Check the labels for following-crop restrictions when controlling cleavers with ALS-inhibitor herbicide sequences using Atlantis and Pacifica in cereal crops.
With over half of UK growers using some form of minimal tillage, and many having to control blackgrass, a high proportion of growers will use Atlantis or Pacifica in sequence with specific cleavers herbicides.
"ALS-inhibitor herbicides have restrictions on following broad-leaved crops in these sequences," explains Dow's technical services leader David Roberts. "Some are not approved, or don't have manufacturer support. Others require additional cultivations to when Atlantis is used alone."
Therefore, choosing the right herbicide is essential to avoid checks to following winter rape crops. It will also avoid costly, time-consuming cultivations. And for those who have used minimal tillage for several years, it will be important not to deep cultivate and remove benefits already gained.
Min-till expert Steve Townsend advises that the optimum depth for minimal tillage cultivations is between 5 and 10 cm. "Cultivations any deeper than this will disturb the valuable biological activity in the top 5 cm gained over several years of minimal tillage. Cultivating deeper than 10 cm will kill the majority of beneficial deep-burrowing earthworms that are a crucial part of maintaining natural drainage."
Cleavers herbicides that can be sequenced, and allow winter oilseed rape as a following crop, will require autumn seedbed cultivations to be at least 15 cm deep when Atlantis is applied in spring, rather than the 6 cm required after autumn/winter Atlantis application.
The only specific cleavers herbicides allowed in sequence with Atlantis without additional cultivation requirements are CMPP, CMPP-based products, Platform S, Boxer (florasulam), Starane 2 (fluroxypyr) and Starane XL (fluroxypyr + florasulam).
Products based on mecoprop are not encouraged due to possible water contamination problems. They also struggle to match the cleavers control achieved by Starane and Boxer.
"Starane XL can be used safely in tank mix with Atlantis, or in sequence with Atlantis or Pacifica applications. There is no need for any additional cultivations to those required when Atlantis or Pacifica are used alone, irrespective of application timing. The combination of fluroxypyr and florasulam in Starane XL provides excellent cleavers control over a wide temperature range up to GS 45 in cereals," says Mr Roberts.
