yellow tuft

Question 1

What is the Causal agent of Yellow Tuft?

Answer 1

Sclerophthora macrospora

Sclerophthora graminicola

Question 2

Yellow Tuft symptoms

Answer 2

Dime sized yellow spots on the green

stunted growth and thickening leaves

abundance of tillers

turns into dime sized Dead spots

‘hard and pointy’ crown

Question 3

describe the Mycelium that Yellow Tuft produces:

Answer 3

It is Sytemic Hyphae which means it grows into the plant.

Question 4

describe the Oospores that Yellow Tuft produces and what they do.

Answer 4

Oospores are produced inside of the plant by hyphae and germinate when the soil is super saturated. They germinate into hyphae….hyphae can produce more spores. (Oospores or Sporangia that produce Zoospores)

Question 5

How are Zoospores produced in this fungus and why are they important?

Answer 5

Zoospores swim in water when the soil is super saturated, they cling onto a plant, turn into a cist and a piece of hyphae grows into the plant and insides of leaves. When it’s wet, hyphae makes Sporangia that pop out of stomates and release more Zoospores.

They travel with water which makes them spread rapidly.

Question 6

How are Oospores produced and where are they normally found?

Answer 6

Zoospores cling to a plant, form a cist, germinate hyphae that grows into the plant. Usually the hyphae reproduces asexually to form sporangia and zoospores but can reproduce sexually to form Oospores that, becuase of their thick wall, are able to survive for long periods inside of the plant. They eventually germinate to produce hyphae and sporangia that release zoospores out of the stomates.

• Oospores are usually found in Annuals like crabgrass or orchard grass but can be in perennials.

Question 7

Disease Cycle of Yellow Tuft:

Answer 7

Zoospores are released by Sporangia that pop out of the stomata of the leaves….they swim and cling onto a new host, form a cist and germinate hyphae that grows into the plant and up in the leaves. The hyphae then produces either Oospores or Sprangia with Zoospores. The Sporangia pop out of stomates and release zoospores. If Oospores are made, they hang out until conditions are right and then they germinate mycelium.