Weed control in cereals starts now!
22 February 2023
- Product News
22 February, 2023
- Product News
22 February, 2023
Harvest is now a distant memory to many.
The impact of grass weeds on crops is very evident but let’s remind ourselves just how yield robbing they can be as it never hurts to do this.
If you attended the FAR Cereal Event in November 2022 you will have seen the Bayer Crop Science demonstration which showed the dramatic impact of ryegrass on a wheat crop.
Without effective ryegrass control from Sakura® the wheat crop was effectively killed. But a pre-emergence application of Sakura resulted in around 90% control which allowed the wheat crop to develop into a profitable crop.
However, to really control ryegrass effectively, to the level required to start reducing 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 at GS30 effectively removed ryegrass competition.
Othello OD is a very effective herbicide but don’t be tempted to rely just on Othello OD applied in early spring as your sole grassweed herbicide.
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?
1. Start with seedbed preparation, aim for a firm, moist and clod free seedbed to promote rapid and even germination.
2. Plant on time and use an appropriate seeding rate. Crop competition very effectively reduces the impact of weeds. This was clearly demonstrated at the FAR arable event when a pre-emergence application of Firebird applied to autumn planted barley was the only herbicide required. To the Bayer team this was a pleasing if surprising result. Normally a herbicide programme is required but the competitive nature of barley sometimes means a pre-emergence application of Firebird is enough.
3. Remove weed competition early. Weeds may be small during winter, but they still compete with the crop.
4. Expect to apply an herbicide programme in most situations. Apply both Firebird or Sakura* pre-emergence of the crop and weeds, followed by Othello OD* or Hussar™ in the early spring.
Firebird and Sakura have different strengths and offer choice when faced with controlling grass weeds.
Firebird is a broad-spectrum pre-emergence herbicide. It controls vulpia hair grass and poa annua, 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 as this technique keeps grass weed seeds closer to the surface. Keeping grass weeds near the surface is a very important factor for successful grass weed control as it results in a more even germination of the grass weeds and it means seeds germinate within the herbicide layer, and not below it.
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.
Early autumn is the time to plan your herbicide programmes. Developing a grass weed control strategy now will not only get your crops off to a great start but help to ensure they deliver their full potential at harvest 2024.