The Peace River region is one of the northern agricultural frontiers in Canada, undergoing farmland expansion as well as intensification with input-intensive industrial agriculture. The cropping systems evolved with the rotations between annual grain and perennial forage crops as a prudent adaptation to fragile, crust-forming, runoff-prone, poorly developed, platy-structured acidic Luvisolic soils. In recent years, there is a decline in the acreage of perennial forage seed crops leading to simplified low-diversity cropping systems with heavy reliance on external inputs. The production systems have been prone to the rapid evolution of herbicide-resistant weeds, and outbreaks of crop diseases and insect pests in the face of global warming. A number of studies conducted in the Peace River region and other parts of North America have shown multiple benefits of integrating perennial forage crops in the cropping systems. By virtue of high root-to-shoot ratio and perennial growth, forage seed crops can provide multiple ecological services in the fragile Luvisolic soil through increased soil organic matter, carbon sequestration, soil biological diversity, soil structural improvement, nutrient mobilization, crop protection and environmental health, thereby creating conducive effects to the resilient performance of the cropping systems. This review discusses the merits of crop rotations in general and those of perennial forage seed crops in particular in the face of changing climate, with special reference to studies conducted in the Prairies and Peace region of western Canada. Research opportunities are highlighted to elucidate multidimensional ecosystem services from diversified cropping sequences integrating perennial forage seed crops.

Au Canada, la région de la rivière de la Paix marque une des limites les plus nordiques de l’agriculture. Les terres arables continuent de s’y étendre et l’agriculture industrielle s’y intensifie grâce à l’usage massif d’intrants. Les systèmes culturaux ont évolué et la prudence a voulu qu’on adopte des assolements annuels de céréales et de plantes fourragères vivaces en raison de la fragilité du sol, constitué de luvisols acides, mal développés, à structure lamellaire, qui forment des croûtes et sont sensibles au ruissellement. Depuis quelques années cependant, on assiste à une diminution de la superficie consacrée à la production de graines de plantes fourragères vivaces et à l’avènement de systèmes culturaux plus simples, moins diversifiés, qui reposent lourdement sur l’apport externe d’intrants. Avec le réchauffement climatique, pareils systèmes favorisent l’apparition rapide d’adventices résistantes aux herbicides, mais aussi de maladies et d’infestations de ravageurs. Plusieurs études réalisées dans la région de la rivière de la Paix et ailleurs en Amérique du Nord ont illustré les nombreux avantages de l’intégration de plantes fourragères vivaces aux systèmes culturaux. En raison de leur rapport racines:pousses élevé et de leur caractère vivace, les cultures grainières de plantes fourragères pourraient améliorer de diverses manières l’écologie fragile des luvisols (hausse de la quantité de matière organique, séquestration du carbone, diversité de la biologie du sol, amélioration de la structure du sol, mobilisation des éléments nutritifs, protection des cultures, vitalité de l’environnement), ce qui rendrait les cultures plus résilientes. Les auteurs examinent les avantages de l’assolement en général et des assolements de culture grainière de plantes fourragères en particulier face au changement climatique, en faisant spécialement référence aux études réalisées dans les Prairies et la région de la rivière de la Paix, dans l’Ouest canadien. Ils signalent les possibilités de recherche qui permettraient d’élucider les services multidimensionnels à l’écosystème attribuables à la diversité des séquences culturales qui intègrent la production des graines de plantes fourragères vivaces. [Traduit par la Rédaction]

