Winter oats have few grass-weed and broad-leaved herbicide options but growers are able to use the residual and contact-acting herbicide SumiMax which has an Extension of Authorisation for Minor Use (EAMU) for use in this increasingly popular crop.
Applied at 100 ml/hectare in a minimum water volume of 200 litres per hectare, SumiMax which contains flumioxazin, can be sprayed pre-crop emergence in all varieties of winter oats for the control of annual meadow-grass and a wide range of broad-leaved weeds including charlock, chickweed, cleavers, common field speedwell, common poppy, field pansy, fumitory, groundsel, ivy-leaved speedwell, mayweed and red deadnettle. It can also offer good control of black-grass and rye-grass. In independent trials it has shown good weed control when applied pre-emergence in oats versus flupyrsulfuron-methyl applied early post-emergence.
When using SumiMax, it is important that a proprietary tank cleaner should be used both before and after spraying to thoroughly clean all spray equipment, including booms, pumps, filters and lids.
Winter oats are a good break crop with a strong market demand. Its ideal drilling window is from mid-September to mid-October and early removal of grass and broad-leaved weeds is advised. SumiMax adds to the restricted range of herbicides that can be used in winter oats. It is a novel herbicide with a different mode of action, which is required in oats where grass-weed resistance can be a problem. It is also an easy to use product with no following crops or cultivation restrictions, making it easy to integrate with other autumn or spring-applied herbicides.
It integrates well into black-grass control programmes. SumiMax is compatible with a wide range of autumn products, but should not be mixed with any adjuvants or pendimethalin containing products. It can be sequenced with any product including sulphonylureas, a limited number of which are recommended in winter oats, but a 14 day interval should be allowed.
SumiMax contains 300 gms ai/litre flumioxazin, formulated as a white, non-staining, easy-to-use suspension concentrate, packed in a 500 ml pack. In addition to the EAMU for oats, it is also recommended in winter wheat, where unlike in winter oats, it can be used pre or post-emergence for the control of a wide range of broad-leaved weeds, including charlock, chickweed, cleavers, common field speedwell, common poppy, field pansy, fumitory, groundsel, ivy-leaved speedwell, mayweed, red deadnettle and Shepherd’s purse, and grass-weeds, including annual meadow-grass.
For any EAMU, growers should obtain a copy of the notice of approval via the Chemicals Regulation Directorate (CRD) web site, ADAS offices or NFU. In the EAMU notice of approval, CRD point out that liability lies with the user and growers are advised to test a small area of crop prior to commercial use.
