Production of fruits and vegetables provides nutrient dense and high value crops. However, horticulture production is often very intensive and degrading to soil, with high levels of soil disturbance, high use of fertilizer inputs, and with prolonged periods of exposed soil. This can lead to increased soil degradation when compared to other types of cropping. We used a subset of the Atlantic Soil Health Laboratory’s database of on-farm soil samples collected between 2016 and 2018 to assess the impact of cover crop (CC) use in horticulture production in Nova Scotia on soil health. We analyzed 21 soil health parameters on soil collected from 14 fields, seven of which incorporated CCs in their crop rotation and seven of which used no CCs. The inclusion of CCs significantly increased permanganate oxidizable carbon (POX), soil respiration, autoclaved-citrate extractable (ACE) protein, residual soil nitrogen (N), and biologically available N. However, we also found that the variation in these parameters was greater when CCs were part of the rotation. This is likely attributable to the wide range of CC species used and differences in their management, such as the chosen termination method. While cover cropping is seen as a best management practice to improve soil health, simply using a CC in a horticulture rotation does not necessarily lead to improved soil health. Research trials on specific CC species and management to target soil degradation are needed to tailor recommendations to ensure the desired soil health outcomes can be achieved with CC use.

Aspen and poplar trees are important horticultural plants grown in Canada for aesthetic, commercial woodlot and windbreak applications. Bronze leaf is a destructive disease in Populus spp. and is caused by the fungal pathogen Apioplagiostoma populi Barr. This pathogen is often difficult to isolate and confirm from infected plant tissues and has been mainly identified by disease symptoms and morphological characteristics of A. populi when fruiting bodies form on infected leaves or branches. Affected leaves and branches typically become necrotic and bronze in colour. Air-borne spores and nursery shipments containing infected plants play an important role in the efficient movement of the pathogen. In this study, bronze leaf disease samples from symptomatic trees in Canada were examined microscopically for A. populi perithecia and asci. Pathogen-specific genomic sequences were identified for the development of sensitive stringent diagnostics that indicated branches and petioles were the most effective tissues for detecting A. populi. Leaf samples from symptomatic trees were collected in Canada and examined for perithecia to microscopically characterize A. populi asci and ascospores. Disease associated DNA sequences of the internal transcribed spacer (ITS) 5.8S region of the nuclear ribosomal, β-tubulin 2, and translation elongation factor-1-γ chain, were isolated from perithecia and symptomatic tree samples. Morphological and molecular biological data from this study characterized the relationship and epidemiology of A. populi and enabled the development of rapid diagnostic methods that restrict the extent of further losses in amenity and commercial plantings of aspen and poplar.

This study aimed to understand the spectral changes induced by Podosphaera xanthii, the causal agent of powdery mildew, in cucumber leaves from the moment of inoculation until visible symptoms are apparent. A principal component analysis (PCA) was applied to the spectra to assess the spectral separability between healthy and infected leaves. A spectral ratio between infected and healthy leaf spectra was used to determine the best wavelengths for detecting the disease. Additionally, the spectra were used to compute two spectral variables [i.e., the red-well point (RWP) and the red-edge inflexion point (REP)]. A linear support vector machine (SVM) classifier was applied to certain spectral features to assess how well these features can separate the infected leaves from the healthy ones. The PCA showed that a good separability could be achieved from 4 days post-inoculation (DPI). The best model to fit the RWP and REP wavelengths corresponded to a linear model. The linear model had a higher adjusted R² for the infected leaves than for the healthy leaves. The SVM trained with five first principal components scores achieved an overall accuracy of 95% at 4 DPI (i.e., two days before the visible symptoms). With the RWP and REP parameters, the SVM accuracy increased as a function of the day of inoculation, reaching 89% and 86%, respectively, when symptoms were visible at 6 DPI. Further research must consider a higher number of samples and more temporal repetitions of the experiment.

