Seed production of perennial grasses is an important industry in Canada, but many fields exhibit high proportions of sterile heads with characteristic symptoms in a condition known as silvertop. In a 3-yr field study, biotic stress treatments were applied to caged plots of Kentucky bluegrass (Poa pratensis) and meadow bromegrass (Bromus riparius) to assess their effects on silvertop incidence. Treatments were (1) control, (2) addition of grass-feeding insects, primarily grass plant bugs (Miridae), (3) inoculation with Fusarium poae spores, (4) both insects and spores, and (5) mechanical piercing of seed heads above the last node (in a single year). Additionally, cores of the two grass species were potted and removed from the field in spring in each of 2 years. After 2, 4, and 6 wk intervals in a cold room at 4 °C to stagger plant development stage, the five treatments were applied to caged plants of both grasses, which were maintained in a greenhouse until seed harvest. In both studies, the numbers of healthy seed heads, percentage of heads with silvertop, and seed weights were determined. In the field, stress treatments infrequently and inconsistently affected silvertop levels. Regression showed that the relationship between silvertop and seed yield, although significant, explained little of the variability in yield. Silvertop developed in all treatments in the greenhouse; treatments had no effect on silvertop levels, which were highest in plants treated at the R1 (spikelets visible) growth stage. This suggests that this stage of the two grass species is most vulnerable to silvertop occurrence.

Celastrus orbiculatus Thunb. is an invasive alien liana native to northern regions of Japan, Korea, China, and Russia. Since its intentional North American introduction in the 1870s, it is now found across eastern Canada and the United States. Through an extensive adventitious root system and twining growth habit, C. orbiculatus smothers and girdles surrounding vegetation, drastically altering the environment and ecosystem processes. C. orbiculatus continues to be distributed as an ornamental. In addition, birds and small mammals consume its prolific fruit and facilitate novel introductions. C. orbiculatus is susceptible to glyphosate and triclopyr. Once established, however, management intensity is compounded by its extensive root system and continual resprouting and root-suckering. The climatic requirements across eastern Canada, ease of dispersal, and rapid growth suggest that C. orbiculatus will continue to spread across its introduced range.

The differentiation of reproductive characteristics not only exists between different populations but also may exist within populations. In this work, the differences between the central and peripheral populations were experimentally compared and analyzed in terms of biodiversity index, plant traits, anthesis, pollen germination, floral visitors, seed setting rate, and ploidy. The results showed that the diversity and richness of other plant species, in the central population were significantly lower than those in the peripheral population, but the plant density was much higher than in the peripheral population. The plant anatomical traits, anthesis, pollen germination, floral visitors, seed setting rate, and ploidy were significantly different between central population and peripheral populations. The term increasing rate (IR) is proposed as a means of comparing morphologies in different organs. IR differences in vegetative characteristics were more stable, while those in reproductive characteristics differed significantly. For the central population, the effect of the intraspecific reproductive competition and pollinator selection on plants may significant, and morphology was differentiated in terms of reproductive characteristics. Plants in the peripheral populations were visited by many more pollinators than in the central population, and all pollinators visited infrequently. The reproductive characteristics of plants in the peripheral populations may therefore only be weakly affected by pollinator selection. The reproductive characteristics of plants in the peripheral population may weakly affected by the selection of pollinators, and the variation was small. In conclusion, morphological differentiation among the different populations was associated with differences in vegetative and reproductive characteristics.

Lodging resistance is an important objective for soybean [Glycine max (L.) Merr.] breeding, but selection for this trait has been difficult since the resistance is controlled by multiple genes, and these genes interact with the environment. A total of 130 of 139 lines constituting a soybean genome-wide association study panel were phenotyped for stem pushing resistance, which is defined as the push-back strength when the plant stem is inclined, by measuring the force required to push a stem to a 45° angle using a force gauge in a greenhouse, and also for lodging, plant height, seed yield, and maturity at three locations in total in eastern Canada in 2013 or 2017. Two quantitative trait loci (QTLs) for pushing resistance were identified on chromosome 5 and 11, and each QTL accounted for 16.0% of phenotypic variation. In our panel, the alleles for higher pushing resistance were always of lower frequency than the alternate allele. Examining the panel at these QTLs identified that higher pushing resistance was associated with lower lodging on chromosomes 5 and 11, and that the difference for lodging between alleles was significant on chromosome 5. There was no difference in plant height or yield at the QTL on chromosomes 5 or 11, while higher pushing resistance was associated with later maturity at both QTLs. The pushing resistance QTL on chromosome 11 will be useful for decreasing lodging in Canadian short-season soybean.

