Fungicide withholding periods for straw and post-harvest grazing in ryegrass seed crops
Be aware of your obligations when trading straw which has been treated with fungicides for the control of disease e.g. stem rust (Puccinia graminis subsp. graminicola). This is of particular importance in crops where the residue (or seed/grain) may be used as animal feed.
When products are registered through ACVM (Agricultural Compounds & Veterinary Medicines) legislation, they are required to include withholding periods for both re-entry of livestock to the paddock where treatment has occurred and for the use of forage (straw) to prevent accumulation of fungicide residues in livestock.
As harvest approaches, carefully consider your options if fungicides have been applied. Options are:
- If fungicide has been applied that contravenes the withholding period, either burn or incorporate all crop straw and seed, ensuring livestock cannot ingest crop residues.
- Undertake a fungicide residue test, at your own cost, to ensure residues are at or below the maximum residue limit (MRL) for the product.
Remember: For all fungicide products, harvest is considered as cutting, not threshing.
Interpretation of the labels for the main fungicides used in ryegrass seed crops.
Opus®
Label withholding period:
- Do not harvest ryegrass seed crops within 21 days of last application. This withholding period means that the ryegrass seed crop should not be cut or direct headed within 21 days of the last Opus application.
2Allow 35 days from last application until re-entry of stock for grazing. This withholding period means that livestock can re-enter the seed crop 35 days after the final application as long as the combined or cut straw has been removed from the paddock. i.e. last application approx. mid head emergence and prior to flowering.
Proline®
Label withholding period:
- Ryegrass seed crops 14 days. This with-holding period means that livestock can re-enter the seed crop 14 days after the final application as long as the combined or cut straw has been removed from the paddock.
- Ryegrass forage 35 days. In seed crops this means that the straw from seed crops cannot be feed to livestock unless the final application was 35 days prior to cutting i.e. last application approx. mid head emergence and prior to flowering.
Comet®
Label withholding period: Do not harvest ryegrass seed crops within 21 days of last application.
- This withholding period means that the ryegrass seed crop should not be cut or direct headed within 21 days of the last Comet application. The Comet® label states a final application at the end of flowering, Zadoks GS 69.
- Allow 35 days from last application until re-entry of stock for grazing. This withholding period means that livestock can re-enter the seed crop 35 days after the final application as long as the combined or cut straw has been removed from the paddock. i.e. last application approx. mid head emergence and prior to flowering.
Amistar®
- Green feed / silage from ryegrass seed crops: 28 days. This with-holding period means that sheep can re-enter the seed crop 28 days after the final application.
- Grain crops: 35 days. In seed crops this means that the straw from seed crops cannot be feed to livestock unless the final application was 35 days prior to cutting i.e. last application approx. mid head emergence and prior to flowering.
Seguris Flexi®
Label withholding period:
- Ryegrass seed crops: 14 days. Seguris Flexi can be applied up to 14 days before cutting with no issues associated with grazing re-growth or feeding crop residue.