Blog: The Wheat Sheaf

How Producers will likely live in the future with Fusarium Head Blight (FHB)

With a title like that who wants to read the rest, correct? But just to be clear, Fusarium Head Blight (FHB) is a complicated disease and as a disease it is not likely to be eradicated any time soon. Agronomic tools and genetic advancements are beginning to be made which help us understand the disease better and the future should look a lot different than the present situation for sure, just not as fast a change as we would likely all want is all.

We are entering an era when the complete genome of wheat, (or its genetic make-up and what genes are there and where), has been successfully mapped out which is a very important piece of the genetic puzzle previous plant breeding attempts had to do without for the most part. Genomic mapping is like a road map for plant breeders. However, unlike many other diseases that attack our wheat and other cereal crops, FHB has many factors that influence its ability to cause infection and or to produce vomitoxin like deoxynivalenol (DON) to which environment and interaction with environment is a huge part of this ability. In this “Wheat Watch” you see the Alberta Wheat Commission (AWC) has announced of a wonderful new tool for helping us predict when the environment is conducive to the infection of FHB on our wheat so we can make informed decisions based on your particular crop and the stage it is at as to whether foliar fungicides should be part of the plan. This environmental information is another leap forward to helping us deal with the disease.  As well, Dr. Doon Pauly has talked about Best Management Practices with FHB as there are other “pre-conditions” that we as producers can control or avoid so that we do not help FHB to get established or become a bigger problem than need be. In the end however, it is recognized that genetics hold the best hope for combating this disease in the long run.

There is a lot of effort being spent looking at the genetic aspects of FHB and there have been a couple success stories to date were by the wheat plant itself has been bred to be a resistant variety toward the disease. First came from a Canada Western Red Winter (CWRW) milling quality winter wheat called AC Emerson, distributed by CANTERRA Seeds Ltd. that was developed through the Lethbridge Agriculture and Agri-Foods Canada (AAFC) winter wheat breeding program. It may not be the highest yielding CWRW according to regional variety trial results, but if offering FHB resistance was not enough it is also resistant to stem and stripe rust, the latter being another major concern among winter wheat growers if not with spring wheat producers too. You will often hear me say “It’s not all about the yield as other things help pay your bills too,” and AC Emerson is one of those examples to support that quote. We need to get past just looking at the yield data columns and put more emphasis on the other attributes offered by a particular variety then we have traditionally. To put it bluntly, I would disagree with anyone who says it is the yield and quality only that pays the bills because a strong disease package and or agronomic trait package (such as straw strength, lodging resistance, height, etc.) will only help preserve those yield and quality potentials.

The second and newest break-through just became commercially available this past spring and indeed involves a breakthrough in spring wheat. AAC Tenacious VB is a Canada Prairie Spring Red (CPSR) wheat and like AC Emerson was for winter wheat, AAC Tenacious VB is doing for spring wheat. It is a variety distributed by Alliance Seed and is resistance to FHB, Leaf Rust, Stripe Rust and Loose Smut, backed by moderate resistance to Stem Rust and Bunt. This is an excellent disease package that will go a long way to protecting your yield and quality potentials in your field. To top it off, it is a Varietal Blend which is to say it is Wheat Midge tolerant too. AAC Tenacious is also similar to AC Emerson with respect to yield, in that it is not the highest yielding line available, but in the “medium yield” category, where it likely fits the best anyway, it yields well. Where this variety will shine is in areas with history of FHB pressure and or Stripe Rust in particular, or if near or in a known Wheat Midge area.

It would be great if I could conclude this article with a prediction we are now finally going to see a whole gamut of new spring wheat lines of all classes and types, or winter wheat lines for that matter, with FHB resistance in them, but after talking to wheat breeders like Dr. Rob Graf out of AAFC Lethbridge, simply crossing with lines that already have the resistance does not always pan out with resistance built into the progeny as it may for other “simpler to work with” diseases. Having said that though, plant breeders now have a genomic map and new technologies for breeding to use, such as CRISPR (a highly targeted and thus safer and cheaper method) to use, plus a better understanding of the interactions between genes involved with FHB resistance thanks to so much research effort of late on this disease. We will be seeing more FHB resistant lines in the future for sure, but we will just have to be patient is all. In the meantime, although recognizing genetic resistance is the ultimate and best way to deal with FHB, we need to make full use of Best Management Practices, predictive modelling for peak infectious periods, and use resistant varieties where applicable.




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