Important Diseases of Landscape Turf in NJ and their Control Dr. Bruce B. Clarke Rutgers University
Dollar Spot Pathogen : Sclerotinia homoeocarpa Grasses Affected : Annual Bluegrass, Bentgrass, Bermudagrass, Centipedegrass, Fine-leaved Fescue, Kentucky Bluegrass, Ryegrasses, Tall Fescue, Zoysiagrass
A New Name for an Old Fungus: Renaming the Dollar Spot Fungus Proposed New Name: Clarireedia homoeocarpa (F.T. Bennett) Beirn, Clarke, & Crouch. Clarus Latin for famous, reedia in honor of Dr. C. Reed Funk, world-renown plant breeder, turfgrass scientist, and humanitarian Dr. C. Reed Funk (1928-2012)
Necrotic ring Spot Disease Calendar for Landscape Turf in New Jersey Dr. Bruce Clarke, Rutgers University turf.rutgers.edu [ Disease Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Anthracnose Brown patch Cool-season brown patch Dollar spot Gray leaf spot Leaf spot and melting-out
Dollar Spot Conditions Favoring Disease : Overwinters as Sclerotia / Mycelium Resumes Growth at 59 0 F Optimum Disease 70 84 0 F High RH (> 85% Night) Thick Thatch (> 0.5 0.75 in.) Low Soil Moisture Extended Dew Low N Fertility
Management of Dollar Spot Maintain balanced N,P,K fertility Maintain adequate N when dollar spot is active Avoid drought stress Do not irrigate toward dusk Remove trees to provide good air circulation Mow at recommended frequencies and heights Aerify to reduce compaction and thatch
Management of Dollar Spot- continued Organic fertilizers and composts can reduce dollar spot but this is due more to increased N availability than to enhanced microbial activity in the soil Microbial products containing Trichoderma harzianum (Root Shield), Bacillus lichenoformens (Ecoguard) can reduce dollar spot but often not to commercially acceptable levels alone Use new improved turfgrass cultivars whenever possible (www.turf.rutgers.edu; RU Turf Proc.)
Endophyte mycelium in leaf sheath Endophyte mycelium in seed
Dollar spot on creeping red fescue E- E+
Chemical Control of Dollar Spot I. Benzimidazoles Fungo, Cleary 3336 II. Demethylation Inhibitors (Sterol Inhibitors) Banner, Bayleton, Eagle, Rubigan, Trinity, Tourney, Triton, Torque IV. Dithiocarbamates Fore, Dithane, Pentathlon, Protect VI. Carboximides Emerald, Velista, Xzemplar VII. QoI s (Strobilurins) Insignia, Disarm
Red Thread/Pink Patch Pathogen: Laetisaria fuciformis causes Red Thread; Limonomyces roseipellis causes Pink Patch Grasses Affected: Kentucky bluegrass, perennial ryegrass, bentgrass, fine-leaved fescue, tall fescue,
Disease Calendar for Landscape Turf in New Jersey Dr. Bruce Clarke, Rutgers University turf.rutgers.edu Disease Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Powdery mildew Pythium blight Red thread Rust Snow mold Stripe smut Summer patch
Red Thread/Pink Patch Conditions Favoring Disease: most severe when day-night temperatures range 60-75 F during periods of frequent rainfall. Disease development is most severe under low nitrogen fertilization.
Red Thread/Pink Patch Control: Banner, Bayleton, Curalan, Chipco 26GT*, Daconil, Heritage, Insignia, Disarm, ProStar, Rubigan, Trinity, Tourney, and Triton
Summer Patch Causal Organism : Magnaporthe poae Susceptible Hosts : Annual Bluegrass Kentucky Bluegrass Fine Fescue Poa annua Poa pretensis Festuca spp.
Disease Calendar for Landscape Turf in New Jersey Dr. Bruce Clarke, Rutgers University turf.rutgers.edu Disease Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Powdery mildew Pythium blight Red thread Rust Snow mold Stripe smut Summer patch
Conditions Favoring Summer Patch Hot, Humid Weather Excessive Soil Moisture Low Mowing Height Soil Compaction / Poor Drainage
Impact of Cultural Practices on Summer Patch Development Compaction Nitrogen fertility Soil and rhizosphere ph
COMPACTION
Sources of Nitrogen Urea Sulfur - Coated Urea Ammonium Sulfate Ammonium Chloride Calcium Nitrate Potassium Nitrate Nutralene Nitroform
No N
4 lb N/M Ca NO 3 Thompson, et.
