Abdel-Aal, E. M. and Choo, T.-M. 2014. Differences in compositional properties of a hulless barley cultivar grown in 23 environments in eastern Canada. Can. J. Plant Sci. 94: 807-815. Barley grains hold a promise for several applications in food, feed, energy and malting industries due to their diverse components and functionalities. The current study aimed to investigate compositional and 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging properties of a newly developed hulless barley cultivar, AAC Azimuth. The cultivar was grown at 11 sites in 2010 and 12 sites in 2011 in Ontario and Quebec, Canada. The results showed that most of the nutrients examined in barley varied significantly among locations. In addition several components varied by year such as β-glucan, protein and phenols. There were significant year×location interactions for all of these nutrient components. The application of fungicides increased the content of moisture, but it decreased the content of phenols. The new cultivar contained relatively low amount of dietary fiber, average amount of β-glucan, and high levels of starch and protein, which could improve the feed and energy value. The cultivar also had total phenols and DPPH antioxidant capacity within the range of yellow and color barleys showing its antioxidant potential. The absence of hulls along with reasonable levels of protein, total antioxidant phenols and DPPH antioxidant capacity would promote the cultivar for food use subject to flour characteristics and functionality.

Li, Y., Iwaasa, A. D., Wang, Y., Jin, L., Han, G. and Zhao, M. 2014. Condensed tannins concentration of selected prairie legume forages as affected by phenological stages during two consecutive growth seasons in western Canada. Can. J. Plant Sci. 94: 817-826. Studies have shown that condensed tannins (CT) at appropriate concentrations improve nutrient digestion in animals and influence ecosystem processes. However, knowledge of CT concentration in different phenological stages and different plant parts of non-conventional legumes growing in the western Canadian prairies is lacking for feed and grazing management. The research objectives were to determine the level and distribution of total CT (TCT), extractable CT (ECT) and protein-bound (PCT) or fiber-bound CT (FCT) concentrations in the whole plant of legume forages at different phenological (vegetative, flowering, seed maturity) stages and plant parts (leaves, stems, inflorescences and inflorescences seedpods) using the Butanol-HCl procedure. Whole plant samples of purple prairie clover (Dalea purpurea Vent.), white prairie clover (D. candida Michx. ex Willd), sainfoin (Onobrychis viciifolia Scop.) and Canadian milkvetch (Astragalus canadensis L.) were collected in the 2011 and 2012 growing seasons from replicated small trial plots at vegetative, flowering and seed maturity stages. Species, phenological stages and their interactions all significantly affect the TCT, ECT, PCT and FCT concentrations in whole plant and plant parts (P<0.001). Concentrations of ECT and TCT increased for all species as they matured from vegetative to seed maturity, except for sainfoin where the vegetative stage had the highest ECT and TCT levels. The highest mean ECT and TCT concentrations for purple prairie clover and white prairie clover were found in the inflorescences part at flowering stage, while sainfoin had the highest ECT and TCT concentrations in the leaves at vegetative stage. There was little variation for PCT among different phenological stages in whole plant for species except for purple prairie clover and white prairie clover which had higher (P<0.05) PCT at seed maturity than at flowering stage. Only trace amounts of FCT were detected from either whole plant or different fractions of all plant species, except Canadian milkvetch. Condensed tannins were not observed in Canadian milkvetch except for trace amounts in the seed coat at seed maturity stage. The results demonstrate that legumes differ in their condensed tannin content which could potentially be used in pasture management.

