27 March 2014 02:18:56 27 March 2014 02:18:56 |
Focus on cleavers when planning spring weed control
Growers need to focus on weeds that are the most competitive or cause the most problems 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 much more competitive than even black-grass. They also are a real nuisance at harvest, interfering with combining and increasing overall cost of harvest. They produce high seed numbers per metre², around 320 seeds per plant, and, if left unchecked, will perpetuate the problem by adding to the seed bank. You can’t afford to ignore them,” says Stewart Woodhead, Technical Manager for Interfarm UK Ltd.“Even though pre-emergence residuals were applied last autumn, the lingering wet conditions from autumn through to winter and into the spring will mean that the length of their residual activity could be shortened. Generally grass-weed herbicides do not control cleavers that well. This could leave quite a few cleaver plants uncontrolled from the autumn, adding to the spring germinators,” explains Stewart.“Because it controls cleavers so well, along with charlock, runch, volunteer rape, Shepherd’s-purse and field forget-me-not, we are expecting the contact-acting Eagle (amidosulfuron) to be regarded as an essential part of this spring’s weed control programme in both cereals and linseed,” he says. Interfarm is the sole marketing company for this herbicide in the UK.Applied from the 1st of February, Eagle has label recommendations for use in winter wheat, winter barley, winter rye, winter linseed, oats, triticale, spring wheat, spring barley and spring linseed. “It is one of the few fully recommended herbicides for spring linseed as well being registered for the majority of major and minor cereals. There will be many spray opportunities for this herbicide in both winter-sown crops or in spring-sown crops in the next few months,” points out Stewart.Eagle can be applied to winter or spring cereals from the 1st February onwards and from crop growth stage GS 12 (two leaves) up to and including first awns just visible (GS49). In linseed the spray window is from the 1st February and with crop growth stage of first pair of leaves unfolded up to before flower buds visible. “In practical terms this is a wide window of application, but weeds should be actively growing,” he says.Eagle has flexible dose rates, mainly according to the weed size. In cereals when cleavers are up to 15 cms across, the dose rate is 30 gms/ha and when mixed with certain other herbicides which have some cleaver activity themselves, such as Atlantis WG, Hatra, Horus, Othello and Pacifica, the dose rate is 15 to 20 gms/ha. In cereals if cleavers are over 15 cms across or for any weed size in linseed, the full dose rate of 40 gms/hectare is recommended. For grass-weed and broad-leaved weed control in wheat, it can be tank-mixed or sequenced with Atlantis WG, Hatra/Horus, Pacifica and Othello. For best results and maximum crop safety, it is advised to tank-mix Eagle with only one of the grass-weed herbicides listed and Biopower. It 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. This marketing arrangement between Interfarm UK and Bayer CropScience UK is part of an on-going distribution strategy within the UK.
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