The passage of time is forcing those involved in crop production on this island to realise that we are losing the battle between decreasing chemical efficacy and nature’s aliens.
Ireland has the highest wheat yields in the world and the second-highest barley yields. This is because we have a benign climate, with temperatures that are neither too high nor too low for crop growth, long summer days due to our northerly latitude and a plentiful water supply. However, these conditions, in particular the water supply, provide ideal conditions for wet weather diseases; septoria and head blight on wheat, Rhynchosporium and net blotch on barley and blight on potatoes, to name but a few.
It is easy to think of a pest as a single organism, but this is far from the reality. Insects and diseases are very diverse populations which are forever changing. Like people, you are different from every other human and your children will be different from you.
When you apply a fungicide or insecticide, you don’t kill all of the pest or disease. Some survive because they are not as susceptible to the chemical as others. These survivors interbreed and eventually produce high numbers of resistant members in the population and these come to dominate it.
If the earth had repeated floods every few decades that drowned most people below a certain height, within very few generations the average height of humans would increase rapidly. This would happen because the remaining tall people could only have children with other tall people.
Thus it is inevitable that if we keep using the same fungicides and insecticides, they will eventually become less effective or stop working. We can slow the rate at which this happens by using mixtures of different products or by alternating the activity mode of the products we use. This practice is known as resistance management, but the inevitable will eventually happen and products will become less effective.
In recent decades, we have managed this by developing and introducing new groups of crop protection products. But the rate of new product development has slowed, in part due to ever more-stringent testing of new products under European legislation.
So the big question is, how do we continue to produce high-yielding crops to feed a growing population against a background of fewer chemical actives? The answer is simple – we grow crops that are not so reliant on crop protection products. But while the answer is simple, achieving it is not so simple.
Integrated pest management
Integrated pest management (IPM) is one approach to help protect chemical inputs that is gaining popularity globally. This is about growing the crop in such a way that the likely yield loss due to pests and diseases is reduced. For example, early March-sown spring barley is much less likely to suffer losses due to BYDV than April-sown barley.
Unfortunately we don’t always have the weather to sow our barley early and, even if we did, it is likely to suffer higher levels of foliar disease than a later-sown crop.
Late-sown winter wheat will have much lower levels of septoria and eyespot, but a risk of delayed sowing is that the crop may not be sown at all or it will have poor establishment. And even if it is sown in good conditions, it may be low-yielding due to a shortened growing season.
Introducing break crops into the rotation will reduce pest and disease pressure on the main cereal crops, but for this to be successful we need reliable and profitable break crop options.
Plant resistance
Using pest and disease-resistant varieties is another potentially profitable approach. However, despite the efforts of plant breeders over many decades, we still do not have high-yielding resistant varieties with good agronomic performance.
The wheat variety Stigg had the best septoria resistance of any wheat variety grown in recent decades, and possibly ever, but it had other problems, such as poor head blight resistance and poor bushel weights, which made it unattractive.
However, the value of the septoria resistance is tangible. A fungicide trial at Oak Park in 2014 showed that Stigg treated with half-rate Bravo (1 litre/ha) twice, at T1 and T2, was the highest-yielding treatment in the trial. This treatment had a greater yield than more-susceptible varieties such as Cordiale or Einstein, which were treated with a full rate of Aviator applied twice (Table 1).
Yield potential and resistance
Combining agronomic characteristics with high yield potential and high levels of resistance to the key Irish pests and diseases is, therefore, the key to success.
New approaches to achieve this are clearly needed, as it has proved difficult or impossible using conventional plant breeding. This challenge is perhaps greater in Ireland than in most other countries because, with the exception of potatoes, ryegrass and clover, we have no domestic plant breeding and we are reliant on varieties bred overseas.
A new research project, funded by the Department of Agriculture’s stimulus fund, aims to address these challenges. While it is led by Teagasc, the project is being done in collaboration with UCD, NUIG, NUIM and TCD. The project is being called the Virtual Irish Centre for Crop Improvement, or VICCI for short.
It is termed a virtual centre because it does not involve investment in new buildings or facilities, but rather it brings together the best facilities and plant and crop science researchers across Ireland to focus on developing improved varieties of key crops for Irish growers.
The crops to be researched include wheat, barley, oats, beans, potatoes and grass. And the key traits for crop enhancement have been identified as disease resistance, nutrient use efficiency, processing quality in potatoes and productivity traits.
The initial productivity traits to be examined will be low temperature growth in ryegrass and waterlogging resistance in ryegrass and barley. There will also be direct selection for yield in beans and oats. It is anticipated that additional crops and traits will be added as the centre develops.
The objective is to exploit the findings of recent and/or current research programmes to effectively translate the application of biotechnology-related tools, developed on model species such as Arabidopsis, to varietal improvement. To help do this, multi-disciplinary approaches will be used to help deliver each crop improvement objective.
Waterlogging resistance
Screens of elite, adapted and heritage breeding material will be examined to look for previously unidentified genetic variation in desirable traits. Varieties from nearby breeding and genetic improvement programmes in the UK, and varieties previously grown in Ireland, are available to the project. These will be tested in up-to-date growing conditions to see if they are suited to growing in Ireland and to identify individuals with traits of interest (eg disease resistance).
