CSI Turfgrass: Deciphering what killed the lawn and what can be done to prevent it

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2/12/15 Learning Objectives CSI Turfgrass: Deciphering what killed the lawn and what can be done to prevent it 1. Identify the most common biotic and abiotic agents present in Wisconsin lawns 2.

1 2/12/15 Learning Objectives CSI Turfgrass: Deciphering what killed the lawn and what can be done to prevent it 1. Identify the most common biotic and abiotic agents present in Wisconsin lawns 2. Identify the key differences between abiotic and biotic-caused symptoms Paul Koch Deciphering what killed the lawn and University of Wisconsin - Madison 18th, 2015 what can February be done to prevent it 3. Be able to prevent and/or manage the most common ailments of Wisconsin lawns in an environmentally sensitive manner 2/12/15 Symptoms PROGRESS - start small and increase in size and severity over a period of several days Symptoms randomly distributed: not in regular patterns Large areas are not killed with adjacent areas untouched Usually one species is affected 2/12/15 Water Shade Fungi Fertility Vertebrates Traffic Soil Conditions Fertilizer or herbicide burn 2/12/15 UNIVERSITY OF WISCONSIN UNIVERSITY OF WISCONSIN 4 Causal agents: Gray snow mold (Typhula incarnata); pink snow mold (Microdochium nivale) Optimum Conditions: Gray snow mold needs cold conditions and approximately 60 consecutive days of snow cover, pink snow mold needs extended periods of cool, wet weather but not necessarily snow Symptoms: Circular patches of matted turfgrass with a white to tan bleached color. Pink snow mold may have more of a reddish hue. In the absence of snow cover, patches of pink snow mold are often smaller and less distinct. Control: Limit nitrogen fertility going into fall (do not confuse with dormant application). Mow grass until dormancy, but do not cut abnormally short. Remove leaves and other debris from the lawn surface. Abiotic Agents Insects What do the symptoms look like? When did the symptoms show up? Have they gotten worse? What grass species is affected? Are there other healthy plants present within the symptoms? What have the recent weather conditions been like? Are there any obvious abiotic issues present? Snow Molds Common Turfgrass Problems Weeds 2 What are the questions to ask? How can you tell? Biotic Agents UNIVERSITY OF WISCONSIN 5 1

Red thread Causal agent: Laetisaria fuciformis Turfgrass hosts: Mostly fine fescues and perennial ryegrass Optimum Conditions: 60-75 F, extended periods of leaf wetness Symptoms: Small, diffuse