Tomato (Solanum lycopersicum L.) is a major vegetable crop world-wide and grown in high tunnels in many regions. This study investigates the use of two fertilizer sources, chemical and integrated (composted poultry manure plus urea) fertilizers, and grafting on growth, nitrate-N content, yield, and fruit quality of tomato grown in high tunnels in northwestern Washington. Grafting treatments consisted of ‘Panzer’ tomato grafted on one of three tomato rootstocks ‘Estamino’, Maxifort’, ‘DRO138TX’, or non-grafted (control). Application of chemical fertilizer increased number of leaves per plant, plant height, and cumulative fresh biomass of pruned suckers relative to tomato plants grown with the integrated fertilizer treatment. Grafted tomato plants had greater plant growth than non-grafted plants throughout the growing season. There was no significant difference between fertilizer treatments on nitrate-N concentration in plant tissue or fresh petiole sap; however, grafted plants contained higher levels of nitrate-N than non-grafted plants. Total and marketable fruit weight and number did not differ due to fertilizer source, but total and marketable fruit weight was higher for grafted plants than for non-grafted plants in 2016. There was no significant effect due to fertilizer source on fruit firmness, water content, pH, titratable acidity, and β-carotene; however, total soluble solids (TSS) and lycopene content were higher for fruit grown with integrated fertilizer in 2016. Grafting enhanced water content of tomato fruit in 2015, and TSS (°Brix) in 2016.

Winter hardiness may be influenced by vineyard terroir-driven factors, and vineyard zones with low water status [leaf water potential (ψ)] could be more winter hardy than vines with high water status (higher leaf ψ). Six Cabernet franc vineyards were chosen throughout the Niagara region in Ontario. Data were collected at fruit set, lag phase, and veraison [soil water content (SWC), leaf ψ], at harvest (yield components, berry composition), and three times during winter (LT₅₀; the temperature at which 50% of buds die) in the 2010–2012 seasons. Interpolation by kriging and mapping of variables was completed using ArcGIS, and statistical analyses (linear correlation, k-means clustering, principal components analysis, multilinear regression) were performed. Spatial trends were observed in each vineyard for SWC, leaf ψ, yield components, berry composition, and LT₅₀. Geographic information systems (GIS) and statistical analysis revealed that leaf ψ could predict LT₅₀, with strong positive correlations between LT₅₀ and leaf ψ values in most vineyards in 2010–2011. In the dry 2012 season, leaf ψ (particularly at veraison; range −1.3 to −1.6 MPa) was positively correlated to LT₅₀, yield, titratable acidity (TA), pH, and Brix and negatively to SWC, color, anthocyanins, and phenols. Overall, vineyards in different appellations (Niagara Lakeshore, Lincoln Lakeshore, Four Mile Creek, Beamsville Bench) showed many similarities. These results suggest that there is a spatial component to winter injury, as with other aspects of terroir. Furthermore, this study allows for means by which to compare winter hardiness to other critical variables to better understand the terroir of the Niagara region.

Whole-genome sequencing technologies provide opportunities to further understand genetic variation among different varieties. Some related genes that are useful for the breeding process could be identified by sequencing technologies. In this study, two peach varieties, Green No. 9 (LH) and its bud mutant Daifei (DT), were analyzed with whole-genome re-sequencing. Approximately 109 million total reads were generated, which covered ∼89% of the peach reference genome. A total of 1 143 757 single nucleotide polymorphisms (SNPs), 169 827 insertion–deletion mutations (InDels), 17 132 structural variations (SVs) and 5 040 copy number variations (CNVs) were detected in Green No. 9 and Daifei. Variant genes were classified by Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway database. Detected genes such as LOC18768059 (carbohydrate metabolism) and LOC18785045 (anthocyanin biosynthesis), were good candidate genes for exploring the phenotypic variations between Green No. 9 and Daifei. Green No. 9 and its bud mutant Daifei showed obvious differences in phenotypes and variant genetic loci. The detected genomic variations will contribute to explorations of important functional genes and to understanding the genetic basis of peach bud mutations.

Annual canarygrass (Phalaris canariensis L.) is a specialty crop grown in Canada and the harvested grain is primarily used to feed wild and domesticated bird species. A field experiment was conducted at 5 locations in both 2012 and 2013 to study the response of annual canarygrass development and grain yield to the combined effects of fungicide (propiconazole + trifloxystrobin) and nitrogen (N) fertilizer, and to determine the minimum number of site years required to detect these effects. The experimental design was a split plot with fungicide application (none or fungicide) as the main plot and N application rate as the sub plot (10, 20, 30, 50, 70, 90 kg N·ha⁻¹). There was a linear increase of 14.5% in grain yield as the rate of N fertilizer increased. The fungicide application increased the grain yield 8.5% by increasing kernel density from 15 197 kernels m⁻² to 16 288 kernels m⁻². There was no interaction between the N rate and fungicide application. The application of a fungicide did not increase the responsiveness of annual canarygrass to N fertilizer. The lack of an interaction between N and fungicide application indicates that these two practices can be managed independently by annual canarygrass producers. To optimize grain yield producers should apply 50 kg N·ha⁻¹ and apply a fungicide to increase grain yield especially in regions where septoria leaf mottle is prevalent. The number of site years needed to consistently detect the impact of N and fungicide on the grain yield were 4 and 5 site years, respectively.

