With the arrival of warmer weather, both spring and winter linseed crops are putting on growth nicely. This brings with it agronomic considerations that must be managed by those looking to win one of the three prestigious categories in the CPM/Premium Crops Great Linseed Challenge (see details at www.premiumcrops.com).
“The warm and windy weather will favour flax flea beetle, and this has been seen in spring crops,” notes Premium Crops agronomist Hannah Foxall. Symptoms are notches on the leaves and growers should spray when damage is seen with pyrethroid insecticides such as lambda-cyhalothrin and cypermethrin.
“More than one spray may be needed for control. Once it gets to around 5cm tall the crop should grow away from damage.”
That’s when post-emergence herbicides can be applied, she advises. “We’ve found Eagle (amidosulfuron), Maya (bromoxynil) and Basagran (bentazone) effective on broadleaf weeds. Centurion Max (clethodim) works well on grassweeds.”
The first dose of nitrogen should have been made to spring linseed, continues Hannah. “This should be just enough to ensure adequate crop height and canopy – put too much on and you’ll increase the risk of lodging. Apply the balance at green bud stage.”
Winter linseed crops are now growing away rapidly in the warmer weather. “Most crops are now in green bud stage and heading to flowering, but to keep the yield potential they must be managed carefully,” notes Hannah.
Herbicide applications should now be complete and the two-spray PGR programme must be applied as there’s a high risk of lodging. “The green bud stage is also the right timing for the remaining nitrogen to be applied to the crop. Aim for a total dressing of around 120kgN/ha, so take off whatever was applied at the first dose.”
Where fungicides with PGR activity have been applied, this should also keep disease in check, says Hannah. “A fungicide application at the end of flowering will be needed to keep the seed bolls clean of disease.”
June priorities:
- Monitor spring linseed for flax flea beetle
- First nitrogen dose to spring linseed
- PGR on winter linseed.
