Diagnosing Summer Turf Problems · 2017. 5. 5. · •Kevin Frank, Ph.D Associate Professor MSU...
Transcript of Diagnosing Summer Turf Problems · 2017. 5. 5. · •Kevin Frank, Ph.D Associate Professor MSU...
Diagnosing Summer Turf Problems
• Webinar for State Hotline/Diagnostic team
• Kevin Frank, Ph.D
Associate Professor
MSU Plant, Soil, and Microbial Science
Hosted by Consumer Horticulture Staff
Bob Bricault & Mary Wilson
Diagnosing Summer Turf Problems
• Environmental
• Cultural
• Insect
• Disease
Environmental
Drought stress symptoms • Bluish green to bluish grey
• Advanced stage is straw colored
• Foot prints persist
• Cultural options
• Increase mowing height
• Check for root feeding insects
• Check for compacted soil
• Dormant grass – when is water necessary to save plants
Heat Tracking
Cultural Induced Stress
•Mowing too short
•Dull mower blade -End of blades shredded
Dull Mower Blade
Cultural Induced Stress
•Mowing too short
•Dull mower blade -End of blades shredded
•Thatch layer is more than ½ inch thick
-Compacted soils, Poor drainage, Over fertilization
Lawn Insects
Japanese Beetle Grubs
• Root feeding
European Chafer Grubs • Root feeding
Sod Webworm • Surface feeding
Common Lawn Insects
Sod webworm
Photo courtesy of the University of Purdue
Chewing damage on edge of grass blades. Areas where grass blades are missing and small green fecal particles present. Small caterpillar found in silken tubes in thatch
Sod Webworm
• Larvae overwinter and resume feeding in the spring
• 2 generations per year
• Dirty white moths may be observed flying across turf at dusk
• Mowing may “kick up” adults
Spring damage
Larva and frass
Adult bluegrass
webworm
Sod Webworms
Summer Turf Diseases
Necrotic Ring Spot
• Yellow patches up to 2 feet often with green patch in center
• Common on compacted, poorly draining turf
• Excess nitrogen can increase problem
Summer Turf Diseases
Necrotic Ring Spot Management
• Resistant cultivars
• Aeration/increase mowing height/irrigate/organic or slow release nitrogen
http://www.msuturfdiseases.net/details/_/necrotic_ring_spot_13/
Summer Turf Diseases
Summer leaf spot • Irregular patches • Yellow to tan lesions with reddish brown margins • Severe at high temperatures and high N conditions
• Management • Alleviate thatch and any compaction • Moderate fertility • Minimize leaf wetness • Raise mowing height
• http://www.msuturfdiseases.net/details/_/leaf_spot_7/
Summer Turf Diseases
Rusts
• Orange to red pustules on blades
• Orange spores gets on shoes
• Management
• Maintain fertility
• Irrigate to prevent drought/ minimize leaf wetness
• Tolerant cultivars
Photo by D. Settle
Summer Turf Diseases
Dollar spot • Bleached lesions with red to brown
margins
• Warm days, prolonged leaf wetness
• Stressed from low nitrogen and dry soils
• Management • Reduce thatch and compaction
• Use tolerant cultivars
• Maintain fertility
• Avoid drought stress
• Minimize leaf wetness
Photo: Eric B. Nelson, Cornell University
Diagnosing Turf Problems
Resources:
MSU Turf Disease
• http://www.msuturfdiseases.net/
MSU Diagnostic Lab
• http://www.pestid.msu.edu/
MSU Turfgrass Science
• http://www.turf.msu.edu/home-lawn-articles