Unusual weed species are being spotted in winter cereals which is causing concern among growers and agronomists, prompting questions about whether typical spring herbicide programmes will be effective this spring.
Hazel Blanshard, product manager at FMC, explained that there are a number of weeds which have established in the unseasonably warm and wet conditions that some growers have not historically seen in such high populations.
“Willowherb, corn spurrey, lesser celandine, and coltsfoot are being reported as unexpected and out of place this year. Volunteer beans, while not that uncommon, are also causing problems, as are larger than expected populations of groundsel,” she says.
“The reasons we’re seeing greater populations of these weeds is threefold. Firstly, the lack of autumn residual herbicides applied in some areas; certain weeds favouring germination in wetter soils, and finally, the relatively high soil and air temperature over the winter.”
Ms Blanshard says that in most cases these weeds are still relatively small and at a growth stage where control remains relatively straightforward.
“None of the unusual species reported so far should cause a headache as long as herbicide strategies are managed correctly,” she said.
“Most of these can still be successfully controlled with metsulfuron based products, with better and more consistent control achieved with metsulfuron and thifensulfuron, or metsulfuron and tribenuron co-formulated products, such as Harmony® M SX® or Ally® Max SX®.”
For those who are tackling volunteer beans, Ms Blanshard recommends tank mixing SU herbicides with a hormone herbicide to provide better control of the bigger plants.
“If weeds are large by the time you come to control them, using higher dose rates is advised,” she said.
“Maintenance of water rates and correct nozzle choice, combined with a reasonable forward speed should always be a high priority, but this year it may also be key to achieving best results.
“Speaking to your agronomist and following product labels is always important to ensure successful weed control is still achieved and a good quality crop is harvested,” she added.
Top picture: Volunteer Beans © Blackthorn Arable
Willowherb
