Greenhouse replacement series studies were conducted to determine the relative competitiveness of NC10-275 (unreleased, drought tolerant; upright, bushy, and vining growth with large leaves) and Covington (the most commonly grown genotype in North Carolina; vining growth with smaller leaves) sweet potato genotypes with weeds. Sweet potato genotypes were grown with Palmer amaranth (tall growing) or common purslane (low growing) at five planting (sweet potato to weed) proportions of 100:0, 75:25, 50:50, 25:75, and 0:100 at a density of four plants per pot. Reduction in common purslane shoot dry biomass was greater when growing with NC10-275 than when growing with Covington or alone. When growing with common purslane, shoot dry and root fresh biomass of Covington was 18% and 26% lower, respectively, than NC10-275. Relative yield (shoot dry biomass) and aggressivity index (AI) of common purslane was lower than both sweet potato genotypes. Palmer amaranth shoot dry biomass was similar when growing alone or with Covington, whereas it was reduced by 10% when growing with NC10-275 than alone. Palmer amaranth competition reduced shoot dry biomass and root fresh biomass of Covington by 23% and 42%, respectively, relative to NC10-275. Relative yield and AI of Palmer amaranth was greater than Covington but lower than NC10-275. This research indicates that sweet potato genotypes differ in their ability to compete with weeds. Both sweet potato genotypes were more competitive than common purslane, and the following species hierarchy exists: NC10-275 > Covington > common purslane. In contrast, NC10-275 was more competitive than Covington with Palmer amaranth, and the following species hierarchy exists: NC10-275 ≥ Palmer amaranth > Covington.

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is a major pest of wheat (Triticum aestivum L.) in the northern Great Plains, where it is a constant threat in Montana and is resurging in Alberta, Saskatchewan, and North Dakota. Adoption of solid-stemmed cultivars is an important management tool for wheat growers; however, the inconsistent pith expression first noted with the release of ‘Rescue’ has been repeatedly observed in modern cultivars such as ‘Lillian’ in Canada. Given the extensive hectares planted to solid-stemmed wheat cultivars during an outbreak, the identification of cultivars that display stable stem solidness, grain yield, and grain protein concentration across a wide range of environments where stem sawfly infestations occur is desirable. We assessed spring wheat plant responses in eight solid-stemmed and two hollow-stemmed genotypes grown across diverse environments using multiple statistical models. Study sites included southern Alberta and Saskatchewan, Montana, and North Dakota. Most models agreed that the genotypes ‘Choteau’, ‘BW925’, and ‘Mott’ consistently displayed high and stable stem solidness concomitant with high grain yield. ‘Choteau’ and ‘BW925’ also consistently met or exceeded the desired threshold of a 3.75/5 pith rating (averaged from the lower four stem internodes) for optimum resistance, whereas ‘Mott’ developed optimal pith at a specific (early) phenological stage when resistance to wheat stem sawfly infestation is critical. Exploring the stability of stem solidness identified ideal genotypes that would enhance germplasm development efforts, which exemplifies how this approach can facilitate the selection, production, and adoption of solid-stemmed wheat cultivars in regions prone to wheat stem sawfly attack.

Characterization of local germplasm is an effective way to identify elite breeding material and develop improved varieties. This study was aimed to assess 52 tomato accessions comprised of local varieties (28), landraces (8), breeding lines (14), and wild relatives (2), and their characterization for 30 morphological/agronomic, four fruit quality, and tomato mosaic virus (ToMV) resistance traits. Morphological, quality, and ToMV traits were evaluated using phenotyping, biochemical assays, and molecular markers, respectively. Fruit shape and size showed appreciable variation, with fruits varying from rounded to heart shaped and small to big size. Significant variation was observed for fruit weight (1.6–564.8 g), fruits per plant (6.0–174.7), productivity (130.5–5146.5 g), soluble solids (4.1%–8.4%), vitamin C (9.5–46.4 mg·100 g⁻¹), antioxidant activity (2.5–9.6 μmol Fe²⁺·g⁻¹ fresh weight), and total polyphenols (23.9–124.2 GAE·100 g⁻¹ fresh weight). All accessions were phenotypically screened for the virus resistance in the growth chamber, and CAPS molecular markers were used to identify accessions with ToMV Tm-2² resistant alleles, and accessions LYC-13, LYC-15, LYC-17, LYC-26, and LYC-52 were identified as resistant. Multivariate analysis of morphological and quality traits showed that 35 principal components contributed to the total variation and the first two and 12 principal components explained 47.2% and 90% of the variation, respectively. The evaluated tomato collection appears to have breeding potential, and around 20% of the accessions in the collection (LYC-6, LYC-17, LYC-18, LYC-26 to LYC-31, and LYC 33) are promising genetic resources for variety development that are enriched with enhanced fruit quality and high yield.

