Protection
Just like you inoculate legume seeds with a rhizobial inoculant, one day you might inoculate canola seeds with a plant-growth-promoting fungus. Greenhouse experiments in Alberta are showing that a fungus called Piriformospora indica can boost canola performance, providing benefits like increased yields, reduced fertilizer needs, and increased tolerance to cold and drought. Now the research team is testing this promising inoculant in the field.

Piriformospora indica was discovered relatively recently in northwest India, and since then has been found in other parts of the world,” notes Janusz Zwiazek, a professor of plant physiology at the University of Alberta, who is leading the research. Since Piriformospora indica’s discovery about two decades ago, researchers have been learning more and more about this interesting fungus. Zwiazek expects it will likely be classified as a type of mycorrhizal fungi.

He explains that Mycorrhizal fungi are a group of fungi that colonize plant roots, forming mutually beneficial relationships with their hosts. “Mycorrhizal fungi are very common. Probably more than 90 per cent of plant species are associated with mycorrhizal fungi in nature. Especially in soils that are poor in nutrients such as phosphorus and nitrogen, these fungi can mobilize these nutrients in the soil and make them available to plants. Mycorrhizal fungi can also protect plants against different environmental stresses such as drought, pathogens, and so on,” says Zwiazek.

“But the exception is the family of Brassicaceae, the cabbage family of plants, to which canola belongs. Cabbage family plants typically don’t form mycorrhizal associations. So they don’t have the added benefit that many other plants receive from having these helpful fungi that can do so much good.”

Luckily for canola growers, Piriformospora indica is a bit different from the average mycorrhizal fungus in a couple of ways.

“Researchers have discovered that Piriformospora indica is capable of forming associations with the roots of a number of cabbage family species,” notes Zwiazek.

Also, most mycorrhizal fungi have to be cultured in a plant host, but Piriformospora indica can be grown in a pure culture without a plant host, so it is easier to grow for commercial production of inoculants. And previous research has shown that Piriformospora indica has the ability to provide multiple benefits to host plant species, such as improving nutrient uptake, increasing stress tolerance, improving disease resistance, and enhancing plant performance.

With all those things going for Piriformospora indica, Zwiazek was keen to see how it might work with canola.

The first phase of the project was done in growth rooms where all the environmental conditions, such as temperature, light and moisture, were strictly controlled. The experiments were done under sterile conditions to exclude the possible effects of any other microbes.

“We inoculated canola plants with a fungal culture of Piriformospora indica, and we studied the effects on plant growth under different environmental conditions, which we controlled in the growth rooms,” he says. Zwiazek’s team evaluated the effects of such things as temperature stress, low nitrogen and phosphorus levels, drought and flooding stress, and salinity stress on canola growth characteristics and yields, with and without the fungus.

The biggest challenge in the project’s first phase was to develop a practical way to inoculate canola plants with the living fungus. Zwiazek explains, “In many cases, [commercial] mycorrhizal associations and mycorrhizal technology have failed because it is very difficult to inoculate the plants on a large scale, to maintain the inoculum alive long enough and develop the conditions which could be used on a commercial level and applied in practice.”

After testing various Piriformospora indica inocula and procedures, the project team has developed an innovative inoculum and protocol that are practical for applying the fungus to seeds in commercial operations. They are currently applying for a patent for this technology.

The project’s first phase is largely completed, and the results are very promising.

“The most important findings are that the fungus can colonize canola plants quite easily and quite effectively, and it can be quite effective in increasing the growth and yield of canola, especially under lower phosphorus levels,” says Zwiazek. “Also, the fungus makes the plants more resistant to low soil temperatures and low air temperatures, and to drought stress conditions.”

Now the next step is to see how well Piriformospora indica works under field conditions. So in 2016 the project team started testing the inoculant in field trials.

In these trials, Zwiazek’s team will be looking at the effects of different soil amendments (including different soil organic matter and growth-promoting bacteria) on canola growth and yield, with and without the inoculant. As well, they are doing some tests in collaboration with Mary Ruth McDonald from the University of Guelph and Habibur Rahman from the University of Alberta to see how the fungus affects the canola plant’s ability to resist clubroot and possibly other canola pathogens.

“The results of the greenhouse studies are very exciting. But everything has to be really tested in the field – this is the ultimate test. Hopefully in two or three years we’ll have a pretty good idea of how the fungus performs under field conditions, and how much farmers can actually benefit from it.”

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Funders for this research include the Agriculture Funding Consortium (AFC), Alberta and Saskatchewan canola producer groups, Alberta Innovates – Bio Solutions, and Western Grains Research Foundation.
Published in Other Crops
Agri-food stakeholders from across the value chain are invited to attend the second annual National Environmental Farm Plan (NEFP) Summit in Ottawa, November 1-2, 2017. As Co-Chair of the NEFP steering committee, the Canadian Federation of Agriculture (CFA) encourages producers and farm groups to be part of this initiative that seeks to harmonize the many different environmental farm plan programs in Canada.

An Environmental Farm Plan (EFP) is a voluntary, whole-farm, self-assessment tool that helps farmers and ranchers identify and build on environmental strengths, as well as mitigate risks on their operations. A National EFP (NEFP) would not be a replacement program, but rather a harmonization effort across the existing EFP programs nation wide.

