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Biological control of allium white rot. - HH1828SFV

Sclerotium cepivorum causing white rot disease in Alliums is the major soil-borne pathogen of onions and leeks in the UK. Currently there are no effective cultural and chemical controls for this pathogen and no disease resistence exists in commercially available cultivars. Consiquently, the aim of this project is to identify and begin to develop alternative biological disease control methods targeted at susceptible periods of the life-cycle of the fungus. Several potential biocontrol agents (BCAs) of S. cepivorum have been identified and activity of these BCAs will be confirmed against a range of different white rot isolatess in soil types used for onion cultivation. The effect of timing of application of BCAs on control of white rot on onion will be assessed in small scale field trials at HRI Wellesbourne. In addition, the feasability of combining reported resistance to Allium white rot in specific onion accessions with BCAs, to enhance white rot control, will be determined in glasshouse bioassays.

This work relates to MAFF policy objectives of reducing pesticide usage considered environmentally desirable and would conform to customer demand for reduced pesticide levels in food.

The data will identify stages in the life cycle of the fungus when it is susceptible to control by BCAs abd will aid subsequent development of startegies for successful biological control of Allium white rot.
1. Determine the effect of sclerotium source on the activity of potential biocontrol agents (BCAs) of Allium white rot.
2. Determine the effect of soil types used in onion cultivation on activity of potential BCAs of Allium white rot.
3. Identify additional microorganisms with potential for biological control of Allium white rot.
4. Examine the effect of timing of application of potential BCAs on control of Allium white rot disease and sclerotial replenishment in the field.
5. Determine whether reported resistace to Allium white rot exists in specific onion accessions and can be combined with BCAs to enhance white rot control.
Project Documents
• Final Report : Biological control of allium white rot.   (2771k)
Time-Scale and Cost
From: 1999

To: 2002

Cost: £262,052
Contractor / Funded Organisations
Horticulture Research International
Biological Control              
Fields of Study