Alber, N. B., Brink, G. E. and Jackson, R. D. 2014. Temperate grass response to extent and timing of grazing. Can. J. Plant Sci. 94: 827-833. Considerable differences exist among cool-season grass species in their production potential and response to management variables. We examined the effects of grazing management on forage and root production of two temperate perennial grasses, meadow fescue [Schedonorus pratensis (Huds.) P. Beauv.] and orchardgrass (Dactylis glomerata L.). Grazing factors studied were extent of defoliation (50 or 100% biomass removal) and stage of maturity (vegetative or mature) at grazing. In 2009 and 2010, orchardgrass produced more above-ground biomass than meadow fescue despite yearly precipitation differences. In the drier year (2009), both grasses produced greater above-ground biomass under 100% extent of defoliation at either maturity stage. In 2010, orchardgrass produced greater above-ground biomass when grazed at a mature stage for either extent of defoliation, while few differences existed among grazing treatments imposed on meadow fescue. Grazing treatments had no effect on below-ground growth of orchardgrass either year. Meadow fescue root production was effected in 2010 only; grazing at a mature stage increased below-ground growth for either extent of defoliation. Results suggest that grazing at maturity to remove 100% of biomass maximizes above-ground production of both meadow fescue and orchardgrass, but lengthens the grazing interval and may have a deleterious effect on grass persistence and nutritive value.

Pageni, B. B., Lupwayi, N. Z., Akter, Z., Larney, F. J., Kawchuk, L. M. and Gan, Y. 2014. Plant growth-promoting and phytopathogen-antagonistic properties of bacterial endophytes from potato (Solanum tuberosum L.) cropping systems. Can. J. Plant Sci. 94: 835-844. Endophytes are microorganisms that live within a plant without harming it. Bacterial endophytes were isolated from roots of potatoes (Solanum tuberosum L.) grown under different rotations (3 to 6 yr in length) and soil management (CONV, conventional; CONS, conservation) in irrigated cropping systems with dry bean (Phaseolus vulgaris L.), sugar beet (Beta vulgaris L.) spring wheat (Triticum aestivum L.) and timothy (Phleum pratense L.). The endophytes were characterized for nitrogen fixation potential, phytohormone production and phytopathogen-antagonistic properties. The nitrogen-fixing nitrogenase (nifH) gene was detected in potato grown in all rotations, presumably partly because the soil in all rotations contained Rhizobium leguminosarum bv. phaseoli from the dry bean phase. Sequence analysis revealed that it was homologous to the genes found in Burkholderia, Azospirillum, Ideonella, Pseudacidovorax and Bradyrhizobium species. Indole acetic acid (IAA) hormone production by endophytes isolated from potato grown under CONS management was 66% greater than that those isolated from potato grown under CONV management, and tended to be greater in longer than shorter rotations. When 12 endophytes were inoculated to dry bean, four increased shoot biomass by 27-34%, and six increased total (shoot root) biomass by 25% on average. Endophytes from the longer CONS rotations (4-6 yr) resulted in significantly higher (by 9%) shoot biomass than the shortest CONS (3 yr) rotation. Six of 108 endophyte isolates exhibited antagonistic properties (reduced pathogen biomass by 12 to 58% in dual culture assays in liquid media) against potato pathogens Pectobacterium atrosepticum, Fusarium sambucinum and Clavibacter michiganensis subsp. epedonicus. All the six isolates were from CONS soil management. Therefore, the benefits of long rotations, with their associated CONS soil management, to crop productivity in these irrigated cropping systems probably include nutritional (biological nitrogen fixation and IAA hormone production) and disease-control benefits imparted by endophytic bacteria.

Oh, S.-K., Jang, H. A., Kim, J., Choi, D., Park, Y.-I. and Kwon, S.-Y. 2014. Expression of cucumber LOX genes in response to powdery mildew and defense-related signal molecules. Can. J. Plant Sci. 94: 845-850. The cucumber genome contains 23 lipoxygenase (LOX) genes. The expression of seven type-I and six type-II LOX genes was induced when cucumber leaves were challenged with Sphaerotheca fuliginea and treated with salicylic acid, methyl jasmonate, and abscisic acid. These 13 CsLOX genes were differentially regulated during biotic and abiotic stresses.