Zero-till seed drills are readily available for crop seeding in the prairie region of western Canada but have not been evaluated for sod-seeding in perennial forage. Sod-seeding a legume, such as alfalfa (Medicago sativa L.), into the existing perennial grass vegetation improves forage yield and quality for ruminant livestock grazing and production. Suppression of the existing vegetation with herbicide has been reported to increase alfalfa seedling establishment. We evaluated six commercially available zero-till seed drill openers by sod-seeding alfalfa into a crested wheatgrass [Agropyron cristatum (L.) Gaertn.] pasture with or without glyphosate suppression of the existing vegetation in Lanigan Saskatchewan. Alfalfa seedling establishment (52.2 vs. 21.9 seedlings m⁻¹ ± 6.8), alfalfa composition (42.5% vs. 0.2% ± 8.6), and alfalfa yield (1105 kg·ha⁻¹ vs. 12 kg·ha⁻¹ ± 206) in 2011 were increased by the application of herbicide. Seed drill openers performed similarly for all three variables. Nine years later, in June 2020, there was greater alfalfa composition (13.3% vs. 0% ± 2.3) and forage yield (1325 vs. 957 kg·ha⁻¹ ± 127) in the sod-seeded plots than in the unseeded controls but the alfalfa plant cover, alfalfa composition, alfalfa yield and forage yield were similar among seed drill openers. There was also no difference in these variables due to herbicide application nine years prior. Livestock producers can utilize currently available zero-till seeding equipment for sod-seeding alfalfa to rejuvenate grass pastures in the thin Black soil zone of western Canada with the expectation of persistence of alfalfa for nine years.

Postharvest water loss in pepper fruit (Capsicum annuum L.) reduces its shelf life. Fruit texture is one of the most important components of fruit quality for consumers. In this study, the anatomical traits of pepper fruit related to postharvest water loss and texture were assessed. There was a strong positive relationship between postharvest water loss and the thickness of the cuticular membrane, cuticular weight, total cutin weight, and polysaccharide-cutan weight. An amorphous fibrous structure that forms a path for diffusion and increases water loss was observed in the thick cuticle of the pericarp. In addition, positive correlations between the hardness of the exocarp and the weight of cuticular membrane, cutin content, and polysaccharide-cutan content were found. These results indicate that the thickness of the cuticular membrane wedged between subepidermal cells may influence water loss through the pericarp of pepper fruit and fruit with a high cutin and polysaccharide content have a hard tough texture.

Calmodulin-like (CML) proteins represent a diverse family of protein in plants, and play significant roles in biotic and abiotic stress responses. However, the involvement of citrus CMLs in plant responses to drought stress (abiotic stress) and arbuscular mycorrhizal fungi (AMF) colonization remain relatively unknown. We characterized the citrus CML genes by analyzing the EF-hand domains and a genome-wide search, and identified a total of 38 such genes, distributed across at least nine chromosomes. Six tandem duplication clusters were observed in the CsCMLs, and 12 CsCMLs exhibited syntenic relationships with Arabidopsis thaliana CMLs. Gene expression analysis showed that 29 CsCMLs were expressed in the roots, and exhibited differential expression patterns. The regulation of CsCMLs expression was not consistent with the cis-elements identified in their promoters. CsCML2, 3, and 5 were upregulated in response to drought stress, and AMF colonization repressed the expression of CsCML7, 9, 12, 13,20, 27, 28, and 35,and induced that of CsCML1, 2, 3, 5, 8, 10, 11, 14, 15, 16, 18, 25, 30, 33, and 37. Furthermore, AMF colonization and drought stress exerted a synergistic effect, evident from the enhanced repression of CsCML7, 9, 12, 13, 27, 28, and 35 and enhanced expression of CsCML2, 3, and 5 under AMF colonization and drought stress. The present study provides valuable insights into the CsCML gene family and its responses to AMF colonization and drought stress.

