For many years, black-grass control has been the main focus of discussions about weed control. After the activity of post-emergence herbicides reduced due to resistance, pre-emergence programmes and cultural control methods became the main talking points about black-grass control. Now there seems to be another change in the air with more concern about broad-leaf weeds and other grass weeds particularly in spring. But what is driving this shift? Are other weeds becoming more of an issue? Have we cracked the black-grass problem? Or has the black-grass topic simply become too familiar?
Bayer teamed up with Crop Production Magazine to survey 277 farmers and agronomists about their perception of weed problems in spring and how they manage them. People took part from all across the country giving a wide variety of views about which weeds are causing problems and why.
Even if other weeds are generating discussion, black-grass is still a huge problem. 76% of farmers and 79% of agronomists identified black-grass as an important weed to control in their wheat crops. Crucially, in the main black-grass areas of the East Midlands, East Anglia and the South East, the figure is above 90%.
Opinion is split on whether the black-grass problem is getting better or worse. 20% of farmers and 31% of agronomists said it is getting worse while 29% of farmers and 23% of farmers said the problem is getting better. Interestingly, in the three main black grass areas farmers and agronomists were far more positive about the black-grass situation indicating successful use of cultural controls and pre-em herbicides. But in the West Midlands & Wales plus Northern England were more worried, probably because the weed is becoming more prevalent in these areas. The good news is that by adopting the techniques used in the East, there is the opportunity to prevent the worst black-grass problems developing.
Brome in particular is causing more concern to farmers and agronomists. Rye-grass is also an issue but appears to be causing problems on fewer farms. Once again there is a regional split with respondents from Northern England and the West Midlands & Wales more concerned about both of these weeds and Scottish farmers very concerned about brome.
One of the reasons for conducting the survey was to check the idea that farmers see black-grass control as an ‘autumn task’ and spring for general weed control. The results of the survey backed this up with over 50% of farmers and agronomists expressing this point of view. Also, 48% of farmers and 63% of farmers said that spring is now focused on broad-leaf weeds while the pre-em is for grass weeds.
Backing up the previous point, respondents were asked what their main target was for the spring herbicide last season and five years ago. There was a notable shift away from black-grass control and towards broad-leaf weeds.
Many broad-leaf weeds feature on farmers’ and agronomists’ list of control targets.
But most farmers and agronomists think they are under control with only 16% of farmers and 21% of agronomists saying they are becoming more of an issue.
Opinion: Ben Coombs
The results of this survey back up reports we have got in from the field about the changing shape of spring weed control. The shift has been subtle but it’s definitely there. Brome and rye-grass are adding to the grass weed burden in many situations and broad-leaf weed control in spring is now very important.
Cultural control and herbicide methods have changed to manage black-grass, and this has created situations where other weeds can flourish. I think the reduction in use of post-ems following resistance concerns has been vital in causing other weeds to rise to prominence. Products like Atlantis (mesosulfuron + iodosulfuron) also did a good job on several other weeds that now require specific control if no black-grass post-em is applied.
Of course, there are huge regional variations and I was particularly interested in how farmers in the West and North seem to be more concerned about increasing grass weed problems whereas those in the East are used to it and are even feeling optimistic. We are already looking at what the West can learn from the East in our Black-Grass Task Force In Action project and these results underline that there is lots of interest in this work.
Looking at this season in particular, we all know autumn was difficult and many wheat crops didn’t get a pre-em or are poorly established so spring weed control will be absolutely crucial to nurse these crops through to a decent yield. To help farmers, we have a new product available this year Pacifica Plus (mesosulfuron + iodosulfuron + amidosulfuron). It has all the grass weed control of Pacifica coupled with broad-leaf weed control from amidosulfuron. As a single product co-formulation, we envisage it being a simple one product solution to the mixed spring weed situations we are now seeing.
Ben Coombs is Combinable Herbicides Campaign Manager for Bayer
Black-grass control is the biggest agronomic challenge facing most UK arable farmers. If you have black-grass, taking steps to reduce the population is key, while farmers fortunate enough to be free of black-grass need to keep it that way.
Trials can provide a great source for ideas but putting them into practice commercially can be challenging. The Black-grass Task Force project aims to help translate the excellent trials work demonstrating how to control black-grass into field scale practices.