Onion (Allium cepa) is an important horticultural crop which is cultivated by every agricultural nation in the world with an annual production of 78.5M tonnes and a value of £9,500M. It is the second most valuable vegetable crop in the world behind the tomato and in the UK, production is valued at approx. £110M per year. Onions are a staple crop and deliver a range of health benefits including anticarcinogenic, antithrombotic and antibiotic effects.

Allium white rot (AWR) caused by the fungus Sclerotium cepivorum is a major soilborne disease of onions and other Allium crops. The disease is very difficult to control as the pathogen forms long-lived survival structures known as sclerotia which remain in the soil for decades. These sclerotia germinate and infect roots through hyphae in response to specific chemical compounds released from onion roots. This results in wilting and subsequent plant death during the growing season with more sclerotia being produced and returned to the soil.

Research Projects

• Defra HH3230SFV: Factors affecting the inoculum potential of soilborne plant pathogens - completed
• HortLINK HL0176 LFV: Integrated Allium white rot control using composts and Trichoderma viride - completed
• Defra HH3204SFV: Integrated use of biological control agents for sustainable control of Allium white rot - completed