Mode of spread and survival:
- Latent disease - although infection takes place in the field
- Softening of scales which take on a water soaked appearance
- Under moist conditions - greyish sporulating mycelial mat develops on the surface of the scales
- Fungus persists saprophytically on dead onion tissue, on humus in soil and as sclerotia near the surface of previous onion crop cells
- Sclerotia germinate in moist weather and produce conidia that are disseminated by air currents
- When conidia land on the onion necks that are cut or wounded they can geminate, penetrate and kill onion tissue
- Dusting the seed with benomyl at 1g/kg of seed
- Avoid excessive and late (after mid-July) applications of nitrogen
- Rapid and thorough drying directly after harvest
- Provide good ventilation for curing onions before storage
| | | |
| Dark water soaked areas | Sporulation | Neck rot |
