Pricing of grassweed herbicide Hawk has been cut by 35%. The move brings it in line with pendimethalin and creates more opportunities to use it in autumn programmes.

Previous pricing had left Hawk too expensive to be considered, particularly in tank-mix with Atlantis, Syngenta’s Rod Burke admits, despite Hawk being the best partner for Atlantis in the firm’s trials.

“It is now an affordable price, similar to the pendimethalin mix.”

The price reduction, which should see Hawk costing about £12.50-£14/ha this season, will mean an increased role for the product this autumn, TAG agronomist David Parish says.

That includes using it in mix with IPU as a holding spray when no pre-emergence has been applied, as well as with Atlantis.
Technically Hawk is a better partner for Atlantis than residuals, such as pendimethalin, Mr Parish believes.

“More and more people are wondering what Stomp brings to the party [in the mix with Atlantis]. It is not the ideal timing for it – it really needs to be pre-emergence or very early post-emergence, and there is concern its activity could be waning.

“When you add it to Atlantis, the Atlantis is doing 95% of the work.” In contrast Hawk’s contact activity supports Atlantis much better, he says.

In TAG trials last season the mixture outperformed Atlantis plus Stomp, he points out. The average control across five trials where Atlantis + Stomp was applied in the autumn without any pre-emergence was 84%, which included one result that achieved only 40%. Atlantis + Hawk, in contrast, gave 99% control.

“Even if you take out the 40% result, the Stomp average was only 95% – good, but not good enough.”

Syngenta trials have shown similar results, Mr Burke says. Either with or without a pre-emergence spray Atlantis + Hawk has given both a higher average level of control and a more consistent performance.

Hawk’s renowned cold weather performance should give growers more confidence to apply Atlantis in the autumn, which is a key objective of many technical advisers this season, after spring application problems last year, Mr Burke says.

“There is a greater understanding of temperature effects on Atlantis now – it seems to work better going from warmer into cooler weather rather than the other way round.”

The key is for the blackgrass to be actively growing at application, Mr Parish notes.

He is unconcerned about applying two high-risk modes of action at the same time. “The principle of using as many different modes of action as you can is right. It is not going to guarantee you won’t get resistance, but hopefully it will delay it.”

The potential for double target site resistance – ie target site resistance to both fops and sulfonylureas is a concern for the future, he admits. “I don’t think this mix will speed up its development though.”

But growers with a history of repeated poor control from fops probably should not use the mix, he notes.