Winter canola or winter oilseed rape (Brassica napus L.) is not commonly grown in Canada. While winter oilseed rape is the dominant growth form in Europe, Canadian canola production is dominated by spring types in western Canada. Research conducted in the 1980s indicated that the environmental conditions in southern Ontario are well suited to the production of winter canola. Since then, however, interest in the crop has ebbed, and little to no research has been conducted on the agronomic issues that potentially limit its adoption in the province. The objective of this research was to identify an optimal seeding date for winter canola in southern Ontario. Three winter canola hybrids were evaluated across five seeding dates, ranging from early September to late October. The results established the first two weeks of September as the optimal seeding period for winter canola in southern Ontario. Seeding winter canola during this period, such that greater than 600 growing degree days could be accumulated before the first fall frost, not only reduced winterkill to approximately 20%, but also maximized yield potential and ensured optimal oil quality. Winter canola showed great potential for production in southern Ontario, and its addition to current crop rotations would diversify and enhance crop production practices in this portion of the province.

A callus line of manila grass [Zoysia matrella (L.) Merr.] has been maintained for 8 years in our laboratory. The present study investigated changes in ultrastructure and antioxidant enzyme activity during regeneration of the callus and examined the correlation between these changes and regeneration ability. The changes in fresh weight and diameter of the callus over time could be described by a sigmoidal growth curve with different stages. Electron microscopy revealed small embryonic callus cells, isodiametric in shape, with large, obvious nuclei, and dense cytoplasm. The cellular structures and morphology changed dramatically as regeneration proceeded. Of particular note was the formation of folded scutellum-like embryos at 14 d, which might be the turning point for morphological differentiation. Catalase (CAT) and peroxidase (POD) activities were the lowest at 14 d, the same time when superoxide dismutase (SOD) activity was highest. Thus, we speculate that the formation of the scutellum-like structures is associated with higher activity of SOD and lower activities of CAT and POD.

Hair fescue (Festuca filiformis Pourr.) is a tuft-forming perennial grass of concern in lowbush blueberry (Vaccinium angustifolium Ait.) as tufts form dense sods that reduce lowbush blueberry yield and inhibit harvest. Although generally tolerant to ACCase-inhibiting herbicides, injury to some Festuca spp. following clethodim applications has been reported. ACCase-inhibiting herbicides are important for non-bearing and bearing year perennial grass management in lowbush blueberry but have not been extensively evaluated for hair fescue management. The objectives of this research were to (1) determine the relative efficacy of foramsulfuron, fluazifop-P-butyl, sethoxydim, and clethodim on hair fescue, and (2) determine if foramsulfuron tank mixtures with fluazifop-P-butyl, sethoxydim, and clethodim improve hair fescue suppression. None of the herbicides evaluated caused unacceptable injury to lowbush blueberry. Foramsulfuron (35 g a.i. ha⁻¹) reduced hair fescue total tuft density, flowering tuft density, and flowering tuft inflorescence number. Fluazifop-P-butyl (250 g a.i. ha⁻¹) and sethoxydim (495 g a.i. ha⁻¹) caused variable levels of visual injury to hair fescue and did not reduce total tuft density, flowering tuft density, or flowering tuft inflorescence number. Clethodim (91 g a.i. ha⁻¹), however, caused >50% visual injury to hair fescue and reduced hair fescue total tuft density, flowering tuft density, and flowering tuft inflorescence number. Fluazifop-P-butyl and sethoxydim tank mixtures with foramsulfuron did not increase hair fescue suppression relative to foramsulfuron alone. A foramsulfuron + clethodim tank mixture provided equivalent hair fescue suppression as either herbicide applied alone. Foramsulfuron and clethodim should therefore be used in rotation rather than tank mixture to manage hair fescue in lowbush blueberry.

