“Even though pre-emergence residual herbicide stacks were applied to winter cereals last autumn, as is standard practise, the dry September, the driest since records began, may have reduced their overall effectiveness and left cleavers and other broad-leaved weeds to grow on through the mild winter. In reality, these pre-em grass-weed herbicides may not have the overall ability to control cleavers that well anyway and certainly wouldn’t have the residual capacity to cover the entire germination period. This is especially so this autumn and winter, as mild conditions have allowed weeds to continue germinating and growing. This spring we will have both autumn and spring germinating cleavers to deal with,” explains Simon Bishop of Interfarm Ltd.
Simon believes that, in times when grain prices are on the gloomy side, growers should focus on weeds that cause the most problems, either in terms of yield erosion or at harvest. “Independent weed experts classify cleavers as the most aggressive weed in the arable rotation – 1.7 cleavers per metre² will cause a 5% yield loss. Cleavers are even more competitive than black-grass. They also are a real nuisance at harvest, interfering with combining and increasing the overall cost of harvest. They produce high seed numbers, around 320 seeds per plant, and, if left unchecked, these will add to the seed bank for the following crop.”
“The contact-acting herbicide Eagle (amidosulfuron) is one of the most effective cleaver killers available and because of this, it has become an essential component in many spring weed control programme. It also controls charlock, runch, volunteer rape, Shepherd’s-purse and field forget-me-not, none of which are easy to control. Advisors and farmers should consider using Eagle in winter cereals, when the weather warms up a bit and weeds start to grow. They should also consider their requirements for spring cereals. Both spring barley and spring wheat are expected to be planted in much greater areas this spring due to the Three Crop rule under the CAP greening policy and Eagle is approved for use in both these spring crops as well as spring linseed,” he says.
The label recommendations for Eagle include use in winter wheat, winter barley, winter rye, winter linseed, oats, triticale, spring wheat, spring barley and spring linseed, starting from the 1st of February. “It is one of the few fully recommended herbicides for spring linseed as well as being registered for the majority cereals,” Simon points out.
Eagle’s window of application fits in well with spring-applied herbicides such as Atlantis WG, Hatra/Horus, Pacifica and Othello. “Weeds need to be actively growing for both cleaver and grass-weed control, and tank-mixing is a sensible solution as it cuts the cost of application,” he says.
Eagle has flexible dose rates, according to size of the weed. In cereals when cleavers are up to 15 cms across, the dose rate is 30 gms/ha and when mixed with herbicides which have some cleaver activity themselves, such as Atlantis WG, Hatra, Horus, Othello and Pacifica, the dose rate can be reduced to 15 to 20 gms/ha. In cereals if cleavers are larger than 15 cms across or for any weed size in linseed, the full dose rate of 40 gms/hectare is recommended. Eagle should not be tank-mixed or used in sequence with any other ALS inhibiting herbicide unless the tank-mix or sequence is approved by CRD. Tank hygiene using All-Clear Extra or similar product is important.
Interfarm is the sole supplier for Eagle in the UK.
