“Controlling weeds in cover crops can be tricky, as there is usually a mix of desired plants, and potentially a lot of target weeds all growing up together,” says Dilwyn Harris, principal biologist for Dow AgroSciences.
“A broad spectrum treatment, such as Dow Shield 400, kills a wide range of weeds without harming the game cover, including kale, maize, millet, miscanthus, phacelia, cereals and stubble turnips. Buckwheat, quinoa and sorghum can suffer a set-back, but any damage will be slight and certainly not life-threatening.”
Dow AgroSciences, working with Oakbank Conservation based near Huntingdon in Cambridgeshire, has carried out trials to examine the best timing and dose rate of Dow Shield 400, in a number of ‘off the shelf’ game cover mixes.
The results showed that applications of between 0.25 L/ha and 0.5 L/ha at the 4-6 leaf stage of the game cover crops, gave high levels of weed control with minimal crop damage, particularly on slightly sensitive crop types like quinoa, compared to later applications.
Thistles a problem?
Where thistles are the main problem weed in game cover crops, spraying Thistlex at 1 L/ha will control them well.
Thistlex can also be used against thistles infesting grass margins being managed under agri-environment schemes, as long as the farmer achieves a derogation from Natural England first.
A number of Dow AgroSciences products have Extensions of Authorisation for Minor Use (EAMU) approval. These are:
• Dow Shield 400
• Kerb Flo
• Starane 2
• Starane XL
More information on weed control in game cover can be found in our Game Cover Crops Topic Sheet