Miscanthus is a C₄ herbaceous perennial genus, and it was chosen as a bioenergy crop due to high biomass yield. Miscanthus sinensis has many phenotypes which are adapted to various environments in China. In this study, 421 accessions of M. sinensis were collected from 22 provinces, and the genetic polymorphisms amongst these germplasm collections were identified using 20 primer pairs designed against 10 each from expressed sequence tag-simple sequence repeats [EST-SSR (eSSR)] and genomic SSR (gSSR) transferable markers from barley. A total of 95 SSR polymorphic bands were detected producing a 100% polymorphic rate among these M. sinensis accessions. The gSSR markers showed a richer genetic polymorphism than eSSR markers. Based on the unweighted pair group method with arithmetic mean (UPGMA) clustering, there was a distinct sub-population separation in M. sinensis, which indicates that geographical differences and natural selection are the driving forces for genetic variation and evolution in the species. The 20 pairs of barley markers matched to 26 polymorphic bands associated with date of heading, plant height, leaf weight, stem weight, leaf/stem ratio, and total biomass yield. Eleven marker polymorphic bands were associated with the date of heading, 4 with plant height, 10 with leaf weight, 7 with stem weight, 3 with leaf/stem ratio, and 10 with biomass yield.

Camellia japonica, an evergreen ornamental plant in the Theaceae family, has a natural range that is now shrinking. This is evident by the fact that the species is on the verge of extinction in Laoshan Mountain (Qingdao), the northernmost area of China known to have a natural population of C. japonica. Little is known about the genetic diversity and relationships among cultivated and wild C. japonica populations. One hundred and eighty samples of six C. japonica populations were tested for genetic diversity with simple sequence repeat (SSR) markers; these included three cultivated populations, two natural populations in Qingdao, and one natural population in Daqingshan. The average values of polymorphism information content (PIC), expected heterozygosity (He), and Shannon’s information index (I) were 0.5849, 0.6385 and 1.3170, respectively, indicating that C. japonica has a high genetic diversity. The genetic diversities of the six populations in rank order were as follows: Daqingshan > Zhongshan Park > Changmenyan Island > Daguan Island > Botanical Garden > May Fourth Square. The geographical isolation of the islands had no significant influence on the genetic diversity of C. japonica. Clustering results showed that the six C. japonica populations could be grouped into three categories, and most populations were clustered according to their geographical origin and genetic background. These results also reconfirmed that the C. japonica (Naidong) population in Qingdao originated from Changmenyan Island. Genetic variation was highest within populations (89%), indicating that C. japonica can be protected at the population level. These findings will prove useful for the genetic analysis, protection, and horticultural use of C. japonica.

Protein ubiquitination is one of the most common modifications that can degrade or modify proteins in eukaryotic cells. The E2 ubiquitin-conjugating enzymes (UBCs) are involved in multiple biological processes of eukaryotes and their response to adverse stresses. Genome-wide survey of the UBC gene family has been performed in many plant species but not in cucumber (Cucumis sativus). In this study, a total of 38 UBC family genes (designated as CsUBC1–CsUBC38) were identified in cucumber. The phylogenetic analysis of UBC proteins from cucumber, Arabidopsis and maize indicated that these proteins could be divided into 15 groups. Most of the phylogenetically related CsUBC members had similar conserved motif patterns and gene structures. The CsUBC genes were unevenly distributed on seven chromosomes, and gene duplication analysis indicated that segmental duplication has played a significant role in the expansion of the cucumber UBC gene family. Promoter analysis of these genes resulted in the identification of many hormone-, stress- and development-related cis-elements. The CsUBC genes exhibited differential expression patterns in different tissues and developmental stages of fruit ripening. In addition, a total of 14 CsUBC genes were differentially expressed upon downy mildew (DM) infection compared with the control. Our results lay the foundation for further clarification of the roles of the CsUBC genes in the future.

The biology of the weed goat’s-rue, Galega officinalis (Fabaceae), is reviewed. Introduced to Canada in the late 19th Century as an ornamental, it has become established at scattered localities and is spreading locally in southern Ontario. The plant is considered a noxious weed and is legally regulated in many jurisdictions due to the production of toxic alkaloids and its invasive characteristics. Primarily a weed of pastures, grasslands and perennial crops, it also displaces native vegetation in areas where it becomes established. Originally endemic in the Black Sea region, it was spread by humans through Europe and eastward to Pakistan as a herbal medicine. More recently it has been introduced widely as a forage and ornamental plant. As a folk remedy it has been used primarily to treat diabetes in humans and to enhance milk production in both humans and livestock. The plant has also been used as a forage by limiting consumption to early growth stages and the quantity ingested. Effective control has been achieved with 2,4-D, dicamba, tryclopyr, metsulfuron methyl and other herbicides. Goat’s-rue forms a highly specific nitrogen-fixing symbiosis with the soil bacterium Neorhizobium galegae symbiovar officinalis. Successful establishment of Goat’s rue in new regions depends on the co-introduction of plant and bacterium. The lack of long-distance dispersal adaptations, soil pH requirements and its symbiont dependency, reduces the ability of G. officinalis to spread into novel areas without anthropogenic activities. These constraints to establishment may facilitate management and eradication strategies.

