Harker, K. N., O'Donovan, J. T., Turkington, T. K., Blackshaw, R. E., Lupwayi, N. Z., Smith, E. G., Klein-Gebbinck, H., Dosdall, L. M., Hall, L. M., Willenborg, C. J., Kutcher, H. R., Malhi, S. S., Vera, C. L., Gan, Y., Lafond, G. P., May, W. E., Grant, C. A. and McLaren, D. L. 2012. High-yield no-till canola production on the Canadian prairies. Can. J. Plant Sci. 92: 221–233. Relatively high prices and increasing demand for canola (Brassica napus L.) have prompted growers to produce more canola on more cropland. Here we determine if canola seed yield and oil concentration can be increased over current levels with high levels of crop inputs. From 2008 to 2010, direct-seeded experiments involving two seeding rates (75 vs. 150 seeds m−2), two nitrogen rates (100 vs. 150% of soil test recommendation), and the presence or absence of polymer-coated nitrogen or fungicides, were conducted at eight western Canada locations in canola-wheat-canola or continuous canola rotations. Herbicides, insecticides and fertilizers other than nitrogen were applied as required for optimal canola production. Increasing recommended nitrogen rates by 50% increased canola yields by up to 0.25 Mg ha−1. High (150 seeds m−2) versus lower (75 seeds m−2) seeding rates increased canola yields by 0.07 to 0.16 Mg ha−1. Fungicide treatment or polymer-coated nitrogen blended with uncoated urea increased canola yields by 0.10 Mg ha−1 in 2010, but not in 2008. The highest canola input combination treatment following wheat (3.50 Mg ha−1) yielded substantially more than the same high input treatment following canola (3.22 Mg ha−1). Average site yields were influenced by site conditions such as soil organic matter, days to maturity, and temperature, but these site and environmental predictors did not alter treatment rankings. Using higher than the soil test recommended rate of nitrogen or planting 150 versus 75 seeds m−2 increased canola yields consistently across western Canada. Canola oil concentration varied among canola cultivars, but was consistently low when N rates were high (150% of recommended). Higher than normal seeding rates led to high canola seed oil concentration in some cases, but the effect was inconsistent.

G. 2015. Canola rotation frequency impacts canola yield and associated pest species. Can. J. Plant Sci. 95: 9Á20. Canola (Brassica napus L.) production has been steadily increasing in western Canada. Here we determine the effect of canola rotation frequency on canola seed yield, quality and associated pest species. From 2008 to 2013, direct-seeded experiments involving continuous canola and all rotation phases of wheat (Triticum aestivum L.) and canola or field pea (Pisum sativum L.), barley (Hordeum vulgare L.) and canola were conducted at five western Canada locations. Fertilizers, herbicides, and insecticides were applied as required for optimal production of all crops. Canola rotation frequency did not influence canola oil or protein concentration or the level of major (composition 1%) seed oil fatty acids. High canola yields were associated with sites that experienced cooler temperatures with adequate and relatively uniform precipitation events. For each annual increase in the number of crops between canola, canola yield increased from 0.20 to 0.36 Mg ha (1 . Although total weed density was not strongly associated with canola yield, decreased blackleg disease and root maggot damage were associated with greater canola yields as rotational diversity increased. Long-term sustainable canola production will increase with cropping system diversity.Key words: Blackleg, Delia spp., direct seeding, Leptosphaeria maculans, no-till, oilseed rape, root maggots, rotational diversity, weed populations Harker, K. N., O'Donovan, J. T., Turkington, T. K., Blackshaw, R. E., Lupwayi, N. Z., Smith, E. G., Johnson, E. N., Gan, Y., Kutcher, H. R., Dosdall, L. M. et Peng, G. 2015. La fre´quence des assolements de canola influe sur le rendement de la culture et sur les ravageurs qui s'y associent. Can. J. Plant Sci. 95: 9Á20. La production de canola (Brassica napus L.) n'a cesse´d'augmenter dans l'Ouest canadien. Les auteurs se sont inte´resse´s aux conse´quences de la fre´quence des assolements de canola sur le rendement grainier de cette culture, sur sa qualite´et sur les ravageurs qui y sont associe´s. De 2008 a`2013, ils ont effectue´des expe´riences de semis directs pour la monoculture de canola et les assolements de ble( Triticum aestivum L.) et de canola ou de pois de grande culture (Pisum sativum L.), d'orge (Hordeum vulgare L.) et de canola a`cinq endroits, dans l'ouest du Canada. Les engrais, les herbicides et les insecticides ont e´te´applique´s au besoin afin que chaque culture donne un rendement optimal. La fre´quence des assolements de canola ne modifie pas la concentration en huile ou en prote´ines du canola, ni la teneur des principaux (composition 1 %) acides gras pre´sents dans l'huile. Le rendement du canola est plus e´leve´aux endroits ou`la tempe´rature est plus fraıˆche et les pre´cipitations, suffisantes et relativement uniformes. Pour chaque hausse annuelle du nombre de cultures dans l'assolement, le rendement du canola augmente de 0,20 a`0,36 Mg par hectare. Bien que la densite´de peuplement globale des a...

