Nearly two-thirds of potatoes receive metribuzin as their mainstay herbicide for broad-leaved and Meadow-grass control and Sencorex Flow is an easy to use flowable formulation of this established active ingredient, controlling most of the difficult weeds found in potatoes.

Stuart Sutherland of Nufarm explains that; “Sencorex Flow is a 600 g/l advanced suspension concentrate recommended in first earlies, second earlies and maincrop potatoes, with an EAMU in outdoor ornamentals. Its unique formulation technology has been demonstrated to lift its efficacy to a higher level. Comparative data from a wide number of trials with the old WDG and new SC shows that the same level of weed control was achieved by using the same rate eg 0.75l/ha of the new SC equalled or exceeded 0.75 kg/ha of WDG. This is because the SC formulation has a much smaller particle size than the WDG’s, making it a better and more efficacious formulation. Sencorex Flow is approved at the dose rate of 0.85 l/ha on first and second earlies on very light or light soils and at 1.15 litre/ha for main crop. The higher 1.15 l/ha dose rate applies to earlies on medium, heavy organic or peaty soils. The SC is also better from the spray operator’s perspective with no dust. It is also easy to pour and mix. Most potato growers will mix it with either a contact or another residual herbicide, such as linuron.”

“This more efficient formulation has greater flexibility and better weed control than other metribuzins which are restricted to a lower maximum dose rate of 0.75 kg/ha,” he explained.

Stuart reports metribuzin in Sencorex has been the foundation active ingredient of any weed control programme in potatoes for many years. “With the loss of actives such as paraquat and the dose rate restrictions of linuron down to 600 gm a.i./hectare, growers have had to look for cost-effective alternatives for weed control. Sencorex has become even more important as it is a flexible and effective herbicide with both contact and residual activity. It is also a flexible active that can be tank mixed with others to make up the right combination for your weed spectrum on the farm. According to the Pesticide Usage Survey for Arable crops in 2014, 66% of potatoes grown received metribuzin in some form or another – nearly 93,000 hectares were treated.”

Sencorex controls most common spring-germinating weeds in potatoes, including most polygonums, mayweeds, small nettle, common poppy, speedwells and smooth sowthistle. It has good grass-weed activity on black-grass, annual meadow-grass and rye-grass. “Other locally important weeds such as fumitory and hemp nettle are also controlled,” said Stuart.

It can be applied pre-planting, pre-emergence and post-emergence depending on variety and weed target. “Growers must check the variety list, which is continually updated, with their local Nufarm contact or with their distributor, to make sure it is safe to apply Sencorex Flow to specific varieties on specific soils at specific times,” he advised.

“Sencorex is a foundation product, proven in most weed control programmes. It gives broad spectrum weed control and combined contact and residual activity and in my mind it would be difficult to see anything replacing it in the near future,” said Stuart.