A helping hand for post-emergence herbicides

From drought to downpour and every scenario in between, it seems that every season comes with a new set of challenges for growers in the UK. Following a wet and waterlogged autumn/winter season, this spring is shaping up to be especially tough in terms of weed control. 

Tougher weed control this spring

Following months of heavy rain, many winter crops sown last autumn missed their usual pre-emergence herbicide treatment, while others have established poorly and lack the competitiveness needed to thrive – or even survive this spring. This means large, vigorous, overwintered weeds could be harder to control this spring, with herbicide coverage and uptake more challenging than ever. 

And it’s not just the lack of early treatment that’s a problem for autumn-sown crops. Lying dormant in wet soils over the winter, black-grass seeds now pose a higher germination threat than usual, something to look forward to when soils dry out in the spring. Worse still, having had the chance to grow and harden over the winter months, large weeds also have the potential to detoxify the herbicide; their tough, waxy cuticles making penetration with post-emergence herbicides ever more difficult. Without action, we are likely to see weeds gain the upper hand in many crops in the coming months

Requirements for effective control

Good post-emergence weed control typically depends on well-timed sprays applied to small weeds in good conditions. These ideal conditions are highly unlikely this year, as large, vigorous, overwintered weeds make coverage and uptake a great deal more difficult. Making a bad situation even worse, we are seeing herbicide resistance issues becoming more and more commonplace in post-emergence chemistry. This means that reducing weed populations to prevent seed return, by optimising the most effective herbicide products will be crucial to safeguard yields and long-term efforts towards sustainable weed control.

The most effective weed control programmes must therefore ensure optimum:

1. Contact – between the herbicide and the leaf
2. Retention – it shouldn’t bounce or run off the leaf
3. Penetration – taking the active ingredients into the leaf 

Unfortunately, most post-emergence herbicides are delivered in a tank-mix of around 95% water. Water has a high surface tension, meaning it doesn’t allow droplets to spread out and be retained easily, making it hard for the herbicide to penetrate the leaf cuticle. Working with a suitable adjuvant will help growers to get around these challenging issues.

Why Sorrento?

Now is the time to take back control of weeds. This spring, more than any other, growers will need to optimise herbicide delivery and performance and new adjuvant Sorrento, is designed to do just that.

Based on branched alkoxylated alcohol, Sorrento is suitable for use against a wide range of common and troublesome weeds, from those with tough, waxy leaves like Fat-Hen, to those with ‘hairy’ leaves like speedwells and brome – anywhere where droplets find it hard to penetrate the cell structure. Sorrento delivers exceptional wetting and spreading of spray droplets, aids retention and binding (perfect for grass-weeds), and penetrates leaf cuticles, meaning superior herbicide delivery to the site of action inside the leaf, resulting in faster kill and higher overall weed control. We have seen impressive results with Sorrento; in extensive replicated field trials, Sorrento enhanced herbicide performance in 51 out of 52 comparisons. In 33% of comparisons, the weed control benefit with Sorrento was statistically significant. In nearly all situations, Sorrento increased the speed of kill. 

Delivering faster and more effective weed control, Sorrento will be a welcome addition to herbicide programmes this spring, helping growers win the battle against weeds in autumn and spring-sown crops, helping to protect profitability and limit weed seed return.