Diversified crop rotation with an appropriate sequence may be a promising strategy for increasing crop productivity while reducing greenhouse gas emissions (GHGs) and lowering carbon (C) footprint for more sustainable agricultural systems. The objectives of this study were to (i) assess the agronomic performance and C footprint of canola (Brassica napus L.) production in different cropping systems, and (ii) better understand how canola could be adapted to existing cropping systems in eastern Canada. A four-year canola-based phase rotation study, including maize (Zea mays L.), wheat (Triticum aestivum L.), and soybean (Glycine max L.), started in 2011 and continued for two cycles in Ottawa, ON; Montreal, QC; and Canning, NS. It was found that, compared to continuous monoculture (canola, maize or wheat), diversified cropping systems increased crop yields by an average of 32% and reduced the C footprint of all rotations by 33%, except under severe heat and drought conditions. The effect of rotation on yield and C footprint of canola production varied significantly among site-years. At Ottawa, the canola following soybean (SC) had 12% higher canola yield than monoculture canola (CC), 5 and 8% higher canola yield than canola following wheat (WC) or maize (MC). At Montreal, canola yield ranked as MC > SC > WC > CC. At Canning, the highest canola yield was in WC (21%) and SC (13%). Overall, most SC rotations had the lowest C footprint, and CC cropping had the highest C footprint, with only a few exceptions. Regardless of the cropping system, canola required more N input and was high in oil and protein in the harvested product, and produced the highest C footprint, while soybean had the lowest C footprint at all three sites. Our findings indicate that a diversified cropping system with canola production following soybean significantly improved canola yield while lowering the C footprint. However, profitable and sustainable canola production in eastern Canada is threatened by climate change-induced drought and heat stress.
Even though worldwide research and teaching in Agroecology blossomed in the 1980s, until recently, the development of Agroecology in China has been constrained by technical, cultural and economic considerations. The delay in the assimilation of Agroecology, as a science, a practice and a movement, has resulted in the discipline of Agroecology in China lacking the holistic, interdisciplinary approaches needed to respond to current global and regional agricultural challenges. There is a need to redefine Agroecology both as a critical discipline and as a pedagogical approach. By using an ecology-oriented systematic approach to integrate education and research, a reframed Agroecology is proposed; this is based on a re-imagined, holistic consideration of the hierarchy of agroecosystems. The practical experience of a 15-year international team-taught Agroecology education programme among participants from Canada and China has helped refine disciplinary classifications, both from horizontal and vertical hierarchies. There are evolving impacts of this experiment in Sino-Canadian cooperation in Agroecological research and education; they include a new generation of highly trained agroecologists prepared to act across inter-related disciplines; the alignment of Chinese universities to international agricultural curricula and a better- informed policy-making process towards greening agriculture in China.
This study investigates the effects of timing of fungicide applications alone or in combinations on Fusarium head blight (FHB), seed deoxynivalenol (DON) concentrations, dominant leaf diseases, grain yield, and thousand-kernel weight in winter wheat, spring wheat, and barley in the Atlantic region of Canada. The experiments were conducted for 3 yr (2010 -2012), with fungicide treatment as the main factor. Selected commercially available fungicide treatments were applied at two timings: (i) Zadoks growth stage (ZGS) 39: check, propiconazole + trifloxystrobin (125 g ha(-1)), propiconazole (125 g ha(-1)), and pyraclostrobin (100 g ha-1); and (ii) ZGS 60: check, prothioconazole (200 g ha(-1)), prothioconazole + tebuconazole (200 g ha(-1)), and metaconazole (90 g ha(-1)). Results show that a single fungicide application was not sufficient to achieve a high yield with good seed quality. Reduction of visual FHB infection due to fungicide applications did not guarantee a reduction in seed DON concentrations. Fungicide application pyraclostrobin at ZGS 39 and prothioconazole + tebuconazole at ZGS 60 was the best treatment, consistently providing the highest crop yield and seed quality, including lowered DON.
