New Tools for Turf Disease Management in the Landscape
1. New Tools for Turf Disease Management in
the Landscape
Lane Tredway
Associate Professor and Extension Specialist
Department of Plant Pathology
North Carolina State University
6. Identification of the affected turf species is essential for
accurate disease diagnosis
Tall fescue
• ridged upper leaf
surface
Kentucky bluegrass
• smooth upper leaf
surface
7. Each Turf Species
Has Unique Problems
Tall Fescue
• brown patch, gray leaf spot,
Pythium blight
Kentucky bluegrass
• dollar spot, summer patch,
Pythium blight, rust,
powdery mildew
8. Symptoms: change in the appearance of the plant
Stand Symptoms
• a change in the appearance of the turf,
evident from a distance
Plant Symptoms
• a change in the appearance of the plant
9. Signs: evidence of the presence of a pathogen
mycelium sclerotia
Pythium blight red thread
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14. turfpathology.org: How to follow along...
turfpathology.org
facebook.com/turfpathology
twitter.com/ncturfpathology
feeds.feedburner.com/turfpathology
24. Rhizoctonia diseases are the most common and
destructive in landscape turfgrasses.
brown patch of tall fescue large patch of zoysiagrass
caused by Rhizoctonia solani caused by Rhizoctonia solani
25. QoI and DMI Fungicides for Rhizoctonia control
QoI Fungicides DMI Fungicides
Compass Bayleton
Disarm Banner
Heritage Eagle
Insignia Torque
Tourney
QoI + DMI Combinations Trinity
Armada
Disarm M
Headway
46. Comparison of Granular and Sprayable Fungicides
Heritage G (3 lb)
Compass G (4 lb)
Disarm G (2.3 lb)
Heritage WG (0.2 oz)
Untreated
0 3 6 9 12 15
Brown Patch Incidence (%)
Granular treatments re-applied every 21 days, Heritage 50WG re-applied every 28 days
47. Environmental Impact Quotient (EIQ)
What’s the real environmental impact?
http://www.nysipm.cornell.edu/publications/eiq/
48. Product Rate/1000 ft2 Interval EIQ/month
Heritage 50WG 0.2 oz 28 days 7.3
Rhapsody 5 oz 7 days 7.6
Bayer Fungus
2 lbs 14 days 28
Control
Scotts Lawn
1.35 lbs 14 days 64
Fungus Control
Daconil Ultrex 3.2 oz 14 days 538
50. Mixtures help to reduce brown patch injury
30.0
Coronado + Livingston
Coronado + Midnight
Brown Patch Incidence (%)
22.5
15.0
7.5
0
100:0 97.5:2.5 95:5 90:10
Mixing Ratio (% by weight)
Mixtures planted in Oct 1999
Data collected on 29 Jun 2001
51. Mixtures are by weight, not number of seeds
Tall Fescue Kentucky Bluegrass
500 seeds/gram 4,800 seeds/gram
52. Mixtures are by weight, not number of seeds
Mix Ratio Tall Fescue Kentucky Bluegrass
TF:KBG Seeds (#) Seeds (#)
90:10 204,000 218,000
95:5 216,000 109,000
97.5:2.5 221,000 54,000
53. Turfgrass populations may shift over time....
100
%TF in 1999
%TF in 2002
75
Percent Tall Fescue
50
25
0
100:0 97.5:2.5 95:5 90:10
Seed Ratio By Weight (TF:KBG)
54. Dollar spot is active when lows are above 50ºF and highs are below 90ºF
55. Summer patch is active when soil temperatures are above 65ºF
56. turfpathology.org: How to follow along...
turfpathology.org
facebook.com/turfpathology
twitter.com/ncturfpathology
feeds.feedburner.com/turfpathology