Individual lines of interest will then be subjected to a rapid genetic assessment to enable the gene(s) that underpin the desired trait to be isolated and characterised. One technique that will assist in this process is called RNA-seq, which provides a snapshot of the activity of every gene in a plant when it comes under a specific stress.
Wheat contains approximately 100,000 genes (about five times as many as humans) and a standard RNA-seq experiment generates a staggering 4.8 million data points.
While these data sets are large, and challenging to interpret, the information is vital to provide an insight into not just how genes operate in isolation, but critically how they interact with other genes in the plant’s defence network.
Lines of wheat, barley and ryegrass that come through positively in these analyses will qualify for incorporation into more modern varieties if they have also shown promise in field-based testing.
Parallel work will look at research projects which have already identified genes of interest in other species, such as those found in Arabidopsis that appear to be strongly linked with waterlogging resistance.
The goal of this arm of VICCI is to determine if these genes are present in other unrelated species, or their relatives, and ascertain if the transfer of these genes (eg from a heritage barley into modern barley varieties) could lead to the development of waterlogging-resistant winter barley varieties.
Taken together, these approaches will either identify good potential varieties that can be taken through the testing system and directly into use or to help introduce genetic markers for useful genes that can be incorporated into breeding programmes to develop new varieties.
Overall, the key to VICCI is that it allows the Irish crop research community to capitalise on the availability of novel breeding lines (generated outside Ireland) and the most state-of-the-art advancements being made in biotechnology-based systems. These initiatives should afford VICCI the opportunity to leapfrog the traditional breeding steps, thereby increasing the probability of finding valuable material for breeding in a shorter period of time.
Delivering the benefits
To ensure that research discoveries are delivered as quickly as possible to the industry, VICCI will integrate into the existing breeding initiatives within Teagasc for potato and ryegrass and also into commercial cereal breeding programmes where Teagasc already has existing collaborations with international breeders.
The future of profitable and sustainable crop production requires a multi-pronged approach. This involves:
Employing best agronomic practice. High yield potential and resistant varieties.Minimal use of crop protection products. Ongoing research in Teagasc and elsewhere is continually seeking to develop improved agronomic practice.
The new crop improvement centre will ultimately deliver improved varieties and the industry, as a whole, has an obligation to use these advances to protect the chemistry we still have so as to ensure that it is available for use in the long-term.
The passage of time is forcing those involved in crop production on this island to realise that we are losing the battle between decreasing chemical efficacy and nature’s aliens.
Ireland has the highest wheat yields in the world and the second-highest barley yields. This is because we have a benign climate, with temperatures that are neither too high nor too low for crop growth, long summer days due to our northerly latitude and a plentiful water supply. However, these conditions, in particular the water supply, provide ideal conditions for wet weather diseases; septoria and head blight on wheat, Rhynchosporium and net blotch on barley and blight on potatoes, to name but a few.
It is easy to think of a pest as a single organism, but this is far from the reality. Insects and diseases are very diverse populations which are forever changing. Like people, you are different from every other human and your children will be different from you.
When you apply a fungicide or insecticide, you don’t kill all of the pest or disease. Some survive because they are not as susceptible to the chemical as others. These survivors interbreed and eventually produce high numbers of resistant members in the population and these come to dominate it.
If the earth had repeated floods every few decades that drowned most people below a certain height, within very few generations the average height of humans would increase rapidly. This would happen because the remaining tall people could only have children with other tall people.
Thus it is inevitable that if we keep using the same fungicides and insecticides, they will eventually become less effective or stop working. We can slow the rate at which this happens by using mixtures of different products or by alternating the activity mode of the products we use. This practice is known as resistance management, but the inevitable will eventually happen and products will become less effective.
In recent decades, we have managed this by developing and introducing new groups of crop protection products. But the rate of new product development has slowed, in part due to ever more-stringent testing of new products under European legislation.
So the big question is, how do we continue to produce high-yielding crops to feed a growing population against a background of fewer chemical actives? The answer is simple – we grow crops that are not so reliant on crop protection products. But while the answer is simple, achieving it is not so simple.
Integrated pest management
Integrated pest management (IPM) is one approach to help protect chemical inputs that is gaining popularity globally. This is about growing the crop in such a way that the likely yield loss due to pests and diseases is reduced. For example, early March-sown spring barley is much less likely to suffer losses due to BYDV than April-sown barley.
Unfortunately we don’t always have the weather to sow our barley early and, even if we did, it is likely to suffer higher levels of foliar disease than a later-sown crop.
Late-sown winter wheat will have much lower levels of septoria and eyespot, but a risk of delayed sowing is that the crop may not be sown at all or it will have poor establishment. And even if it is sown in good conditions, it may be low-yielding due to a shortened growing season.
Introducing break crops into the rotation will reduce pest and disease pressure on the main cereal crops, but for this to be successful we need reliable and profitable break crop options.