Building on an inaugural event held last year, summit attendees will further develop a national standard designed to connect environmentally sustainable practices at the farm level with global food buyers' growing need to source sustainable ingredients.

The NEFP program is well into development, led by a steering committee comprised of participants from across the agri-food value chain. Four sub-committees are working toward developing a national protocol as it relates to data collection, standards and verification, all of which will be supported through comprehensive communications and stakeholder outreach. Summit attendees will hear from each committee, along with subject matter experts, about the progress to-date - information that will further guide steps toward this national standard.

Learn more and register for the 2017 National EFP Summit by visiting nationalefp.ca. The NEFP is always seeking to add to its list of stakeholders involved in shaping this made-in-Canada solution. Interested organizations should contact co-chairs Drew Black or Paul Watson.
Published in Business Management
New PowerCore from Dow AgroSciences offers control of a number of key, above-ground corn insect pests Canadian corn growers battle, including black cutworm.
Published in Corporate News
Wheat is an important crop in Canada, representing nine per cent of total farm cash receipts in 2015, and averaging 16 per cent of crop receipts in Canada from 2011 to 2015, according to Statistics Canada. And Fusarium head blight caused by Fusarium graminearum is the most important wheat disease. Fusarium head blight also infects barley and is a problem in malt barley production. With increasing corn acreage in Manitoba, there is a greater incidence of ear rot caused by F. graminearum as well.

The first and worst epidemic in Manitoba was in 1993. Since then, Fusarium has slowly spread to new areas across the Prairies, and by 2008, it was commonly found in the Dark Brown and Black soil zones in all three Prairie provinces.

There has been an emergence of new Fusarium populations and shifts in existing populations since 2000. A possible cause is the accidental introduction of isolates from one area to another, or one country to another.

Fusarium head blight is a concern because of the mycotoxins that can be produced by the pathogens. Fusarium graminearum produces two toxicologically relevant groups of mycotoxins. These mycotoxins have major impacts on swine feeding, resulting in poor feed intake and poor growth. Swine feed intake is reduced 7.5 per cent for every one part per million (ppm) of deoxynivalenol (DON) found in the diet.

The first mycotoxin group is the Trichothercens, which includes DON and the acetylated derivatives such as 15-ADON and 3-ADON. The DON mycotoxin is very stable during storage, milling, processing and cooking and doesn’t degrade at high temperatures. The other mycotoxin group in the Trichothercens is Nivalenol (NIV) caused by F. cerealis. It is not a virulent but is 10 times more toxic than DON. This group could become a concern and we don’t have a good monitoring system for NIV.

The second major mycotoxin group is Zearalenone and its derivatives.

The current issues with Fusarium mycotoxins in the Canadian feed supply is that Fusarium pressure in Canada is widespread and may be increasing because of wet seasons that promote the disease. There is also the additional risk of mycotoxin exposure from new feed ingredients such as distiller’s dried grains with solubles (DDGS) that are corn or wheat based. There is an increased risk in livestock feed with DDGS, since DON concentrates in in DDGS by approximately three times.

There appears to be a shift in the pathogen population with 3-ADON becoming more prevalent. This is a concern since 3-ADON makes significantly more toxin that is also more toxic. The LD50 for swine with 15-ADON is 113 milligrams per kilogram (mg/kg) while it is 49 mg/kg for 3-ADON. Analysis conducted by Ward et al in 2008 found that 3-ADON was found in six per cent of Alberta samples tested, 11 per cent of Saskatchewan samples, and 39 per cent of Manitoba samples.

We have looked at genetic chemotyping of DON isolates. On winter wheat, we found 3-ADON accounted for 82.4 per cent of F. graminearum isolates in Winnipeg and 84.6 per cent in Carman, Man. At Melfort, Sask., 3-ADON accounted for 100 per cent of the DON population. Canadian Grain Commission samples of CWRS wheat in 2015 indicated a shift to 3-ADON in the Black and Dark Brown soils zones.

This shift to a greater prevalence of 3-ADON brings new issues in managing the disease because of the increased virulence of 3-ADON. And because of the higher toxin production, there will be new issues at the elevator, in DDGS feeding and at the trade level because of potential downgrading.

The accidental discovery of NIV producing isolates in winter wheat at Carman by Chami Amarasinghe at the University of Manitoba is also a concern. Five of 132 Fusarium isolates were found to be NIV. In these isolates, 65 per cent were identified as 3-ADON, 31 per cent 15-ADON, and four per cent NIV. The presence of NIV is a concern, since it is 10 times more toxic to livestock than DON.

The identification of NIV is a concern because F. cerealis and F. graminearum are very similar and difficult to distinguish from each other. Until 2012, NIV had only been detected in a few barley samples in Canadian grain. However, testing for NIV in Canada is not routinely conducted at grain mills or elevators.

Amarasinghe also investigated the possibility of masked mycotoxins in our grains. These mycotoxins are masked because their structure has been changed in the plant. This process occurs when plants detoxify DON by converting it to DON-3-Glucosides (D3G). Masked mycotoxins are also known as modified mycotoxins and can’t be detected by conventional chemical analysis. However the danger is that gut microbes in livestock digestive systems may be able to convert D3G back to DON.