Cicer milkvetch (Astragalus cicer L.) (CMV) is a non-bloating, perennial legume that has shown persistence under grazing. Limited information is available on its seedling establishment and subsequent forage yield and nutritive value in alfalfa (Medicago sativa L.) mixtures. Field plots were seeded in May 2013 at Melfort, SK, Canada, to evaluate ‘Oxley II’ cicer milkvetch performance in ‘AC Grazeland’ alfalfa or alfalfa and ‘AC Success’ hybrid bromegrass (Bromus riparius Rehmann×Bromus inermis Leyss.) mixtures from 2014 to 2017. Two controlled environment tests were also conducted by treating seeds of CMV using alfalfa root aqueous extract. Seed germination and seedling height of CMV were significantly reduced in aqueous extract. In the field, establishment of CMV in a mixture containing alfalfa was reduced, and CMV dry matter proportion in the mixture increased only 3.5% over three years. Increasing CMV seeding rate did not increase its dry matter (DM) percent in the mixtures, indicating a high allelopathic effect of alfalfa. Forage DM yield of all mixtures was linearly correlated to the proportion of alfalfa, and adding hybrid brome did not increase the DM yield. Forage DM yield was higher for the three-cut than the two-cut treatments for CMV–alfalfa mixtures, but there was no difference between the cutting frequency for CMV–alfalfa–hybrid brome mixtures. Fiber concentrations decreased linearly with increased CMV seeding rate in the mixtures. This study showed that CMV establishment in alfalfa mixtures was reduced in a same-row seeding, and the allelopathic effect was not reduced by lower alfalfa seeding rates or adding a grass.

Protection from fungal plant pathogens is key for optimizing the yield and quality of wheat (Triticum aestivum L.). However, current grower practices and historical research do not always align with respect to optimum fungicide timing to maximize disease control, yield, quality, and profitability of Canadian Western Red Spring (CWRS) wheat. Six fungicide treatments were evaluated at eight site–years across Alberta in 2018 and 2019 to determine the optimum time for fungicide application. The treatments included early fungicide applications at BBCH 22–23 (herbicide timing), early- to mid-season application at BBCH 30–32 (plant growth regulator timing), ‘traditional’ timing at BBCH 39–45 (flag leaf), and head timing at BBCH 61–63 (Fusarium head blight timing) and were compared with a non-treated control. Yield responses to fungicide treatments occurred at 50% of the site–years when disease pressure was 32% higher than in non-responsive site–years. Responsive site–years were characterized by higher relative humidity (65.4%–74.0%) and an average 273 mm of precipitation. At responsive site–years, McFadden leaf spot disease severity ratings were 50% greater in early August when fungicides were applied at BBCH 22–23 and 30–32 versus at BBCH 39–45. At responsive sites, yield and thousand-kernel weight were 9.3% and 5.2%, higher, respectively, for fungicide applications at BBCH 39–45 and BBCH 61–63 compared with fungicide applications at BBCH 22–23 and BBCH 30–32. The most economically beneficial practices were applications of propiconazole, benzovindiflupyr and azoxystrobin (Trivapro A+B) at BBCH 39–45 or prothioconazole and tebuconazole (Prosaro XTR) at BBCH 61–63 when environmental conditions were conducive for disease development.