Dark glume color in Triticinae is a much-studied morphological character. However, pigments that cause the color, the molecular basis of their biosynthesis, and mechanisms of its regulation are still unknown. Dark glume is a common trait in Triticum aestivum lines with alien introgressions. To elucidate the molecular basis of this character, we analyzed the total phenolic content (TPC) in the dark glumed introgression lines (ILs) and their parents. TPC in the dark ILs was found to be higher than their parents and light-glumed lines. All the genotypes were screened for the expression of eight genes encoding the flavonoid biosynthesis pathway enzymes. Expression of three flavonoid genes in the pathway was changed in the introgression lines as compared with their parents. The expression of F3′H and FNS was absent in the lines with introgressions from Aegilops spp. The expression of three genes, F3′H, FLS, and FNS, was found to be altered in the light glumed lines with introgressions from Amblyopyrum muticum. No expression of F3′H was detected in the T. aestivum/Am. muticum lines with light and dark plants, and the other genes of the pathway were found to be expressed at the parental levels. No correlation between the expression profiles and the phenotype was found in the T. aestivum/Am. muticum lines indicating other undetected changes in these lines.

Blueberry (Vaccinium ashei) is a popular fruit due to its high anthocyanin content. This study aimed to analyze the transcriptome profile of V. ashei cv. ‘Brightwell’ fruits at different stages of development. A total of 314.26 GB of clean data were obtained and de novo assembled into 254 196 unigenes. In comparisons between the early and late stages of fruit ripening, 27 genes (including PAL, CHS, F3H, F3′H, F3′5′H, LDOX, etc.) were found to cover the main steps in the anthocyanin biosynthesis pathway. Most of these genes were highly expressed in the late stage of fruit development, suggesting that anthocyanins mainly accumulate in the late stage. During the late stage of fruit development, most structural and regulatory genes such as F3′5′H and F3′H, which are involved in the anthocyanin biosynthetic pathway, were upregulated, causing the fruit to turn blue. Decreased expression of a large number of chloroplast-related genes during the fruit ripening period could explain why the green fruit color fades over time. Additionally, abscisic acid and ethylene may play positive roles in promoting fruit ripening and anthocyanin accumulation. This research reveals the transcriptomic characteristics of immature and mature fruits and enhances our understanding of the molecular mechanisms of anthocyanin biosynthesis and accumulation in blueberry fruit.

Quantitative real-time polymerase chain reaction (PCR) is a powerful tool for investigating relevant changes in gene expression. At present, there are no reports on reference genes for Vaccinium dunalianum Wight (V. dunalianum Wight). Here, the expression profiles of 15 frequently used reference genes were used to screen for appropriate reference genes in different tissues of V. dunalianum Wight collected in Yunnan and Wuding, China. The cycle threshold (Ct) values of genes in different samples were compared and analyzed. Furthermore, BestKeeper, NormFinder, and geNorm software were used to evaluate the stability of each candidate reference gene. Analysis using geNorm showed that the expression levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and protein phosphatase 2A-2 (PP2A-2) were the most stable. In turn, the expression level of eukaryotic initiation factor-2 (EIF-4A-2) was the most stable as per analysis by NormFinder, while Bestkeeper revealed that actin-related protein-1 (ARP-1) was the most stably expressed. Comprehensive analysis and validation experiments showed that EIF-4A-2 and PP2A-2 were the most suitable reference genes for V. dunalianum Wight.

