| Material Information
||Plant Pathology Fact Sheet PP-58
||Elliot, Monica L.
Simone, Gary W.
||University of Florida -- Florida Cooperative Extension Service -- Department of Plant Pathology -- Institute of Food and Agricultural Sciences -- Ft. Lauderdale Research and Education Center
||Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
||North America -- United States of America -- Florida
Plant Pathology Fact Sheet
Monica L Elliott, Associate Professor, Ft. Lauderdale Research and Education
Center, University of Florida, 3205 College Ave, Ft. Lauderdale, Fl 33314 and
Gary W. Simone, Professor Emeritus, Plant Pathology Department, University of
Florida, Gainesville, Florida 32611. Revised April 2001
Florida Cooperative Extension Service/ Institute of Food and Agricultural Sciences/ University of Florida/ Christine Waddill, Dean
St. Augustinegrass and zoysiagrass; it may also
be observed on perennial ryegrass used to
overseed lawns in the winter months.
This disease can occur from late fall to
early spring when the turfgrass is not growing
rapidly due to cool weather. It will be more
severe on turfgrass areas that are stressed from
nutrient deficiencies or shade (ex: under trees,
north side of building). The leaves must be wet
for infection to occur. This wetness may be from
dew, high humidity, rain or irrigation.
Initially, light yellow flecks will appear
on the leaves. If the disease progresses, these
flecks will enlarge into spots that are parallel
to the leaf vein. Eventually, orange pustules
(spots) will form containing spores (Figures 1
and 2). These pustules will also be parallel to
the leaf vein. The spores will rub off on your
fingers. Heavily infected areas will appear thin
and chlorotic (yellow to light brown).
Maintain an adequate, balanced fertility
program using slow-release nutrient sources.
In shady areas, monitor the irrigation closely
to keep the leaves as dry as possible. In most
situations, the disease will disappear as soon
as the weather warms and the turfgrass starts
to grow vigorously again. The disease may
cause the turfgrass to look ugly, but it will not
kill the turfgrass.
azoxystrobin, mancozeb, propiconazole,
thiophanate methyl, triadimefon,
Mancozeb can be applied to a residen-
tial lawn only by a professional pesticide
Refer to Turfgrass Disease manage-
ment" PPP-64 for explanations of chemical and
Figure 1. Rust symptoms on zoysiagrass.
Figure 2. Rust symptoms on ryegrass. Or-
ange spores will rub off.