Findings from Amarasinghe’s research showed Canadian spring wheat cultivars produced D3G upon Fusarium infection, and there were significant differences among wheat cultivars. The susceptible cultivars showed a lower D3G to DON ratio (less D3G content) compared to the moderately resistant/intermediate cultivars. She found the level of resistance might have an effect on the production of D3G during the infection.

Looking into the future, Canadian wheat production may be at greater risk of Fusarium infections. An increase of 3-ADON, the potential for NIV to establish, and masked mycotoxins in our grain may be food safety issues. Additionally, with climate change, there is a possible threat of an increase in mycotoxins or having new mycotoxins such as the new NX-2 population establish.

Historically, in Canada we have seen shifts in the past. In the Great Lakes area, we saw a shift from ZEN to DON in the mid-70s, similar to the shift from 15-ADON to 3-ADON on the Prairies in the 2000s.

There are now some wheat varieties that have resistance to Fusarium in winter wheat and Canadian Spring wheat. Other classes also have varieties that are moderately resistant to Fusarium as well. These are important and should be considered as management tools.

This article is a summary of the presentation "War of the titans: The battle for supremacy in wheat-fusarium interactions," delivered by Dr. Dilantha Fernando, University of Manitoba, at the Field Crop Disease Summit, Feb. 21-22 in Saskatoon. Click here to download the full presentation.

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Published in Diseases
Worker and queen honeybees exposed to field realistic levels of neonicotinoids die sooner, reducing the health of the entire colony, a new study led by York University (Your U) biologists has found.
Published in Corporate News
I work in Manitoba and we’ve been dealing with Fusarium head blight (FHB) for the last 25 years. In the 1990s, Manitoba started seeing severe infections. Those of you who are from Saskatchewan and Alberta, over the last two to three years, have definitely seen what it can be like when conditions are correct for Fusarium head blight infection.
Published in Diseases
In 2016, we conducted field surveys for root rot of pea and lentil in Alberta and Saskatchewan. In Alberta we surveyed 27 lentil and 89 pea fields during flowering, and 67 lentil and 68 pea fields in Saskatchewan.
Published in Diseases
Alberta’s wheat farmers can now add a Fusarium Head Blight (FHB) risk tool to their agronomy toolbox, improving their ability to make well-informed decisions related to FHB disease management. The risk tool was developed in a partnership between the Alberta Wheat Commission and Alberta Climate Information Service (ACIS) with expert support from researchers based at Agriculture and Forestry (AF) and Agriculture and Agri-Food Canada (AAFC).
Published in Corporate News
Montana has seen a spike in pulse crop acres in the last 10 to 20 years. When I started 10 years ago, my crop responsibilities included spring wheat, winter wheat, durum, and maybe a little barley. Now wheat is becoming a rotational crop for pulse production.
Published in Diseases
As a response to declining Bobolink and Eastern Meadowlark populations across the province, the Ontario Soil and Crop Improvement Association (OSCIA) has teamed up with researchers to launch a platform for farmers to record sightings of these two species at risk. GrassLander, a web-based map, gives Ontario farmers the ability to easily collect data on grassland bird behaviour. The data will contribute to a better scientific understanding of population trends that can help to inform science-based decision-making.

GrassLander is designed to be accessible to farmers, whether they’re out in the field or sitting at the kitchen table; the platform is optimized for computer, tablet or smart phone. Completely free, an online tutorial is available to take registrants through the steps of how to use GrassLander. All the information collected through GrassLander is secure; and to protect the privacy of GrassLander participants, the data is aggregated and only you are able to see your individual information.

GrassLander is ideal for producers who work agricultural land that includes pastures, meadows, native grasslands, restored grasslands, hayfields, or any other agricultural grassland spaces. Ontario producers and OSCIA have contributed to grassland bird conservation across the province in a variety of ways, including cost-share programs, research, education, and awareness initiatives; GrassLander is the latest addition to these valuable conservation efforts.

For more information on GrassLander or to get involved and start recording your sightings, visit ontariograsslander.ca.
Published in Corporate News
OSCIA has announced the return of the BadgerWay Program for 2017, with applications now being accepted for eligible projects initiated on or after April 1, 2017. BadgerWay is part of the Species at Risk Partnerships on Agricultural Lands (SARPAL) initiative funded by Environment and Climate Change Canada, and supports farm habitat for the American badger, a species at risk in Ontario.

The BadgerWay Program provides funding opportunities for farmers in southwestern Ontario who wish to implement specific Best Management Practices (BMPs) that create new habitat or connect existing on farm habitat. Up to 75 per cent cost-share is available, to a maximum of $20,000 per farm business. The eligible BMPs are:

BMP 1: Establishment of perennial contour cropping or other in-field perennial grass strips
BMP 2: Tree and shrub planting
BMP 3: Native grassland restoration

