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Integrated of biological control agents for sustainable control of Allium white rot - HH3204SFV

Sclerotium cepivorum causing white rot disease of Alliums is the major soil-borne pathogen of onions and leeks in the UK. Currently, there are no effective cultural controls for this pathogen and chemical control is limited to off-label seed and foliar treatment with tebuconazole which sometimes results in phytotoxicity. Indeed, loss of the soils due to infestation with this pathogen has, in some cases, forced onion growing into less suitable soils and climates for growing high quality produce. No didease resistance exists in commercially available cultivars. Nevertheless, some resistance may be present in specific onion accessions and three Trichoderma isolates have been identified as potential bio-control agents (BCA) of allium whie rot with activity against a range of Sclerotium cepivorum isolates. Thus the main project aim will be to examine the possibilty of combining the host resistance present in some species of Allium with BCA treatment to provide enhanced, or at least additive, levels of disease control in comparison with either used alone. The potential for integration of BCAs with tebuconazole treatment and with composted onion waste will also be considered. The activity of BCAs against the pathogen will als be examined over a range of temperatures and water availabilities found under UK onion growing conditions.

The intended use of this project is to develop alternative, integrated, biologically-based sustainable control methods for this disease.
1) Determine the effect of soik water potential on activity of potential biocontrol agents of allium white rot.
2) Assess the effect of temperature on the activity of potential BCAs of Allium white rot.
3) Examine the effect on white rot if combining known BCAs with both onion accession exhibiting resistance to white rot and similar commercially available onion cultivars.
4) Examine the effect on white rot of combining known BCAs with tebuconazole treatment.
5) Examine the effect on white rot of combining known BCAs with onion waste compost.
Project Documents
• Final Report : HH3204 Final report   (375k)
Time-Scale and Cost
From: 2002

To: 2005

Cost: £293,606
Contractor / Funded Organisations
Warwick - HRI, Horticulture Research International
Biological Control              
Crop Diseases              
Disease Control              
Organic Farming              
Sustainable Farming and Food              
Sustainable Production              
Fields of Study