Sclerotinia Stem Rot (SSR) Flashcards
What is the causal agent for Sclerotinia Stem Rot?
Sclerotinia Sclerotiorum
How many hosts does SSR have?
over 400 plant species
Give 8 examples of hosts of SSR.
Sunflowers, Lentils, Peas, Beans, Flax, Alfalfa, Potatoes, and Hemp
Give 6 examples of non-host crops.
Wheat, Rice, Oats, Rye, Barley and Corn.
What percentage of host crops for SSR is grown in Canada?
90%
What kind of a fungus is SSR?
Apothecium
What kind of spores are produces by SSR?
Ascospores
How much humidity does SSR like?
75 - 80%
What kind of a parasite is SSR?
Facultative parasite.
Which part of the plant do ascospores from SSR adhere to?
The flowers
When is the best time to apply fungicide for SSR?
During the flowering stage.
What are 4 symptoms of SSR?
- Light brown patches on stems, branches, and pods. These legions expand and take on a greyish white color.
- Early ripening
- Bleaching.
- Shredded stems.
Where can sclerotia be found in SSR?
Inside the stem.
When do symptoms of SSR usually appear?
2-3 weeks after infection.
What are the favorable environmental conditions for SSR?
Soil and canopy moisture. 20-25 degree C and high humidity. Warm dry conditions will pause infection until conditions are favorable again.
How much yield is lost due to SSR under favorable conditions?
50%
How is yield lost due to SSR?
Smaller and fewer seeds.
Premature ripening
shattered pods.
Reduced seed filling
Loss of smaller seeds during combining.
How are management practices with SSR related to canola cultivars with fewer petals?
Cultivars with fewer petals show less infection.
What are 6 ways to manage SSR?
- Clean seed
- Weed control
- Crop rotation
- Burning Stubble to irradicate sclerotia.
- Foliar fungicide
- Biocontrol.
When should you apply the foliar fungicide for SSR?
When 20 - 30% of the flowers are in bloom.