For full program details or to apply, visit the OSCIA website.
Published in Corporate News
Canadians now have access to a new level of personal emergency assistance and peace of mind, backed by an organization known for its expertise in finding and caring for critically ill and injured patients.
Published in Corporate News
Hard to identify and distinguish from one another, the annual grasses compete with winter wheat and fall rye because their growth habits are similar. Downy brome (Bromus tectorum) densities of 50 to 100 plants per square metre that emerge within three weeks of the crop can reduce winter wheat yields by 30 to 40 per cent. Both downy brome and Japanese brome (Bromus japonicas) are classified as noxious weeds in Alberta.  
Published in Weeds
Local Liberal MP Francis Scarpaleggia and Jean-Claude Poissant, Parliamentary Secretary for the Minister of Agriculture, announced $2.9 million in funding at a press conference for two McGill projects aimed at mitigating greenhouse gas emissions caused by water and fertilizer use in agriculture.
Published in Emerging Trends
What I’d like to give you is a view from my previous careers working in Europe, New Zealand, and now Australia with regards to disease management. I’d like to give you a flavour of some of my impressions of disease management over the last 35 years with reference to getting the balance right with regard to the disease triangle and integrated disease management. 

Where are we in terms of integrated disease management (IDM)? What is IDM all about? Principally it’s about trying to make sure we use all the tools in the toolbox, integrating genetic resistance with chemical fungicides, cultural control and overall crop agronomy. When we sow the crop and how we look after it with nitrogen can profoundly affect how much disease pressure we’re under.

Getting it just right is never going to be easy. What’s happened in Australia? Before 2002, there wasn’t a huge amount of fungicide usage because it’s a much less responsive environment. Then we had an “exotic incursion.” Stripe rust came in from North America, probably on a grower’s boots. That changed the pendulum, from a dependence on genetic resistance to a reliance on fungicides, because, overnight, a huge proportion of all of the germplasm in Australia became susceptible to stripe rust.

Meanwhile in Europe, there was a totally different swing of the pendulum. It was inspired by a new set of varieties, in this case semi-dwarf varieties. With the new cultivars and more nitrogen, crops stayed greener for longer. Suddenly yields increased enormously in the ’70s. Higher yields and longer growing seasons in Europe drove growers to apply more and more fungicide. If you go to Europe now, it’s all about T1, T2 and T3 – Timing 1, Timing 2, Timing 3 with fungicides as a fixed part of crop agronomy. Up until 2005 in Europe, the pendulum had swung very much to the fungicide side of the IDM pendulum.

Slide 6
However, that’s all changed. In Europe, the profound driver for change has been fungicide resistance. Fungicide resistance influences everything that a European grower now does with fungicides. If there’s one thing that I think is really important to take on, it is that fungicide resistance – if it’s not affecting you now, it will be shortly unless you can moderate your use of fungicides.

What’s gradually happened over time is that we’ve got better products with greater activity, but at the same time fewer products based on limited modes of action. There are fewer products that are more and more environmentally benign, but at the same time at greater risk of resistance development. In other words, we’ve moved from multi-site fungicides that killed the fungus in many different ways to single-site fungicides that do less damage in the environment but actually are much more vulnerable to resistance.

Fungicide insensitivity and resistance
Fungicide insensitivity and resistance has occurred principally in two ways. In Europe in the late 1990s and early 2000s, strobilurins, such as pyraclostrobin and azoxystrobin, came along with the biggest media hype since glyphosate. However, after only three to four years, the pathogen causing powdery mildew and then Septoria tritici (now Zymoseptoria tritici) in wheat developed resistance to stobilurins, and that’s been a real challenge ever since. In two to three years, the strobilurins went from being the best products to control foliar diseases in broad acre cereals to products that wouldn’t work against Septoria, a disease that is widespread in northwest Europe. I think that’s when attitudes really changed and people started asking the question, “Is there a different way to control disease?”

Slide 16
We’re in our infancy with fungicide resistance issues in Australia. We can see it in the field with powdery mildew in barley. Our triazole fungicides such as Tilt (propiconazole), Folicur (tebuconazole), Proline (prothioconazole), Prosaro (prothioconazole and tebuconazole co-formulated) don’t work as effectively to control powdery mildew. With Septoria, we’re not yet seeing reduced activity in the field, but the samples are showing insensitivity in the laboratory, so there is increasing threat that we will see resistance to fungicides in the field. 

Europe and triazole use
What has happened in Europe with the triazoles over the last 20 years is that triazole fungicides have gradually become less effective against key diseases, firstly not working as effectively in the lab and then gradually being noted to be less effective in the field. That’s why with triazoles I think it’s important to talk about “fungicide insensitivity” and not “fungicide resistance.”

For example, it’s taken 20 years of exposing the Septoria pathogen population to the triazoles for them to become less effective. They still have activity but are now only 60 to 70 per cent effective when it used to be 90 to 100 per cent. So in Europe the triazoles and the strobilurins become less effective and ineffective for key diseases in a similar time period, but the triazoles had been gradually degrading in their effectiveness over time. 

Therefore with the terminology we use, I think it’s important to recognize we really have three basic modes of action that we use in broad acre cereal disease control – triazoles, strobilurins, and the new SDHIs [succinate dehydrogenase inhibitors].

With the triazoles I think it is probably more appropriate to call it “insensitivity” rather than resistance, since if you say to a grower, “It’s resistant,” the tendency is to think that it won’t work when in reality it is still partially effective.