Iwaasa, A. D., Jefferson, P. G. and Birkedal, E. J. 2014. Beef cattle grazing behaviour differs among diploid and tetraploid crested wheatgrasses (Agropyron cristatum and A. desertorum). Can. J. Plant Sci. 94: 851-855. A study was conducted over 4 yr (1999, 2000, 2002 and 2003) at Swift Current to evaluate the forage preferences of steers grazing five different crested wheatgrass (CWG) cultivars: Kirk (2n=28), Fairway (2n=14) and Parkway (2n=14) [Agropyron cristatum (L.) Gaertn.], Hycrest (2n=28) (A. cristatum×A. desertorum) and Nordan (2n=28) [(A. desertorum (Fisch. Ex Link) Schult.)]. Animal grazing frequencies for each CWG cultivar patch were converted to percentages (Grazing%) for each grazing time period. Grazing% for Kirk and Hycrest CWGs were similar with Nordan having higher (P<0.05) Grazing% compared with the hybrid and diploid CWGs. Contrasts revealed no differences (P=0.48) in Grazing% between diploid versus hybrid cultivars, while higher (P<0.01) Grazing% were observed for tetraploid compared with diploid and hybrid CWG cultivars. For forage nutritive values, significant Cultivar (P<0.01) and Year (P<0.0001) main effects were observed. Overall mean values for percent crude protein (%CP) and percent acid detergent fibre (�F) for Nordan, Kirk, Hycrest, Fairway and Parkway were 10.6±0.3 and 29.2±0.4, 11.0±0.3 and 28.7±0.4, 10.4±0.3 and 29.7±0.4, 9.9±0.3 and 28.5±0.4, and 10.0±0.3 and 28.7±0.4, respectively (± SE). Correlation coefficients between Grazing% and all nutritive value constituents were low and not significant. This study observed grazing preference differences among different CWG cultivars that may lead to grazing management strategies to improve pasture utilization potential and animal production.

Deyman, K. L., Chiu, G., Liu, J., Brikis, C. J., Trobacher, C. P., DeEll, J. R., Shelp, B. J. and Bozzo, G. G. 2014. Effects of elevated CO₂ and 1-methylcyclopropene on storage-related disorders of Ontario-grown Empire apples. Can. J. Plant Sci. 94: 857-865. The impact of 1-methylcyclopropene (1-MCP) application on CO₂-induced physiological injury in Empire apple fruit during controlled atmosphere storage was assessed over a 3-yr period using an experimental design involving multiple treatment replicates. Fruit harvested at optimal maturity from one or two orchards were treated with or without 1 µL L^-1 1-MCP, then chilled at 0 or 3°C under various CO₂ partial pressures (5, 2.5 or 0.03 kPa CO₂) in the presence of 2.5 kPa O₂ for up to 46 wk using a split-plot design. Fruit were sampled periodically for assessment of flesh browning and external peel injury. The maximal incidence of external CO₂ injury varied from 15 to 100% over the 3 yr, and the most rapid development of this disorder was evident at 5 kPa CO₂. The incidence of external CO₂ injury as a function of storage time was influenced by orchard location and storage temperature. Moreover, the incidence of flesh browning at 0°C and 5 kPa CO₂ was influenced slightly by orchard; this disorder was never higher than 30%, and the impact of elevated CO₂ was inconsistent across years. Notably, there was no evidence for negative effects of 1-MCP on the incidence of storage-related disorders.

MacDonald, W. N., Tsujita, M. J., Blom, T. J. and Shelp, B. J. 2014. Impact of : ratio and nitrogen supply on nitrogen remobilization in potted chrysanthemum grown in a subirrigation system. Can. J. Plant Sci. 94: 867-880. Subirrigation is being adopted as an environmentally friendly strategy for managing the nutrition of potted greenhouse plants. Here, we investigated two strategies for enhancing the remobilization of N during the development of the inflorescence in subirrigated potted chrysanthemum (Chrysanthemum morifolium Ramat.) in an attempt to improve nitrogen (N) use efficiency. (1) The replacement of a portion of the nitrate in the nutrient solution with ammonium decreased the nitrate content, especially in the stem plus petioles, and increased the reduced N content early in the growth cycle, but did not improve N use efficiency. (2) The use of a lower N supply (200 vs. 400 mg total N per pot delivered over 3 and 5 wk, respectively), either as nitrate or ammonium nitrate, eliminated nitrate accumulation prior to inflorescence development, thereby improving N use efficiency. Inflorescence quality was unaffected; however, at the lower N level there was some evidence of chlorosis on the oldest leaves. Thus, there may be considerable potential to reduce the N supply in a commercial greenhouse setting as long as an adequate supply is provided early in the growing period.

