NALP COOL SEASON TURFGRASSES
CH 8 (MANAGING TURFGRASS
DISEASES) EXAM QUESTIONS WITH
CORRECT ANSWERS
Describe the disease cycle of slime mold's: - Answer-They survive adverse conditions in
the spore stage. And cool, humid weather, the spores absorb water. The spores will
crack open, And a motile spore emerges. The motile spores feed on other micro
organisms and decaying organic matter, but do not infect living turf grasses. Eventually,
pairs of spores unite and increase in size. This form of the organism is called a
plasmodium, and it is this stage that produces the slimy overgrowth on turf grass is.
Slime mold plasmodia and reproductive structures may shade the grass leaves to the
extent that the leaves are yellowed, but damage seldom is severe
Describe the disease cycle of snow mold: - Answer-Sclerotia, the cause of gray snow
mold, oversummers in that thatch, clippings, and the crown area of the grass plants.
They germinate in fall and produce mycelial growth beneath the snow cover and infect
plants. In most instances, the fungus kills the blades of the plant, but does not kill the
crown and nodes.
Pink snow mold survives warm dry weather as dormant fungal mycelium or as dormant
spores in soil and thatch. Spores germinate and cool, wet conditions, producing
mycelium that infects grass leaves.
Describe the disease cycle of summer patch: - Answer-Because all fungus colonizers
grass roots in advance of disease causing activities. When conditions are favorable for
a disease activity, the fungus will invade the roots. Commonly occurs in mid summer
during extended periods of high temperatures following wet weather or heavy irrigation.
Describe the disease cycles of red thread and pink patch: - Answer-The fungi
overwinter as dried mycelium on infected dead leaves or in clipping debris's from
previously infected plants. The fungi spread by transport of mycelium or infected leads
to new areas. The Mycelium on living, infected plants are easily broken loose and
transported mechanically. The fungus enters the leaves through natural openings and
cut tips, and spreads rapidly through the remainder of the leaf. Red thread and pink
patch disease develop more readily one air temperatures are 65 to 75°F, with prolonged
periods of rainy or humid weather.
Describe the symptoms of summer patch: - Answer-They appear identical to necrotic
ring spot. Hence, diseased specimens may have to be examined by a qualified
diagnostician if positive identification is necessary.
, How are slime mold different from most other turf grass pathogens? - Answer-Slime
mold do not directly infect the plant. Instead, this group of organisms feeds on micro
organisms and decaying organic debris. During periods of warm, wet weather, slime
mold migrate onto the surface of turf grass leaves were they produce massive amounts
of colored spores.
How can you reduce the possibility of fungal resistance to a specific fungicide? -
Answer-Only apply fungicides when absolutely necessary, alternate and mix fungicide
with different modes of action, and use broad-spectrum contact fungicides in place of
systemic fungicides whenever possible.
How do you contact fungicides generally work? - Answer-They are applied to the leaf
and stem surface of turf grasses and do not move appreciably within the plant. They
may be washed or mowed off of the leaf surface. They are only effective for a short
period of time, usually 7 to 14 days, and do not protect new foliage. These fungicides
are usually used for the control of foliar diseases and not diseases of the routes in
crowns. Contact fungicides generally have a broad spectrum of control and have been
used extensively in the turf industry for a number of years.
How do you systemic fungicides work? - Answer-Chemicals that are absorbed and
translocated within the plant. They are not as likely to be removed from plant by rainfall
and mowing. They may protect plants for a period of 2 to 4 weeks and will protect new
growth. Most systemic fungicides can control both foliar and root/crown disease. They
are somewhat prone to resistance.
Is it a good idea to use a single species or cultivar of grass for turf establishment or
renovation? Why or why not? - Answer-No, it is always preferable to use mixtures of
different grass species or blends of different cultivars. Seeding mixtures and/or blends
produce a diverse population of grass plants. diversity in planting almost always
increases odds of survival.
What are effective control measures for pink patch and red thread? - Answer-Adequate
nitrogen levels for turf growth usually will reduce the problem. Be mindful that high
nitrogen levels can cause other diseases. These diseases are not normally severe
enough to warrant fungicide treatment. If needed fungicide treatment will simply
minimize symptoms.
What are some affective control measures for powdery mildew? - Answer-Changing
Landscape plantings to improve air circulation and reduce turf shading will aid in
disease reduction. Prune over story trees to allow sunlight to reach the turf grass. Turf
grass species differ in there susceptibility to powdery mildew. Fine fescue and tall
fescue are quite resistant. Fungicides are usually not needed to maintain this disease.