The in vitro development of a plant is controlled by factors that promote a series of plant responses, which interfere with tissue organogenesis and morphology. For plants of the family Lamiaceae, these factors remain unknown or poorly understood, hindering in vitro cultivation of these plants. The basil cultivar ‘Grecco a palla’ has attractive chemical properties for medicinal, pharmaceutical, and cosmetic industries; however, its production is limited due to the lack of appropriate cultivation conditions. Two types of explants of this species (nodal segments and stem apexes) were grown in culture media with auxin and cytokinin, and their development was followed for 60 days. During in vitro cultivation, both explants were subjected to higher concentrations of plant growth regulators (PGRs) produced only calluses, without induction of shoots. Small amounts of regulators favored hyperhydricity as nodal segments or stem apexes in the absence of PGRs produced plants with disturbances, including brittle, light green, and thick leaves. In this case, there was an increase in the cell layers of palisade parenchyma, which had large cell spaces and larger cells. This tissue also advanced to spongy parenchyma and compressed it. The stomatal density was low; however, the stomata were larger with additions mainly in the guard cells and the stomatic opening. Therefore, stem apexes in the absence of PGRs produced more vigorous plants, whereas nodal segments with low amounts of cytokinins and auxins developed a well-branched and abundant root system.

Many questions remain concerning the viability and productivity of seeding native legumes in the Canadian Prairies for forage production. Field research was conducted with four native legume species (Astragalus flexuosus, Dalea purpurea, Hedysarum boreale, and Vicia americana) to evaluate performance in Swift Current and Saskatoon, SK. The experimental design was a randomized complete block design with four replicates to evaluate legume–grass mixtures and monoculture performance, botanical composition, and effect of harvest dates (July and August) from 2016 to 2018. The native legume–grass mixtures performed differently at the sites, with greater foliar cover at Saskatoon but a greater proportion of legumes in mixtures at Swift Current. The mixtures had similar forage nutritive value as monoculture Bromus riparius, with legumes contributing 10% or less of the forage dry matter yield (DMY) at both sites. Astragalus flexuosus showed the greatest foliar cover and produced the greatest DMY in monoculture at both sites. Based on this study, native legumes would need to make up a larger proportion of forage dry matter yield to change the nutritional value of mixtures. In a subsequent seeding rate evaluation, the four legume species were planted at three seeding rates [300, 200, and 100 pure live seeds (PLS) per metre] and tested for DMY one year following establishment near Swift Current. Increasing seeding rates up to 300 PLS·m⁻¹ corresponded with an increase in seedling density and foliar cover, but DMY was not affected. Additional research with A. flexuosus is needed to demonstrate its value as a forage.

Clubroot, caused by the obligate pathogen Plasmodiophora brassicae Woronin, has been present on brassica vegetables in Ontario for decades, but was only recently identified on canola (Brassica napus L.). Once P. brassicae is present in a field, eradication is difficult, but resistant cultivars can provide effective management. Pathotype 6 has been the predominant pathotype on vegetable crops for decades, but pathotype 2 is predominant in canola fields in Ontario. Field trials were used to assess the reaction of selected canola and vegetable Brassica cultivars to pathotype 2, and controlled environment studies were conducted to evaluate the reaction of the same cultivars to pathotypes 2 and 6. Four canola cultivars with putative clubroot resistance were compared with two cultivars that were expected to be susceptible and three susceptible control cultivars. Several brassica vegetables were assessed: cabbage, cauliflower, broccoli, napa cabbage, rutabaga, and Shanghai pak choi (a susceptible control). The canola cultivars marketed as resistant were highly resistant in both the field and growth room trials. The canola cultivars not marketed as resistant were susceptible to pathotype 2, as expected. All of the canola cultivars were resistant to pathotype 6. The vegetable cultivars marketed as resistant or tolerant were resistant to pathotype 6 and most were resistant to pathotype 2. A putative resistant cultivar of cabbage and one of broccoli were resistant to pathotype 6 but susceptible to pathotype 2. Clubroot consistently reduced fresh shoot weight in susceptible cultivars of canola and brassica vegetables relative to resistant cultivars.

