Winter weed control opportunities-there’s still time for flumioxazin
Unlike flufenacet-containing herbicides that can’t be used after the 31st of December, flumioxazin (SumiMax) has a growth stage cut off of 5 leaves on the main tiller, which means growers can continue to use it right through the winter, reminds Interfarm UK Ltd.
"Applying herbicides in wheat this autumn hasn’t been that easy. Early on it was too dry and some growers held off their pre-ems. Then it turned wet in many parts of the country and so applications of post-emergence herbicides were delayed and now with the cold weather Atlantis (mesosulfuron-methyl and iodosulfuron-methyl-sodium) applications are being planned for the early spring when the crop and weeds are actively growing. The good news is that growers still have the opportunity to use the contact and residual acting herbicide flumioxazin (FMX), as in SumiMax, during January and February. FMX, which offers excellent control of broad-leaved weeds and valuable control of annual meadow-grass, rye-grass and black-grass, works best when applied post-emergence. This is normally from November onwards but can stretch well into the early part of the New Year, particularly for later sown crops," says Dr. David Stormonth, Technical Manager for Interfarm UK Ltd.
"At the start of the new year, many weed control recommendations that were made in the autumn will have to be reconsidered. The autumn didn’t present many spray opportunities, but the early New Year may well do so. There are many crops out there still to receive an herbicide," says Dr. Stormonth.
He advises growers to use a robust "holding" spray such as flumioxazin until the weed control programme is completed at the beginning of spring with relevant post-em treatments when conditions are more appropriate. "SumiMax can be the residual pre-treatment before later treatments of products for black-grass, wild-oats, rye-grass or brome. Not being an ALS inhibitor means that SumiMax can sequenced with just about any other relevant herbicide."
"SumiMax can be used well into the New Year as its cut-off is according to crop Growth Stage - before five leaves on the main tiller. It is worth reminding growers and advisors that other herbicides, such as those containing flufenacet, have an end of December cut-off date for use."
"Flumioxazin works well in the cool and moist winter conditions. The cold weather more recently has meant that crops have hardened off well, just right for application. As is the case for most post-emergence herbicides, it is best to avoid soft or lush crops, waterlogged crops or crops under stress. The use of a tank cleaner is recommended after spraying."
"Ideally weeds should be between 1-3 leaves at application. But the timing for broad-leaved weed control is not as critical as SumiMax controls a full range of broad-leaved weeds from germination to the 4-6 leaf stage, depending on the species. It has an excellent broad-leaved weed spectrum including charlock, chickweed, cleavers, poppy, field pansy, fumitory, groundsel, speedwell, mayweed, red deadnettle and Shepherd’s purse," David says.
Where grass-weeds are an issue, SumiMax can be tank-mixed with a suitable graminicide in order to strengthen its grass-weed control. "Applied at the 1-2 leaf stage, SumiMax will give control of 90% plus of Annual Meadow-grass on its own. It will also give a good effect on black-grass. If weed populations are particularly high or if conditions are marginal, you can always add in a low rate of chlorotoluron after the 31st of December," advises David.
For further comment and information, please contact Dr. David Stormonth, Technical Manager, Interfarm UK Ltd. on 01354 741414 or 07818 036506 (mobile) or via e-mail david.stormonth@interfarm.co.uk
SumiMax contains 300 gms ai/litre flumioxazin, formulated as a white, non-staining, easy-to-use suspension concentrate, packed in a 500 ml pack. Recommended in winter wheat, it can be used pre or post-emergence up to before GS 15 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 and loose silky bent. It is recommended at 100 ml/ha in 200 litres of water, with one application per crop. It has residual and contact activity.
It is compatible with a wide range of autumn products but should not be used with any adjuvants or pendimethalin. It can be sequenced with any product including sulphonylureas, but a 14 day interval should be allowed. Don’t forget the use of a proprietary tank cleaner after spraying to thoroughly clean all spray equipment, including booms, pumps, filters and lids.
Flumioxazin is available as SumiMax, Digital and Guillotine.
