VN05010 Folicur - alternative carriers

Onion white rot, Sclerotium cepivorum, is the most widespread and destructive disease affecting onions and other Allium crops.

This persistent, soil-borne fungus has been known to cause complete crop loss, and is found in most onion growing regions in Australia.

In 1990s, Folicur-lime super was found to be the most effective treatment for white rot control. This resulted its registered use in Tasmania.

Growers in Tasmania rely solely on Folicur-lime super, applied at sowing for white rot control.

Lime super production stop in 2007, other alternative carriers must be considered.

Increased white rot incidence observed in recent years, raising concerns on the efficacy of Folicur.

Efficacy of Folicur

� No fungicide resistant isolates

� No enhanced degradation in soils

Fungicide options

� Bayfidan � effective at 1.5 L/ha but phytotoxic at sowing

� Folicur � effective at 1.0 L/ha & not phytotoxic at sowing

� SR tebuconazole � need fine tuning with slow release formulation

Recommendations

� Folicur-single super � effective in preventing/reducing white rot ~ $270/ha

� Folicur-bentonite � estimated cost ~ $150/ha when applied at 20 kg/ha though must apply with Gandy applicator

Acknowledgments

Funding from the Australian government through Horticulture Australia Limited, Australian vegetable growers, Tasmanian pyrethrum growers, Botanical Resources Australia Pty Ltd and Nufarm Australia Limited are gratefully acknowledged.

Many people and organisations provided assistance to make this research possible including:

� Research facilitated by Horticulture Australia Ltd and Onion Australia

�  Levy from onion growers and matching funds from the Australian Government through Horticulture Australia Ltd

� Bayer CropScience Pty Ltd for chemical analysis

� Anthony Flynn of Eureka! AgResearch on alternative carriers

� Support from Ernie Burglund, Lyndon Butler, Harvest Moon, Premium Fresh Tasmania, Webster Fresh, Impact Fertilisers and Incitec Pivot