Soybean (Glycine max L.) is the most important legume crop in the world and provides protein and oil for human consumption and animal feed. Cold and waterlogging or flooding are abiotic stress that are commonly encountered during soybean germination in short-season growing conditions in the Northern latitudes. Imbibition of cold water during the germination disrupts the cell membranes and increases leakage of their contents and makes seeds vulnerable to biotic stress. The cold tolerance is associated with the ability of cells to avoid or repair the damage to their membranes and organelles, restoring membrane function and metabolism, and managing the reactive oxygen species generated during the process. Excess moisture impedes aerobic respiration by oxygen deprivation and increases the likelihood of soil-borne diseases further reducing the germination rate. Tolerance to waterlogging is associated with mechanisms that slow down the rate of water uptake and help maintain efficient anaerobic metabolism. The quantitative trait loci mapping, transcriptomics, and proteomic studies have revealed several genes and pathways that likely play a role in seed response to cold and waterlogging stress. This review discusses the effects of cold and waterlogging on soybean seed germination at the physiological level, describes the molecular mechanisms involved, and provides an overview of soybean waterlogging and cold tolerance research. The methodologies commonly used to study the molecular mechanisms controlling tolerance to waterlogging and cold stress are also reviewed and discussed.

Clubroot, a damaging disease of canola (Brassica napus L.) caused by the soilborne parasite Plasmodiophora brassicae Woronin, is spreading across Alberta and other provinces of western Canada. The movement of infested soil on field machinery is the main mechanism of dispersal, with clubroot generally occurring first as localized patches near field entrances. In this study, the soil fumigant Vapam (metam sodium) was evaluated as a management option for foci of P. brassicae infestation. Replicated experiments at two field sites in central Alberta showed reductions in clubroot severity ranging from 9% to 51% following treatment with varying rates of Vapam. Decreases in clubroot severity of up to 28% were observed in the year following Vapam treatment, indicating some potential residual effects and (or) a reduction in the amount of inoculum returned to the soil in the previous year. While Vapam shows some promise as a clubroot management tool, an integrated approach will be required for the sustainable management of this disease on canola.

Hydrogen peroxide (H₂O₂) is a reactive oxygen species that can damage a variety of cellular structures. Recent studies have shown that H₂O₂ can mediate multiple physiological and biochemical processes by acting as a signaling molecule. This study was performed to explore the optimum H₂O₂ treatments for increasing the bioactive compounds in Agastache rugosa Fisch. & C.A. May plants with roots temporarily immersed in H₂O₂ concentrations of 0 (control), 4, 8, 16, 32, 64, and 128mmolL⁻¹ in a hydroponic culture system. All cultivated plants were subjected to root soaking with diniconazole (120µmolL⁻¹) at 7days after transplanting to restrict plant height. H₂O₂ concentrations of 4, 16, and 64mmolL⁻¹ significantly reduced root length compared with no H₂O₂ treatment. Root fresh weight was significantly lower in response to exposure to 128mmolL⁻¹ H₂O₂ compared with control plants. Although shoot and root dry weights were lower in plants exposed to 128mmolL⁻¹ H₂O₂ compared with control plants, no significant differences were detected among treatments. Soaking roots in 16mmolL⁻¹ H₂O₂ induced the highest rosmarinic acid (RA) content, and 16, 32, and 64mmolL⁻¹ H₂O₂ significantly increased tilianin content in the whole plant compared with the control. The highest acacetin content was detected under 32mmolL⁻¹ H₂O₂. In addition, root extract of A. rugosa had the highest RA concentration, and the tilianin concentration was the highest in flowers. Collectively, these results show that soaking roots in 16 and 32mmolL⁻¹ H₂O₂ at 3.5weeks after transplanting promotes secondary metabolites of hydroponically grown A. rugosa.

Studies on wild and landrace hops from the Canadian Maritimes are scarce. This study was undertaken to broaden the genetic base of hops and to assess the reaction of the generated variants to downy mildew (DM) disease. A landrace hop (PE Royalty (P-RL)) and a commercial cultivar (Alpharoma) were mutagenized using ethylmethane sulphonate (EMS), and single nucleotide polymorphism (SNP) variations were determined using an amplicon sequencing genetic diversity study. A subset of wild types and a subset of mutagenized hops were inoculated with DM spores and rated for disease symptoms in a controlled environment. The data showed large EMS-induced genetic diversity in the target genes along with natural variations in the wild types. A diversity in DM resistance within the studied collection was also observed. The study showed DM tolerance in some P-RL landrace seedlings, suggesting that these P-RL landraces must have acquired and developed adaptation mechanisms to co-evolve with DM disease in the environment. Further, EMS-induced mutagenesis increased allelic variations that contributed to increased DM resistance in some seedlings. The data recommend the use of true hop seeds for increased genetic variability in breeding programs.

Intensifying winter wheat (Triticum aestivum)–grain sorghum [Sorghum bicolor (L.) Moench]–fallow (W–GS–FL) crop rotation with annual forages can increase productivity and resource use efficiency. The objective of this research was to quantify the impact of increasing crop intensity by growing forages in a traditional W–GS–FL rotation on cropping system productivity, water use, precipitation use efficiency, and net income. The study was conducted at the Southwest Research-Extension Center near Garden City, Kansas, from 2013 through 2020. Winter wheat (W), grain sorghum (GS), forage sorghum (FS), and forage oats (FO, Avena sativa L.) were used to generate six crop rotation treatments. These rotation treatments interspersed with fallow periods (FL) were W–GS–FL, W–FS–FL, W/FS–GS–FO, W/FS–FS–FO, W/FS–GS–FL, and W/FS–FS–FL. A W/FS indicates winter wheat double crop FS planted in the same year. The yield of FS was 45%–56% more with W/FS–FS–FO and W/FS–FS–FL compared with W–FS–FL. Available soil water at GS planting was 23%–30% less, and GS yield was 52%–60% smaller with W/FS–GS–FL compared to W–GS–FL. Water productivity and pre-season soil water storage were greatest with W/FS–FS–FL and W/FS–FS–FO. Inclusion of W/FS increased cost of production compared with W–GS(FS)–FL rotations. Gross return was greatest with W/FS–FS–FO and W/FS–FS–FL. The W/FS–FS–FO increased cropping intensity, productivity, resource use, and gross margin relative to other rotations in the semi-arid Great Plains. Producers should consider double-cropping of FS after wheat harvest, followed by a second year of FS in dryland cropping systems if there is sufficient forage demand.

The timing and availability of water supply are changing in the Okanagan Valley, and the availability of irrigation water in the late summers is a growing concern. Postharvest deficit irrigation (PDI) is a strategy that can be used to reduce water demands in sweet cherry orchards; previous studies in this region have reported no change in plant physiology or tree growth with irrigation volume reductions of up to 25%, postharvest. However, the effects of more severe postharvest reductions in irrigation volume remain unknown. We compared the effects of full irrigation (100% of conventional grower practice through the growing season) with 27%–33% reductions in irrigation postharvest (∼70% of conventional grower practice) and 47%–52% reductions in irrigation postharvest (∼50% of conventional grower practice) over a 3-year period (2019–2021) in five commercial sweet cherry orchards that ranged in elevation and latitude across the Okanagan Valley, BC, Canada. In the growing season following treatment application, PDI had no effect on stem water potential or photosynthesis in any year and at any site; there were also no effects of PDI treatment on tree growth. Findings from this study suggest that postharvest stem water potentials from −0.5 to −1.3 MPa, and one-time stem water potentials as low as −2.0 MPa, have no lasting effects on future plant water status, rates of photosynthesis, or plant growth. PDI shows potential as an effective water-saving measure in sweet cherry orchards in the Okanagan Valley.