This study aimed to evaluate the total phenol, flavonoid, and individual phenolic acid contents and the antioxidant and cytotoxic activities of methanol extracts from Ficus cordata ssp. salicifolia. Spectrophotometry and gas chromatography – mass spectrometry (GC–MS) were used for chemical analyses, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was conducted to determine the antioxidant activity. The cytotoxic activity was assessed against MCF7 (human breast adenocarcinoma), A2780 (human ovary adenocarcinoma), HT29 (human colon adenocarcinoma), and MRC5 (normal human fetal lung fibroblast) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The total content of phenols, flavonoids, and antioxidant activity of the studied dry leaf, stem bark, twig, and fruit extracts were between 13.14 and 22.94 mg·GAE g⁻¹ dry weight, 8.03 and 12.72 mg ·QE g⁻¹ dry weight, and 75.59% and 83.96%, respectively. Ten individual phenolic acids were quantified in the studied plant parts. The prominent phenolic acid was p-hydroxybenzoic acid, followed by vanillic acid. Methanolic fruit extracts exhibited promising cytotoxic activity against MCF7 (IC₅₀: 21.11 μg·mL⁻¹). Additionally, A2780 cell lines responded very well to all the extracts, with an IC₅₀ from 8.16 to 13.72 μg·mL⁻¹, except for the fruit extract, which was 47.39 μg·mL⁻¹. The leaf extract showed significant cytotoxicity against HT29 cell lines, with an IC₅₀ of 8.81 μg·mL⁻¹. All extracts showed IC₅₀ values ranging from 24.68 to 56.15 μg·mL⁻¹ on normal cells. Further examination of the plant parts in this study could identify compounds accounting for the observed antioxidant and cytotoxic activities and might represent potential novel anticancer drugs.

Condensed tannins in sainfoin (Onobrychis viciifolia) improve forage digestion and reduce the risk of ruminant bloat caused by grazing alfalfa (Medicago sativa). The objectives of this study were to evaluate the forage dry matter yield (DMY) and persistence of newer sainfoin cultivars in mixtures with alfalfa, and to determine the impact of harvest frequency on the persistence of sainfoin. Sainfoin cultivars ‘AAC Mountainview’, ‘AAC Glenview’, ‘Delaney’, ‘Shoshone’, and six experimental populations were compared with ‘Nova’ and ‘Melrose’ at Lanigan, SK, from 2016 to 2018. Field plots were seeded in either monocultures of sainfoin at 33 kg·ha⁻¹ or sainfoin–‘AC Grazeland’ alfalfa mixtures at 16:9 kg·ha⁻¹ in alternate rows. Forage DMY was greater (P = 0.001) in mixtures than in sainfoin monocultures in all harvests. The proportion of sainfoin in mixtures at Cut 1 declined from 4.1% to 1.3% of total DMY from 2016 to 2018, and 19.0% to 4.8% in Cut 2, which was less than the recommended level to eliminate ruminant bloat risk. A second field trial was established in 2017 to compare responses of ‘AAC Mountainview’, ‘Nova’, and ‘Shoshone’ sainfoin under one-, two- or three-harvest frequencies in 2018 and 2019. The increase of harvest frequency did not reduce sainfoin stand (%). Stand percentage of ‘AAC Mountainview’ (91%) was greater (P = 0.01) than ‘Nova’ sainfoin (62%). Further agronomic studies focusing on weed control in sainfoin stands and the optimum seeding ratios of sainfoin–alfalfa within the Parkland region of Saskatchewan are needed.

