With sugar beet growers facing their first full season without desmedipham, 2021 could be the year in which the sector witnesses a resurgence in the use of metamitron and quinmerac-based pre-emergence herbicides such as Goltix (700g/l metamitron) and Goltix Titan (525g/l metamitron and 40g/l quinmerac).
That is according to Bill Lankford, herbicides technical specialist at ADAMA UK, who advises that as well as giving weed control an early season kickstart, the inclusion of a pre-emergence treatment as part of a sequenced herbicide programme can also boost crop yields by 7.5 to 21 tonnes per hectare.
“With desmedipham no longer available, sugar beet growers aren’t entirely able to depend on post-emergence treatments alone to achieve the necessary level of weed control,” Dr Lankford explains.
“Herbicide programmes will therefore need a little more thought this year. Unfortunately, the choice of pre-emergence herbicides is currently somewhat limited as a result of the revocation of chloridazon and the removal of pre-emergence usage from the lenacil label.
“Thankfully, Goltix and Goltix Titan are more than capable of filling the gap, with the inclusion of quinmerac in the latter providing excellent protection against several of the more difficult to control weeds such as cleavers, orache and bindweed.”
Because modern sugar beet varieties are so quick to germinate, pre-emergence herbicides should ideally be applied within 24-48 hours of drilling and certainly within an absolute maximum of five days post-drilling Dr Lankford adds.
Whilst Dr Lankford recognises there might be some reticence in terms of adding a pre-emergence treatment to spring herbicide programmes – due to the additional input cost, extra workload and the need for adequate soil moisture to make pre-ems work effectively – he believes that the pros often outweigh the cons: “Crucially, the inclusion of a pre-emergence treatment as part of a wider weed control programme can significantly improve final crop yields,” he explains.
“In fact, trials have shown that the addition of Goltix Titan at the beginning of a sequence of pre- and post-emergence treatments can contribute to yield improvements of 7.5t/ha to 21t/ha over untreated plots. That alone is enough to warrant its inclusion but there are other benefits as well, not least the ability to create some latitude in the timing of post-em treatments.”
Including a pre-emergence herbicide also offers potential advantages in terms of workload management: “Applying a pre-em to crops located far from the farm or to land where wet conditions will delay the application of a post-emergence treatment enables these crops to be protected ahead of time,” Bill adds.
“Similarly, using a pre-emergence treatment should also be considered on land with a high weed burden (either in terms of difficult to control species or sheer population of weeds) or on crops which may not receive a post-em treatment at the ideal timing due to contractor commitments.”
Goltix and Goltix Titan can also be used as early post-emergence treatment. For more information, visit www.adama.com/uk or speak to your agronomist.