What are some affective control measures for summer patch? - Answer-Since summer
patch is a root disease, cultural practices that promote good root growth will aid in
reducing disease severity. Increased aeration and improve drainage on compacted and
CH 8 (MANAGING TURFGRASS
DISEASES) EXAM QUESTIONS WITH
CORRECT ANSWERS
Describe the disease cycle of slime mold's: - Answer-They survive adverse conditions in
the spore stage. And cool, humid weather, the spores absorb water. The spores will
crack open, And a motile spore emerges. The motile spores feed on other micro
organisms and decaying organic matter, but do not infect living turf grasses. Eventually,
pairs of spores unite and increase in size. This form of the organism is called a
plasmodium, and it is this stage that produces the slimy overgrowth on turf grass is.
Slime mold plasmodia and reproductive structures may shade the grass leaves to the
extent that the leaves are yellowed, but damage seldom is severe
Describe the disease cycle of snow mold: - Answer-Sclerotia, the cause of gray snow
mold, oversummers in that thatch, clippings, and the crown area of the grass plants.
They germinate in fall and produce mycelial growth beneath the snow cover and infect
plants. In most instances, the fungus kills the blades of the plant, but does not kill the
crown and nodes.
Pink snow mold survives warm dry weather as dormant fungal mycelium or as dormant
spores in soil and thatch. Spores germinate and cool, wet conditions, producing
mycelium that infects grass leaves.
Describe the disease cycle of summer patch: - Answer-Because all fungus colonizers
grass roots in advance of disease causing activities. When conditions are favorable for
a disease activity, the fungus will invade the roots. Commonly occurs in mid summer
during extended periods of high temperatures following wet weather or heavy irrigation.
Describe the disease cycles of red thread and pink patch: - Answer-The fungi
overwinter as dried mycelium on infected dead leaves or in clipping debris's from
previously infected plants. The fungi spread by transport of mycelium or infected leads
to new areas. The Mycelium on living, infected plants are easily broken loose and
transported mechanically. The fungus enters the leaves through natural openings and
cut tips, and spreads rapidly through the remainder of the leaf. Red thread and pink
patch disease develop more readily one air temperatures are 65 to 75°F, with prolonged
periods of rainy or humid weather.
Describe the symptoms of summer patch: - Answer-They appear identical to necrotic
ring spot. Hence, diseased specimens may have to be examined by a qualified
diagnostician if positive identification is necessary.
, How are slime mold different from most other turf grass pathogens? - Answer-Slime
mold do not directly infect the plant. Instead, this group of organisms feeds on micro
organisms and decaying organic debris. During periods of warm, wet weather, slime
mold migrate onto the surface of turf grass leaves were they produce massive amounts
of colored spores.
How can you reduce the possibility of fungal resistance to a specific fungicide? -
Answer-Only apply fungicides when absolutely necessary, alternate and mix fungicide
with different modes of action, and use broad-spectrum contact fungicides in place of
systemic fungicides whenever possible.
How do you contact fungicides generally work? - Answer-They are applied to the leaf
and stem surface of turf grasses and do not move appreciably within the plant. They
may be washed or mowed off of the leaf surface. They are only effective for a short
period of time, usually 7 to 14 days, and do not protect new foliage. These fungicides
are usually used for the control of foliar diseases and not diseases of the routes in
crowns. Contact fungicides generally have a broad spectrum of control and have been
used extensively in the turf industry for a number of years.
How do you systemic fungicides work? - Answer-Chemicals that are absorbed and
translocated within the plant. They are not as likely to be removed from plant by rainfall
and mowing. They may protect plants for a period of 2 to 4 weeks and will protect new
growth. Most systemic fungicides can control both foliar and root/crown disease. They
are somewhat prone to resistance.
Is it a good idea to use a single species or cultivar of grass for turf establishment or
renovation? Why or why not? - Answer-No, it is always preferable to use mixtures of
different grass species or blends of different cultivars. Seeding mixtures and/or blends
produce a diverse population of grass plants. diversity in planting almost always
increases odds of survival.
What are effective control measures for pink patch and red thread? - Answer-Adequate
nitrogen levels for turf growth usually will reduce the problem. Be mindful that high
nitrogen levels can cause other diseases. These diseases are not normally severe
enough to warrant fungicide treatment. If needed fungicide treatment will simply
minimize symptoms.
What are some affective control measures for powdery mildew? - Answer-Changing
Landscape plantings to improve air circulation and reduce turf shading will aid in
disease reduction. Prune over story trees to allow sunlight to reach the turf grass. Turf
grass species differ in there susceptibility to powdery mildew. Fine fescue and tall
fescue are quite resistant. Fungicides are usually not needed to maintain this disease.
What are some affective control measures for summer patch? - Answer-Since summer
patch is a root disease, cultural practices that promote good root growth will aid in
reducing disease severity. Increased aeration and improve drainage on compacted and
