12 minute read
Improving crop resilience in the face of a changing climatic, agronomic and political landscape
Next Article
Arable Improving crop resilience in the face of a changing climatic, agronomic and political landscape
How are wheat and OSR breeders working to combat the e ects of extreme weather events, gradual loss of many key agrochemicals and the need to change farm practices in order to meet Carbon Net Zero targets? Rachel Hicks writes.
Over the last few years, a huge reduction in the ag-chem armoury has meant the remaining actives need careful stewardship, with the threat of resistance hanging like a heavy cloud above agronomists and growers alike.
Add to this regular and prolonged extreme weather events at the polar ends of the scale, and the pressure to be carbon neutral, and it’s no wonder so many farmers are considering retiring the combine to the shed and selling up. But it’s not all doom and gloom – in fact, there has never before been so much research carried out into the physiology and geneology of cereals and oilseeds; and genetics, including gene editing, are playing a major part in breeding decisions.
Studies on how UK crop yields are in uenced by weather patterns have indicated that low wheat and OSR yields are associated with wet winters and hot/dull conditions during spring and summer, comments ADAS’ head of crop physiology, Pete Berry (right). “Low OSR yields have also been associated with cold autumn and low minimum temperatures in early spring. Low yields in 2020 have been at least partially attributed to the very dry spring. Pest pressures, such as CSFB, can make crops less resilient to extreme weather.
“The association of low yields with wet winters is probably caused by waterlogging, therefore developing varieties that can tolerate these conditions will be important – this is a particular priority for OSR.
“Developing varieties with more autumn vigour may also help to establish a robust root system before winter which is more resilient to waterlogging, as well as helping to tolerate any cold autumn conditions. A warmer spring and summer mean that crops require fewer calendar days to pass through their developmental stages, which means there is less time for them to intercept light, photosynthesise and accumulate biomass. Therefore, developing crops which are less sensitive to rising temperatures will be an advantage.
“The obvious solution for minimising risk of drought stress is to grow crops with
deeper roots. Soil management should be the rst approach considered for improving this, but varieties with faster autumn/spring root growth, and that can penetrate dense soil, will also be important.” ADAS’ technical director – disease and pest management, Faye Ritchie (right), further comments: “Weather will impact disease risk on OSR. Light leaf spot is active and causing damage even when conditions are cold. Warmer conditions are more favourable for phoma stem canker development, with higher temperatures increasing the severity of the disease and leading to early senescence. “There will be pressure for varieties to be resilient against a wide range of threats – however, and OSR yields are associated with wet winters pathogens tend to evolve and overcome the pathogens tend to evolve and overcome the control measures we use against them. control measures we use against them. We need to consider not only how to We need to consider not only how to maximise yields but how to protect genetic resistance and consider other strategies that also contribute to reducing disease risk e.g. sowing date.”
approach considered for improving this, but growth, and that can penetrate dense soil, This organisation is working in extremely challenging environments and, by working together, we can learn from each other base – something we value in terms of
Change takes time
Of course, developing new, more resistant varieties isn’t an overnight process – but it is one that will ensure the survival of cereal and oilseed crops in the future. As Bill Angus, of Angus Wheat Consultants explains: “Climate change is not new, but the pace of change has accelerated in the last few years. This brings challenges to many crops that we grow globally. Here in the UK, a new winter wheat variety can take anything from seven to 12 years from the original hybridisation to being present in a farmer’s eld.
“Although our wheat breeding programme (F1 Seed Ltd) selection process is seen by many as somewhat slow, compared to the larger breeders, consistency of performance over a number of challenging years in the eld is becoming more critical and thus we test under adverse as well as optimal conditions – stretching the variety’s ability to deliver consistent yields and grain quality.
“There is no shortage of genetic variability – wheat is a global crop – and we therefore pay attention to key physiological traits which are important under our climatic conditions. We are currently working closely with CIMMYT – the largest publicly funded wheat programme on the planet, breeding wheat for 200 million hectares.
This organisation is working in extremely challenging environments and, by working together, we can learn from each other about valuable traits to mutual bene t. The freedom to exchange genetic resources is critical for not only the UK but for global food security. In addition, the UK is well served by a strong pre-competitive public research base – something we value in terms of genetic resources but also ‘know how’.
“In the longer term, hybrid wheat, which is known for its ability to withstand major environmental challenges, will play a bigger part in growers’ choices. The most critical step will be having a UK-wide testing capability, t for purpose, which will be able to identify and promote proven reliable varieties.”
Range of challenges
Another breeder who continues to put the ability of its varieties to thrive in a range of challenging growing conditions at the heart of its breeding development programme is DSV, comments the company’s Sarah Hawthorne.
Improving yield is still very much at the forefront of breeding development work whilst increasing e ciency of nitrogen utilisation and making plants increasingly resilient are some of the many development areas now being focused on, she says.
“When it comes to oilseed rape, for example, developing varieties that can better stand up to ea beetle is a de nite priority.
“But three years of challenging weather across Europe, ranging from dry conditions at sowing to too wet to drill and hot dry weather at owering to ‘beasts from the east’, have proven just how resilient modern oilseed can be.
“Whilst the inherent high vigour of modern hybrids undoubtedly has much to do with this, the breeders’ focus on developing varieties with deep taproots and large branching root architectures has also really come into its own in recent years.”
