Final - Section 4 Flashcards
What is a common sign for brown patch on bentgrass?
Smoke Ring of hyphae
When is Yellow Patch active?
Cool Weather
45 - 65 degrees
What characteristic is unique for Pythium mycelium?
It is aseptate
What time of year can Pythium cause disease in turf?
It is active in Cool - Hot temperatures but causes plant disease in the hot months because the plant will suffer from heat and drought stress.
Name two fungicides that will NOT control Pythium.
Azoxystrobin
Pyraclostrobin
How does Nitrogen affect snow molds?
Excess nitrogen makes the turf more susceptible to disease
What management practice may increase Basal Crown Rot?
Short HOC
Name the Favored host for Anthracnose.
Poa annua
What effect does Nitrogen have on Leaf Spot and Melting Out?
Excess nitrogen makes the plant more susceptible to disease
What environmental condition increases Gray Leaf Spot?
ALternating period of weat and dry in the heat
Draw the conidia of the leaf spot fungus.
.
What single cultural approach can we use to reduce the severity of all patch diseases?
Mow at reccomended cutting heights
What fertilizer strategy can we use to control Summer Patch and Take-All?
Avoid Nitrate nitrogen sources
What turf is the common host for Take-All.
.Agrostis spp.
What two fungicides are effective against water molds?
Heritage
Segway
Name two diseases that have Smoke Ring symptoms.
Rhizoctonia solani
Waitea circinata
Name the piercing mouthpart of a nematode.
stylet
What types of Fungicides make Leaf Spot ant Melting Out worse?
DMI’s and Thiophanate-methyl
Draw the conidia of the leaf spot fungus.
.
When making chemical application for summer patch control what must be done to get good control?
You must water in the fungicide so it gets to the roots
What is a Syndrome?
A group of diseases that all have very similar effects on turf and can be controlled in similar ways
Name a grass in which brown patch is the #1 disease.
Colonial Bentgrass
How many different species of Pythium can cause disease in turf?
36
Name 2 fungicides that can effectively control pythium.
Insignia
Segway
What is a clamp connection?
It is a clamp-like structure that forms on the outside of hyphae at the septa. On basidiomycota fungi
List 3 types of penetrant Fungicides.
Localized
Systemic
Acropetal
List 3 biotic causal agents.
Fungi
Bacteria
Virus
describe a snow mold fungicide program.
Use Iprodione and Chlorothalonil and begin spraying in early November and continue at 4 week intervals until temperature exceed 60 degrees.
what would you do to remedy snow mold injured turf in the spring after the snow melts?
Rake up dead turf and clippings, Renovate the area and use resistant varieties to grow in new turf.
What is Mycology?
The study of Fungi
What characteristic of turf predisposes it to Red Thread?
Damaged and Infertile
Describe a chemical control program for Summer Patch
- Apply Headway fungicide
- Begin treatments when soil stabilizes at 65 deg.
- Use High label rates
- Apply with 3-5 gallons of water / 100 sq. ft
- Repeat at 28 day intervals for preventative and at 14 day intervals for curative
describe the anthracnose cultural control program.
- 3 -5 lbs Nitrogen/1000
- Reccomended HOC
- Topdress lightly and frequently
- Have a Rolling program
- Replace 80% of ET
- Aerify
- If using PGR, add Primo
What is the best way to make chemical applications for Anthracnose control?
- Tank mix contacts and penetrants
- Rotate products
- apply on 14 day intervals
- Begin program mid-May and continue into September
- Choose products that control other diseases at the same time
Where and on what grasses is Gray Leaf Spot a serious problem?
High Cut Turf Area’s
- Perennial Rye
- Tall Fescue
- St. Augustine
Whatis the causal agent of Gray Leaf Spot?
Pyricularia oryzae
How can you tell if Colletotrichum is actually killing your grass?
Pull the infected plant out of the ground and look for Black Stroma on the Crown or Stolons.
list 2 environmental factors that promote dollar spot.
Warm Days - Cool Nights
8 - 10 hours of continual leaf wetness
What management practice may increase Anthracnose Basal Crown Rot?
Low HOC
Name the hair-like appendage in an anthracnose fruiting body.
Setose Acervuli
Water soluble nitrogen sources reduce Leaf Spot and Melting Out. True or False?
False