Mapes, C. and Xu, Y. 2014. Photosynthesis, vegetative habit and culinary properties of sage (Salvia officinalis) in response to low-light conditions. Can. J. Plant Sci. 94: 881-889. Culinary sage (Salvia officinalis) is known to grow better at sunny locations with good drainage. However, when there is a necessity to propagate it in controlled environments with minimal additional lighting, or at shady locations, how significantly its growth and production would be restricted has not been well investigated. The objective of this study was to examine the responses of sage grown in a greenhouse over the winter when ambient light in the greenhouse is lower than 212 µmol m^-2 s^-1 (or a daily light integral of 9.2 mol m^-2 d^-1). Sage seedlings were planted in growing media and covered with various shade cloths to reach 70, 50 and 30% of the ambient irradiance. Photochemical efficiency and in situ chlorophyll status were estimated at 7, 21, and 56 d. The daily leaf emergence rate was calculated by monitoring changes in leaf number. Plant height, leaf size, biomass, aroma rating and soluble protein content of the sage plants grown under various light levels were measured at 84 d. The results indicate that light impacted the integrity of chloroplasts and the photosynthetic capacity of sage plants, as manifested by the lower the light level, the more the declines in variable fluorescence/maximal fluorescence and chlorophyll content index. Biochemical analysis revealed that the concentration of chlorophyll (per gram leaf dry mass) slightly increased under 50 and 30% light, but that of carotenoids was not changed. Light also affected the vegetative habit of sage plants. With reduced light intensity, plant height increased, whereas leaf size and number decreased. Double-blind aroma testing suggested that adequate light intesity might be required for the biosynthesis of essential oil in sage, attenuating its aroma. The soluble protein content in sage leaves declined at 50 and 30% light, suggesting a deminished source of essential amino acids contained in the plant. In summary, sage responds sensitively to reducing irradiance, which directly restricts its photosynthesis, and thus alters its vegetative growth and culinary properties.

Fernandez, M. R., May, W. E., Chalmers, S., Savard, M. E. and Singh, A. K. 2014. Are early foliar fungicide applications on durum wheat grown in southeast Saskatchewan beneficial in increasing grain productivity? Can. J. Plant. Sci. 94: 891-903. Producers have expressed interest in applying fungicides early in the development of durum wheat to reduce disease severity and increase grain yield. To address this issue, a field trial was conducted in southeast Saskatchewan (2004-2006) to determine the impacts of single and double foliar fungicide (tebuconazole) applications at various growth stages on leaf spotting, Fusarium head blight/Fusarium-damaged kernels, deoxynivalenol concentration, dark kernel discolouration, and grain traits of durum wheat. In most cases, application at stem elongation was not effective in reducing Fusarium diseases, or improving yield and grain characteristics. Application at flag leaf emergence was more effective, but for the most part, application at anthesis resulted in the most consistent reduction in disease levels, and improvement in test weight. Double fungicide applications (stem elongation or flag leaf emergence, and anthesis) were not more effective in disease control than a single application at anthesis. Grain yield did not differ significantly among any of the treatments. In contrast to Fusarium diseases and leaf spotting, fungicide applications at stem elongation and/or flag leaf emergence resulted in increased kernel weight and percentage dark kernel discolouration, which was significant in 2005 (10.53-10.60% total kernel discolouration in the stem and flag leaf treatments vs. 6.13% for the untreated control). In one or more years, kernel weight was negatively associated with Fusarium disease variables and leaf spotting, but positively associated with kernel discolouration. We conclude that under variable environmental conditions in Saskatchewan, early preventative fungicide use on durum wheat should not be recommended as a strategy to improve productivity, and might even result in increases in dark kernel discolouration and grain downgrading.

Mahoney, K. J., McCreary, C. M. and Gillard, C. L. 2014. Response of dry bean white mould [Sclerotinia sclerotiorum(Lib.) de Bary, causal organism] to fungicides. Can. J. Plant Sci. 94: 905-910. White mould [Sclerotinia sclerotiorum (Lib.) de Bary, causal organism] is a serious disease of dry bean (Phaseolus vulgaris L.). Producers frequently rely on preventative fungicides, yet, this represents a significant production cost. Studies were conducted in 2009, 2010, and 2011 to determine fungicide efficacy under conditions optimized for white mould. Disease incidence×severity ratings were used to calculate the area under the disease progress curve (AUDPC). After harvest, a return on investment (ROI) was calculated. AUDPC values were similar across boscalid, fluazinam, fluopyram, and thiophanate-methyl and lower than Bacillus subtilis, CaCl₂, and the untreated. Yield was greatest for fluazinam and fluopyram, followed by thiophanate-methyl. Bacillus subtilis and CaCl₂ yields were similar to the untreated. In early-planted environments, using fluazinam and fluopyram resulted in a $500 ha^-1 greater ROI than the untreated with $554 gained for every tonne per hectare of dry bean harvested. In late-planted environments, fluazinam and fluopyram averaged about $200 ha^-1 greater ROI than the untreated and $494 was returned for every tonne per hectare of dry bean. When dry bean yield potential is reduced under conditions of increased white mould severity, profit margins become narrowed and producers may have to select fungicides that are both efficacious and economical.

May, W. E., Ames, N., Irvine, R. B., Kutcher, H. R., Lafond, G. P. and Shirtliffe, S. J. 2014. Are fungicide applications to control crown rust of oat beneficial? Can. J. Plant Sci. 94: 911-922. Crown rust (Puccinia coronata Corda f. sp. avenae Eriks.) negatively impacts seed quality and yield in oat (Avena sativa L.) in rust-prone areas of eastern Saskatchewan, Manitoba, Ontario, and Quebec. Genetic resistance is the primary means for controlling this disease, but early seeding and fungicide applications have been suggested to reduce yield losses. Trials were conducted in six locations in Saskatchewan and Manitoba in 2009-2011 to determine the interactions between cultivar, fungicide application, crown rust and seeding date. The cultivars were chosen to represent a range of resistance to the current races of crown rust: AC Morgan, very susceptible; CDC Orrin, susceptible; CDC Boyer, partially resistant; and Leggett, resistant. Crown rust severity varied among locations and cultivars. The sprayed flag and penultimate leaves of AC Morgan tended to have similar amounts of crown rust as the unsprayed leaves of CDC Boyer and CDC Orrin regardless of the level of crown rust infection. Leggett's yield and quality did not respond to fungicide application. Only AC Morgan consistently benefited from a fungicide application. At high crown rust sites fungicide application improved AC Morgan's yield by 17 to 27% (690 kg ha^-1 to 781 kg ha^-1). Delayed seeding reduced grain yield from 8 to 26% with 8% occurring at low crown rust sites and the largest reductions occurring at high crown rust sites in susceptible cultivars. The test weight of AC Morgan increased from 242 g 0.5 L^-1 to 255 g 0.5 L^-1 when fungicide was applied at high crown rust sites seeded in mid-May. Fungicide application did not change the test weight of Leggett. The β-glucan level was affected more by seeding date (0.4%) and cultivar (0.4%) than fungicide application (0.1%). Seeding a cultivar with better crown rust resistance than AC Morgan in mid-May eliminated most of the benefits derived from fungicide application. These results indicate that prophylactic fungicide applications are unlikely to provide yield improvement when early planting is combined with even a moderately disease-resistant cultivar.