Pan, X., Caldwell, C. D., Falk, K. C. and Lada, R. 2012. The effect of cultivar, seeding rate and applied nitrogen on Brassica carinata seed yield and quality in contrasting environments. Can. J. Plant Sci. 92: 961–971. The unremitting growth of oilseed demand makes it necessary to explore alternative oilseed crops to meet this requirement. This study evaluated the effects of genotype, seeding rate and nitrogen (N) supply on the seed yield and quality of oilseed Brassica carinata A. Braun in three contrasting environments (Truro, NS, Harrington, PE and Saskatoon, SK). Useful genetic variation in agronomic and seed quality characteristics was found among these 10 B. carinata genotypes and genotype selection requires location specific recommendation. Line 050488EM had consistently good yield in both Nova Scotia and Prince Edward Island, while line 070768EM displayed better yield stability across 2 yr in Saskatchewan. Because of the high degree of compensatory ability to low plant population, maximum seed yield of B. carinata can be achieved over the range from 34 to 114 plants m−2. No significant difference in oil and protein content of seed due to seeding rates was observed. The linear increase in seed and oil yield with increased N rate up to 150 kg ha−1indicates that B. carinata is highly responsive to applied N. Increases in N supply resulted in a decrease in oil content and a corresponding increase in protein content in all experiments. In summary, the findings of this study provide convincing evidence of the agronomic adaptation of B. carinata to all three locations.
Water and nitrogen (N) deficiency are two major constraints limiting the yield and quality of many oilseed crops worldwide. This study was designed to assess the response of Camelina sativa (L.) Crantz to the availability of N and water resources on photosynthesis and yield parameters. All the measured variables, which included plant height, root and shoot dry matter, root:shoot ratio, xylem pressure potential (XPP), yield components, photosynthetic parameters, and instantaneous water-use efficiency (WUE) were remarkably influenced by water and nitrogen supply. Net photosynthetic rate (P N) and yield components were significantly decreased more by water deficit than by N deficiency. XPP, stomatal conductance (g s), and intercellular CO2 concentration (C i) decreased substantially as the water deficit increased irrespective of the level of N application. WUE at the high N supply [100 and 150 kg(N) ha−1] dropped in a large degree as the increased water deficit due to a larger decrease in P N than transpiration rate (E). The results of this study suggest that the regulative capacity of N supply on photosynthetic and plant growth response is significantly affected by soil water status and C. sativa is more sensitive to water deficit than N supply.
Effects of water and nitrogen (N) supply on growth and photosynthetic response of B. carinata were examined in this study. Plant growth and related characteristics varied significantly in response to the availability of water and nitrogen. B. carinata maximized the utilization efficiency of the most limiting resources by developing physiological adaptations, such as changes in root and leaf development. The utilization of water and N was tightly linked with the availability of each resource. Instantaneous water-use efficiency (WUE) was always greater in plants with high-N nutrition [50, 100, and 150 kg(N) ha−1] than in the low-N-treated plants [0 kg(N) ha−1] in all watering treatments. Instantaneous N-use efficiency (PNUE) decreased significantly with increasing water stress in all N treatments. Seed yield is significantly related to PNUE (p>0.05) but not WUE (p<0.05). The positive relationship between leaf net photosynthetic rate (P N) and seed yield suggests that P N can be used as an important tool for selection of new strains with high seed yield.
Leader is a two-row spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Canada Barley Breeding Group, Agriculture and Agri-Food Canada. It has high grain yield, high straw yield, high test weight, high seed weight, good resistance to lodging, and moderate resistance to deoxynivalenol accumulation. Leader performs well across Eastern Canada.Key words: Barley, Hordeum vulgare L., cultivar description, test weight, seed weight, deoxynivalenol
There is renewed interest in the crucifer Camelina sativa (false flax, camelina, gold of pleasure) as an alternative oilseed crop because of its potential value for food, feed, and industrial applications. This species is adapted to canola-growing areas in many regions of the world and is generally considered to be resistant to many diseases. A review of the literature indicates that C. sativa is highly resistant to alternaria black spot and blackleg of crucifers. Genotypes resistant to sclerotinia stem rot, brown girdling root rot, and downy mildew can be found among C. sativa accessions, raising the possibility of developing cultivars resistant to these diseases. However, C. sativa is susceptible to clubroot, white rust, and aster yellows disease. Until resistant cultivars or effective management practices have been developed, the susceptibility of C. sativa to these diseases will limit the cultivation of the crop in areas where these diseases are prevalent.
