A new black-grass herbicide will be available to growers this coming spring. The herbicide Monolith (mesosulfuron + propoxycarbazone) boasts superior and more consistent levels of black-grass control in winter wheat crops.
Monolith gives a significant step up in black-grass control compared with its predecessor Atlantis WG (mesosulfuron + iodosulfuron). In trials, it provided an average of 10% more control of black-grass than Atlantis and has other useful features too, according to Ben Coombs, cereals herbicide campign manager for Bayer.
“First and foremost, it controls black-grass effectively, total control is on average 10% better than Atlantis,” he says. “But the trials results also show that Monolith is more consistent and overall control never dipped below 50% with Monolith.”
In 19 comparative trials, the control from Monolith ranged from 53–95% while, for Atlantis WG, it was 16–94%. All trials took place in fields with black-grass problems and reflect the kind of black-grass populations farmers have to deal with, including those with resistance.
“Herbicide resistance is a major concern for farmers, Atlantis performance has declined so they will want to know how Monolith changes the situation. The trial results already show it outperforms Atlantis for control and consistency on difficult populations. Secondly, the chemical composition of Monolith has two actives with grass-weed activity that support each other.”
Bayer developed Monolith specifically for grass weeds. It combines mesosulfuron which is found in Atlantis and propoxycarbazone which farmers know as Attribut. Both actives are highly-effective against grass weeds and formulated together they make a very potent tool for controlling black-grass and other common grass weeds such as brome, rye-grass and wild oats.
“We developed Monolith with black-grass in mind because this is the biggest problem for most farmers’ wheat crops. It controls other grass weeds but not most broad-leaved weeds which means growers can better target broad-leaved weed control where it is needed. As with any herbicide, it’s really important to use Monolith as part of a full programme of cultural controls and varied actives to both protect the product and to ensure the best results.”
Monolith is for spring application in winter wheat crops. It can be applied from 1 February and when the crop is at the first tiller stage until 2nd node detectable (GS21–32). Apart from the timing restrictions, application advice is similar to other Bayer post-emergence herbicides such as Atlantis WG.
Monolith is taken in by the leaves so it is essential to have active growth when it is applied. It is also more effective against plants at earlier growth stages so Bayer is encouraging people to treat their crops as soon as conditions allow. Monolith should be applied as a fine spray at 200 litres of water/ha and mixed with the adjuvant biopower (1L/ha).
While farmers are not likely to switch all their post-em programme to Monolith in one season Mr Coombs and Bayer are keen for farmers to try out the new herbicide. “For this season, we’d really encourage farmers who require post-emergence black-grass control to try Monolith on a few of their fields. In our trials, there were visual differences between the plots so we think you will be pleasantly surprised by the results.”
