Conditions are just right for post-em FMX

Crops have been hardened off, the weather is cooling down and weeds are still small and this means that conditions are just right for the post-emergence application of the contact and residual acting herbicide flumioxazin (FMX) in wheat, according to Dr. David Stormonth, Technical Manager for Interfarm UK Ltd.

Early post-emergence when the soil is moist and conditions are cool is the best time for Annual Meadow-grass control and difficult-to-control broad-leaved weeds such as cleavers, groundsel and poppies. "It is also the time when growers are used to applying an herbicide for these weeds. Growers no longer have IPU to fall back on, but they have a very useful alternative in FMX that will, in fact, give better control of Meadow-grass than IPU ever did - and at a low rate of just 100ml./ha."

Dr. Stormonth reports that trials and commercial use demonstrate that FMX, sold as SumiMax and Digital, performs very well on Annual Meadow-grass, giving 95% control on average, more consistently than IPU ever did. "For what I would call a ’normal’ Annual Meadow-grass population, FMX can be a stand-alone option. If weed populations are more challenging, add in a very low rate of just 0.1 l/ha of Liberator, which will raise control levels from 95% up to 100%. Or, if growing a tolerant wheat variety, you can mix with a low dose of chlorotoluron, but be careful with watercourses. You can also add in a pyrethroid, such as esfenvalerate (Sumi-Alpha), for BYDV prevention. A word of warning though – make sure that you start with a clean tank and finish with a clean tank. It is surprising how much residue of other products can be found in spray tanks from previous applications."

FMX has the widest weed spectrum of any current cereal herbicide, controlling a full range of weeds from germination to the 4-6 leaf stage. "With other herbicides that are no longer available, weeds such as poppy, groundsel and charlock used to be easy to control, and other common weeds such as chickweed and mayweed continue to be problematic. In trials, FMX applied early post-emergence, gave 100% control of charlock, chickweed, fumitory, field pansy, groundsel, ivy-leaved speedwell, mayweed and red deadnettle, 99% control of cleavers, common field speedwell and Shepherd’s purse and 98% control of poppy."

Dr. Stormonth explains that FMX can be used pre or post-emergence up to before GS 15. "GS 15 means when the crop has 5 leaves on the main tiller. This unusual growth stage limit was set by CRD, the registration authorities, even though crops with 5 leaves on the main tiller are usually described in the GS 20’s. What it means in practical terms is that FMX can be used throughout the autumn and winter during tillering."

David advises that crops need to be sufficiently hardened off for post-em treatments. "From the PPO inhibitor group, FMX has strong contact activity as well as residual activity. Crops need to be reasonably hardened to reduce any risk of foliar spotting. We have had some frosts in mid October so any crops emerged by then will be OK to treat. Given the recent cold spell most crops will be hardened now. Soft crops, lush crops, waterlogged crops or crops under stress should not be treated however. We already have had good reports of successful usage of FMX in central and southern counties, the Midlands and further north including Scotland."

Dr. David Stormonth urges growers to learn how to use FMX in their autumn weed control programmes as there are very few cereal herbicides in development. "The cost per hectare of FMX has been adjusted this season to make it more cost-effective, particularly for growers with Meadow-grass and broad-leaved weeds."

®SumiMax/Digital contains 300 gms ai/litre flumioxazin, formulated as a white, non-staining, 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 mixed with any adjuvants or with pendimethalin products. Nor should it be mixed with Defy post-emergence. It can be sequenced with any product including SU’s, but a 14 day interval should be allowed. Always use of a proprietary tank cleaner before and after spraying to thoroughly clean all spray equipment, including booms, pumps, filters and lids.