Dollar Spot

Question 1

Dollar Spot

Cause:

Answer 1

Sclerotinia homeocarpa

Question 2

Dollar Spot

Signs:

Answer 2

• Sterile, septate mycelium with different diameters and random branching

Question 3

Dollar Spot

Host:

Answer 3

All

Question 4

Dollar Spot

Symptoms:

Answer 4

• 1” size spots of dead grass
• taller grass is 1-5” spots
• blighted leaves appear WHITE
• white leaf lesions w/ reddish brown border
  
  • “hourglass” or Bowtie” shape that goes all the way across the leaf
  • If all the way to leaf tip - called “flagging”

Question 5

Dollar Spot

Predisposing Factors:

Answer 5

• Warm Days - Cool Nights
  
  • Optimal is 60 - 85F
• 8 - 12 hours of continuous leaf wetness
• Thatch accumulation
• Low HOC
• Low Nitrogen
• Drought Stress

Question 6

What is an effective way to reduce dollar spot with your mowing strategies?

Answer 6

• Disruption of leaf wetness after 6 hours.
  
  • keep it dry!
    *

Question 7

Management practices to reduce dollar spot include:

Answer 7

• Remove dew
• Don’t let leaves stay wet longer than 6 hours
• Daily Rolling if not mowing…or do both!
• Whip the dew
• Topdress

Question 8

Dollar Spot

Chemical Classes that can be effective:

Answer 8

• Chlorotnitriles
• DMI’s
• Dicarboximides
• Dinitro-anilines
• MBC’s
• SDHI’s

Question 9

Dollar Spot

Chemical Control Program:

Answer 9

• Begin treatment program at 2nd true cut in the spring
• repeat every 28 days until conditions dictate a 14 day schedule
• TANK MIX and ROTATE!!

Question 10

What is important to know about DMI fungicide and PGR’s?

Answer 10

• Some PGR’s have DMI charecteristics
  
  • paclobutrazol and flurprimidol

Question 11

What Microbials that can be a good defense against dollar spot?

Answer 11

• Trichoderma harzianum
• Pseudomonas aureofaciens
• Bacillus subtilis
• Basilis licheniformis - Eco Guard

Question 12

Dinitro-anilins

Answer 12

fluazinam