2 Red thread Causal agent: Laetisaria fuciformis Turfgrass hosts: Mostly fine fescues and perennial ryegrass Optimum Conditions: F, extended periods of leaf wetness Symptoms: Small, diffuse patches of turfgrass varying in size from 2 to 3 inches all the way to over a foot. The turfgrass turns a tan or bleached color, and often times red thread-like tendrils are observed protruding from the turf. Control: This disease is dependent on extended periods of leaf wetness, so irrigate infrequently and only in the early morning hours. During extended periods of cool/wet weather in the spring minor amounts of the disease may have to be tolerated, recovery can be aided by light nitrogen fertilization. Kentucky bluegrass can be planted in place of fine fescues or perennial ryegrass. Necrotic Ring Spot Causal agent: Ophiosphaerella korrae Turfgrass hosts: Kentucky bluegrass, fine fescues, perennial ryegrass Optimum conditions: Cool, wet weather in spring followed by warm, dry weather in summer. Symptoms: Is a root-rotting disease. Circular or arc-like patches of yellow to tan turf several inches to several feet in diameter form in late spring or early summer. Resistant weeds and grasses may fill in the center of the patch giving it a frog-eye appearance. Most severe on sodded lawns within 2-10 years of establishment. Disease severity drops off quickly 8-10 years after establishment. Fungus actually attacks the turfgrass roots in spring and fall with soil temperatures between 50-65, but disease is not observed until summer. Why????? Control: Frustrating!!! Necrotic Ring Spot Once symptoms are observed nothing can be done to affect the fungus and the turf has to be nursed along with light, frequent irrigation until the fall. NRS is also difficult to prevent on newly sodded lawns. Plant resistant cultivars of Kentucky bluegrass. Limit nitrogen fertilizer application to no more than 4 lbs/1000 sq. ft. per year. Do not fertilize much before Memorial Day. Keep thatch under one inch. Deep, infrequent irrigation. Summer patch Causal agent: Magnaporthe poae Turfgrass hosts: Kentucky bluegrass and fine fescues Optimum conditions: Sustained temperatures greater than 85 F and wet soils. Symptoms: Is a root-rotting disease. Circular or arc-like patches of yellow to tan turf several inches to several feet in diameter form in mid to late summer. Resistant weeds and grasses may fill in the center of the patch giving it a frog-eye appearance. Most severe on lawns established on compacted soils, wet soils, soils with high ph, or soils over-fertilized with quick-release nitrogen. Fungus becomes active at soil temperatures of approximately 60 F, and causes the most damage at temperatures greater than 85 F. Summer patch Control: Similar to NRS, once symptoms are observed nothing can be done to affect the fungus and the turf has to be nursed along with light, frequent irrigation until conditions cool. Preventatively, general healthy rooting practices can be employed: - Deep, infrequent irrigation -Proper mowing height -Well-drained soil -Aerify in fall if needed (reduce compaction, reduce thatch layer) -Proper nutrition balance (do not fertilize in hot conditions) -If necessary, lower soil ph using acidifying fertilizers White Grubs Grubs have three immature life stages (instars): 1 st instar larval stage 2 nd instar larval stage 3 rd instar larval stage Grubs develop (grow) via a process called molting which is regulated by insect hormones 2

Preventative Control Apply BEFORE or at egg hatch! May be applied in May, June, July Long-residual activity (>120 days) NOT effective on larger grubs (3 rd instars)!

) NOTE: Larger grubs (3 rd instars) are more difficult to control, so get them early!

3 Preventative Control Apply BEFORE or at egg hatch! May be applied in May, June, July Long-residual activity (>120 days) NOT effective on larger grubs (3 rd instars)! Acelepryn (chlorantraniliprole) Arena (clothianidin) Mach 2 (halofenozide) Meridian (thiamethoxam) Merit (imidacloprid) Curative Control Apply once grubs are present (Aug. Oct.) NOTE: Larger grubs (3 rd instars) are more difficult to control, so get them early! Some products have short-residual activity (<10 days) Viable products suggested: Arena (clothianidin) Dylox (trichlorfon) Sevin (carbaryl) Chinch Bugs Importance and Nature of Injury Chinch bugs damage turfgrass by sucking juices from leaves, stems and crowns, gradually causing yellowing As feeding progresses, the turf dries out and turns brown Ultimately, as sever chinch bug damage can result in drastic thinning or even death of the turf stand Management Vertebrates Sound cultural practices that maintain turf in optimum condition are the best defense against chinch bugs Turf that is irrigated during dry periods is better able to tolerate chinch bug damage Endophyte infected turfgrasses will provide meaningful resistance 2/12/15 UNIVERSITY OF WISCONSIN 18 3

2/12/15 Mowing Removes photosynthe3c 3ssue Reduces carbohydrate produc3on and consumes carbohydrates to re- grow leaves Reduces

Rule Mowing height (inches) Annual bluegrass Don t remove 0.1 0.75 Creeping bentgrass 0.1 0.75 more than 1/3 of the leaf 3ssue at one 3me Fine fescue 0.