The hypothesis of this study was that spring camelina (Camelina sativa L.) could be grown as a high-value crop under the moist, cool conditions of the Maritime Provinces in Canada and seeding date, seeding rate, and type of seeder will modify productivity and oil composition. The objectives were (1) to determine the optimum seeding date and seeding rate for camelina production in the Maritimes; and (2) to evaluate the effect of seeder type (seed drill and forage seeder) on camelina establishment and seed yield. A seeding date and rate experiment and a seeder type and seeding rate experiment were conducted in 2005 and 2006 in Nova Scotia and Prince Edwards Island. Seeding date did not affect camelina emergence, plant height, seed yield and oil content. The earlier seeding date increased the concentration of stearic acid in the oil compared with the later seeding date. Seed yield of camelina was not affected by seeding rate in the seeder type by rate trial but higher yields were observed up to 600 seeds m-2 in the seeding date by rate trial. The weak yield response to seeding rate could be explained by the high yield compensation ability of camelina through branching. It was suggested that seeding rates in the range of 400 to 600 seeds m-2 would likely be best for camelina grown in the Maritime region. The forage seeder provided a better crop stand compared with the seed drill, although both seeders provided satisfactory crop establishment. Camelina has the potential to be produced successfully in the Maritime Provinces due to its adaptability to seeder type, low seeding rate requirements, and a wide window for seeding date. Key words: Camelina, seeding date, seeding rate, seeder type
Worldwide, oilseed demand is steadily expanding. This study assessed the novel oilseed crop Camelina sativa L. in the Maritime Provinces of Canada. Evaluations of cultivar and applied N were performed at Truro, NS, Harrington, PEI, and Hartland, NB, in 2005 and 2006. The results show that the selection of cultivar is an important determinant for the potential success or failure of C. sativa production. Differences in plant stand, plant height, seed yield, oil content and fatty acid profile were found among the cultivars. The cultivar Calena provided the most consistent performance in terms of plant establishment, yield and oil content across all year-sites. Plant height, seed yield, oil content, total plant N and seed protein all responded to applied N rate. Applied N increased the seed yield of C. sativa, but the increase was not significant when the application rates were over 60 kg N ha-1 in NS or 80 kg N ha-1 in PEI. Plant height, total N content in plant tissue and seed protein content increased with increased N application, while oil content decreased. With the exception of erucic acid, all the main fatty acids in C. sativa oil responded to applied N levels or the interaction of N levels and year. Regression analysis showed that the contents of oleic acid and eicosenoic acid decreased with increased N application. The response of linolenic acid to N application was not consistent at each year-site. Results of this study provide convincing evidence of the agronomic suitability of C. sativa to the Maritime Provinces of Canada. Key words: Camelina sativa, cultivar, nitrogen, yield, seed quality
Fusarium head blight (FHB), caused by the fungus Fusarium graminearum (Schwabe), is one of the most destructive diseases in cereals worldwide. It may severely reduce both grain yield and quality, with potential contamination from trichothecene mycotoxins such as deoxynivalenol (DON). Spring and winter triticales (X Triticosecale Wittmack) were evaluated in a multi site and year field study to determine their susceptibility to FHB and DON accumulation. Fusarium-damaged kernels (FDK) and DON levels were affected significantly by both cultivar and site-year. Triticales were generally more susceptible to FHB compared with winter and spring wheat checks, as indicated by the higher levels of FDK and DON levels. A significantly positive linear relationship was observed between FDK and DON levels in winter triticales. This relationship in spring triticales was not significant on the combined data, but at each site-year, the regression was strong. FDK can be a good predictor of DON levels when environmental conditions are similar. The Atlantic region would appear to be a very good location in Canada for screening for fusarium head blight resistance. Key words: Winter triticale, spring triticale, cultivar; fusarium head blight, fusarium head blight, fusarium-damaged kernels, deoxynivalenol