Not Controlling Autumn Grassweeds is such a false economy

One issue that has reared its head more than usual this harvest is grassweed issues and the ergot that can come with it, whether it’s in wheat, barley, rye, oats and also grassweed ergot.

With most people having environmental schemes of some sort around the field as margins, there is little we can do to control ergot in those, other than select a later flowering variety of grasses. To restrict overall contamination of the field sample, combine and store field headlands separately.

So, this leaves control of grass weeds in field more important than ever, especially with the tightening of restrictions on Ergot.

When you look at what can be done to control grass weeds in field, they are all cheaper options versus having to have a rejected load redirected and then colour sorted. If you biased this on your average yield it is staggering the addition cost that could possibly have been avoided by controlling the grass weeds in field.

One option is to deep cultivate, and delay drilling till mid-October, but given 2 difficult autumn drilling seasons people are more inclined to drill as soon as they can mid-September onwards. This is not ideal as you would not have had the opportunity to get a couple of stale seedbed treatments, and it puts more pressure on pre-emergence and post emergence sprays. But, it’s better to have a good crop in the ground, than none at all.

With this in mind it is key that communication between farmer and agronomist is spot on, so there is a clear idea from both parties on what they are trying to achieve, and how it’s going to be achieved. An understanding of not just what chemical is likely to be used, but also the work load the farmer has ahead of him, the likelihood of getting pre emergence on at the optimum timing within 48 hours of drilling, and let’s not forget the unforecasted weather events that ruin best made plans…

With all this in mind it is best to have a well discussed plan in place with general scenarios covered, from cultivation, stale seedbeds, seed rate, drill timings, pre and post emergence herbicide.

When you look at grassweed control in winter cereals, one of the most effective ways to control them is in your cultural controls, and a well-timed target specific pre and post emergence sprays. This is obviously getting a bit trickier with resistance issue in blackgrass and ryegrass, so getting control of them early is vital with a strong residual stack.

When you look at your pre and post emergence options you should consider weed burdens, soil type, organic matter content, and try to use different modes of action to aid resistance in the weed population.

With ELMs likely to be focusing on soil health, it makes you wonder how long you can keep using the plough to bury issues rather than dealing with them. Unfortunately, the plough is the best form of weed control when you look at things like brome, but we will have to look at things differently sooner than most would probably like with the new scheme coming in.

Speak to our crop protection and agronomy team today. Call 01243 784171 or email agri@bartholomews.co.uk