Zoysiagrass Management Clint Waltz, Ph.D. Professor The University of Georgia Zoysiagrass Species & Cultivars Zoysiagrass Species Positive Attributes Perennial Winter hardiness Better shade tolerance Unique green color Unique brown (dormant) color Lower fertility requirements Salt tolerant Slow growth habit C. Waltz - EDGE Expo 2015 1
Zoysiagrass Species Negative Attributes Slow growing Thatch Diseases & Insects Large patch & Rust Billbugs & Mites High water requirements Shallow rooting Billbug damage on zoysiagrass Zoysiagrass Species Z. japonica Japanese, Korean & Chinese Lawngrass Coarse leaf texture Good cold tolerance Vegetative & seed propagation Lawns & recreational uses Zoysiagrass Species Z. matrella a.k.a. - Manilagrass Fine leaf texture Marginal cold tolerance Susceptible to nematodes Vegetative propagation Diamond as Putting Green C. Waltz - EDGE Expo 2015 2
Zoysiagrass Species Z. tenuifolia Mascarenegrass & Korean Velvetgrass Finest leaf texture Fair cold tolerance Slow growth Unique brown (dormant) color Lower fertility requirements Salt tolerant Vegetative propagation Zoysiagrass for Landscapes Leaf Texture Coarse Compadre, El Toro, JaMur, Zenith Medium Empire, Leisure Time, Meyer, Palisades Fine Cavalier, Emerald, Geo, L1F, Royal, Zeon, Zorro Green-up Problems Possible Causes Cool Temperatures Slow green-up typical Early Spring Temps. Soil Temp. Guideline 65 F Slow to green-up zoysiagrass C. Waltz - EDGE Expo 2015 3
Environmental Effects Spring 2015 Easter Freeze March 29 Griffin, GA 27.7ᵒ F Sunlight April Griffin, GA 10 days Rain Cool soil slow to warm Courtesy of Sod Solutions Tough year for zoysiagrass green-up! Why Turfgrass? Benefits Permanent Vegetative Cover Filter Protect water quality Slows down runoff Traps dust & smoke CO 2 & O 2 30 million acres N of lawns remove 5% of CO 2 2,500 ft 2 lawn produces enough O 2 for family of 4 Environmental Effects Fall 2015 Griffin, GA Sep. 22 to Oct. 6 Measurable rain 13 of 15 d (4.69 inches) Average night / low temperature 62.4ᵒ F Griffin, GA Oct. 26 to Nov. 11 Measurable rain 15 of 17 d (8.58 inches) Average night / low temperature 50.3ᵒ F Favorable conditions for C. Waltz - EDGE Expo 2015 4
Zoysiagrass - Diseases Large Patch (Rhizoctonia sp.) It s Spring, What Do I Do? Do I proceed with caution? Fertility Disease Control Mow Water Do I stop? Let the grass green-up Why do we fertilize turf? Basic Reasons Color We are in a quality business it must look good Growth & Recovery Divots, wear and tear, surface interaction (play) Yields are not important C. Waltz - EDGE Expo 2015 5
Is now a good time to fertilize? Phosphorus Soil Test Avoid environmental issues Many 0 P fertilizers Potassium Potassium (K) good carrier preemergence herbicide insecticide Timing N Fertilization Warm-season Grasses Soil Temperatures Active root growth & activity 65 F Consistently multiple days 4-inch depth www.georgiaweather.net Combination products Warm-season Grasses: No Spring N! Agronomic Lack of uptake while dormant Let soil temps guide 1 st spring application Environmental Loss of nutrients to non-target sites leaching to ground water runoff C. Waltz - EDGE Expo 2015 6
Warm-season Grasses: No Spring N! Pest Management Increase susceptibility to diseases Opens canopy for weeds Economic Why pay for nutrients when the plant cannot use them? Why pay more to control pests? Zoysiagrass Fertility Annual Nitrogen 2 to 3 pounds N / year 0.5 lb N May, Jun., Jul., & Aug. Thatch excessive nitrogen over watering Bermudagrass invasion Bermudagrass Stolon Zoysiagrass Stolon Disease Control C. Waltz - EDGE Expo 2015 7
Disease Triangle with Time Susceptible Host Virulent Pathogen Disease Infection Time Favorable Environment Disease Control Options Turfgrass Fertility - Zoysiagrass High nitrogen rates encourage disease Timing - turfgrass is actively growing Never exceed 1 lb N / 1000 ft 2 Soil Test P & K Soil ph 6.0 to 7.0 Disease Control Options Chemical Control Proper identification Systemic material Heritage (azoxystrobin) Contact material Terrazole (etridiazol) Preventative - low rates & long intervals Curative high rates & short intervals C. Waltz - EDGE Expo 2015 8