Plant resistance
Using pest and disease-resistant varieties is another potentially profitable approach. However, despite the efforts of plant breeders over many decades, we still do not have high-yielding resistant varieties with good agronomic performance.
The wheat variety Stigg had the best septoria resistance of any wheat variety grown in recent decades, and possibly ever, but it had other problems, such as poor head blight resistance and poor bushel weights, which made it unattractive.
However, the value of the septoria resistance is tangible. A fungicide trial at Oak Park in 2014 showed that Stigg treated with half-rate Bravo (1 litre/ha) twice, at T1 and T2, was the highest-yielding treatment in the trial. This treatment had a greater yield than more-susceptible varieties such as Cordiale or Einstein, which were treated with a full rate of Aviator applied twice (Table 1).
Yield potential and resistance
Combining agronomic characteristics with high yield potential and high levels of resistance to the key Irish pests and diseases is, therefore, the key to success.
New approaches to achieve this are clearly needed, as it has proved difficult or impossible using conventional plant breeding. This challenge is perhaps greater in Ireland than in most other countries because, with the exception of potatoes, ryegrass and clover, we have no domestic plant breeding and we are reliant on varieties bred overseas.
A new research project, funded by the Department of Agriculture’s stimulus fund, aims to address these challenges. While it is led by Teagasc, the project is being done in collaboration with UCD, NUIG, NUIM and TCD. The project is being called the Virtual Irish Centre for Crop Improvement, or VICCI for short.
It is termed a virtual centre because it does not involve investment in new buildings or facilities, but rather it brings together the best facilities and plant and crop science researchers across Ireland to focus on developing improved varieties of key crops for Irish growers.
The crops to be researched include wheat, barley, oats, beans, potatoes and grass. And the key traits for crop enhancement have been identified as disease resistance, nutrient use efficiency, processing quality in potatoes and productivity traits.
The initial productivity traits to be examined will be low temperature growth in ryegrass and waterlogging resistance in ryegrass and barley. There will also be direct selection for yield in beans and oats. It is anticipated that additional crops and traits will be added as the centre develops.
The objective is to exploit the findings of recent and/or current research programmes to effectively translate the application of biotechnology-related tools, developed on model species such as Arabidopsis, to varietal improvement. To help do this, multi-disciplinary approaches will be used to help deliver each crop improvement objective.
Waterlogging resistance
Screens of elite, adapted and heritage breeding material will be examined to look for previously unidentified genetic variation in desirable traits. Varieties from nearby breeding and genetic improvement programmes in the UK, and varieties previously grown in Ireland, are available to the project. These will be tested in up-to-date growing conditions to see if they are suited to growing in Ireland and to identify individuals with traits of interest (eg disease resistance).
Individual lines of interest will then be subjected to a rapid genetic assessment to enable the gene(s) that underpin the desired trait to be isolated and characterised. One technique that will assist in this process is called RNA-seq, which provides a snapshot of the activity of every gene in a plant when it comes under a specific stress.
Wheat contains approximately 100,000 genes (about five times as many as humans) and a standard RNA-seq experiment generates a staggering 4.8 million data points.
While these data sets are large, and challenging to interpret, the information is vital to provide an insight into not just how genes operate in isolation, but critically how they interact with other genes in the plant’s defence network.
Lines of wheat, barley and ryegrass that come through positively in these analyses will qualify for incorporation into more modern varieties if they have also shown promise in field-based testing.
Parallel work will look at research projects which have already identified genes of interest in other species, such as those found in Arabidopsis that appear to be strongly linked with waterlogging resistance.
The goal of this arm of VICCI is to determine if these genes are present in other unrelated species, or their relatives, and ascertain if the transfer of these genes (eg from a heritage barley into modern barley varieties) could lead to the development of waterlogging-resistant winter barley varieties.
Taken together, these approaches will either identify good potential varieties that can be taken through the testing system and directly into use or to help introduce genetic markers for useful genes that can be incorporated into breeding programmes to develop new varieties.
Overall, the key to VICCI is that it allows the Irish crop research community to capitalise on the availability of novel breeding lines (generated outside Ireland) and the most state-of-the-art advancements being made in biotechnology-based systems. These initiatives should afford VICCI the opportunity to leapfrog the traditional breeding steps, thereby increasing the probability of finding valuable material for breeding in a shorter period of time.
Delivering the benefits
To ensure that research discoveries are delivered as quickly as possible to the industry, VICCI will integrate into the existing breeding initiatives within Teagasc for potato and ryegrass and also into commercial cereal breeding programmes where Teagasc already has existing collaborations with international breeders.
The future of profitable and sustainable crop production requires a multi-pronged approach. This involves:
Employing best agronomic practice. High yield potential and resistant varieties.Minimal use of crop protection products. Ongoing research in Teagasc and elsewhere is continually seeking to develop improved agronomic practice.
The new crop improvement centre will ultimately deliver improved varieties and the industry, as a whole, has an obligation to use these advances to protect the chemistry we still have so as to ensure that it is available for use in the long-term.
SHARING OPTIONS