O'Donovan, J. T., Turkington, T. K., Edney, M. J., Juskiw, P. E., McKenzie, R. H., Harker, K. N., Clayton, G. W., Lafond, G. P., Grant, C. A., Brandt, S., Johnson, E. N., May, W. E. and Smith, E. 2012. Effect of seeding date and seeding rate on malting barley production in western Canada. Can. J. Plant Sci. 92: 321–330. Barley (Hordeum vulgare L.) growers in western Canada often have difficulty achieving malting grade. This is usually due to unfavourable climatic conditions, but sub-optimal agronomic practices may also be a factor. Field experiments were conducted in 2006, 2007 and 2008 at eight locations in western Canada (24 site-years) to evaluate the effects of seeding date (relatively early and late) and seeding rate (100, 200, 300, 400 and 500 seeds m−2) on AC Metcalfe barley yield and malt quality parameters. Delayed seeding often resulted in negative effects including increased protein concentration, decreased kernel plumpness and yield. However, at 6 site-years, higher yields occurred at the later seeding date. 300 seeds m−2 was usually optimal; maintained or improved yield, decreased protein concentration, increased kernel uniformity and time to seed maturity, and decreased tillering. In most cases, seeding at more than 300 seeds m−2 did not result in an improved outcome, and there was a risk of reduced yield and kernel plumpness at rates above this level. A multivariate analysis indicated that relatively low barley plant densities were associated primarily with northern locations with low soil pH.

Harker, K. N., O’Donovan, J. T., Smith, E. G., Johnson, E. N., Peng, G., Willenborg, C. J., Gulden, R. H., Mohr, R., Gill, K. S. and Grenkow, L. A. 2015. Seed size and seeding rate effects on canola emergence, development, yield and seed weight. Can. J. Plant Sci. 95: 1–8. Canola (Brassica napus L.) is the most common dicotyledonous crop in Canada. Here we determine the effect of canola seed size and seeding rate on canola emergence, development, yield and seed weight. In 2013, direct-seeded experiments were conducted at nine western Canada locations. Four canola seed sizes (1000-seed weights ranging from 3.96 to 5.7 g) and one un-sized treatment (4.4 g average) were seeded at two rates (75 and 150 seeds m−2). Higher seeding rates led to higher canola emergence and stubble density at harvest. Higher seeding rates also increased early crop biomass, 1000-seed weights and seed oil content and reduced days to start of flowering and days to crop maturity. Seed size effects on canola emergence, yield or seed quality were not significant. Increasing seed size had a positive linear association with early canola biomass and 1000-seed weights, whereas, both days to flowering and days to the end of flowering had a negative linear association with seed size. Greater biomass from large seeds increases crop competition with weeds and also hastens flowering, shortens the flowering period and reduces the risk that canola will be exposed to high temperatures that can negatively impact flowering and pod development.

Turkington, T. K., O'Donovan, J. T., Edney, M. J., Juskiw, P. E., McKenzie, R. H., Harker, K. N., Clayton, G. W., Xi, K., Lafond, G. P., Irvine, R. B., Brandt, S., Johnson, E. N., May, W. E. and Smith, E. 2012. Effect of crop residue, nitrogen rate and fungicide application on malting barley productivity, quality, and foliar disease severity. Can. J. Plant Sci. 92: 577–588. The productivity and quality of the malting barley cultivar AC Metcalfe and leaf disease severity were evaluated under three residue types [barley (Hordeum vulgare L.), canola (Brassica napus L.), field pea (Pisum sativum L.)], two nitrogen (N) fertilizer rates (50 or 100% of soil test recommendation for N), and two fungicide treatments (no fungicide or fungicide applied) at seven sites across western Canada from 2006 to 2009. Residue type had a significant effect on leaf disease severity, which was increased when barley was the previous crop compared with canola and field peas. In general, emergence, head counts, grain yield, kernel weight, test weight, kernel plumpness were lowest for barley grown on barley residue compared with canola and field pea residue. Fungicide application reduced leaf disease severity and increased yield, kernel weight, test weight, and kernel plumpness, while decreasing dockage and thins. However, the magnitude of the impact of fungicide on one or more of these parameters was lower compared with planting barley on field pea or canola residue. Overall, increasing the N rate from 50 to 100% had no effect on leaf disease levels and only increased yields slightly compared with not planting barley on barley residue. However, the 100% rate of N did significantly increase grain protein levels. In contrast, planting barley on field pea residue did not result in a consistent increase in grain protein.