White Mould = Stalk Break
Causative agent and transmission
Rotting of the neck or white mould disease is mainly caused by the fungus Sclerotinia sclerotiorum, and more rarely by S. minor.
The disease develops above all in a cold climate, with alternating dry and rainy periods, after delicate crops such as rapeseed or protein oil seeds.
Description of symptoms
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• On crops: rotting of the stem-ends, covered with a whitish mycelium. The affected plants collapse and wither. The presence of large black sclerotia can often be noted inside the stems.
• On tubers: rot is relatively rare, starting on the stem-heel, with sclerotia present on the rot.
- Avoid rotation with too frequent return to delicate crops and limit the attacks of white mould disease in these crops;
- Avoid too much nitrogen.