’Biofumigants’ to help beat the wilt

Poor farmers in developing countries could soon be using a range of ’biofumigant’ plants to help increase tropical vegetable yields.

CSIRO is part of a research team from Australia and the Philippines which has found that brassica species such as radish, mustard or broccoli can be used to help reduce yield losses from Bacterial Wilt – the major pathogen of vegetables in tropical farming.

“Brassicas contain compounds that suppress pests and pathogens, principally isothiocyanates (ITCs),” says CSIRO Plant Industry researcher, Dr John Kirkegaard.

“When ITCs are released by manuring, soil-borne pests and pathogens are suppressed and yields of solanaceous vegetables such as potatoes, tomatoes and eggplants can be increased by up to 40 per cent. The effect is known as ’biofumigation’.”

The project has already evaluated brassica species and management techniques with the aim of maximising the biofumigant effect. Current field trials in the Philippines and in North Queensland are examining ways of making biofumigation practical and effective for developing countries.

Using brassicas to manage soil-borne pests is not new – there are many previous reports of disease suppression – but new insights and techniques to measure the processes involved in the release of chemicals in soil has provided opportunities to enhance the reliability of the effect.

“The project builds on that research and is making it practical for small-scale farmers around the world,” Dr Kirkegaard says.

“There are economic and social benefits for small-scale farmers, as improved crop yields lead to increased incomes. There are also a range of environmental and health benefits, as a result of reduced reliance on toxic fumigants and synthetic pesticides.

“The next stage of the project seeks farmer involvement to integrate biofumigation into the cropping system, using farming networks throughout South-East Asia and the Pacific.”

The team includes researchers from CSIRO Plant Industry, the Queensland Department of Primary Industry and the Philippines National Crop Protection Centre. The project is funded by the Australian Centre for International Agricultural Research (ACIAR).

More information
Dr John Kirkegaard, CSIRO Plant Industry, 02 6246 5095
Email: john.kirkegaard@csiro.au