WITH THE pressure mounting on growers to minimise overheads and focus on targeted and strategic herbicide applications to maximise efficacy, the arrival of a new, broad spectrum herbicide from Dupont, has been welcomed by Scottish agronomist, Iain Learmonth.

He advises for Gardiner ICM, part of the Hutchinson Group and is a onsultant on more than 9000ha, where he is responsible for the agronomy on mainly arable rotations, on a fertile ribbon of land stretching from just North of Aberdeen to the Black Isle.

With winter cereals constituting the bulk of his cropping and oilseed rape and potatoes as a break, the ability to successfully control aggressive populations of cleavers and groundsel and, potentially ALS resistant populations of chickweed and mayweed, has become even more important since the demise of IPU as a reliable source of autumn weed control.

Since then, pre and early post-emergence mixtures containing pendimethalin and diflufenican have afforded satisfactory control, he says. But, limited weather opportunities for spring applications, coupled with increased suspected ALS resistance to some SUs, means that chickweed often slips through the net.

“I find myself recommending at least one extra application post GS 32 to clean up the crop,” he said.

The new, revolutionary, combination of metsulfuron-methyl, thifensulfuron-methyl and fluroxpyr in Provalia LQM is set to dictate the spring broadleaved weed control strategy for many this year.

Having successfully trialled Provalia LQM last season, he is delighted with its performance against well-established weeds, under rapid and competitive growth conditions.

“Using Provalia on our trial acreage in both winter wheat and barley demonstrated that, post-GS32, substantial winter-hardened and normally difficult to control, cleavers, chickweed and groundsel were successfully killed with rapid dieback. This effectively negated competition with the crop at a crucial phase following the emergence of leaf three, where nitrogen uptake, water and light interception become increasingly important.”

With a spectrum of more than 40 weed species, Provalia looks set to account for a large portion of his herbicide recommendations this coming spring.

“It won’t be used exclusively,” he said. “But prescriptive and well-targeted applications from GS32 to GS39 will mean that the headache of dealing with those aggressive and hugely competitive populations that have slipped through the autumn herbicide net, can be dealt with effectively."

Although grassweeds are not a major problem in Mr Learmonth’s area, he is convinced that further south, where resistant and aggressive populations of blackgrass are the main target species, the unique ability to sequence this innovative product will make it a popular choice for this spring with excellent flexibility.

“It’s going to be a useful tool for our armoury,” he added. “If we encounter a difficult spring with challenging conditions, I am confident we can combine both efficacy with cost effectiveness, using this product.”