Rhizoctonia Solani Flashcards
What is rhizoctonia
A ubiquitous soil born fungus responsible for stem canker, stolon canker and black scurf
What crops can it be found on
Lettuce, potatoes sugar beet, and barley
Is rhizoctonia netrophic
Yes- it feeds on the dead tissue and has the ability to survive on OM in the soil
How many groups are there
interspecies variation they are sub divided into 14 anastomoses groups
Which are the main groups
1-4 causes the most damage through stem canker and black scurf on potatoes
How do they reproduce in potatoes
Asexually reproduce- hyphae and sclerotia
What are the symptoms
Delay emergence
Affects yields by stunting growth then neighbouring plants outgrow and block out light
Stem canker- Deep necrotic lesions causing main and 2ndary stem pruning
Superficial lesions interfere with translocation
Stem/stolon canker can’t produce tubers- or very small
black scurf
Is the sclerotia of the fungi- comprised of dense masses of barrel shaped cells, if it’s was on seed it would initiate stolon canker again when it grows
Saprophyte
When fungi live on decaying OM
What does it cause on Barley
Stunting growth and root rot (AG8)
What does it cause on rice lol
Causes rice sheath blight- circular lesions causing lodging and yield loss of 20-50% (AG1)
What does it cause on lettuce
Lettuce bottom rot- dry rot spreads leading to bacterial soft rot (AG5)
What does it cause on sugar beet
Crater like rots causing 30-60% yield loss
What are the current management controls
Seed treatments
Soil treatments
Timely harvest
Certified seed
Weed management
Seed soil tests
Faster emergence
Give an example of a seed treatment
Rhino (Flutolanil)