With regard to the SDHIs, they’re not actually that new since the family of chemistry has been around for 40 years. But a new branch of SDHI chemistry is now taking Europe by storm, as the strobilurins now have less application because of resistance in key pathogens. But after only three years of commercial use with these new SDHIs, resistance is developing quickly in the net blotch and Septoria pathogens.

It’s really important to recognize that fungicide resistance is changing the way in which growers and advisors elsewhere in the world manage their cereal crops. In Australia, growers and advisors are just beginning on that resistance journey. You’ve already had some exposure in Canada to the fact that the strobilurins are at high risk of resistance development in the pathogen.  It begs the question, “What can you do about it?”

Click here for part two: The importance of multiple modes of action and linking pathology with crop physiology.
Published in Diseases
[Miss part one? Click here]
Importance of multiple modes of action

I’m horrified to hear that you can apply straight strobilurin fungicide to your crops, since there’s no other mode of action in the application to protect you from pathogen mutants that might be strobilurin resistant. If you went back to when the strobilurins were breaking down to Ascochyta in some of your pulse crops, it’s worth asking yourself, wouldn’t it have been better to have been using them in combination with other older multi-site fungicides in order to give the strobilurins a degree of protection? 

What’s now happening in Europe is that there’s a lot of dependence on the triazole fungicides since there is widespread resistance amongst a number of pathogens to strobilurins and increasingly to SDHIs. However it’s not the same with all pathogens. For example, the rusts – stripe rust, leaf rust – seem particularly stable. But with the necrotrophic diseases such as Septoria, such as net blotch, such as scald, populations are shifting. That stated, the triazoles remain the backbone of disease management programs all over the world.

It’s actually becoming more complicated for advisors in Europe. What’s happening is that different regions in Europe have different pathogen populations that are differentially susceptible to triazoles. What researchers are finding is that the triazole that works best in one area of Europe might not be the triazole that works best in another.

Now I know what you’re thinking: aren’t triazoles all from the same family of chemistry with the same mode of action? That’s where the resistance to these molecules is more complicated. For example, in one region, Folicur might not work very well on the Septoria pathogen, but a Tilt still does a reasonable job, depending on the history of fungicide use. Somewhere else in Europe, the exact reverse might be happening.

In Europe, they’ve set up a project called EuroWheat with 26 trials all across Europe examining triazole fungicides and their activity against key diseases, looking at not only what’s happening in the field in terms of foliar control, but then taking samples for lab analysis. It’s revealing that the pathogen is adapting in different regions differently, depending on what fungicides have been used, particularly the Septoria population. 

We are now beginning to see the same thing with Septoria in Australia. Some products that are effective on the mainland of Australia don’t work well in Tasmania. 

What can we do to protect fungicides going forward? We can minimize our use of them. Pick the best adapted, highest yielding, and most resistant varieties we can use. Such a choice might enable you to use just one fungicide application instead of two applications. In some parts of the world, there are guidelines advising using that active ingredient just once in a growing season. But probably the strongest message that comes out around the different regions of the world is the one about mixing different modes of action in cereal crops. 

So think about fungicides as part of that integrated disease management package – use them, but don’t overuse them. 

Across Europe at the moment, the new SDHIs are entering the market already mixed and formulated with a triazole in order to ensure the use of two modes of action in a fungicide application. “Make sure that you’re mixing different modes of action” is the strongest message that comes out of the scientific studies on fungicide resistance and it’s the one key take-home that I can give you. If you’re not mixing, ask why not.

There is one area that is important to clarify and that is with regard to fungicide rate and resistance. I don’t believe that there’s a lot of scientific evidence in the literature that suggests keeping fungicide rates high is a good anti-resistance strategy. Generally it is with herbicides, but I’m not sure that evidence exists for fungicides. Frank van den Bosch from Rothamsted in the U.K. did a literature search on 46 different fungicide studies and found there were more studies showing that increasing fungicide rate increased resistance selection pressure than the reverse. I think it’s more appropriate that we consider fungicide rate as an efficacy message, not a resistance message: i.e. what rate of fungicide is appropriate to obtain the best economic outcome. There are other things, like mixing our active ingredients with different modes of action, which are far more important in resistance management than considering fungicide rates.

Linking pathology with crop physiology
The other factor that is really important is linking our knowledge of pathology with crop physiology. Fungicides don’t only kill a disease, they keep plant leaves greener for longer, providing soil water is available to express the benefit of the disease free leaves. The upper leaves of the cereal crop canopy, particularly the top four, affect the ability of a plant to produce yield. In Australia, disease management strategies based on fungicides are particularly dependent on the presence of soil water to express the benefit of a fungicide both in terms of yield response and economic return. 

One of the things from Europe that I think they have right is that they talk all the time about “What are the key parts of the plant to protect from disease?” If you’re growing a cereal crop, what do the individual leaves on that cereal crop contribute to yield? That’s an incredibly important part of any strategy using a fungicide. We use fungicides to make money, not just control disease, and what’s been really good in Europe is actually characterizing which parts of the plant are best to protect from disease.

When it comes to thinking about fungicides, don’t only think about the disease. The time of disease onset in the crop will determine to which leaves fungicides are applied. In Europe, set development timings trigger the questions. “Do we have the disease? Are the conditions conducive for the disease? What’s this crop going to yield?” These are key questions that link the effect of the disease with the physiology of the crop.

