Take-all root rot is a disease that is common on warm season turfgrass. It occurs during the summer and fall months when Florida receives the majority of its rainfall. Extended rainfall or long periods when the turfgrass is wet are especially conducive to this disease. The disease is worsened when any type of stress is placed on the turfgrass.
Take-all root rot does not attack turfgrass leaves. Instead, the roots become damaged and are unable to absorb water and nutrients. Leaf symptoms appear during periods of high stress because of the pathogen’s damage to the roots. By the time symptoms appear on the leaves, the pathogen has already severely damaged the roots.
The first symptoms of this disease are yellow or light green patches of turfgrass up to a few feet in diameter. Roots eventually become short, black, and rotted. Thinning patches of grass may eventually become bare.
The disease is very difficult to control so steps must be taken to help reduce turfgrass stress as much as possible. Stress can result from several factors. It is essential that turfgrass is mowed at the proper height and that no more than one third of the leaf blade be removed at each mowing. St. Augustinegrass is especially sensitive to herbicides, particularly at summer temperatures. Care should be taken to read and follow all label directions. Fungicides are available to help prevent the disease but are not as effective as proper cultural controls.
For further information about take-all root rot, see the publication below: