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Climate change presents unique challenges for grape growers across the world. In Ontario, three distinct viticultural regions are experiencing climatic shifts towards warmer growing seasons. According to historical records collected from Environment and Climate Change Canada, Lake Erie North Shore has transitioned from an intermediate-to-warm growing season classification, the Niagara Peninsula from the lower to upper limits of the intermediate zone, and Prince Edward County from cool to intermediate, when analyzing their average growing season temperatures. Terroir is directly related to vine water status, an indicator of grapevine stress. Biophysical responses controlled by air temperature and precipitation include fluctuations in vapour pressure deficits, evapotranspiration, and water-use-efficiency rates, as well as soil water content levels. By conducting an extensive literature review, the development of a conceptual model addresses how variations in climatic controls, under the scope of climate change, may influence grapevine water status, biophysical responses, and associated production outcomes for Ontario vineyards. Cool-to-intermediate air temperatures, when paired with increased precipitation will lead to no or low vine stress, increasing photosynthesis and transpiration rates, and variable plant water-use-efficiency levels, producing higher yields and lower quality grapes, if no management strategies are applied. Oppositely, higher air temperature as a product of climate change, when paired with variable precipitation may produce mild-to-severe stress, reducing yield, and increasing grape quality. With the appropriate management strategies, both traditional and new, growers may be able to accommodate for the influence of climate change on their vineyards.
Yield and quality improvements in Canada Western Red Spring (CWRS) wheat (Triticum aestivum L.) are increasingly difficult to attain, which behooves a systems approach to unlock genotype (G) × environment (E) × management (M) synergies. This 25 site-year study was designed to assess a G × E × M systems approach to improve CWRS agronomics, quality, and N use efficiency (NUE). The investigation consisted of genetics (AAC Viewfield vs. AC Stettler), N source (untreated urea; urea + urease inhibitor, N-(n-butyl) thiophosphoric triamide (NBPT); urea + nitrification inhibitor, nitrapyrin; urea + dual-inhibitor (NBPT + dicyandiamide); and polymer-coated) and N timing/placement (all-banded at planting, two-split applications and three-split applications), deployed across diverse soil zones in western Canada. Differential yield responses were observed between cultivars as AAC Viewfield produced superior yield over AC Stettler (+4.3%) in black and grey soils, while yield attainment was similar in dark brown soils. Genetic improvement over AC Stettler seemed most apparent in water abundant environments; however, AC Stettler was often superior in drier conditions. All N sources produced comparable outcomes for yield, quality, NUE, and net returns. In black and grey soils, adopting either all-banded or two-splits improved grain yield due to augmented seedling vigor, heads per plant, and N recovery. The timing of split-applications introduces more risk to yield and is likely attributed to a poorly developed source:sink relationship in the critical growth period if applied late to optimize grain protein. This highlights the complexity of the system and balance needed to harness the potential synergy between G, E, and M components.
John T. O'Donovan, Hiroshi Kubota, K. Neil Harker, T. Kelly Turkington, William May, Eric N. Johnson, Brian Beres, Marta Izydorczyk, Lori Oatway, Henry de Gooijer, Alick Mulenga, Timothy Schwinghamer, Breanne D. Tidemann
The production of barley cultivars with malting and brewing quality characteristics is subject to strict grading and technical standards for the end-use market. Environmental and management factors can significantly alter grain quality, and the qualities required for malting. Crop and kernel uniformity are critical factors where variability can exceed the tolerance for meeting malt quality. A practice to address variations in crop maturity is the application of pre-harvest glyphosate. Pre-harvest glyphosate applications can, however, alter malting characteristics in barley, and, if mis-timed, can also reduce yield. A 4-year study at five locations in Alberta and Saskatchewan from 2013 to 2017 was conducted to determine the effects of pre-harvest glyphosate applications on malting barley characteristics. Glyphosate was applied at 900 and 1125 g ae ha−1 on malting barley cultivars ‘CDC Meredith’ and ‘AC Metcalfe’ malting barley at soft dough, hard dough, and physiological maturity growth stages. Yield reductions of up to 12% were observed from glyphosate applications at soft dough, and yield was maximized with applications at physiological maturity. Glyphosate application, at two rates, reduced percentage plump kernels, but did not affect kernel weight or protein concentration. The growth stage of barley plants did not provide an accurate indicator of seed moisture levels at the time of application, which motivated our conclusion that glyphosate applications can be mistimed by inaccurate indicators. The results motivate our questioning of the utility of pre-harvest glyphosate applications, given the adverse effects to barley yield and quality observed, even when applied according to the label instructions.