Duncan, R. W., Gilbertson, R. L., Lema, M. and Singh, S. P. 2014. Inheritance of resistance to the widely distributed race 6 of Pseudomonas syringae pv. phaseolicola in common bean pinto US14HBR6. Can. J. Plant Sci. 94: 923-928. Halo blight disease of common bean (Phaseolus vulgaris L.) is caused by Pseudomonas syringae pv. phaseolicola (Psp) and is found worldwide in bean growing regions with temperate climates, such as the Midwestern United States. In situations where high levels of primary inoculum are present (e.g., in seed) and the climate is favorable, yield losses as high as 45% have been reported for susceptible cultivars. Disease resistance is the most desirable management strategy, and resistant cultivars and germplasm to some Psp races are available. However, high levels of resistance to Psp race 6, one of the most prevalent and economically important races, are not present in available cultivars. Here, we report the inheritance of a newly described source of resistance to Psp race 6 in the recently registered common bean pinto US14HBR6. The inheritance of resistance in US14HBR6 was investigated by making crosses between resistant (R) US14HBR6 and the susceptible (S) breeding line 92BG-7 and inoculating the parents, F₁, F₂, F₃, and the respective backcrosses to either parent with Psp race 6. All 159 F₁ plants were susceptible, the F₂ segregated into 237S:16R and the F₃ segregated into 309S:26R. The US14HBR6*2×92BG-7 F₁ segregated into 83S:41R, and the US14HBR6×92BG-7*2 F₁ segregated into 116S:0R. Together, these results suggest that the resistance to Psp race 6 in US14HBR6 is controlled by two independently inherited recessive genes. Evidence is also presented that dominant alleles of these resistance genes, at one or both loci, contribute to dosage-dependent susceptibility to halo blight. These halo blight resistance genes can be used in the development of common bean germplasm and cultivars with high levels of resistance to Psp race 6. In combination with other race-specific and non-race specific resistance genes from diverse Phaseolus germplasm, these genes could also be used to generate germplasm lines and cultivars with resistance to all known races of Psp.

Fernandez, M. R., Fox, S. L., Hucl, P. and Singh, A. K. 2014. Leaf spotting reaction of spring common, durum and spelt wheat, and Kamut under organic management in western Canada. Can. J. Plant Sci. 94: 929-935. A 3-yr field study (2010 to 2012) was conducted in southwest Saskatchewan to determine the reaction of common, durum and spelt wheat cultivars currently registered in western Canada, and of Kamut wheat, to the leaf spot disease complex (LS) under organic management. The genotypes selected for this study are often grown by organic producers in this region. Overall, the most common LS diseases observed had been observed in previous studies under conventional management in the same area. For all 3 yr, common wheat cultivars with the highest LS scores were AC Barrie, CDC Go, Superb, and Unity, while those with the lowest scores were AC Andrew, CDC Bounty and Lillian. For durum wheat, Kyle had overall the greatest LS scores. CDC Zorba had lower LS scores than the other spelt wheat, CDC Origin, and it also had the lowest LS levels of all genotypes in this study. Kamut wheat was similar to the common and durum wheat cultivars for LS severity. The relative presence of the most common LS pathogens isolated (Pyrenophora tritici-repentis, Phaeosphaeria nodorum, Phaeosphaeria avenaria f. sp. triticea, Cochliobolus sativus, Mycosphaerella graminicola) from each of the four wheat species in each of the three years is also presented and discussed.

Fernandez, M. R., Fox, S. L., Hucl, P., Singh, A. K. and Stevenson, F. C. 2014. Root rot severity and fungal populations in spring common, durum and spelt wheat, and Kamut grown under organic management in western Canada. Can. J. Plant Sci. 94: 937-946. A 3-yr field study (2010 to 2012) was conducted in the Brown soil zone of southwest Saskatchewan to determine the reactions of common, durum and spelt wheat cultivars currently registered in western Canada, and of Kamut wheat, to common root rot (CRR) under organic management. The genotypes selected for this study are often grown by organic producers in this region. Over the 3 yr of this study, Cochliobolus sativus, the main causal agent of CRR, was the fungus most frequently isolated from discoloured subcrown internodes, followed by Fusarium spp. The latter constituted an overall total of over 19% of all isolations and consisted of at least 12 different species, the most frequently detected of which were F. equiseti, F. avenaceum, F. acuminatum and F. oxysporum. The relative prevalence of the most commonly isolated genera/species agrees most closely with previous studies conducted under organic management. In general, C. sativus was less common in Kamut than in durum and spelt wheat, and it was more frequently isolated from durum than common wheat. In contrast, there were few differences in the isolation of Fusarium spp. among wheat species. Their isolation was greater for common wheat and Kamut than for durum wheat. For all 3 yr, the greatest mean CRR severity was observed in spelt wheat, followed by durum wheat and Kamut, with common wheat having the lowest average severity. For individual cultivars, the durum wheat AC Avonlea, Kyle and Transcend had the greatest CRR severity of all cultivars in this species and CDC Verona the lowest. Common wheat cultivars AC Elsa, CDC Kernen and Red Fife had the greatest CRR severity and Superb and Unity the lowest severity within their species. Under organic conditions, avoiding growing cultivars with high susceptibility to CRR is recommended given the expected presence of this disease in most fields and environments.