Slide 29
slide 30
I think the key message when it comes to thinking about using fungicides as part of an integrated disease management package is to recognize that they’re not very effective at protecting tissue that’s not emerged at the time of application. Other than reducing overall inoculum in the crop, fungicides only directly protect the leaves and plant structures that are emerged at the time of application, so you need to target the most important leaves that contribute to yield.

The interaction of crop disease development and crop physiology is now a target for an Australian modelling team. In summary, it’s important to look at disease development and crop development together. 

I’d like to finish off with a reference to future developments. The Magnetic Induction Cycler (MIC) is about the size of a four-litre pail. From leaf samples using MIC, you can determine the genetic makeup of the pathogen population, determining not only the presence of genetic mutations that might affect fungicide performance but also the frequency of the population with that mutation. In the future this technology will assist the advisor in making the right product choice for individual paddocks. That technology moving forward could be linked with automated spore traps informing us when pathogen spores are moving into the paddock, their genetic makeup and how that’s going to affect product choice.

Lastly, I believe RNA interference technology has the potential to produce the next phase of environmentally-friendly fungicides. The technology is based on short segments of nucleotide that are absorbed into the plant and pathogen, and which can switch off the RNA messenger before it can synthesize the proteins for fungal development in that plant. It is very specific technology and offers some great potential for disease management in the future.
Published in Diseases
Blackleg is caused by two species of the pathogen. The major one is called Leptosphaeria maculans. The other one is a much less virulent species called Leptosphaeria biglobosa. For control of the disease, pathologists look at some of the weak links where we can apply most of the impact on the disease. The pathogen only survives on residues. If you don’t have a residue, it doesn’t survive well in the soil. That’s why rotation is important.

The pathogen produces a fruiting body in the spring called a pseudothecium or another type called a pycnidium. They produce spores that land on the cotyledons of canola. If you have insect damage from pests like flea beetles, the infection can be worse. With wounding, the pathogen can get into the cotyledon tissue even without moisture. From there the infection develops and you see the cankers at the base of the stem later on in the growing season.
Slide 4
Photo courtesy of Gary Peng.

There are three important things that can lead to an infection:
·      there’s residue to harbour the pathogen inoculum
·      you need to have early infection to get into the stem
·      insect damage may help the infection to occur more severely. 

The disease was very prevalent in the late ’80s, early ’90s. Then we introduced some resistant varieties in the early ’90s, which brought down the occurrence for many years. Partially that was resistance bred into varieties, but we also had three- or four-year rotations. That was a big part of the whole management effectiveness.

In the last five to six years, the disease incidence has been creeping back up to 20 to 25 per cent in Alberta and Manitoba, and about 10 per cent in Saskatchewan. However, the average severity remained below level 1 (light). Research by Sheau-Fang Hwang in Alberta indicates that in most years, this level of severity could result in a yield loss of about two to eight per cent on a susceptible variety. But from a trade perspective, our trading partners want to see the disease level trend going down.

Why the upward trend?
The first reason for an increase in blackleg incidence is likely the change of the pathogen population, which is adapting to the resistant varieties. The pathogen population may be becoming more virulent or with a greater proportion of virulent isolates in it. 

Plant breeders have used major gene resistance to control the disease. The resistant gene blocks the infection by the pathogen carrying the corresponding avirulence gene. For example, an Rlm3 resistant gene would block the pathogen with avirulence AvrLm3 gene (abbreviated to Av3). It might be like a lock-and-key, but for some reason, over time, the Av gene may change and the resistant gene may not be able to recognize it.

My colleague, Randy Kutcher, looked at the change in pathogen populations in 2007 when he looked at the avirulent gene prevalence on the Prairies. In his work looking at 800 isolates of L. maculans, the percentage of Av2 and Av6 genes were very high in the population, and the others at more moderate to low levels. Further work in 2010 and 2011 with Dilantha Fernando at the University of Manitoba found the picture had changed quite a bit. The presence of the Av3 and Av9 genes had decreased quite a bit, but at the same time Av7 seemed to be increasing quite a bit. That means the Rlm3 gene would be less likely to be effective across the Prairies because the Av3 gene had changed mostly to the virulent type. The Rlm3 gene was first introduced back in early 1990s and has been used for over 20 years.

Other research in Fernando’s lab also looked at what resistant genes are present in 206 varieties/breeding lines in Western Canada. The resistance gene that was predominantly found was Rlm3 in around 70 per cent of the varieties/breeding lines. There was also a bit of Rlm1 detected as well. Overall, the diversity of R genes is still quite limited in the germplasm tested. The important message is that Rlm3 is not going to remain effective on the Prairies because the corresponding Av3 gene is already fairly low in the pathogen population. 

However, when we looked at field data in Alberta and Manitoba, while the occurrence of other Av genes was high, disease levels ranged widely. This told us there was something else going on, which we called non-specific resistance in our varieties, although the effect was definitely less than the major gene resistance.

We further investigated this non-specific resistance in our varieties. We tested commercial varieties with a pathogen without a corresponding Av gene so any resistance observed would be due to non-specific gene resistance. Almost all the varieties had a slightly smaller amount of the disease on inoculated cotyledons than the susceptible Westar. At the same time, it’s a totally different kind of resistance reaction as opposed to the major gene resistance. It would not stop the infection completely – it just slowed it down a little bit, and on some varieties, substantially.