On the wheat front, new DSV Champion has
continued over…
…from previous page been bred for low-input regenerative farming systems as well as ones focused on maximising outputs, she says.
“DSV is the only company breeding wheat in the west of the country and this gives varieties like DSV Champion and Theodore real UK-wide disease resistance and resilience.
“Such varieties are going to become even more important in the future as growers look to cut back on inputs and move to more sustainable production systems.
“But it’s always important to keep genetic strength at the heart of new varieties so they have the best chance of delivering their full potential in the face of increasingly challenging growing conditions in the future.”
Meanwhile, KWS’s Sowing for Peak Performance Initiative (SPP) is all about making sure growers have the genetics they need to meet the challenges of the future. Commenting, Dr Kirsty Richards says: “Our belief is that 80 per cent of what your crop can deliver is locked into the seed you buy and its match to your own individual growing conditions.
“For KWS, the challenge of the future is to develop seed varieties that not only deliver the highest performance possible but also allow growers to achieve this in the context of the new production environment we are inevitably moving towards.
“For example, in a world where more volatile weather conditions are the norm, stem sti ness and standing power become increasingly relevant and in more challenging autumn drilling scenarios, later drilling capability becomes increasingly important.
“KWS is focused on a robust line of SPP varieties coming through the pipeline. All-in-all, we have seven new wheats entering candidate trials with some exciting developments taking place in barley, too.”
SHORT OF SHORT OF SHORT OF STORAGE STORAGE STORAGE SPACE? SPACE? SPACE?
BOWIE LOCKWOOD
02476 459000
Treating seeds
According to Syngenta, stability, exibility, resilience and rooting are all key variety traits to cope with extremes of weather. Yield stability across di erent seasons is becoming a bigger priority in variety selection with more weather extremes, says Syngenta seeds marketing manager, Tracy Creasy. From a practical perspective, Mrs Creasy reckons an early consequence of extreme weather is its impact on planting date – as seen over the last two seasons, when wet autumns pushed people to drill later and later. In line with this, she says Syngenta routinely assesses new varieties for their suitability to di erent drilling windows.
“By doing this, we can help growers select appropriate varieties for their situations. SY Insitor, for example, is suited to later drilling scenarios: we wouldn’t recommend drilling it in early September. Gleam, on the other hand, has a wider window and with its high tillering capacity and tiller retention, it can deliver more equal yields under challenging conditions.
“As a side note, we also examine the value of seed treatments in conjunction with varieties. Vibrance Duo, known for improving root development, has been shown to deliver its largest bene ts in more marginal conditions, for example on light land which is more prone to spring drought.”
Another breeder who is looking at treating seeds in order to boost establishment and root growth is Elsoms, which has been using priming as a method to control germination and vigour – in particular root crops such as parsnips, but it is also trialling the treatment on OSR. According to Elsoms’ break crop and cover crop manager, Jack Holgate: “The process controls the amount of moisture given to seeds through a series of exact calibrations. The seed is brought to a point where it has had just enough water to germinate, but not enough temperature (heat units).
“Once drilled, the seed rapidly takes up the remaining moisture and heat required, resulting in an even and rapid germination.
“It is used on crops where there is a naturally slow or erratic germination and is also used to overcome poor germination conditions – so it is e ectively an insurance policy for crops. Resulting seedlings tend to be stronger and more robust than non-primed seeds.”
Fundamental to Bayer’s e orts to improve the resilience of oilseed rape-growing are completely untreated Dekalb breeding and selection trials run across a huge range of stress situations throughout Europe.
“It’s easy to under-estimate the value of these rather than ‘new’ traits,” remarks Dekalb UK and Nordics breeding leader, Matthew Clarke. “But they are one of the most important jewels in the crown when it comes to delivering the sort of reliability that has always been our trademark.
“We insist on testing all our emerging hybrids as well as parent lines without any crop protection support right thorough to their NL2 stage of development. And we deliberately do so in situations presenting particular disease, pest and other environmental challenges.
“This allows us to only bring forward hybrids we are con dent have the underlying genetic strength to perform consistently under increasingly unpredictable and often challenging conditions.”
Nitrogen trait
Last year breeder Limagrain UK introduced a new genetic characteristic, the N-Flex trait, to its OSR o ering. Varieties with N-Flex have the ability to use nitrogen more e ciently, making them better able to withstand delayed or sub-optimal nitrogen applications.
Will Charlton, Limagrain UK’s arable marketing manager, explains: “Soil structure and biology, along with weather conditions, lead to leaching and low solubilisation or mineralisation of nitrogen. Farm practices such as rotations and cover cropping also a ect nitrogen levels, and of course we have legislative guidelines to adhere to with regards to how much can be used and where.
“As breeders, our challenge was to look at how we could use genetics to cope with these ambiguities and introduce varieties that would be able to maintain high yields in lower than ideal nitrogen conditions by optimising every unit of available nitrogen.
“Last year we launched the rst of our OSR varieties to o er the N-Flex characteristic, LG Aviron, then Ambassador, and earlier this year, very high yielding hybrid oilseed rape LG Antigua was also con rmed to o er the N-Flex characteristic.” FG
Grain stores and other agricultural and commercial buildings available
Competitive prices Competitive prices Competitive prices 80406