0 Compensatory growth As mowing height decrease, management inputs increase Disadvantages of lower end of height range Decrease

shoot growth rate Shorter shoots = ﬁner shoots = Increase height in: Shaded condi3ons more leaf area Mid summer stress deeper

4 2/12/15 Mowing Removes photosynthe3c 3ssue Reduces carbohydrate produc3on and consumes carbohydrates to re- grow leaves Reduces root growth Mowing has some benefits too Great weed control Improved density Will also improve aesthe3cs and uniformity The 1/3 Rule Mowing height (inches) Annual bluegrass Don t remove Creeping bentgrass more than 1/3 of the leaf 3ssue at one 3me Fine fescue Kentucky bluegrass Perennial ryegrass Tall fescue Zoysiagrass Compensatory growth As mowing height decrease, management inputs increase Disadvantages of lower end of height range Decrease root / stolon / rhizome growth Decrease carbohydrate storage and produc3on Beneﬁts of lower end Increase 3llering Increase shoot growth rate Shorter shoots = ﬁner shoots = Increase height in: Shaded condi3ons more leaf area Mid summer stress deeper roots Weakened condi3on reduce stress Establishment promote lateral growth denser turf More frequent irriga.on More disease / stress 4

5 A dull mower blade: Decreases turf quality Increases water use rates Increases disease Increase gasoline use Mower sharpening Rotary mower Stone grinder or file Too much N Reduced root growth Nitrogen Decreases stress tolerance - esp. water Excessive thatch development Increased mowing requirement Increases incidence of many diseases brown patch, snow mold, gray leaf spot, take-all patch Nitrogen Not enough Reduced shoot density Increased weed invasion esp. clover and crabgrass Increased reliance on pesticides May need to completely renovate if weeds win Unsafe playing conditions Unattractive Increases incidence of certain diseases Rust, red thread, dollar spot Guidelines for N Fertilization: High maintenance Kentucky bluegrass lawns Time of Application Clippings removed Rate of Application lbs N/M Clippings returned May July * Sept After Oct Season Total * Skip if dormant, if non-dormant 100% slow release preferred Guidelines for N Fertilization: Lower maintenance lawns Time of Application Rate of Application lbs N/M May Sept After Oct Season Total Irrigation Water the grass to keep it green. Apply 0.5 to 1 inch of water in early morning once or twice a week Footprin3ng, screwdriver test Don t water. Let it turn brown and go dormant. Turn off the 3mer!!!!!!!!! 5

Managing turf in the shade Mowing Increase : 3-4 Fertilization Maintain frequency (3-4 times/ yr) Half

!! Deep, infrequent Early in day Grasses Adapted to Shade Supina bluegrass Native to sub-alpine Europe

tolerance Lower fertility requirements Core Aerating Best done in fall Recommended for: Sodded lawns

Healthy Lawn 1. Make sure you have the right grass 2. Mow between 2.

Irrigate no more than twice per week if at all! 5. Be patient!

6 Managing turf in the shade Mowing Increase : 3-4 Fertilization Maintain frequency (3-4 times/ yr) Half rates (0.5 lb N/1000 ft 2 ) 30-50%+ slow-release N Irrigation Irrigate LESS!!! Deep, infrequent Early in day Grasses Adapted to Shade Supina bluegrass Native to sub-alpine Europe Stoloniferous Shade and traffic tolerant Fine fescues and Tall Fescues Shade tolerant Drought tolerance Lower fertility requirements Core Aerating Best done in fall Recommended for: Sodded lawns (7+ years old) Seeded lawns (15+ years old) Compacted soils Good 3me to overseed Paul s 5 Tips to a Healthy Lawn 1. Make sure you have the right grass 2. Mow between inches, don t collect clippings 3. Fertilize 2 3 times per year 4. Irrigate no more than twice per week if at all! 5. Be patient! The grass often recovers Turfgrass Diagnostic Lab Thank you! Bruce Schweiger bschweiger@wisc.edu Turfgrass Diagnostic Lab 2502 Highway M Verona, WI plkoch@wisc.edu tdl.wisc.edu 6

Spring Turf Care. Pedro Perdomo Nisso America, Inc. HGS March

Spring Turf Care. Pedro Perdomo Nisso America, Inc. HGS March Spring Turf Care Pedro Perdomo Nisso America, Inc. HGS March 18 2017 Lawn Inspection What concerns or problems do you have? What have you done/will do? To figure it out. 1 2 3 Topics Species selection