Heterogeneity among grape berries directly affects wine quality and restricts the wine grape industry’s development. To study the heterogeneous development of Vitis amurensis berries, the morphology and physiology of three different types—large berry, medium berry, and live green ovary (LGO)—in the same clusters of wine-making cultivar ‘Shuangfeng’ were monitored at different growth stages from June to September. External differences in berry development were distinguishable at 12 days after full bloom (DAF). The pedicel, berry size, fresh weight, and seed length of the medium berries were intermediate between those of large berries and LGOs. Seeds are crucial for fruit set and normal berry development. The activity levels of soluble acid invertase and cell-wall-bound acid invertase in large berries increased earlier, at 18 DAF, than the accumulation of sugar. Abscisic acid concentrations in medium berries and LGOs were greater than that in large berries at 18 DAF. The greater endogenous indole-3-acetic acid concentration in the medium berries compared with LGOs might protect the former from abscission.

Three trials (two in 2019 and one in 2020) were completed at the University of Guelph, Huron Research Station near Exeter, ON, to determine if the co-application of thifensulfuron with glyphosate accentuates soybean injury in glyphosate-resistant (GR) soybean. At 1, 2, 4, and 8 weeks after treatment (WAT), thifensulfuron (6 and 12 g a.i.·ha⁻¹ representing the 1× and 2× rate, respectively) applied POST with no adjuvants caused up to 5% soybean injury. The addition of a non-ionic surfactant + UAN to thifensulfuron increased soybean injury to up to 24%. There was no decrease in soybean density, dry biomass, height, and yield, except soybean dry biomass was reduced up to 22% with the addition of adjuvants to thifensulfuron at the 2× rate. Glyphosate (1800 and 3600 g·ha⁻¹ representing the 1× and 2× rate, respectively) applied POST caused no adverse effect on soybean injury parameters evaluated. The co-application of glyphosate + thifensulfuron at the 1× and 2× rates, without additional adjuvants, caused a synergistic increase in soybean injury at 1, 2, 4, and 8 WAT, and a synergistic decrease in dry biomass and height. All other interactions were additive. The co-application of glyphosate + thifensulfuron at the 1× and 2× rates, with additional adjuvants, produced a synergistic increase in injury at 1 (1× and 2× rate), 4 (1× rate), and 8 (1× rate) WAT in soybean. All other interactions were additive.

Hailstorms can be responsible for significant economic loss to the agricultural sector in Alberta, Canada. Foliar applications of certain fungicides and nutrient blends have been advocated to promote recovery and yield of hail-damaged crops. Proper understanding of different crop and hail-related factors is required for an accurate assessment of hail damage to crops and for evaluations of hail-recovery product claims. This study was undertaken at three locations in Alberta during three growing seasons (2016–2018) to determine the effects of two levels of simulated hail severity at three different crop developmental stages, including the early growth (BBCH 30 for wheat; BBCH 14–16 for pulses), mid-growth (BBCH 39 for wheat; BBCH 60 for pulses), and late growth (BBCH 60 for wheat; BBCH 71 for pulses) stages. Plant growth and yield parameters of wheat (Triticum aestivum L.), field pea (Pisum sativum L.), and dry bean (Phaseolus vulgaris L.) crops were measured. Simulated hail damage led to reductions in height, biomass, NDVI, grain yield, and kernel weight of all three crops. Average yield decreased by 24% and 35% for wheat, 17% and 35% for dry beans, and 37% and 45% for field peas for light and heavy hail severity, respectively. Hail timing was a critical factor influencing the extent of crop damage, with hail damage during the early growth stage leading to a lesser yield reduction compared with hail damage at the mid-growth and late growth stages. Fungicides and nutrient blends applications did not significantly improve crop recovery, grain yield, or kernel weight for any of the crops in this study.

Expansion of perennial grain and forage Kernza intermediate wheatgrass to temperate regions may be limited by its vernalization requirements. We compared vegetative and reproductive traits of Kernza plants grown in the greenhouse under four environmental treatments of temperature and day length for a 7 week induction period. The percent of plants that flowered and spikes per plant decreased from 83% and 8.2 at 4 °C and 10 h to 15% and 0.4 at 26 °C and 15 h, respectively. The variability observed suggests that there is potential for selection for reduced vernalization requirements in Kernza populations.

