The spray window is still open for weed control in wheat
Even when the pre and peri-emergence spray window has closed, the spray window remains wide open for the contact and residual acting wheat herbicide, SumiMax which can be applied to wheat up to five true leaves on the main tiller.
"Conditions this autumn have meant that many pre-emergence herbicide applications were never made. Growers have been awaiting the post-emergence opportunities, but whilst conditions have been poor and travelling difficult, the opportunity to apply residual-only chemistry early post-emergence is also rapidly closing. SumiMax however which has both residual and contact activity gives these anxious growers the whole of the winter to get their weed control on. It can be used as a holding spray prior to any spring herbicide applications. This holding position will be mainly for grass-weeds as SumiMax controls a wide range of broad-leaved weeds to such a level that a spring follow-up treatments will be very unlikely," says Dr. David Stormonth, Technical Manager for Interfarm UK Ltd.
The herbicide SumiMax works particularly well in cool and moist conditions. "The cold weather means that crops have had the opportunity to harden off, an opportunity that they didn’t get last autumn. 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," he 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 however. If weed populations are particularly high or if conditions are marginal, you can always add in a low rate of isoproturon or chlorotoluron or a low rate of Liberator. The addition of 0.15 l/ha of Liberator to SumiMax gave 100% control of high populations of Meadow-grass in trials last year," advises David.
Dr. Stormonth points out that SumiMax can be a useful holding spray when it comes to black-grass control. "It seems unlikely that much Atlantis will be applied this side of Christmas, yet there is quite a bit of black-grass out there. SumiMax not only gives top level broad-leaved weed control but acts as the late autumn ’holding spray’ until the programme is completed at the beginning of spring. For high black-grass populations, a mix with chlorotoluron, IPU or Liberator can give excellent autumn/winter control until a spring treatment can be applied."
"SumiMax is very easy to integrate into any weed control programme, as it can be sequenced with any other herbicide or group and mixed with a wide range of grass-weed herbicides. It has no following crop restrictions or following cultivation issues. It is also easy to use having a low dose rate and being a liquid formulation" says David Stormonth.
David concludes by saying that cool moist conditions are ideal conditions for flumioxazin, contrasting to last autumn when it was too warm and crops were too lush. "Soil moisture will help move the product in the soil profile, with no danger of leaching. Cool conditions will make sure the crops are well hardened off whilst aiding the strong contact activity on weeds."
For further 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. (These features of SumiMax were reported in a survey as being of major benefit.) 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. It can be sequenced with any product including sulphonylureas, but a 14 day interval should be allowed. Flumioxazin is available as SumiMax, Digital and Guillotine.
