January window for weed control in oilseed rape
Whilst many growers struggled to get their winter oilseed rape herbicides on last autumn, the New Year, and January in particular, offers a key application window for the effective residual herbicide, propyzamide in order to control grass-weeds and deal with resistance issues, says Interfarm UK Ltd.
Dr. David Stormonth, Technical Manager of Interfarm UK Ltd, points out that opportunities to control black-grass and other weeds last autumn were very much reduced. "We had difficult and extended plantings of oilseed rape and then the weather conditions were too wet to travel and too warm for applying residuals. After Christmas, oilseed rape growers have a short but ideal weed control window during January. Trials and commercial experience show that effective weed control can still be achieved from applications of propyzamide right up to the end of the month and this opportunity shouldn’t be missed."
"Propyzamide, as in Flomide or Engage, remains one of the most highly effective herbicides against black-grass and can be applied up to the end of January, importantly even in frosty weather. Lower temperatures will mean longer persistence, as degradation of the herbicide in the soil is temperature-related. Propyzamide works well at lower temperatures, but when it is colder the weed control symptoms will logically take longer to be seen. Excessively wet soils should be avoided, particularly if surface water run-off is likely to occur," advises Dr. Stormonth.
David points out that growers may want to consider combining Flomide or Engage with a contact-acting graminicide if the grass-weed target is larger, as is normally the case at this stage. "Whilst there is no black-grass resistance to propyzamide, control is reliant on the product reaching the weed’s root system. The combination of propyzamide and a fop/dim type graminicide often results in surprisingly good control, even if the black-grass is known to exhibit fop/dim resistance. This mix will need checking with regard to weed size and also the graminicide label recommendations, but it will enhance grass-weed control. In recent trials on a range of resistant weed strains, propyzamide has still achieved total control. A suitable fungicide can be added to this mixture, optimising spray application costs."
"January is usually a dark and cold month, but it can offer growers an ideal opportunity to tackle the most serious grass-weed in UK agriculture," concludes David.
Propyzamide is available as Engage (50% WP) and Flomide (400g/L SC). Both are recommended for the control of cereal volunteers, annual meadow-grass, black-grass, brome, wild-oats, chickweed, bindweed, fat hen, redshank, small nettle, speedwells and black nightshade. In oilseed rape, Engage is recommended at 1.4 kg or 1.7 kg/ha and Flomide at 1.7 l/ha or 2.1 l/ha. Engage and Flomide are compatible with pyrethroid insecticides, graminicides and relevant fungicides including Quell Flo (mancozeb).
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