The Andean mortiño (Vaccinium floribundum Kunth) grows wild in the northern paramos of South América. The berries present potential opportunities for agribusiness, but an efficient technology for the production of plants and berries is required. On the other hand, the development of plant production methods from mortiño seeds will allow the plants’ accessibility and its potential use in breeding programs. The objective of this study was to develop an efficient in vitro protocol for accelerated production using seeds. We carried out the research in four phases: seed germination, plant multiplication, rooting, and acclimatization in the greenhouse. For in vitro seed germination, we studied the effect of two culture media [woody plant medium (WPM) and Murashige and Skoog medium (MS], two photoperiods (16 and 24 hours of light), and two temperatures (18 and 28 °C). The best treatment was found to be WPM + 24 h light + 18 °C. In the micropropagation of seedlings, the effect of two concentrations of three cytokinines [(trans-zeatin riboside (TZR), zeatin (ZEA), and 2-isopentenyl adenine (2iP)], and two photoperiods (16 and 0 h light) was evaluated, whereby the concentration of 0.5 mg L⁻¹ of TZR was the best treatment. For rooting, two doses of three auxins [indole-3-butyric acid (IBA), 1-naphthaleneacetic acid (NAA), and indole-3-acetic acid (IAA)] were evaluated, resulting in the 2 mg·L⁻¹ concentration of IBA giving the best root induction. Finally, the in vitro rooted plants were acclimatized in a greenhouse. We found that peat was the best substrate. These results show that the technology developed here is useful for in vitro production of V. floribundum using seeds.

Diseases such as Sclerotinia white mold (SWM), caused by the fungus Sclerotinia sclerotiorum (Lib.) de Bary, and Botrytis grey mold (BGM), caused by the fungus Botrytis cinerea Pers., may be limiting factors for lentil production in wetter areas of Alberta, Canada. Field trials were conducted at the Lethbridge Research and Development Centre from 2013 to 2015 to evaluate the response of lentil cultivars to SWM and BGM and yield impacts. Ten lentil cultivars from five market classes were evaluated under irrigated and dryland plots with two planting densities (120 and 160 plants·m⁻²). Year and irrigation had the largest effect on disease incidence, with highest SWM incidence occurring under irrigation in 2013, followed by 2014 and 2015. Conversely, BGM incidence under irrigation was highest in 2015 and lowest in 2013, but levels were lower than SWM. Significantly (P < 0.05) lower disease incidences were observed in dryland plots, which also produced higher yield than irrigated plots. Cultivars varied significantly in SWM incidence and yield under irrigated and dryland conditions, perhaps due to variable disease pressure, but there was no consistent trend in cultivar performance. BGM incidence was similar in cultivars, but differed among years. These findings indicate that SWM may be a limiting factor to lentil production in wetter areas, as the 10 cultivars from five market classes tested were all highly susceptible to SWM.

With soybean [Glycine max (L.) Merr.] seed cost increasing in Alberta, understanding economic optimum plant density (EOPD) could help growers save on input expenses. A study was conducted at two irrigated locations in southern Alberta (Bow Island and Lethbridge), in three growing seasons (2014–2016), using two maturity group (MG) 00 soybean genotypes, two row spacings (RS; narrow, 17.5 cm; wide, 35 cm), and three seeding densities (SD; 30, 50 and 80 seeds·m⁻²). Exponential plant density–yield relationships were used to estimate EOPD. The earlier MG 00.4 genotype compensated yield at lower plant density (39 vs. 43 plants·m⁻²) and emergence (74% vs. 80%) than the later MG 00.8 genotype. The EOPD gaps between environments, genotypes, and RS were minimal (from 1–3 plants·m⁻²), resulting in only 1.3%–2.0% differences in grain yield (37–56 kg·ha⁻¹), and gross revenue at EOPD ($16–24·ha⁻¹). The overall EOPD estimate was 46 plants·m⁻², regardless of environment, genotype or RS. The study highlighted the difference between agronomic production and profit maximization in choosing an optimum plant density, and the need to establish a seeding density calculator for irrigated soybean in southern Alberta.

Recent confirmations of glyphosate-resistant Russian thistle (Salsola tragus L.) in Montana, Washington, and Oregon, warrant greater surveillance of herbicide-resistant Russian thistle in western Canada. A randomized-stratified survey of 315 sites in Manitoba was conducted in 2018 to determine the incidence of herbicide resistance in Russian thistle and other weeds sampled post-harvest. Russian thistle populations were collected from 14 of the 315 sites surveyed. None of these populations exhibited resistance to acetolactate synthase inhibitors (tribenuron/thifensulfuron), synthetic auxins (2,4-D ester or fluroxypyr), or glyphosate. This Manitoba survey of herbicide-resistant Russian thistle serves as a baseline for future surveillance efforts.