Climate change, resulting from increased atmospheric CO₂, will affect temperature and precipitation amount and regularity. Changes in solar radiation have been observed in the recent past. Precipitation irregularity is a measure of rainfall distribution during a growing season (calculated as the standard error of the slope from regression of cumulative precipitation on day of the growing season). We investigated whether precipitation irregularity and solar radiation contributed to soybean yield. Fourteen short-season cultivars, released from 1930 to 1992, were grown from 1993 to 2019 at Ottawa, Canada. Stepwise multiple linear regression was used to investigate the contribution to seed yield of precipitation irregularity and solar radiation, and also previously modeled parameters genetic improvement, annual [CO₂], and cumulative precipitation and average minimum temperature during the vegetative, flowering and podding, and seed filling growth stages. While solar radiation and precipitation irregularity did not trend over the years of our study and precipitation irregularity was not related to growing season precipitation, both were significant factors in our model, accounting for 2.5% and 6.5%, respectively, of the seed yield variability. Precipitation during all three stages were similar as they each accounted for 4%–7% of seed yield variability. We observed contrasting temperature effects where higher minimum temperature during vegetative and seed filling reduced yield, while during flowering and podding increased yield. Estimated yield improvement due to elevated [CO₂] was 7.8 kg ha⁻¹ ppm⁻¹ and to genetic improvement over time was 7.1 kg ha⁻¹ year⁻¹. Over the extremes of our study we found that precipitation irregularity could cause up to a 30% yield reduction.

A major concern with container seedlings is root circling and deformation that will affect post-planting performance and stability. To improve root quality, 3-year-old Begonia (Malus × micromalus) plants were grown in the containers treated on interior surfaces with different concentrations of copper hydroxide (Cu(OH)₂) (0, 40, 80, 120, 160, and 200 g L⁻¹) for 1 year. Compared with the standard container control (SC) and carrier asphalt container control (AC), the number of terminal lateral roots and lateral root volume were increased by 21% and 13% at 80 and 120 g L⁻¹ Cu(OH)₂ but decreased by 8% and 10% at 200 g L⁻¹ Cu(OH)₂. Only 80 g L⁻¹ Cu(OH)₂ increased the plant height and root weight, while other concentrations of Cu(OH)₂ resulted in the declines. Phosphorus and potassium were improved with lower concentrations of Cu(OH)₂ but decreased with 160 and 200 g L⁻¹ Cu(OH)₂. No significant difference in the concentrations of soluble protein and sugars in leaves was observed between Cu(OH)₂ treatments and the controls. AC decreased nitrogen concentration in leaves by 12% over the SC across the whole growing season and increased taproot diameter by 17%. Our results indicate that 80 g L⁻¹ Cu(OH)₂ was the optimum concentration for root pruning and the maintenance of physiological function. Disadvantages in growth and physiology gradually showed up with increased concentrations.

Red sorrel is a common herbaceous perennial weed species in lowbush blueberry fields that may be managed with acetolactate synthase (ALS)-inhibiting herbicides. Greenhouse and field experiments were established to determine the crop tolerance and potential efficacy on red sorrel of tribenuron-methyl, nicosulfuron + rimsulfuron, foramsulfuron, flazasulfuron, pyroxsulam, and halosulfuron-methyl. Ramet density of greenhouse-grown red sorrel plants established from root fragments was reduced by tribenuron-methyl, flazasulfuron, and pyroxsulam, though tribenuron-methyl and flazasulfuron were the most consistently effective herbicides under field conditions. Spring non-bearing year tribenuron-methyl and flazasulfuron applications reduced both non-bearing and bearing year total red sorrel ramet density and reduced non-bearing year red sorrel flowering ramet and seedling density without injuring lowbush blueberry. Fall non-bearing year tribenuron-methyl and flazasulfuron applications reduced bearing year red sorrel total and flowering ramet density, and this application timing should be evaluated further to improve understanding of crop injury risks. Fall bearing year tribenuron-methyl and flazasulfuron applications reduced non-bearing year red sorrel total and flowering ramet density but did not reduce seedling density. Nicosulfuron + rimsulfuron, foramsulfuron, pyroxsulam, and halosulfuron-methyl efficacy on red sorrel were inconsistent or limited, and these herbicides are not recommended for red sorrel management in lowbush blueberry.