Continued interest in the commercial production of cider in Ontario has revealed that there is a lack of information available to apple producers and cidermakers on the juice attributes of culinary dessert apple for making cider and how they may vary from orchard to orchard. A two-year study was conducted to characterize the juice characteristics of 18 common culinary dessert apple cultivars grown at several locations in Ontario. Juice was assayed for soluble solids concentration, pH, titratable acidity (TA), juice extraction efficiency, yeast assimilable nitrogen (YAN), polyphenols, and soluble solids to TA ratio. Significant differences among cultivars were observed for all parameters, which varied by orchard and year, except juice extraction efficiency. These data underly the importance of assaying juice every growing season prior to fermentation. Cidermakers should focus on juice characteristics from culinary apples that are more difficult to alter (with amendments), and use juice with lower pH, higher TA and polyphenols, and moderate to higher YAN to optimize cider quality and flavour. Overall, this study will inform cidermakers of which culinary apple cultivars might be preferable for fermentation as well as how they might be blended to optimize cider quality. Notwithstanding annual and orchard variation, cultivars that meet these criteria include Cortland, Crimson Crisp, Honeycrisp, Jonagold, McIntosh, and Northern Spy. If making cider from Ambrosia, Crispin, Empire, Fuji, Gala, Golden Delicious, or Idared, cidermakers should expect to blend the juice from these cultivars to create a more fully balanced juice prior to fermentation.

Application of nitrogen fertilizer and commercial seed treatments are two strategies dry bean growers in Ontario utilize to manage root rot and maximize yields. However, data solidifying these practices is absent or outdated. Experiments were conducted at the Huron Research Station, near Exeter, Ontario, from 2008 to 2010, to measure plant growth and yield responses for navy, kidney, and cranberry dry bean market classes (cv. T9905, Pink Panther, and Etna, respectively) to seed treatment (NST, no seed treatment; CMBD, Cruiser Maxx Bean + Dynasty) and N fertilizer rates of 0, 35, 70, 105, 140, and 175 kg N·ha⁻¹. Plant measurements taken included plant emergence, vigour, height and maturity, plant and seed mass, and grain moisture and yield. Over three years, plant growth and yield responses to seed treatment and nitrogen fertilizer were very scarce. Plant emergence and vigour either improved or were not affected by seed treatment or N rate, while increasing N rates increased plant height of only Pink Panther in 2008. Plant mass was unaffected by either factor while seed treatment decreased days to maturity and grain moisture of T9905 in 2008. Nitrogen fertilizer improved the grain yield of Etna, with the highest yields occurring with 70 kg N·ha⁻¹ or more, while other cultivar site–years did not respond. Overall, these results demonstrate dry beans rarely respond to N fertilizer or seed treatment at the Huron Research Station. Additional testing over multiple years and locations would assist in predicting these responses.

Canola (Brassica napus L.) and soybean [Glycine max (L.) Merr.] are currently two of the three most common crops grown in Manitoba, which comprises the eastern regions of the Canadian Prairies. Volunteer B. napus is a prominent weed in soybean in Manitoba and glyphosate-resistant (GR) volunteer B. napus often is the only weed remaining after in-crop weed control with glyphosate in soybean. Additive-series field experiments were established at three locations in Manitoba in 2012 and 2013 to study volunteer B. napus interference with soybean and develop action and economic thresholds for this weed. Soybean were planted in narrow (25 cm) or wide (75 cm) row spacing and glyphosate-resistant B. napus seed was broadcast at densities of 0, 10, 20, 40, 80, 160, 320, and 640 seeds·m⁻² at the time of soybean planting. Development of soybean and volunteer B. napus were determined throughout the growing season and seed yield of both species was determined at their respective physiological maturity. Volunteer B. napus is highly competitive with soybean, as action (<9 plants·m⁻²) and economic (<5 plants·m⁻²) thresholds were low. At these action thresholds, volunteer B. napus seed return to the weed seedbank was on average 14 400 seeds·m⁻² and 10 400 seeds·m⁻² in narrow- and wide-row soybean, respectively.