A further look at three of those varieties found the progress of plant mortality originated from cotyledon or petiole inoculation was somehow reduced, but varied between the varieties. Using a fluorescent protein gene labeled isolate, photography was able to show the reduced spread of the pathogen in the cotyledon compared to the susceptible Westar variety.

If you can slow down the movement from the cotyledon via the petiole into the stem, there may not be enough of the pathogen getting into the stem before the cotyledons drop off. This is one of the reasons that non-race-specific resistance works in some of those varieties we have.
SLIDE 22
Photo courtesy of Gary Peng.
Click here for part two: management strategies

This article is a summary of the presentation “Managing blackleg of canola in Western Canada,” delivered by Dr. Gary Peng, Agriculture and Agri-Food Canada, Saskatoon, at the Field Crop Disease Summit, Feb. 21-22, 2017. Click here to download the full presentation.

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Top Crop Manager's Herbicide Resistance Summit has been announced! Sign up today for early-bird pricing: https://www.weedsummit.ca/event/registration

Published in Diseases
Management strategies
The Canola Council of Canada is proposing a risk assessment chart. If you have a four-year rotation, likely your risk of having blackleg is very low. We know it’s effective, but I realize it isn’t always easy to implement. [Miss part one? Click here]

Scouting is important because it gives you a sense of your risk situation. There is an easy procedure that can be used to assess risk. After swathing, pull 50 plants, cut the stems at the base of the plant where blackleg develops and assess the damage to the stem. Use the pictorial guide I developed to assess the level of disease. If you don’t have any disease or very light disease, your variety might still be holding fairly well as long as you continue with longer crop rotation. But if you have an R-rated variety with a much higher disease level than you expected, your variety may not be holding up.

If you do want to switch varieties, try to rotate to another major resistance gene. We currently don’t have enough public information from seed companies to know what their resistance sources are. The Canola Council of Canada has proposed a new resistance labelling system to show the resistance gene labelling. It is voluntary and may start in 2018.   
Slide 25
Photo courtesy of Gary Peng.

If you don’t have any issues or major blackleg damage, there’s no urgency for you to switch between resistance groups right away, but it’s always a good practice to rotate them if you know the R genes. We understand 90 per cent of growers would rotate among the different varieties today mostly for weed management options. There is a similar principle in rotating varieties for disease management.

I want to also stress that we have quite a diverse pathogen population on the Prairies. In reality, over 90 races have been detected. That means with every known resistance gene, there is a different virulent isolate out there that would be able to overcome the resistance right away. We really need to consider, if we have different R genes available, rotation of those R genes. And we also need to maintain the non-race-specific resistance, which has been serving us relatively well.

What about fungicides?
Research on various fungicide products and application timings has been conducted. One involved 17 station years across the Prairies. We used four fungicide products, mostly the strobilurins and a triazole, and a combination of both active ingredients. We looked at applications at the two- to four-leaf stage, the bolting stage, and an application at both stages.  We also compared a susceptible variety with a resistant and a moderately resistant variety.

When we put all the data from 17 station years together, the early application of a strobilurin fungicide reduced the disease severity and also increased yield quite significantly compared to the non-treated check. The average disease severity was around about 1.5. The later application did not work, which makes sense because the key stage of infection is the cotyledon. 

We further looked at the data and divided it into two scenarios: those fields with much lower disease levels of around a 0.5 severity rating, and those with a disease severity of about 2.5. In the fields with low disease severity, the fungicide application did not provide any yield benefit. Where disease severity was about 2.5, a fungicide application at the two- to four-leaf stage reduced the disease severity significantly and also increased yield by seven bushels per acre compared to the non-treated check. 

However, these results were on Westar – a susceptible variety that was used to show the worst case when an R/MR variety is losing resistance. We looked at R/MR canola varieties at the 17 site years and found none of the fungicide applications were effective in providing a yield advantage (also indicating that the R/MR varieties have stronger tolerance to blackleg impact). That means if you have a certain level of resistance in your variety, in most cases the fungicide application would not provide a substantial yield benefit.

Where a fungicide treatment might come in is if the varieties you have been using are starting to show signs of an increased amount of blackleg. You should scout crops and assess the level of disease development over time. Also consider the length of the crop rotation and other risk factors outlined by the Canola Council of Canada. If you feel you are at high risk, an early application at the two- to four-leaf stage may be warranted.
Risk chart


This article is a summary of the presentation “Managing blackleg of canola in Western Canada,” delivered by Dr. Gary Peng, Agriculture and Agri-Food Canada, Saskatoon, at the Field Crop Disease Summit, Feb. 21-22, 2017. Click here to download the full presentation.

Don't forget to subscribe to our email newsletters so you're the first to know about current research in crop management.

Top Crop Manager's Herbicide Resistance Summit has been announced! Sign up today for early-bird pricing: https://www.weedsummit.ca/event/registration
Published in Diseases
Every farmer has to deal with weed control. With the introduction of new weeds compounded by the growing issue of herbicide resistance, choosing effective herbicides has become a daunting task. Savvy Farmer, Canada’s foremost on-line authority on crop protection, has released two free new apps that every farmer who deals with weed control should have on their smartphone or tablet.

