Weed control has never been simple, but as resistance starts to build up to common herbicides it is becoming more difficult.
We often talk about grass weeds when we think of weeds that are difficult to control, but broad-leaved weeds are a big issue and it looks like resistance issues are increasing on many farms.
Poppies have long been a weed that is hard to get under control. Zypar and Pixarro can be used to control them in spring crops, as well as MCPA or in some cases pendimethalin pre-emergence.
In the past decade chickweed has become resistant to sulphonyl urea products and resistance in corn marigold has been around for a long time, but looks to be increasing.
Resistant corn marigold
If you have noticed weeds that haven’t been controlled in recent years then you should discuss a plan to control those weeds with your agronomist. This might involve changing the crop that’s grown in the field next season, but for now will have to focus on herbicides.
If you think these weeds are resistant because they have not been controlled then you should try and keep seeds from some of these plants and send them to Teagasc for testing. This is a free service. So, if some of the weeds remain uncontrolled this year you can bring them to seed and save that seed for Teagasc to test.
Chickweed.
Chickweed
To control resistant chickweed you now need fluroxypyr in the tank mix. The rate of Galaxy which contains fluroxypyr has been reduced in recent years. The new rate of 1l/ha is generally not enough to control chickweed so the product needs to be topped up with Pastor Trio, which is basically the same product or you can top up with straight fluroxypyr, so a product like Binder or Reaper.
Pixxaro is another option. Pixarro contains the Arlyex herbicide, along with fluroxypyr. A full rate of Pixarro of 0.5l/ha, along with an adjuvant should control it. You don’t need an adjuvant if there are a number of products in the tank.
Corn marigold in a field of spring barley.
Corn Marigold
If you have Corn Marigold then you need to include Clopyralid in the mix. Clopyralid is also contained in Galaxy. However, once again you need to top it up. This time with straight Clopyralid. Lontrel, formerly known as Shield can be used for this.
Weed control has never been simple, but as resistance starts to build up to common herbicides it is becoming more difficult.
We often talk about grass weeds when we think of weeds that are difficult to control, but broad-leaved weeds are a big issue and it looks like resistance issues are increasing on many farms.
Poppies have long been a weed that is hard to get under control. Zypar and Pixarro can be used to control them in spring crops, as well as MCPA or in some cases pendimethalin pre-emergence.
In the past decade chickweed has become resistant to sulphonyl urea products and resistance in corn marigold has been around for a long time, but looks to be increasing.
Resistant corn marigold
If you have noticed weeds that haven’t been controlled in recent years then you should discuss a plan to control those weeds with your agronomist. This might involve changing the crop that’s grown in the field next season, but for now will have to focus on herbicides.
If you think these weeds are resistant because they have not been controlled then you should try and keep seeds from some of these plants and send them to Teagasc for testing. This is a free service. So, if some of the weeds remain uncontrolled this year you can bring them to seed and save that seed for Teagasc to test.
Chickweed.
Chickweed
To control resistant chickweed you now need fluroxypyr in the tank mix. The rate of Galaxy which contains fluroxypyr has been reduced in recent years. The new rate of 1l/ha is generally not enough to control chickweed so the product needs to be topped up with Pastor Trio, which is basically the same product or you can top up with straight fluroxypyr, so a product like Binder or Reaper.
Pixxaro is another option. Pixarro contains the Arlyex herbicide, along with fluroxypyr. A full rate of Pixarro of 0.5l/ha, along with an adjuvant should control it. You don’t need an adjuvant if there are a number of products in the tank.
Corn marigold in a field of spring barley.
Corn Marigold
If you have Corn Marigold then you need to include Clopyralid in the mix. Clopyralid is also contained in Galaxy. However, once again you need to top it up. This time with straight Clopyralid. Lontrel, formerly known as Shield can be used for this.
SHARING OPTIONS