Information is required to understand how novel biodiversity strategies can improve cropping system resilience to climate change. A “business as usual” (BAU) rotation (wheat–canola–wheat–soybean) was compared with a “warm-season crop” (WS) rotation (corn–sunflower–dry bean–canola); a “biodiverse” (BD) rotation (fall rye with cover crop– corn/soybean intercrop—pea/canola intercrop–green fallow mixture); a “perennial grain” (Kernza) rotation (Kernza grain intermediate wheatgrass); and an organic (ORG) rotation (millet-green fallow mixture-wheat). Drought conditions prevailed in both study years. The BAU rotation had the lowest average yield (1821 kg ha−1 compared with 2533 and 3083 kg ha−1 for the BD and WS rotations, respectively), less post-harvest residual biomass, and a lower net return than the WS rotation. The WS rotation was limited by herbicide-resistant weeds in dry beans. Kernza seed yield was five times lower than for spring wheat. ORG wheat yielded the same as other wheat and had a higher net return. Live roots days, a measure of soil health potential, were 95 for the BAU rotation and 174 and 113 for the BD and WS rotations, respectively; the most were recorded for Kernza (365). Seasonal crop growth duration was increased by including Kernza and fall rye for early season growth, and corn, sunflower, a corn–soybean intercrop, a cover crop, and fall-seeded rye for late season growth. WS and BD rotations outperformed the BAU rotation and the BD system accomplished this with half the N fertilizer. Results demonstrate the potential of biodiverse rotations; barriers to their adoption should be addressed.
Current practices of flea beetle (Phyllotreta spp.) control in Brassica napus L. rely heavily on seed treatments and due to growing concerns regarding the safety of such treatments on non-target and beneficial insect populations, genetic resistance would be beneficial for a more balanced integrated pest management strategy. However, none of the registered B. napus. canola varieties exhibit measurable resistance to flea beetle injury. To this end, an evaluation of 14 winter-type B. napus breeding lines and 15 spring-type B. napus breeding lines for resistance to flea beetle feedings was conducted, as it was found that at least one line in each family exhibited noticeably reduced flea beetle damage compared to sister lines in a breeding nursery. The study revealed natural genetic variation within B. napus for flea beetle antixenosis which could be used by dedicated breeders to develop canola varieties with higher levels of flea beetle resistance. Data indicated that host plant resistance did not vary between feeding by newly emerged adult flea beetles in the fall and the overwintered adults in the spring in either winter-type or spring-type canola, as well as for adult feeding preferences. This indicates that favourable genes identified in in either habitat-type could be used interchangeably to confer resistance even though the flea beetle life cycle is different for each planting period, while either overwintered adults or newly emerged adults can be used to evaluate feeding damage.
Diverse growing season weather in western Canada has large effects on wheat quality. Management practices, such as pesticide application, may also affect wheat quality, but are largely unknown. This study measured pesticide application effects on grain quality for six hard red spring wheat cultivars over three growing seasons at four prairie locations. Each siteyear included (i) an untreated control, (ii) fungicide applied at anthesis for Fusarium head blight (FHB) control, (iii) pre-harvest glyphosate applied at physiological maturity, and (iv) a combination of both pesticides. Generally warmer and drier conditions in 2015 and 2017 compared to 2016 resulted in wheat with higher grades, test weight, thousand-kernel weight, and grain protein content but lower Fusarium damaged kernel (FDK) content. Siteyear, reflecting weather variation by location, was the major factor affecting grain quality, contributing from 39% to 77% of total variance. Rainfall variation was greater than that for air temperature and appeared to be the main weather factor affecting quality. Genotype had a significant impact on grain quality but contributed 1%–20% of total variance. The pesticide treatments had a significant effect on several quality parameters, but they contributed only 0.2%–2% to total variance, implying that they have no detrimental effect on wheat grain quality when applied as recommended. Fungicide significantly reduced FDK level in four of ten siteyears, all with high FDK levels, but not when applied at the low FDK siteyears. Fungicide for FHB control should be used only when weather is conducive to high FHB disease pressure.
