Farmers and contractors are being urged to get ready to apply the residual granular herbicide Avadex Excel 15G this autumn as a key component of their black-grass control programme. Kuldip Mudhar, development manager for Gowan’s UK and Ireland business, reports that a well-timed application of Avadex Granules (tri-allate) should give, on average, an additional 15 to 20% control of black-grass. Many farmers who have used the product in the past have been happy with its contribution to the herbicide “stack”.
“We saw good levels of control with Avadex this year when used with either Crystal or Liberator as part of the stack. With low dormancy and high seed numbers likely, it will continue to be a challenge to achieve the highest levels of control again in the coming autumn. For best results Avadex Granules need to be applied correctly, pre-emergence of the crop and weed to a moist well-consolidated seedbed.”
Whilst the pre-emergence timing is critical, it is vital to ensure the accuracy of the application. Kuldip suggests that any Avadex Granules applicator must be calibrated before the season and recommends a patternation test along with the normal calibration to ensure evenness of application across the boom width.
Avadex Granules can be used on winter wheat, winter barley and spring barley. “More Avadex than ever before went out onto farm last year, as many more growers see it as one of the key actives as part of the pre-em herbicides. It fulfils a key role in the control of difficult-to-control grass-weeds such as black-grass, wild-oats and Italian Ryegrass and should be considered in any brome control programmes. It also offers some common broad-leaved weed control, including speedwells, cleavers, chickweed, mayweeds and poppy. Farmers are keen to integrate this valuable active ingredient into their weed control programme in both winter and spring crops,” he says.
“We also know that Avadex Excel 15G is a robust residual when it comes to dry conditions. Herbicide expert John Cussans of NIABTAG several years ago reported that there are differences between herbicides when it comes to performance under dry conditions.
“He looked at several physical and chemical criteria including Vapour Pressure and Henry’s Constant (dimensionless) to help predict herbicide activity in dry soils. Unfortunately this information confirms field results that flufenacet, the bedrock of all pre-em programmes, is vulnerable to dry conditions, as is DFF and chlorotoluron. Prosulfocarb and flupyrsulfuron are a little less vulnerable and pendimethalin less so. The efficacy of tri-allate is the least affected by dry conditions.”
“Extreme dry conditions will be difficult for any residual herbicide to work effectively therefore for Avadex Granules it is imperative that it is given the best chance to work – a well timed and accurate application,” says Kuldip.