Zoysiagrass - Diseases Large Patch (Rhizoctonia sp.) Night Temperatures 50 to 60 F Fall & Spring 2 applications Residual 21 to 28 d Nitrogen Fertility Large Patch on zoysiagrass Brown Patch & Large Patch (Rhizoctonia sp.) Hosts All turfgrasses (warm- and cool-season) Symptoms patches or rings circular or irregular patches or rings turf purplish and fades to light brown frog eye green center Leaf spots on foliage Brown Patch & Large Patch (Rhizoctonia sp.) Disease Cycle Fungi are ubiquitous dormancy mechanisms (OM decomposers) Active Growth hyphae grow into leaves & sheaths of turf becomes water-soaked & dark foliage dies and turns brown C. Waltz - EDGE Expo 2015 9
Brown Patch & Large Patch (Rhizoctonia sp.) Epidemiology Prolonged Humidity 59 90 F (R. cerealis R. zeae) dense turfs highly fertilized highly irrigated Large Patch Rhizoctonia Blight Warm-Season Turfgrasses Prolonged rain & supplemental irrigation Nighttime temps. Below 70 F Daytime temps. low- to mid- 80 F Treat affected areas during extended cool wet periods in fall & spring Heritage, Banner, Chipco 26GT, Daconil, etc. Common Thoughts Zoysiagrass Must be maintained with a reel-type mower. Proper adjustment & sharp Reel-type Mower Slow growing species older cultivar Rotary-type Mower Good for xeriscape research not supported C. Waltz - EDGE Expo 2015 10
Proper Mowing Height Inches 3.0 2.0 1.5 1.0 St. Augustinegrass Tall Fescue Centipedegrass Bermudagrass Zoysiagrass Picture from Twitter Home Lawns Mowing Problems Mowing Height Scalping Likely above 2 HOC Excessive nitrogen Excessive irrigation ½ to 1½ inches 1/3 mowing rule PGRs Scalping IRRIGATION REQUIREMENT Adapted from White et al. 1993 C. Waltz - EDGE Expo 2015 11
Low-Temperature Injury Desiccation (Drying out) Environmental influences wind & low humidity limited soil moisture drought or frozen soil Maintain soil moisture monitor soil moisture light irrigation during winter if no rainfall spring during root development Low-Temperature Injury Manageable Factors Irrigation limited soil moisture drought or frozen soil moisture deficiency crown desiccation less buffering capacity for temperature swings light irrigation during winter if no rainfall soil moisture at or slightly below field capacity normal rainfall typically sufficient Low-Temperature Injury Manageable Factors - now Drainage poor drainage result in direct low-temp. injury high moisture, greater susceptibility to injury compounded by compaction & excessive irrigation improve surface & subsurface drainage C. Waltz - EDGE Expo 2015 12
Winter Kill Is it really dead? Zoysia takes shade, right? Proper species selection know the microclimate Begins to thin Weedy Bad reputation Industry producer grass Shade Study - 2012 Set-up & Design Heavy, hardwood shade Intermittent sunlight measured monthly Tree root competition Mowing Height 1.5-inch Irrigation prevent stress (1.0 in / wk) Fertility 2 lb / 1000 ft 2 / yr Pest Management as needed C. Waltz - EDGE Expo 2015 13
Shade Study - 2012 17 Cultivars of 4 Warm-season Species est. 2012 Shade Study - 2012 Warm-season Species Bermudagrass Celebration, Discovery, TifGrand, TifTuf St. Augustinegrass Mercedes & Palmetto Zoysiagrass Dynasty, El Toro, Emerald, Empire, Geo, JaMur, L1F, Leisure Time, Palisades, Zenith, Zeon Shade Tolerance Zoysiagrass El Toro 4.0 to 4.5 h/d JaMur 4.5 to 5.0 h/d Zeon 4.5 to 5.0 h/d Zorro 4.5 to 5.0 h/d Emerald TBD Empire TBD Geo TBD L1F TBD Leisure Time - TBD Palisades TBD Zenith TBD C. Waltz - EDGE Expo 2015 14
Zoysiagrass Problems & Management Zoysiagrass Lawn turning black Likely Seedheads Spring & Fall Cultivars Mowing Can look bad Cutting the seed stalk Seedheads Emerald Zoysiagrass What s going on? Varietal differences Plant collections Known Emerald DNA fingerprint Source Retailer / broker Producer DNA Fingerprint C. Waltz - EDGE Expo 2015 15
Emerald Zoysiagrass Clade 1 Clade 2 Phylogenetic Tree Results Clade 1 Early transition Similar to NTEP Plots Clade 2 Late transition Non-certified One outlier (C14) Important Dates in 2016 UGA Turfgrass Research Field Day August 4 EDGE Expo December For other local programs contact your CEA Thank You @GeorgiaTurf Visit www.georgiaturf.com C. Waltz - EDGE Expo 2015 16