Although much of the manure in Canada is surface-applied to forages, little research exists evaluating time of year (Time) and rate (Rate) of application on forage yield and nutrient uptake. Field trials (10 yr) on two soils (sandy loam upland and silty clay loam dykeland) investigated this. Experimental arrangement was a factorial [Time (spring, summer, early, and late fall manure applications)] plus a control [spring-applied ammonium nitrate fertilizer (ANF)] in a Latinized split plot. ANF at 0, 25, 50, 100 and 200 kg N·ha⁻¹; 0, 75, 150, and 300 as semi-solid beef (SSM) and 150 kg N·ha⁻¹ as liquid dairy manure (LDM), constituted respective splits. The Time × Rate interaction, later in the trial on the upland soil, showed higher yields and nutrient uptakes with fall manure application. There was little interaction on the dykeland soil; summer application resulted in higher yields at times. For both soils, the optimal long-term application rate of SSM was approximately 150 kg N·ha⁻¹ while that of ANF was approximately 100 kg N·ha⁻¹. Inherent fertility of dykelands resulted in lesser responses to manure addition. Negligible and significant residual N occurred with fertilizer and manure, respectively. Nitrogen, phosphorus, potassium, calcium, magnesium, manganese, copper, zinc, and boron uptakes were due to amendment impact on yield. The recommended rate is 150 kg N·ha⁻¹ of SSM or LDM applied in fall and summer to Maritime grasslands grown on upland and dykeland soils, respectively. Yield differences may not warrant producers adjusting timing of in-season manure application.

Soil salinity is a serious problem that negatively affects the productivity of plants. Reducing the impact of salinity to sustain production is a goal of scientists. The objective of this study was to determine the effect of potato peel amendments at different rates in reducing the negative impact of saline water. Common bean (Phaseolus vulgaris L. ‘Valentine’) was grown in soil mixed with potato peel at different rates (0%, 2.5%, 5%, and 7.5%). To achieve this objective, plants were irrigated with three levels of saline water (0, 50, and 100 mmol L⁻¹) to induce stress at the vegetative stage. The results demonstrated the significant reduction in physiological parameters, plant growth, and yield of common bean after irrigation with saline water. Soil amendment with different rates of potato peel significantly increased the number of pods per plant, weight of pods per plant, pod length, chlorophyll content, and relative water content of common bean irrigated with saline water (50 mmol L⁻¹) as compared with non-amended soil. Potato peel application also reduced electrolyte leakage and improved soil properties by reducing the salinity of the soil. Furthermore, among all potato peel rates used in this investigation, the 7.5% rate had a better result for common bean production. Conversely, potato peel did not improve the yield of beans grown under a high concentration of saline water (100 mmol L⁻¹). In conclusion, soil amendments with potato peel at a 7.5% rate could be successfully used as a cost effective management practice to enhance bean production in soils stressed with high salt content.

Kochia [Bassia scoparia (L.) A.J. Scott] is a summer annual tumbleweed that is tolerant of heat, drought, and salinity and capable of causing large yield losses in spring wheat (Triticum aestivum L). Increased incidence of glyphosate- and acetolactate synthase (ALS) inhibitor-resistant kochia in western Canada warrants investigation of alternative herbicides to manage these biotypes. Herbicides applied pre- or post-emergence in spring wheat were evaluated based on crop tolerance and control of ALS inhibitor-resistant kochia accessions with and without the glyphosate resistance trait in five environments near Lethbridge and Coalhurst, Alberta, from 2013 to 2015. The most effective and consistent treatments for kochia management included sulfentrazone applied pre-emergence and fluroxypyr/bromoxynil/2,4-D or pyrasulfotole/bromoxynil applied post-emergence. All of these treatments resulted in ≥90% visible control in all environments and ≥90% kochia biomass reduction compared with the untreated control in Lethbridge 2014 and 2015. MCPA/dichlorprop-p/mecoprop-p, dicamba/2,4-D/mecoprop-p, and dicamba/fluroxypyr resulted in acceptable control among environments (≥80% visible control in all environments and ≥80% kochia biomass reduction in Lethbridge 2014 and 2015); however, the latter two options caused unacceptable (>10%) wheat visible injury in Coalhurst 2014. Recent confirmations of auxinic herbicide-resistant kochia in western Canada—due, in part, to use of synthetic auxins to manage glyphosate-resistant kochia in small-grain cereals—will limit kochia management options. When implemented with non-chemical tools as part of an integrated weed management program, alternative herbicide modes of action like protoporphyrinogen oxidase inhibitors before and photosystem II or 4-hydroxyphenylpyruvate dioxygenase inhibitor(s) within spring wheat could mitigate selection for multiple herbicide-resistant kochia.