Favourable autumn and winter conditions for cereal growers will not negate the need for a contact herbicide this spring in most cases.
Fine drilling weather was followed by a mild December and January, giving residual chemistry the best chance to dampen the weed burden.
But as temperatures rise in the coming weeks, Corteva Agriscience™ says flushes of grassweeds and broad-leaved weeds will appear.
The wheat area in England rose 28% in 2020 to 1.62 million hectares, and the AHDB estimates that even more was planted last autumn. This means about 1.8m hectares will need to be assessed for herbicide applications this spring.
With wheat currently commanding more than £200/tonne, there is a strong incentive to invest in products which will prevent weeds from stealing yield.
Early indications are that the burden in cereal crops is limited. Drilling conditions were generally good, and dry winter soils allowed sprayers to travel late into the year.
Alister McRobbie, Cereal Herbicides Product Manager for Corteva Agriscience, said: “Following good conditions for autumn residuals in 2021, some might question the need for a contact herbicide for grassweed control this spring.
“But the warmer autumn will have had an effect on residual herbicide stacks, meaning they will run out of steam earlier, allowing grassweeds to germinate later in the season.”
Alister added that some farms experienced issues with product availability which could have a knock-on effect this spring.
“The reduced availability of glyphosate pre-drilling meant that many growers were unable to spray off emerging grassweeds prior to drilling, resulting in a greater weed burden going into the winter,” he said.
He advises a spring application of a contact graminicide to control grassweeds and protect yields.
“Broadway® Star gives excellent control of brome species, ryegrass and wild oats in winter wheat,” Alister said. “It is also effective against a wide range of broad-leaved weeds. Using in conjunction with a pre-herbicide residual programme, it provides robust control going into the key period of the growing season.
“For best results, include a recommended adjuvant and always target weeds when they are small and actively growing, and don’t spray when it is cold as efficacy will be reduced. A good rule of thumb is that if the grass is growing and needs a cut, it’s probably suitable for applications of Broadway Star.”
Early applications for sterile brome control will benefit from tank-mixing with pendimethalin to provide some residual control where there is the potential for further germination.
Broadway Star will also control a range of difficult broad-leaved weeds such as cleavers, groundsel, brassica weeds, pansy, poppy and speedwell. In addition, 265g/ha of Broadway Star plus an adjuvant will control umbelliferous weeds such as bur chervil and shepherd’s needle, provided the weeds are small at application.
“Some farmers may have missed the fact that Broadway Star now has approval for use in spring wheat. It can be applied at 200g/ha plus an adjuvant to target wild oats and broad-leaved weeds too,” Alister said.
Tel: 01327 438617 / 07832168560