International Wheat Congress delegates meet in Saskatoon to discuss how to increase production of the crop
Hundreds of the world’s brightest plant scientists congregated in the heart of the western Canadian grain belt last week to discuss ways to expand production of one of the planet’s most widely grown grain crops.
The International Wheat Congress, held July 21-26 in Saskatoon, attracted roughly 900 scientists from around the world, including experts in genomics, plant breeding and wheat agronomy.
The event was the first of its kind, combining sessions on genomic research, as well the importance of field-level management strategies.
“This is the first International Wheat Congress so it’s evolved from an event (the International Wheat Genomics Symposium) … that used to be focused specifically on genomics,” said Brian Beres, an Agriculture Canada research scientist from Lethbridge who chaired several sessions at the event.
“The idea was that going forward … we needed to have a forum that is much more cross disciplinary, and if we we’re going to say that we need more cross disciplinary research at an international level, we also need a forum in which those same researchers can sit down together, in the same room and the same place, so that some of those synergies can start to happen.”
Wheat is one of the most widely grown crops in the world and global demand continues to grow.
Consumption is expected to rise by about 50 percent over the next 30 years or so.
According to the International Maize and Wheat Improvement Center (CIMMYT), about 2.5 billion people in 89 countries depend on wheat as a food staple.
As global wheat demand increases, resources used to grow the crop — including water, farmland and fertilizer — are becoming more scarce.
Against this backdrop, scientists are looking for ways to expand global wheat production sustainably, squeezing more grain out of every unit of energy and resources invested.
Enhancing wheat’s yield potential through genomic research and modern plant breeding was a dominant theme during the event.
Another recurring theme was optimizing production by learning more about production-limiting factors related to the environment and management practices.
In a July 25 plenary presentation, U.S. Department of Agriculture scientist Jerry Hatfield spoke to delegates about yield gap, the difference between maximum genetic potential and actual yields.
Under perfect environmental conditions and optimal management systems, the genetics contained in seed will reach their optimal potential.
But when environmental and management-related limitations are introduced, the productive capacity is reduced.
Hatfield said yield gaps in wheat are variable between different regions, depending on climatic conditions and prevailing management practices.
They are typically highest in dryland production areas, most notably in drought-prone countries including Canada and Australia.
In his presentation, Hatfield presented data that showed Canada and Australia with average annual yield gaps of 24 percent during a 57-year period ending in 2017. Researchers are also examining the impact of management practices as a determinant of yield gaps.
Sheri Strydhorst, a research scientist with Alberta Agriculture, told delegates that varietal selection should be taken into consideration when determining nitrogen application rates.
Strydhorst presented data that suggested optimal fertility rates can vary greatly between different varieties of hard red spring wheat, particularly if growers are looking to maximize yield potential and attain grain protein levels of 13.5 or higher.
Under controlled trials and intensive management practices, the AAC Brandon variety produced yields of 7.3 tonnes per hectare at some Alberta locations in 2018, compared to average yields of 3.6 tonnes per hectare among the province’s commercial growers.
The intensive management regime used in the trials had a target plant density of 377 plants per square metre and applied nitrogen rates of 160 to 225 kilograms per hectare.
Under the same intensive management scenario, AAC Viewfield produced yields of 7.7 tonnes per hectare, compared to 5.3 tonnes per hectare in 2018 regional variety trials and 4.4 tonnes per hectare, on average, under field-scale production, primarily among pedigreed seed growers.
Strydhorst’s presentation supported the notion that different varieties of wheat typically have different genetic yield potential and different optimal fertility requirements.
The relationship between nitrogen requirements and target protein levels was demonstrated in trials conducted at Bon Accord, Alta., and Vermilion, Alta., in 2017 and 2018.
Those trials suggested that AAC Viewfield required significantly more nitrogen than AAC Brandon (an additional 39 to 45 kilograms per hectare depending on location) to attain minimum protein levels of 13.5 percent.
British research scientist Alison Bentley from the National Institute of Agricultural Botany (NIAB) at Cambridge told congress delegates that the relationship between nitrogen use, grain protein and grain yield is an area that requires further examination, particularly in light of concerns over nutrient stewardship and the environmental impacts of excess fertilizer use.
In her presentation, Bentley suggested that research focused on lowering the nitrogen demands of wheat without negatively impacting yield or quality will be a key to sustainable wheat production.
Bentley said world demand for total fertilizer nutrients is growing at a rate of about 1.8 percent per year.
Along with water, nitrogen availability is recognized as the most important crop-yield limiting factors in the world, she added.
However, excess fertilizer use contributes to unnecessary greenhouse gas emissions.
In the United Kingdom, assessments of optimal nitrogen response in wheat suggest that target application rates should be in the range 80 to 160 kg per hectare, considerably less than the blanket industry recommendation of 200 kg per hectare in the U.K.