Singh, S. P., Schwartz, H. F., Terán, H., Viteri, D. and Otto, K. 2014. Pyramiding white mould resistance between and within common bean gene pools. Can. J. Plant Sci. 94: 947-954. White mould caused by Sclerotinia sclerotiorum (Lib.) de Bary is a severe disease of common bean (Phaseolus vulgaris L.) in North America and similar production regions. Low to high levels of white mould resistance exist in cultivated and wild common bean and the secondary gene pool. But, cultivars with high levels of resistance are not yet available. The objectives of this study were: (1) to combine or pyramid high levels of resistance from multiple-parent populations between and within gene pools, and (2) to compare the response of pyramided breeding lines (PBL) to four isolates of the white mould pathogen with that of known sources of resistance. Two Andean PBL each derived from an Andean intra-gene pool and inter-gene pool, four Middle American pinto bean PBL from one inter-gene pool multiple-parent population, their seven resistant parents, and susceptible pinto, Othello, were inoculated in the greenhouse with pathogen isolates ARS12D and ND710 at University of Idaho, Kimberly in 2012, and isolates CO467 and NY133 at Colorado State University, Fort Collins in 2013. The percentage of resistant plants for the PBL ranged from 62.5 to 81.9, and mean white mould score from 4.0 to 4.6. The respective values for the white mould resistant parents ranged from 3.1 to 57.0 for the percentage of resistant plants and from 4.8 to 7.5 for the mean white mould score. Furthermore, PBL SE154-1 inoculated with isolate ARS12D, and SE152-6 with isolates ARS12D and ND710 had 100% resistant plants. But, only SE153-1 and SE155-9 inoculated with isolates CO467 and NY133 had significantly (P ≤0.05) higher levels of resistance than the most resistant parents A 195 and VA 19. The pinto bean PBL SE153-1, SE153-6, and SE153-7, and Andean types SE152-6 and SE155-9 were the most resistant among all genotypes inoculated with the four isolates of the white mould pathogen in both greenhouses.

Zhang, J. X. and Xue, A. G. 2014. Evaluation of soybean cultivars for resistance to Phomopsis longicolla and Sclerotinia sclerotiorum using excised leaves. Can. J. Plant Sci. 94: 955–961. The resistance of short-season soybean cultivars in Canada to Phomopsis longicolla and Sclerotinia sclerotiorum was measured on excised leaves based on the disease severity. Lesions caused by both fungi were first observed at inoculation sites within 24 to 36 h after excised leaflets were inoculated, varying among cultivars, and whole leaflets rot within 5–6 d for susceptible cultivars. Of the 74 cultivars evaluated, 20 were significantly more resistant to P. longicolla (LSD=1.1, P<0.05) and 19 to S. sclerotiorum (LSD=1.0, P<0.05), with mean severity ratings ranging from 1.3 to 2.3 caused by both fungi. Seven cultivars including Medallion, M. Arrow Brown, Alta, Portage, AC Albatros, Comet, and Pagoda, showed partial resistance to both of pathogens. These resistant cultivars identified in this study may be used as sources of resistance in future field breeding programs in Canada.

