Anthracnose

Question 1

Anthrancnose

Cause:

Answer 1

Colletotrichum cereale

Question 2

Colletotrichum cereale

Host:

Answer 2

Poa

Agrostis

Lolium

Festuca

(primarily on putting greens)

Question 3

Colletotrichum cereale

Signs:

Answer 3

• setose acervulus with lunate conidia w/ oil drop in the middle
• Stroma (mycelial mat) on stolons with appresoria

Question 4

Colletotrichum cereale

Symptoms of foliar blight:

Answer 4

• General thinning / yellowing & bronzing
  
  • poa = yellow
  • bent = bronze

Question 5

Generally speaking…what grass species will begin to thin first when infected with Anthracnose?

Answer 5

Poa Annua

Question 6

What is the structure on the mycelium mat that acts silimar to a hyphopodia and extracts nutrients from the roots?

Answer 6

Appresoria

Question 7

When thinning starts to take place from Anthracnose…what color will the leaf tissue begin to turn?

For Poa Annua?

For Bentgrass?

Answer 7

• Poa will begin to turn Yellow
• Bentgrass will begin to turn Bronze

Question 8

Colletotrichum cereale is a saphrophite.

True or False?

Answer 8

True.

Question 9

How can you tell if the fungus is causing foliar blight?

Answer 9

look at the green tissues and see if you find acervuli

Question 10

Anthracnose

Symptoms of Basal Crown Rot:

Answer 10

• small yellow spots show individual plants failing
  
  • dime sized spots get bigger as it gets worse

Question 11

When turf in infected with anthracnose and you are trying to determine if it’s foliar blight or basal crown rot…what do you look for on the plant and how can you determine which one it has?

Answer 11

• Foliar blight will have setose acervuli on the “green” tissue
• Basal crown rot will have black stroma on the crown and/ or stolons

Question 12

Anthracnose

Predisposing factors:

Answer 12

• 60 - 90F
• Low Nitrogen Input
• Optimal 80 - 90F for Foliar Blight
  
  • (middle if summer)
• Basal infections at cooler soil temps (60F)
• Extended leaf wetness
• Thatch
  
  • (the fungus lives off of dead shit)

Question 13

Fertility Management for Anthracnose:

Answer 13

• Soil Test
• Maintain pH (5.2 - 6.5)
• At least 3 lbs/1000 square feet
  
  • use slow release granular in spring and fall
  • spoon feed during summer

Question 14

What should you do to begin to manage Anthracnose?

Answer 14

• Raise HOC, skips cuts or roll
• Avoid grooming, top-dressing, aerification and any other mechanical stresses until grass begins to recover
• Avoid PGR’s
• Water drought stressed turf
• Apply Nitrogen
• Make 3 consecutive applications of fungicides
  
  • DMI, MBC or Qoi
• Be sure to add Daconil to the mix

Question 15

Management tactics to prevent Anthracnose?

Answer 15

• Lite and Frequent topdressing every 7 - 14 days
• Aerify and Verticut to remove thatch
• Rplace 80% ET
• Remove Dew in AM
• Maintain pH of irrigation water
• If using PGR’s, use Primo

Question 16

What is the Chemical Control program for Anthracnose?

Answer 16

• Begin in Mid May and go into September
• Rotate materials every 14 days
• Tank Mix products
  
  • Contacts with Penetrants
• MBC, Qoi, DMI, Chlorothalonil
• Choose products that control other diseases at the same time