• Leaves decay at the base, turn yellow, wilt, and topple over
• Roots and bulbs - covered with a fluffy white mycelium
• Affected bulbs may become watery, and the outer scales crack as the bulb dries and shrinks
• Small black sclerotia form on and in affected bulb parts

Mode of spread and survival:

• Cool weather - needed for germination of sclerotia and hyphal growth
• Mycelium - encounters a host root, the fungus will form appresoria 
• Mycelium can grow outwards from the roots of one plant to the roots of a adjacent  plant

• Rotating out of Allium crops for ten years 
• Destroying infected tissue
• Planting disease - free seed stock
• Seed dressing with benomyl or carbendazim(100-150g/kg of seed)