After a season when sugar beet crops were ravaged by virus yellows, growers will be doing everything possible to help speed growth and propel crops towards adult plant resistance.
David Allison, Frontier Agriculture sugar beet crop protection specialist, says: “Recent conversations about sugar beet have been dominated by virus yellows.
This is understandable, but it shouldn’t distract from the need to consider weed control without desmedipham.
“For more than a generation, the likes of Betanal maxxPro and other desmedipham-containing products made weed control easy.
These products delivered a broad-spectrum of activity and high crop safety.
Without desmedipham weed control at the pre-emergence stage will need to be better and the first post-emergence application delayed until the crop is at the expanded cotyledon stage.
This may involve more regular inspections if the spray is to be well timed,” he adds.
Although strategies will need to evolve in response, growers should not despair, says Mr Allison.
“It is important to consider how programmes can be adapted to avoid placing undue pressure on phenmedipham and ethofumesate.
On land known to harbour a high weed burden, a pre-drilling application of Roundup [glyphosate] may be the best policy, while a robust residual will almost certainly be necessary to provide control through until the first post-em spray can be applied.”
For some growers there will be the temptation to return to straights, but the workload these exert on the sprayer operator mean this is unlikely to be the favoured approach of many.
For those who prefer the convenience of a formulated product, there is a choice of Betanal Tandem or Powertwin, both containing phenmedipham + ethofumesate, but in many situations, these will need a residual such as metamitron to bolster control, Mr Allison says.
Last year, the introduction of varieties tolerant to the acetolactate synthase (ALS) group of herbicides introduced a new weed control system under the Conviso Smart brand.
This promised to simplify weed control while expanding the range of weed species which could be reliably controlled.
“The loss of desmedipham is perhaps the catalyst needed for growers to take a closer look at what Conviso Smart has to offer.
“It certainly adds to control but should not be used in isolation.
In my experience the Conviso One herbicide fits best at the end of a programme comprising classic herbicides of both a residual and contact nature,” Mr Allison adds.