Published on 28/04/2023
Planning is always beneficial so now is the time to prepare your autumn herbicide programme. The impact of grass weeds on crops is very evident but it never hurts to be reminded just how yield robbing they can be.
If you attended the FAR Cereal Event in November 2022, you will have seen the Bayer CropScience demonstration which showed the dramatic impact of ryegrass on a wheat crop.
Without effective ryegrass control from Sakura®, the wheat crop was completely outcompeted. But a pre-emergence application of Sakura resulted in around 90 per cent ryegrass control which allowed the wheat to develop into a profitable crop.
However, to maximise ryegrass control to reduce the seed bank, a spring application of Othello® OD showed it was the way forward.
The two-spray programme of Sakura applied pre-emergence followed by Othello OD applied before GS30 effectively removed ryegrass competition.
Othello OD is a very effective herbicide, and it can be tempting to just rely on this herbicide applied in early spring. But as well as being a very high-risk approach in terms of developing herbicide resistance, it also allows significant weed competition to occur during the winter, as was evident in the Bayer demonstration at the FAR event.
When Othello OD was applied in September at GS30 without a previous application of Sakura, it gave exceptional ryegrass control, but the impact of ryegrass competition during the winter was evident, with plants shorter and with fewer tillers. Grassweed populations are increasing.
So, what steps can you take to ensure your control programme is effective?
Start with seedbed preparation; aim for a firm, moist and cold free seedbed to promote rapid and even germination.
Plant on time and use an appropriate seeding rate. Crop competition very effectively reduces the impact of weeds.
Remove weed competition early. Weeds may be small during winter, but they still compete with the crop.
Expect to apply an herbicide programme. Apply Firebird or Sakura* at pre-emergence of the crop and weeds, followed by Othello OD* or Hussar™ in the early spring
It is about choosing the right herbicide to use. Firebird and Sakura have different strengths and offer choice for agronomists faced with controlling grassweeds.
Firebird is a broad-spectrum pre-emergence herbicide. It controls vulpia hair grass and poa annua, and a wide range of broad leaf weeds, and it can be used in both wheat and barley.
Sakura is a grass weed specialist, controlling ryegrass, vulpia hair grass, annual poa, soft brome and barley grass while suppressing wild oats and ripgut brome. Sakura is recommended for application to wheat (not durum wheat) and triticale, but not barley.
Both herbicides perform best in minimum till situations where grass weeds tend to germinate closer to the surface.
Keeping grass weeds near the surface is a very important factor for successful grass weed control.
Both Firebird and Sakura require soil moisture to activate so applying them immediately after drilling takes advantage of available soil moisture.
This is especially the case for Sakura which is primarily taken up by the roots of germinating weeds. To incorporate Sakura into the root zone, typically at least 10-15 mm of rainfall or irrigation is required.
You still have an opportunity to plan your herbicide programmes. Use this time wisely to get your crops off to a great start.
*Sakura and Othello OD are not recommended for use on barley crops.
WORDS: Neil Waddingham, Bayer customer marketing manager