A deeper dive into the new Broadway® Ultra herbicide which will debut on farms this spring.
A new herbicide with the ability to control a broad spectrum of grass and broad-leaved weeds was announced at the end of 2024. Broadway Ultra contains pyroxsulam and mesosulfuron which Corteva says is an upgrade from Broadway® Star as it brings annual meadow grass control onto the label.
Annual meadow grass is the most common grassweed in the UK, primarily germinating from April to November with a six-week lifecycle.
Seed remains viable in the soil for five years and it is hardy, tolerating waterlogging and heat stress.
Hugh Guinan, Cereal Herbicides Field Technical Manager for Corteva, said: “It thrives in fertile soils and is encouraged by min-till practices. While less competitive than other grassweeds, it does steal nitrogen from the soil.
“Perhaps the greatest issue annual meadow grass poses is increasing the moisture content of the straw at harvest which slows progress and affects quality.”
A higher presence of annual meadow grass would be expected where residual chemistry hasn’t been used or didn’t perform well.
Hugh added: “Populations are often high in winter cereal crops because many lifecycles can occur within the cropping cycle. The seedbank can also act as a reservoir, impacting more susceptible crops in the rotation where control may be more difficult.
“It remains to be seen what spring 2025 will look like, but the two wet autumns farmers experienced in 2022 and 2023 certainly optimised conditions for weeds to thrive.”
Broadway Ultra applied at 100g/ha, delivers 14 grams of active each of pyroxsulam and mesosulfuron in a wettable granule, arriving on farm in a 500g pack.
“Growers will know that pyroxsulam provides excellent grass weed control and captures a really wide spectrum of broad-leaved weeds too,” Hugh said.
“Cleavers, speedwell, mayweed and charlock can be taken out as well as some umbellifers and brassica weeds too.
“There is a synergistic effect with the mesosulfuron which brings in chickweed, sow thistle and shepherd’s purse, alongside meadow grasses. There is also anecdotal evidence of reasonable control of rat’s tail fescue.”
In Corteva trials, annual meadow grass control proved to be greater than products containing mesosulfuron and iodosulfuron.
Applications can be made to winter wheat and triticale from 1 January to the middle of May.
Growers should use it a rate of 100g/ha in combination with an adjuvant, Corteva says.
Hugh said: “It’s quite a wide window but we always advise growers to treat weeds early when they are small and actively growing.”
He added that the product could deliver the greatest benefit in wet or warm autumns when residual programmes have been compromised, leading to an increased presence of key grass and broad-leaved weeds to tidy up in the spring.
“The product is ideally suited to traditional rotations where meadow grasses and broad-leaved weeds are the driver,” Hugh said. “It also has a fit on lighter or organic soils and can be a used effectively on late drilled crops following sugar beet or potatoes where residuals may not have been applied.”
The tank-mix compatibility list is long, allowing sprayer operators a broad range of ALS joint applications, including combinations with Corteva ALS herbicides as well as those from other manufacturers.
A five-metre reduceable buffer zone should be used, and a spray tank washout should be carried out after application, before application to a sensitive crop.