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Download both apps today by searching for “Savvy Weed” or “Savvy Resistance” in either the App Store (Apple) or Play Store (Android)
Published in Corporate News

Small planes have been flying over local farms and taking aerial photos for decades. Now, individual farmers are able to get an aerial view of a field using a small remote-controlled drone equipped with a camera.

But Agriculture and Agri-Food Canada (AAFC) has been receiving information from a far more sophisticated data collection network for at least the past 30 years, according to Leander Campbell.

Campbell, a geographer who specializes in geomatics, works as a remote sensing specialist with the Earth Observation team at AAFC. He says most of his work is on the AAFC Annual Space-Based Crop Inventory. He gets his data in the form of imagery from satellites and uses it to produce an accurate national crop map.

“The crop map, the one I work on, is at a 30 metre resolution so each pixel is a 30 metre by 30 metre square. It covers all of Canada,” he explains. Campbell adds one of the crops mapped in year one of the crop inventory in 2009 was soybeans. Since then, the data has shown how the crop is spreading west and north on the Prairies.
WTCM30.1 MB soybean 2009 2012
Campbell extracted only the soybean fields (in yellow) from Manitoba crop maps for the years 2009 and 2012.
Photo courtesy of Leander Campbell, AAFC.

The network Campbell gets his data from consists of several international satellites. The American satellite Landsat-8 provides optical data to create crop maps anyone can download. In addition to these data, Campbell’s team also uses microwave data from the Canadian RADARSAT-2 satellite.

The combination of optical and microwave data has been shown to produce more accurate maps than maps created from either single source. These maps are created and validated using data collected by people in the field. For the Prairies, “we have agreements with the provincial crop insurance companies,” Campbell says. “It’s not a perfect system but we’re about 85 per cent and 90 per cent accurate and working to improve that.”

Satellites don’t stay in orbit forever and Campbell says a backup is always an asset. Canada has plans to launch a constellation of three microwave satellites in 2018, the RADARSAT Constellation Mission (RCM), to gather data that’s even more detailed and precise than what’s available now.

“There are more uses than I ever thought of,” Campbell says. For instance, crop placements, crop monitoring, research, commodity marketing, land use management and even flood forecasting in Manitoba.

Microwave data collected by the European SMOS (Soil Moisture and Ocean Salinity) satellite allows Campbell’s team to operationally measure soil moisture in the top five centimetres of soil. He says most people don’t realize the Earth naturally radiates very low-level microwave energy and a satellite in space can pick up the variations in waves. Water absorbs microwave energy. When the microwaves radiate out from the Earth and pass through the soil, some of them are captured by moisture in the soil. 

According to Campbell, in September 2015, Statistics Canada did not do a farmer survey, opting to use AAFC climate data to complete their crop yield forecast. Satellite data can describe how agriculture land is changing or evolving over the years, whether it’s farmland expanding by eliminating small woodlots or urban expansion covering agricultural land. These phenomena can be monitored year over year using the AAFC crop maps.

Campbell has compiled maps that helped document the areas where clubroot is developing in canola. Scott Keller, a farmer from Camrose County in Alberta, contacted AAFC, asking Campbell if he could map Camrose County to determine how often canola was grown in particular fields. Keller wanted to determine which fields grew canola most often, either in a tight rotation over multiple years or in succession, in order to determine if there was a correlation between the escalation of clubroot and the rotation schedule.
Canola crop
Map created by Campbell to monitor canola crop frequency in Camrose County, Alta. 
Photo courtesy of Leander Campbell, AAFC.

That’s just one way satellite data can support crop management. Campbell says he’s confident that as computer technology and Internet costs come down, AAFC will be able to create more products from data because they can monitor specific areas once or several times over a growing season, or over years.

Campbell and his six colleagues who create the crop maps, soil moisture reports and the normalized difference vegetation index (NDVI) reports have an international presence as well. “I know some of our maps are incorporated into more global crop assessments for global market information, especially the NDVI maps,” Campbell says.

He explains that several nations around the world use satellite imagery to monitor their own crops. They meet on a monthly basis and compare data on major crops like corn, wheat, rice and soybeans through an organization called GEOGLAM. The group’s website states its vision is to “use coordinated, comprehensive and sustained Earth observations to inform decisions and actions in agriculture through a system of agricultural monitoring.” https://cropmonitor.org

Canadian farmers can access existing maps and data products online from the AAFC website. Because these maps are highly detailed, producers may experience difficulty downloading them on devices while in the field, but they can still view them online. According to Campbell, that’s the sort feedback he needs to hear from farmers.

“In our little world we have all these high-end computers and that works fine for us, but it may not be the most practical thing for others,” Campbell says. And, he’s looking forward to finding more ways to help farmers and make the website more user-friendly.

As satellite mapping matures, both farmers and scientists will view agriculture in new ways and Campbell is enthusiastic about the possibilities. “It’s a really exciting time to be in our field,” Campbell says.


This article originally appeared in the June 2016 issue of Top Crop Manager West

Published in Emerging Trends
Page 1 of 19

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