The evolution and spread of herbicide resistance among the weed community has increased interest in alternative weed management strategies such as harvest weed seed control. Western Canadian producers have begun adopting physical impact mills as an additional weed management strategy. A survey of early adopters of physical impact mill technology in Canada was conducted to better understand the motivations behind producers adopting, initial experiences, and research needs. Ten producers responded to the survey, accounting for 18 out of an estimated 30 impact mills in use in Canada, believed to be located primarily in the Canadian Prairies. These producers were mainly from larger farms (>4000 ha), equipped the majority of their combines (75% average) and used the mills in essentially all crops grown. The majority of respondents were located in Saskatchewan, with two mills being used in Alberta. Wild oat (Avena fatua L.) (60%) and kochia (Bassia scoparia (L.) A.J. Scott) (50%) were the weeds most frequently mentioned as specific motivators of impact mill adoption. Average increased fuel cost from the mill was estimated at CAD$3.46 ha−1, with average annual maintenance costs of about $1500 per impact mill. Producers relied on information from mill companies and other early-adopting farmers primarily, followed by extension talks and social media. Research needs were also identified by producers that could inform the future direction of harvest weed seed control research in Canada. Future research should focus on confirming efficacy, optimizing combine settings, and looking at integrated systems with precision agriculture technologies.
Herbicide-resistant weeds threaten contemporary agriculture by reducing crop yields and quality. Monitoring of herbicide-resistant weeds is essential to the development of informed integrated weed management (IWM) strategies. In 2019 and 2020, a randomized-stratified preharvest survey of 419 fields in Saskatchewan, Canada, was conducted to determine the distribution, frequency of occurrence, and impact of herbicide-resistant weeds. Mature seeds were collected from uncontrolled weeds in each field. The samples were tested for resistance to acetyl-CoA carboxylase (ACCase) and/or acetolactate synthase (ALS)-inhibiting herbicides using whole-plant bioassays under a controlled-environment. In 2019/2020, herbicide-resistant weeds occupied 72% of the surveyed fields, corresponding to an estimated 6.2 million ha of annual cropland and a total field area of 11.4 million ha. Herbicide-resistant weeds cost Saskatchewan farmers an estimated $343 million CAD annually in reduced crop yields and quality, and increased weed control expenditures. Wild oat (Avena fatua L.) had the greatest impact among grass weeds, with ACCase inhibitor resistance documented in 77% and ALS inhibitor resistance in 30% of fields where the weed seeds were collected and tested (47% and 18% of all fields surveyed, respectively). Multiple herbicide (ACCase and ALS inhibitor)-resistant wild oat were documented in 26% of the tested fields. Kochia (Bassia scoparia (L.) A.J. Scott) had the greatest impact among broadleaf weeds, where 100% of the samples tested were ALS inhibitor-resistant (39% of all fields surveyed). The growing prevalence of herbicide-resistant weeds in Saskatchewan warrants further adoption of IWM where non-chemical tactics play an important role in stewardship of the remaining effective herbicides.
Increased adoption of no-till and extensive cultivation of herbicide-resistant (HR) crops in low diversity rotations are some transformations that occurred during the 1970s–2000s in western Canada. Historical data analysis of weed survey data (Saskatchewan, Manitoba, and Alberta) in canola crops and a canola rotation field experiment were used to understand how tillage, herbicide-resistant cropping systems, and the temporal frequency of canola in the rotation can impact weed abundance, composition, and diversity in the Canadian prairies. Weed survey data revealed that the spatial frequency of many weed species declined in years after 1995 compared with before 1995, the year HR cultivars were introduced. False cleavers (Galeum spurium L.) and volunteer wheat (Triticum aestivum L.) were the only species showing a continuous increase in frequency throughout the surveyed years. Species richness showed no trajectories but varied depending on climatic conditions. Roundup-Ready (RR) systems were associated with green foxtail (Setaria viridis L.) irrespective of their frequency in the rotation. Continuous canola systems had an obvious association with chickweed (Stellaria media L.) regardless of herbicide systems. Wild oats (Avena fatua L.) were predominant in the longer rotations with glufosinate and imidazolinone-resistant canola. In the field study, weeds associated before in crop herbicide application were relatively controlled after herbicides were applied, except for foxtail barley (Hordeum Jubatum L.), which was not controlled in most HR systems. Overall, both weed survey data and field experiment data revealed greater control of most weed species due to the adoption of HR canola cultivars and the associated cultural practices.
Camelina (Camelina sativa) elite germplasm C17-833 was developed at the Agriculture and Agri-Food Canada Saskatoon Research and Development Centre. It was developed through hybridization of camelina cultivar AAC 10CS0048 and F4 line 11CS0231-24-10 and subsequent pedigree selection. C17-833 yields significantly higher (114%) than the check cultivar AAC 10CS0048. It also has significantly higher seed oil content (42.6% vs. 41.9%) and significantly larger seeds (126%). C17-833 has very good resistance to downy mildew disease caused by Hyalonospora camelinae and is adapted to all soil zones of the Canadian Prairies.
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