A fungus called Botrytis cinerea infects many different crops, fruits, vegetables, ornamental plants, weeds, and tubers causing what is commonly called grey mold.
Why Does it Matter?
- Botrytis grey mold is common to all pulse growing regions.
- This disease can attack and kill plants from the seedling to the early flowering stage.
- Quality loss. Late-season infection on pods can result in unfilled pods, or shrunken, discoloured seed.
- Yield loss. When weather conditions are favourable (16o C to 21o C and humid), and crop canopies are dense, yield losses can be severe.
What are the Symptoms?
- Infected seed causes seedling blight.
- Infected plant parts, stems, leaves, flowers and/or pods, turn light tan to brown and become covered with grey mold.
- Infected pods fail to fill or produce discolored and/or shriveled seed.
- Hard black over-wintering structures (sclerotia), similar to those of Sclerotinia, may form on dead and dying plants.
What is the Disease Cycle?
- Infection can come from diseased seed, infected crop debris or weeds, or by sclerotia in debris or soil. Any of these sources can cause symptoms of seedling blight.
- Once a plant is infected, sporulation and disease spread occurs rapidly.
- The fuzzy grey mold on plant tissue produces thousands of spores that are easily carried by wind or rain splash to other plant parts or other plants. Spores can also be spread by irrigation or farm machinery.
- Wet weather and dense crop canopies enhance the growth of this fungus.
How is it Controlled?
- Use clean, disease free seed.
- Observe proper crop rotations using non-host crops, such as cereals.
- Infected crop debris can be deep plowed under (to 8 cm).
- Good weed control helps reduce crop density for better ventilation.
- Use fungicides, being careful to observe pre-harvest intervals.
- Fungicides use for late season blight symptoms may not provide good control.
How Does 20/20 Seed Labs Inc. Test for Botrytis Grey Mold?
- 200 seeds (400 for chickpeas and lentils) are surface sterilized to remove surface contaminants from the seed coat then placed on agar plates and incubated for 7 days.
- A qualified staff member examines the plates for the presence of the fungus. The type of spores produced and/or the presence of sclerotia forming on the plate identify this fungus.
- This test gives the percentage of infected seeds to 0.5% (0.25% for chickpeas and lentils).
- This test takes 7 days to complete.
Combined tests for botrytis, ascochyta, anthracnose and sclerotinia are available at reduced rates, depending on the number of disease tests requested. Please contact us for more information.