Willow (Salix viminalis spp.) shrubs are being planted along riverbanks, on erodible and marginal farmland. Wood chips made from the woody biomass could improve the properties of light-textured soils with low organic matter content in potato-based systems. Willow chips were applied at 0, 20, 40, and 60mgha^?1 (fresh weight) as a soil amendment. Soil health parameters were evaluated after 12months, followed by C and N contents in whole soil, particulate, and mineral-associated organic matter fractions after 18months. Willow chip application increased soil aggregation, respiration, C and N contents in whole soil, and plant-available K.

On plante l’osier blanc (Salix viminalis spp.) le long des berges ainsi que sur les terres agricoles sujettes à l’érosion ou peu rentables. Des copeaux de bois tirés de la biomasse ligneuse pourraient améliorer les propriétés des sols à texture légère pauvres en matière organique, comme ceux servant à la culture de la pomme de terre. Les auteurs ont appliqué un amendement correspondant à 0, 20, 40 ou 60 Mg (poids frais) de copeaux d’osier par hectare. Douze mois plus tard, ils ont évalué la vitalité du sol puis, au bout de dix-huit mois, la teneur en C et en N du sol complet ainsi que les fractions de matière organique associées aux particules et aux minéraux. Les copeaux d’osier améliorent l’agrégation et la respiration du sol, la concentration de C et de N dans le sol complet, de même que le K assimilable par les plantes. [Traduit par la Rédaction]

Suitable rootstock enhances apple tree resilience. In 2021, we studied “Buckeye Gala” apple (Malus domestica var. Buckeye Gala") on nine rootstocks with contrasting vigor in NS and BC, Canada. Rootstock effects on vigor, yield, and midday stem water potential were significant in BC. After sustained heat events, the large-dwarfing rootstocks Geneva 935, Geneva 4814, and Geneva 969 had lower ratio of sunburn fruits, resulting in higher projected damage-free yield. We discussed how higher stem water potential and larger canopy volume supported by vigorous rootstocks contributed to alleviate heat stress and improve apple resilience to global warming.

AAC Aberdeen is a semi-leafless, yellow cotyledonary field pea (Pisum sativum L.) cultivar developed at Lacombe Research and Development Centre, Agriculture and Agri-Food Canada, Lacombe, AB, Canada. It has a maturity of 98days, 1000-seed weight of 243g, and a lodging score of 3.3 on the scale of 1–9. The seed crude protein content of AAC Aberdeen is 20.1%. AAC Aberdeen is resistant to powdery mildew (caused by Erysiphe pisi D.C.) and moderately susceptible to mycosphaerella blight (caused by Mycosphaerella pinodes) and Fusarium root rot (caused by Fusarium avenaceum (Fr.) Sacc.).

AAC Julius is a semi-leafless, yellow cotyledonary field pea (Pisum sativum L.) variety developed at Lacombe Research and Development Centre, Agriculture and Agri-Food Canada , Lacombe, AB, Canada. It has a maturity of 100days, 1000-seed weight of 210g, and a lodging score of 3.6 on the scale of 1–9. The seed crude protein content of AAC Julius is 24.8%. AAC Julius is resistant to powdery mildew (caused by Erysiphe pisi D.C.) and moderately susceptible to mycosphaerella blight (caused by Mycosphaerella pinodes) and Fusarium root rot (caused by Fusarium avenaceum (Fr.) Sacc. and F. solani).

AAC Prairie is a hulled two-row spring malting barley (Hordeum vulgare L.) cultivar widely adapted to western Canada. It was developed from the cross CDC Kindersley/TR08204 made in 2008 and it was evaluated in the Western Cooperative Two-row Barley Registration Test (2017–2018) as well as the Collaborative Malting Barley Trials (2018–2019) conducted by the malting and brewing industry before being registered in 2021. AAC Prairie’s good combination of agronomic and disease resistance traits as well as a desired malting quality profile should make it a useful cultivar for the barley industry.