Tozzi, E., Lyons, E. M. and Van Acker, R. C. 2014. The effect of simulated winter warming spells on Canada fleabane [Conyza canadensis (L.) Cronq. var. canadensis] seeds and plants. Can. J. Plant Sci. 94: 963-969. Experiments were establish at three sites in southern Ontario, Canada in 2009 and 2010 to determine the possible effect of winter warming spells applied in either January, February or March on seed, seedlings, or rosettes of Canada fleabane including effects on winter survival, fecundity, above-ground biomass, and flowering timing. Warming spells reduced survival of fall-established rosettes and fall established seedlings. Warming spells occurring late in winter (March) had a greater effect where March warming spells reduced the survival of rosettes and seedlings on average by 53% and 80%, respectively. In addition, overwintering Canada fleabane plants (rosettes or seedlings) exposed to warming spells flowered earlier (between 29 and 71 days earlier). This study also confirms that Canada fleabane seed has little or no dormancy and that the great majority of seed recruits (either in fall or spring) within a given season (between 84% and 93%). We also determined that timing of seed shed in the fall significantly affects the proportion of seedlings emerging either in the spring or fall with late shed favoring seed overwintering and spring seedling emergence. The results of this study suggest that winter warming spells, especially later in the winter (into early spring), may limit the success of Canada fleabane and in particular its success as a winter annual.

Jiang, Y., Caldwell, C. D. and Falk, K. C. 2014. Camelina seed quality in response to applied nitrogen, genotype and environment. Can. J. Plant Sci. 94: 971-980. Camelina (Camelina sativa L.), Brassicaceae, has great potential for food and industrial use. This study analyzed the seed oil content, oil yield, protein content, protein yield, as well as fatty acid profile relative to varying nitrogen (N) rates and in different genotypes under several environmental conditions. Seed samples were obtained from a 2-yr field study with five environments (site-years), five genotypes, and six N rates. Applied N increased protein content, protein yield, oil yield, and polyunsaturated fatty acids (PUFA), but decreased oil content and monounsaturated fatty acids (MUFA). Saturated fatty acids did not respond consistently to applied N. Lower air temperatures during the reproductive stages increased the total seed oil content, but the fatty acid composition was not affected. The experimental line CDI007 had the highest oil content, oil yield, protein yield, and PUFA, but contained the lowest protein content and MUFA. CDI002 contained the highest protein content and PUFA. CDI005 had the highest amount of MUFA. CDI008 was not considered to be a promising genotype since it had the lowest oil content and highest amount of saturated fatty acids.

Nkoa, R., Kendall, K. and Deen, W. 2014. Ecozone dynamics of crop residue biomass, macronutrient removals, replacement costs, and bioenergy potential in corn-soybean-winter wheat cropping systems in southern Ontario. Can. J. Plant Sci. 94: 981-993. In light of frequent price hikes of imported fuels and the everlasting growth in the world's crude oil consumption, producing energy from renewable, non-fossil sources, such as crop residues and dedicated energy crops, has gained an unprecedented attraction across developed countries. This study aimed at assessing the dynamics of crop residues biomass, NPK removals, bioenergy potentials, in southern Ontario. Two surveys were carried out across 20 counties, and data were analyzed using one-way classification random and three-way crossed classification mixed effects models, respectively. Corn stover was estimated at 7.5 t ha^-1 yr^-1, equivalent to 139.7×10⁹ J ha^-1 yr^-1, and NPK-removal rates of 53, 4, and 62 kg ha^-1, respectively. For wheat, the straw biomass was estimated at 4.3 t ha^-1 yr^-1, equivalent to 79.4×10⁹ J ha^-1 yr^-1, and NPK removal rates of 28, 3, and 35 kg ha^-1, respectively. Soybean straw biomass was estimated at 3.1 t ha^-1 yr^-1, equivalent to 24.76×10⁹ J ha^-1 yr^-1, and NPK-removal rates of 33, 5, and 35 kg ha^-1, respectively. Overall, cutting corn and winter wheat stalks at ground level rather than at 15 cm above ground yielded higher residue biomasses, which did not statistically translate into higher NPK removal rates due to lower NPK concentrations in the stubbles.