Plants by their nature are designed to evolve. Through generations of natural selection, plants have evolved to overcome the physical, biological and chemical stresses in their environment.
This may be as simple as moving their flowering head towards the sun to maximise light interception, developing a waxy cuticle to conserve moisture or vigorously producing tillers to maximise the number of heads per plant.
Evolution
We see many forms of these features in plants, including the varieties used in commercial agriculture which have been bred to make better use some of these features of evolution.
The development of resistance to herbicide actives is just another example of evolution.
In global agriculture, we now see many weeds which are resistant to key herbicide actives causing real challenges for crop farmers.
Arguably, the development of some of these resistance weeds has been exaggerated through the use of genetically engineered crops and the reliance on one or two herbicide actives for years.
Irish resistance
Closer to home, we now have a number of confirmed cases of herbicide tolerance in common weeds in our tillage fields.
In terms of grass weeds, we have suspected cases of resistance in some wild oat and sterile brome populations, as well as canary grass.
We are also now dealing with blackgrass, which has most likely originated from the UK.
Ninety-eight percent of UK blackgrass populations are resistant to at least one herbicide active.
The evolution of resistance in these weed populations has been greatly assisted by poor management practices over the years, including:
Continuous autumn cropping.Poor stubble hygiene.Early drilling. Same cultivation type year on year.Using less competitive crops.Post-emergence herbicides only.Grass weed resistance survey
As part of the Enable Conservation Tillage (ECT) programme, Teagasc aims to determine the level and spread of herbicide resistance of Ireland’s key grass weeds.
If you suspect any level of resistance to herbicides in any grass weeds on your farm, especially bromes, blackgrass, canary grass and wild oats, then Teagasc wants samples.
Project adviser Jimmy Stables explains that that he is beginning to receive samples of grassweeds already.
These samples will be grown in the glasshouses at Teagasc, Oak Park, and tested for resistance.
Sampling procedure
1. Fill out an information sheet to include name, address, field location, weed species, location of weeds, historical use of herbicide and a number of other details. Contact Jimmy directly to receive a copy of this information sheet.
2. Where weeds are seen in a field in only small numbers, walk all or most of the infected area and take samples periodically and bulk together.
3. Isolated weed patches can be suspected of resistance, so it is important to include them in the sampling process.
4. Sample diagonally in two or three different places across any given pact of weeds.
5. If weeds are present in high numbers across the field, sample the field via the tramlines as before, but there is no need to walk all tramlines once a representative sample has been collected.
6. Sample must be harvested at the ripe stage - ie when the seeds are hard. If collected wet, leave on the window sill to dry. Collect around two cup-fulls per sample.
7. Put the seeds in a clear sealed plastic bag ensuring to label different samples. Ensure not to mix weed sample from different fields or species.
8. Put the seed and information sheet in an envelope addressed to Jimmy Stables, ECT project adviser, Teagasc, Oak Park, Co Carlow, R93XE12 or drop them in to your local Teagasc office.
For more information contact:
Adviser: Jimmy Staples 087-7907758 Jimmy.staples@teagasc.ie
Technician: David Schilder 059-9170239David.schilder@teagasc.ie
Read more
Listen: Blackgrass is here and it's on the rise
Plants by their nature are designed to evolve. Through generations of natural selection, plants have evolved to overcome the physical, biological and chemical stresses in their environment.
This may be as simple as moving their flowering head towards the sun to maximise light interception, developing a waxy cuticle to conserve moisture or vigorously producing tillers to maximise the number of heads per plant.
Evolution
We see many forms of these features in plants, including the varieties used in commercial agriculture which have been bred to make better use some of these features of evolution.
The development of resistance to herbicide actives is just another example of evolution.
In global agriculture, we now see many weeds which are resistant to key herbicide actives causing real challenges for crop farmers.
Arguably, the development of some of these resistance weeds has been exaggerated through the use of genetically engineered crops and the reliance on one or two herbicide actives for years.
Irish resistance
Closer to home, we now have a number of confirmed cases of herbicide tolerance in common weeds in our tillage fields.
In terms of grass weeds, we have suspected cases of resistance in some wild oat and sterile brome populations, as well as canary grass.
We are also now dealing with blackgrass, which has most likely originated from the UK.
Ninety-eight percent of UK blackgrass populations are resistant to at least one herbicide active.
The evolution of resistance in these weed populations has been greatly assisted by poor management practices over the years, including:
Continuous autumn cropping.Poor stubble hygiene.Early drilling. Same cultivation type year on year.Using less competitive crops.Post-emergence herbicides only.Grass weed resistance survey
As part of the Enable Conservation Tillage (ECT) programme, Teagasc aims to determine the level and spread of herbicide resistance of Ireland’s key grass weeds.
If you suspect any level of resistance to herbicides in any grass weeds on your farm, especially bromes, blackgrass, canary grass and wild oats, then Teagasc wants samples.
Project adviser Jimmy Stables explains that that he is beginning to receive samples of grassweeds already.
These samples will be grown in the glasshouses at Teagasc, Oak Park, and tested for resistance.
Sampling procedure
1. Fill out an information sheet to include name, address, field location, weed species, location of weeds, historical use of herbicide and a number of other details. Contact Jimmy directly to receive a copy of this information sheet.
2. Where weeds are seen in a field in only small numbers, walk all or most of the infected area and take samples periodically and bulk together.
3. Isolated weed patches can be suspected of resistance, so it is important to include them in the sampling process.
4. Sample diagonally in two or three different places across any given pact of weeds.
5. If weeds are present in high numbers across the field, sample the field via the tramlines as before, but there is no need to walk all tramlines once a representative sample has been collected.
6. Sample must be harvested at the ripe stage - ie when the seeds are hard. If collected wet, leave on the window sill to dry. Collect around two cup-fulls per sample.
7. Put the seeds in a clear sealed plastic bag ensuring to label different samples. Ensure not to mix weed sample from different fields or species.
8. Put the seed and information sheet in an envelope addressed to Jimmy Stables, ECT project adviser, Teagasc, Oak Park, Co Carlow, R93XE12 or drop them in to your local Teagasc office.
For more information contact:
Adviser: Jimmy Staples 087-7907758 Jimmy.staples@teagasc.ie
Technician: David Schilder 059-9170239David.schilder@teagasc.ie
Read more
Listen: Blackgrass is here and it's on the rise
This is a subscriber-only article
SHARING OPTIONS: