VG05007 Onion White Rot – post plant fungicides

Evaluation of post-planting fungicide applications for control of onion white rot, Sclerotium cepivorum, on alliums, onions, leeks, garlic, chives, shallots, spring and salad onions.

Currently, fungicide is only applied to prevent early white rot disease, but there is no commercially effective program to extend crop protection until harvest. If widespread late infections occur, are fungicide applications useful ?

The objectives of this study was to evaluate & identify suitable fungicide options. and develop a post-plant foliar application program for Onion White Rot.

Fungicide options for post-plant applications

• Bayfidan – effective at 1.5 L/ha, no phytotoxicity

• Folicur – effective at 1.0 L/ha, no phytotoxicity

• Filan – depend on soil type, moisture, application method

Control Options :

• Pre-plant treatments to reduce inoculum including DADs, garlic powder, garlic granules
• At sowing treatments it is critical to apply Folicur-single super or Folicur-bentonite
• Post-plant treatments include :
  • Bayfidan at 1.5 L/ha   or
  • Folicur at 1 L/ha   or
  • Filan at 1 kg/ha
  • Low volume spray + irrigation or apply with carrier.

Acknowledgements :
Levy funding from onion growers and matching funds from the Australian government through Horticulture Australia Ltd

Voluntary contributions from Syngenta Crop Protection Pty Ltd, DuPont (Australia) Ltd, Bayer Crop Science Pty Ltd, BASF Australia Ltd and Nufarm Australia Ltd.