlorotic spotting on St. Augustinegrass leaf blades
Lawn infected with St. Augustine Decline
One way to reduce disease incidence and accelerate turfgrass recovery is to maintain a healthy lawn through balanced fertilization and irrigation and regular mowing. However, these cultural practices do not prevent or cure SAD. Some simple guidelines to grow vigorous lawns include:
There is no cure for St. Augustine decline. To help prevent the spread of the virus from infected lawns to healthy lawns, steam clean mowing equipment after mowing. Disinfecting mowing equipment with a 10 percent bleach solution can also help prevent the spread of the virus.
For information on sample collection and submission guidelines please visit the Plant Diagnostic Center.
Download here: Louisiana Home Lawn Series: St. Augustine Decline 3624-AA