Palmer amaranth is one of the most economically important and widespread weeds of arable land in the United States. Although no populations are currently known to exist in Canada, its distribution has expanded northward such that it is present in many of the states bordering Canada and multiple pathways exist for its introduction. In this short communication, we report on the transport of viable Palmer amaranth seed on imported sweet potato slips. A reproductive pair of Palmer amaranth seedlings were identified from soil accompanying imported sweet potato slips in 2018. Identification was confirmed using species-specific single nucleotide polymorphisms.

CDC Rowland, a late-maturing oilseed flax (Linum usitatissimum L.), was registered in 2018 by the Crop Development Centre, University of Saskatchewan, Saskatoon, Saskatchewan. This cultivar had a significant yield advantage (12% higher) comparable to CDC Bethune in all soil zones of the Northern Prairies. The yield of CDC Rowland was 117%, 116%, and 105% of CDC Bethune in the Black, Brown, Black and Grey soil zones of Western Canada, respectively. This cultivar has medium (44.6%) oil content, superior oil quality (IV 194.5; ALA content 59.3%), and large seed size (TSW 6.8 g) coupled with resistance to lodging. It is immune to North American rust (race 371) caused by Melampsora lini and moderately resistant to wilt caused by Fusarium oxysporum f. sp. lini and powdery mildew caused by Oidium lini.

SES0787LS is a camelina (Camelina sativa) cultivar developed at Smart Earth Camelina Corporation in Saskatoon, SK. It was developed via hybridization followed by pedigree selection. SES0787LS has significantly higher (12%) seed yield and significantly larger seeds (29.6%) than the check cultivar AAC 10CS0048 and is adapted to all soil zones of the Canadian Prairies.

Noor hard red spring wheat (Triticum aestivum L.) was developed using a modified bulk breeding method at the University of Alberta, Edmonton, AB Canada. Noor is an apically awnletted, hollow-stemmed line with a combination of high yield potential, good lodging tolerance, and medium maturity. During the three years (2016–2018) of evaluation in the Parkland Wheat Cooperative test, Noor yielded 12% higher than the mean of all the checks and matured similarly to Carberry and Glenn, but 3.1 and 2.6 d later than AC Splendor and Parata, respectively. Noor was 94.9 cm tall, shorter than AC Splendor (98.4 cm), similar in height to Glenn (94.0 cm) and Parata (93.5 cm), but taller than Carberry (86.0 cm). The lodging score of Noor (2.1) was lower than Parata (3.0) and AC Splendor (3.0), but similar to Carberry (2.3) and Glenn (2.1). The test weight (kg·hL⁻¹) of Noor (80.0) was higher than AC Splendor (78.6), similar to Carberry (80.2) and Parata (80.4), but lower than Glenn (82.2). Grain weight (35 g) and NIR protein of Noor (14.1%) was lower than all the checks. Overall, Noor was rated resistant (R) to the prevalent races of leaf, stem, and stripe rusts during the three years of testing. Noor was rated intermediate (I) to common bunt and Fusarium head blight. Three years of end-use quality evaluation indicated that Noor is acceptable for the Canada Western Red Spring class, with fewer flags.

AAC Succeed durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.] is adapted to the durum production area of the Canadian prairies. AAC Succeed carries the Sm1 gene, which confers antibiosis-based resistance to orange wheat blossom midge [Sitodiplosis mosellana (Gehin)]. Averaged over three years, AAC Succeed yielded significantly more grain than Strongfield (7%) and AC Navigator (21%). AAC Succeed had a protein concentration significantly higher than Brigade and AC Navigator, and similar to Strongfield. AAC Succeed had significantly stronger straw as measured by lodging score than Strongfield, and similar to Brigade. AAC Succeed is eligible for grades of Canada Western Amber Durum, has low grain cadmium concentration, and has higher yellow pigment concentration than the check cultivars.