troubleshooting

Slide 1 LHAP 106: TESM. Troubleshooting: Disease, Deficiency and Damage Slide 2 Which diseases and damage due to pests or climate have you seen in industry? Slide 3 Slide 4 Turfgrass Nutrient Deficiencies Patterned? (poor application) Salt burning? (big splotch where it fell) Generalized - look at the blades to further diagnose Slide 5 Nitrogen deficiency due to poor application practices Slide 6 Early signs of Phosphorous deficiency – looks similar to early drought stress ( dark green ) Slide 7 Phosphorous deficiency 6 weeks after seeding Kentucky Bluegrass Slide 8 Advanced Phosphorus deficiency on bentgrass, reddish purple stand due to deficiency in older leaves Slide 9 Early spring chlorosis due to Potassium deficiency (right side of plot) Slide 10 Chlorosis on bluegrass showing Iron deficiency in irregular patterns Slide 11 Interveinal chlorosis caused by iron deficiency Slide 12 Weeds!! Slide 13 Cold Damage Frost Replaces dew in cold season: Water in cells freezes Traffic over the frozen tissues ruptures cells Avoid traffic until frost has disappeared Consider irrigation to melt frost Ice damage also occurs where drainage is poor (greens tarps) Winter Desiccation: In Chinook zones, consider use of snow fence to help accumulate and protect from warming winds on high value turf. Slide 14 Slide 15 Damage & Disease Insects Invertebrates Rodents Fungi Slide 16 Slide 17 DEW WORMS Slide 18 Rodents and Insects Mice, Ground Squirrels, Pocket Gophers (burrow) Moles (damage turf looking for insects to eat) … and Dew Worms… as well as dogs (urine) Insects: Correctly ID the Insect Know it’s lifecycle and when / how it causes damage Ascertain tolerances: Deal with it when it is most vulnerable Root feeders: Grubs (beetle larvae) Shoot feeders: Sod Webworm (lawn moth larvae) Burrowing: Ants Slide 19 Chinch Bug Symptoms: Irregular shaped brown spots Especially near pavement / concrete Identify the insect first! Control: Usually insecticides Slide 20 Turfgrass Diseases Relative Humidity (RH) Refers to the amount of moisture in the air Affects evapotranspiration (ET) RH is greater at plant canopy level Affects potential for disease (next slide) Slide 21 Humidity Potential for disease High humidity favours penetration and infection of certain pathogens (fungus) KB/Fescue mixes - powdery mildew, dollar spot, snowmoulds Bentgrass – brown patch, fusarium patch, dollar spot, melting out, blight Fungal growth in Alberta favoured by cool wet weather Slide 22 Will not kill turf Appears as whitish powder on the leaves Caused by low nightly temps, high humidity, and shade May appear quite suddenly Diseases: Powdery Mildew Slide 23 Powdery Mildew Slide 24 Powdery Mildew Powdery Mildew left over, likely from Fall, living under the snow Note, it is against a building, full shade exposure. Best response is to get rid of lawn in this area Slide 25 Caused by fungi that create web-like mycelium Gray mould – damages mostly the leaves Pink mould – invades crowns and roots Damage is seen as snow melts (late winter, early spring) Circular patches of dead and matted leaf blades; smaller patches may join together Not usually a problem on medium managed lawns Major concern on golf courses and high play areas Snow Moulds Slide 26 Snow Molds Fungi are active at temperatures just above freezing in moist conditions Under snow cover or anything that covers the grass (ie. leaves) Normally killed by dry cold winter air Fall care is crucial Apply fall fertilizers well before dormancy, or after leaf growth has stopped Remove all leaves from the lawn Avoid piling snow deeply along pathways etc. No chemical treatment is recommended In most cases healthy growth will resume Slide 27 Slide 28 Slide 29 Can be a problem on all types of turf Caused by a variety of fungi Mushroom is the fruiting body Converts decomposing matter to N Irregular circles of darker green turf with compacted area in the center Mycelial growth causes soil to be impervious to water Can mask with heavy fertilization and watering Fairy Ring Slide 30 Slide 31 Other Mushrooms… Slide 32 Circular dead areas or rings of dead grass (often with live grass in the center) Yellow patch, summer patch, fusarium patch, take-all patch - includes rhizoctonia Fungi favoured by wet conditions in spring and fall Attack root systems and crowns Factors - soil compaction, soil layering, excessive thatch Remedy – mow higher, overseed Patch Diseases Slide 33 Appears as large, irregular dead patches Spreads quickly affecting leaves and crowns killing plants Occurs in the summer with dews and higher evening temperatures Hot, humid weather Often seen first in low areas or swales where soil moisture is maintained Pythium Blight You may recognize Pythium from Damping Off disease in 1st year… Slide 34 Usually occurs on taller mown turfgrasses in spring and fall Crowns and roots not infected - plants are not killed and will usually recover Red threads results in patches of tan or pink turf KB, Perennial ryegrass, Tall fescue Usually where nutrition is poor, long evening dew Important to provide adequate N Red Thread Slide 35 Slide 36 TAKE HOME MESSAGES… Stay within mowing height ranges Provide balanced Nitrogen Provide good drainage Avoid thick thatch layers Watch areas of shade Be diligent during times of low night temperatures and high humidity, heat and drought stress susceptible host + pathogen + environment = Disease Slide 37 Why does my grass look so crappy? Slide 38 Slide 39 Homeowner has 2 large dogs and does not clean up after them… but look at where the downspouts are and how much under fence clearance there is… Slide 40 Slide 41 So, Managers must ask: Why DOES my grass look so crappy? What are the Symptoms Is it a patch? is it fungal, fertiliser, thatch, urine, or chemical? Is it leaf discolouring? Is it yellow / brown, white, or red? Is it on the new growth or the old? Is it a ring? Is it green or brown? Is it spongy? Thatch Is it patterned? Marcelling? Mower problem or Thatch problem? What are the regular cultural practices Mowing, Watering and Fertilising done properly? Could Compaction be the problem? Could Thatch be the problem? Soil Tests read correctly What is the environment like Are fertiliser formulations correct for the weather? Is it hot, or cold; humid or dry? Has it been frosty? Slide 42 Before you go… please fill out the course feedback form!!