AAC Oravena is a white-hulled spring oat (Avena sativa L.) cultivar selected and developed under organic management. AAC Oravena yields well under organic and conventional production systems, compared with check cultivars. AAC Oravena has good milling quality. AAC Oravena was registered (Reg. No. 7561) by the Variety Registration Office, Canada Food Inspection Agency, on 3 July 2014.

AAC Paramount is a soft white spring wheat (Triticum aestivum L.) cultivar that meets the end-use quality specifications of the Canada Western Soft White Spring (CWSWS) class. AAC Paramount is adapted to the irrigated wheat growing regions of southern Alberta and southern Saskatchewan, and for dry land production in the western prairies. On average, AAC Paramount had 6% higher grain yield (under both irrigated and dry land conditions) than the check cultivar AC Andrew. AAC Paramount exhibited excellent straw strength and similar maturity to AC Andrew and Sadash but was 2 d earlier than AAC Indus. Its plant height was taller than both AC Andrew and Sadash but similar to AAC Indus. AAC Paramount exhibited high levels of resistance to the prevalent races of stripe rust, powdery mildew, and loose smut; intermediate reactions to leaf rust, stem rust, and kernel black point; was moderately susceptible to Fusarium head blight and leaf spot diseases, and susceptible to common bunt.

AAC Awesome is a high yielding spring wheat (Triticum aestivum L.) cultivar eligible for the Canada Western Special Purpose (CWSP) wheat class. Based on 29 site-years of testing over 3 years in the General Purpose Wheat Registration trial (2013–2015), AAC Awesome yielded 14% more grain than AC Andrew, and surpassed yields of Sadash, 5702PR, and Pasteur by 12%, 22%, and 9%, respectively. AAC Awesome had similar maturity, was slightly taller, had higher test weight and larger kernels as compared to AC Andrew. AAC Awesome had excellent levels of resistance to the prevalent races of leaf, stem and stripe rust. It expressed an intermediate level of resistance to Fusarium head blight (FHB), common bunt and loose smut. It also expressed tolerance to the orange wheat blossom midge. AAC Awesome is eligible for grades of Canada Western Special Purpose Wheat class.

AAC Whitehead, an awned hard white spring wheat (Triticum aestivum L.) cultivar, combines high grain yield and good agronomic characteristics with excellent disease resistance. Based on 34 station-years of registration trial data from 2017 to 2019, AAC Whitehead had grain yield significantly higher than all of the check cultivars. AAC Whitehead had maturity similar to the checks, low lodging scores, and significantly shorter plant height than Snowstar and Whitehawk. AAC Whitehead had significantly lower test weight and higher kernel mass than than all the check cultivars. AAC Whitehead expressed resistance to the prevalent races of leaf, stripe and stem rust, and common bunt; and moderate resistance to Fusarium head blight (FHB). It also expressed tolerance to the orange wheat blossom midge. AAC Whitehead expresses quality attributes within the range of the check cultivars and is eligible for grades of Canada Western Hard White Spring wheat.

AAC Castle, an awned hard red spring wheat (Triticum aestivum L.), cultivar, combines high grain yield and good agronomic characteristics with excellent resistance to leaf, stem, stripe rust, common bunt and loose smut. It also expressed tolerance to the orange wheat blossom midge. Based on 39 station years of data in the registration trials from 2014 to 2016, the grain yield of AAC Castle was about 17% higher than 5700PR but similar to the other checks. AAC Castle was significantly shorter than AAC Foray and CDC Terrain, but had similar lodging resistance and maturity. AAC Castle had higher test weight, protein concentration, falling number and flour yield than AAC Foray and CDC Terrain. AAC Castle is eligible for grade of the Canada Prairie Spring Red wheat market class.

AAC Perform, an awned hard red spring wheat (Triticum aestivum L.) cultivar, combines high grain yield and good agronomic characteristics with excellent resistance to leaf, stem, and stripe rust. Based on 43 station years of registration trial data from 2017 to 2019, the grain yield of AAC Perform was about 6% higher than AAC Foray and about 12% over AAC Penhold. AAC Perform was significantly shorter than AAC Foray and had straw strength similar to AAC Penhold. It was about two days later maturing than AAC Foray. AAC Perform had similar test weight, smaller kernel size and lower protein concentration as compared with AAC Foray. AAC Perform had milling and baking quality suitable for grades of the Canada Prairie Spring Red wheat market class.