4 lb N/M AS Thompson et. al, 199
Plot area damaged (%) Mowing Height on Summer Patch University of Maryland University a S-21 Kentucky Bluegrass 1987 a a a a a b b b b Means followed by the same letter for each date are not significantly different at P=0.05 level.
Summer Patch Management Aerify and Improve Drainage Raise Mowing Height during Heat Stress Overseed with Perennial Ryegrass, Tall Fescue, or Bentgrass (www.turf.rutgers.edu) Fertilize with Ammonium Sources, SCU; Avoid using Nitrate Source Maintain ph at or Below 6.0 Apply Systemic Fungicides (4 gal water)
I DMIs : Control of Summer Patch - Banner, Bayleton, Eagle, Trinity, Triton, Tourney, Torque II Benzimidazoles : - Cleary 3336 III Strobilurins (QoI): - Compass, Disarm, Heritage, Insignia - Headway and Tartan IV Carboximides: Xzemplar (fluxapyroxad) Velista (penthiopyrad), Lexicon (Insignia + fluxapyroxad)
Brown Patch Causal Agent : Rhizoctonia solani Host : Bentgrass Ryegrass Fescue Agrostis sp. Lolium sp. Festuca sp.
Disease Calendar for Landscape Turf in New Jersey Dr. Bruce Clarke, Rutgers University turf.rutgers.edu Disease Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Anthracnose Brown patch Cool-season brown patch Dollar spot Gray leaf spot Leaf spot and melting-out Necrotic ring Spot
Conditions Favoring Brown Patch * Hot, Wet Weather * Minimum Air Temp. >59 0 F * High Humidity * Excess Nitrogen * Thatch Accumulation
Environmental Parameters Necessary for Brown Patch Development * RH >95% for 10 hours * Minimum Air Temp. > 59 0 F * > 0.1 inch Rainfall within 36 hours
Brown Patch of Cool-season Turfgrasses Management Balanced fertility Improve air movement Decrease leaf wetness Correct subsurface drainage problems Reduce thatch Avoid high N fertility during periods of heat stress Improved cultivars for better disease and heat stress tolerance (www.turf.rutgers.edu) Proper mowing Ht. Use of fungicides
DO NOT IRRIGATE 12 AM DEW AND GUTTATION WATER 6 PM 6 AM LEAVES DRY 12 PM DO NOT IRRIGATE
Chemical Control of Brown Patch I Benzimidazoles : 3336, Fungo 50 II Carboximides : ProStar, Xzemplar, Velista III DMIs : Banner, Bayleton, Eagle, Rubigan, Trinity, Triton IV Dicarboximides : Chipco 26GT, Curalan, Touche V Dithiocarbamates : mancozeb VI Nitriles : chlorothalonil (Daconil, Echo, etc) VII Strobilurins : Compass, Heritage, Insignia, Disarm VIII Phenylpyrrole: Medallion
Major Rust Diseases of Turfgrasses Pathogens: Puccinia sp., Uromyces sp., Grasses affected: Kentucky bluegrass, ryegrass, tall fescue, zoysiagrass, and bentgrass,
Disease Calendar for Landscape Turf in New Jersey Dr. Bruce Clarke, Rutgers University turf.rutgers.edu Disease Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Powdery mildew Pythium blight Red thread Rust Snow mold Stripe smut Summer patch
Stem Rust in Kentucky Bluegrass
Crown Rust on Perennial Ryegrass
Management / Control Maintain adequate fertility (balanced N:P:K) Mow frequently, but avoid scalping Blend resistant cultivars (www.turf.rutgers.edu) Prevent drought stress Apply fungicides according to local recommendations - DMI s, Dithiocarbamates, Nitriles, Strobilurins
Mark Your Calendars Now for the Rutgers Landscape Turf and Equipment Demonstration Field Day July 30, 2013 Rutgers Plant Science Farm Halls Mills Rd, Adelphia, NJ www.turf.rutgers.edu