Transcript turf_diseases

Diseases of
Turfgrasses
Disease Diagnosis
3 Look for patterns in the landscape
3 Positively ID the plant affected
3 Determine what part of the plant is infected
3 Is the damage limited to one species of plant or several different
species
3 Check for signs of pollution or contaminated intrusion
3 Check for any chemical usage in nearby areas & what the toxicity to
the infected may be
3 Determine fertility rate and formulation
3 Check pH of soil if available
3 Look for insect or mite damage
3 When did the symptoms first appear
3 Try to equate this a particular event
Disease Diagnosis
3 Investigate management practices
3 Recommend cultural practice change to
eliminate positive environment for disease
3 If needed implement a chemical control to
alleviate pest pressure
Common Local Turf Diseases
• Brown Patch
• Gray Leaf Spot
• Dollar Spot
Brown Patch
Rhizoctonia sp.
• Occurs on all grasses.
• Predominately occurs during warm-humid
weather conditions.
• More prevalent on poorly managed
grasses.
• Symptoms include circular to irregular
patches of brown turf.
• Inside may green-up causing a frog-eyed
effect.
• Individual plants will rot at the sheath.
• Preventative fungicide applications in the
fall will help reduce infection in the spring.
Control:
use good management practices
use labeled fungicides
Gray Leaf Spot
Pyricularia sp.
• Occurs on St Augustinegrass.
• Predominately occurs during
warm-humid weather conditions.
• More prevalent on poorly
managed, overly fertilized grasses.
• Symptoms include small spots
appearing on leaves with purplish
margins.
• Advanced stages will show a
scorched area in the turf.
Control:
use good management practices
use labeled fungicides
Dollar Spot
Sclerotinia sp.
• Occurs on all warm-season grasses.
• Predominately occurs during warm-humid
weather conditions.
• More prevalent on poorly managed, under
fertilized grasses.
• Symptoms include small spots appearing on
leaves which coalesce to cut the leaf in half.
• Advanced stages will show small circular
spots in the turf.
• Mycelium may be present in the spots
during the early morning hours.
Control:
use good management practices
use labeled fungicides
fertilize properly
Questions?
Comments?