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.

2013. Relative performance of resistant wheat varietal blends and susceptible wheat cultivars exposed to wheat midge, Sitodiplosis mosellana (Ge´hin). Can. J. Plant Sci. 93: 59Á66. Wheat midge, Sitodiplosis mosellana (Ge´hin), causes significant yield losses to spring wheat in western Canada. To mitigate these losses, midge-resistant wheat varietal blends, consisting of cultivars with the Sm1 midge resistance gene and containing 10% of a midge susceptible cultivar (interspersed refuge), were made available to farmers. To test their performance relative to conventional midge-susceptible cultivars, four varietal blends were grown during four consecutive growing seasons at eight locations in the provinces of Manitoba, Saskatchewan and Alberta, Canada, and compared with four conventional midge-susceptible cultivars. Midge damage varied from year to year during the 4-yr study. In general, the varietal blends, as a group, yielded more grain than the susceptible cultivars, especially when grown in environments with high (12.8%) seed damage. In environments with low (0.9%) seed damage, the varietal blend yield increases were smaller but still significant, suggesting that some of the varietal blends may be endowed with additional superior attributes, unrelated to midge resistance. The Sm1 gene was independent of time to heading and maturity, plant height, lodging and seed weight. Lukow, O. M. 2013. Rendement relatif des me´langes varie´taux de ble´re´sistant et des cultivars sensibles apre`s exposition a`la ce´cidomyie du ble´[Sitodiplosis mosellana (Ge´hin)]. Can. J. Plant Sci. 93: 59Á66. La ce´cidomyie du ble´[Sitodiplosis mosellana (Ge´hin)] cause d'importantes pertes de rendement dans l'Ouest canadien. Pour les atte´nuer, on a propose´aux cultivateurs des me´langes varie´taux re´sistants compose´s de cultivars portant le ge`ne de re´sistance Sm1 et de 10 % de cultivars sensibles (refuge disse´mine´). Quatre me´langes varie´taux ont e´te´cultive´s pendant quatre pe´riodes de croissance conse´cutives a`huit endroits du Manitoba, de la Saskatchewan et de l'Alberta, au Canada, en vue d'en comparer la performance a`celle de quatre cultivars sensibles usuels. Les dommages attribuables a`la ce´cidomyie ont varie´d'une anne´e a`l'autre durant l'e´tude de quatre ans. En ge´ne´ral, les me´langes varie´taux donnent collectivement un meilleur rendement grainier que les cultivars sensibles, surtout aux endroits ou`les de´gaˆts cause´s aux semences sont importants (12,8 %). La`ou`les graines sont peu abıˆme´es (0,9 %), la hausse de rendement autorise´e par les me´langes varie´taux, quoique plus faible, demeure significative, signe que certains me´langes pourraient profiter d'autres caracte`res supe´rieurs n'ayant aucun lien avec la re´sistance au ravageur. Le ge`ne Sm1 ne de´pend pas du temps e´coule´avant l'e´piaison et la maturite´, ni de la hauteur du plant, de la verse et du poids des grains.Mots clé s: Ce´cidomyie du ble´, Sitodiplosis mosellana (Ge´hin), ge`ne Sm1, me´langes varie´taux de ble´, refuge disse´mine´, re´sistance...

2012. SHORT COMMUNICATION: Comparative effect of lodging on seed yield of flax and wheat. Can. J. Plant Sci. 92: 39Á43. Lodging may limit crop productivity and hinder the normal process of harvesting crops. Results from 16 yr (1994Á2009) of the Flax Cooperative test and from 29 yr (1981Á2009) of the Central Bread Wheat Co-operative test, conducted annually for the evaluation of advanced breeding lines at various locations in the provinces of Manitoba, Saskatchewan and Alberta, Canada, were used to determine the effect of lodging on the seed yield of these two crop species. Seed yield data were regressed on corresponding lodging scores (1Á9 scale) collected from field evaluations. Lodging was more frequently a problem in flax (Linum usitatissimum L.) than in wheat (Triticum aestivum L.), with average seed yield reductions of 32% and 16%, respectively, when lodging was most severe. Disease has been observed in association with the occurrence of lodging in flax. Further research is necessary to elucidate the participation of airborne and soil microorganisms, particularly pasmo, caused by Septoria linicola (Speg.) Garassini, in the mode and degree to which flax is subjected to, and affected by, lodging. Comparaison des effets de la verse sur le rendement grainier du lin et du ble´. Can. J. Plant Sci. 92: 39Á43. La verse peur re´duire la productivite´des cultures et nuire a`la re´colte. Les auteurs ont compulse´les re´sultats de 16 anne´es (1994Á2009) d'essais entrepris par la Flax Co-operative et de 29 anne´es (1981Á2009) d'essais effectue´s par la Central Bread Wheat Co-operative ad ivers endroits du Manitoba, de la Saskatchewan et de l'Alberta, au Canada, dans le cadre de l'e´valuation annuelle des ligne´es hybrides e´volue´es, afin de pre´ciser les conse´quences de la verse sur le rendement grainier du lin et du ble´. Les donne´es sur le rendement grainier ont e´te´associe´es par re´gression a`la note correspondante pour la verse (e´chelle de 1 a`9) issue des e´valuations sur le terrain. La verse s'ave`re plus souvent proble´matique pour le lin (Linum usitatissimum L.) que pour le ble´(Triticum aestivum L.), avec une diminution moyenne du rendement grainier de 32% et de 16%, respectivement, quand la verse est particulie`rement importante. La verse est associe´e a`la maladie chez le lin. Il faudrait entreprendre d'autres recherches pour de´terminer comment les microorganismes ve´hicule´s par l'air ou pre´sents dans le sol, notamment Septoria linicola (Speg.) Garassini, qui entraıˆne le pasmo, contribuent a`la manie`re dont le lin est affecte´par la verse et a`la gravite´de cette dernie`re.Mots clé s: Lin, verse, pasmo, bleĹ Can.

Foster, A., Vera, C. L., Malhi, S. S. and Clarke, F. R. 2014. Forage yield of simple and complex grass–legume mixtures under two management strategies. Can. J. Plant Sci. 94: 41–50. Limited information is available on the dry matter production, protein content and species composition of complex mixtures of introduced perennial forage crop species for hay and pasture in the moister regions of Saskatchewan. A field experiment was sown on 2008 May 27 at Melfort, Saskatchewan, Canada, on a thick Black Chernozem (Udic Boroll) silty clay soil, to compare the effects on dry matter yield (DMY), protein content and species composition of perennial forage crop monocultures and mixtures, under a two-cut and a three-cut management system, in 2009, 2010, 2011 and 2012. Eleven treatments consisted of monocultures of hybrid bromegrass (Bromus riparius Rehm.×Bromus inermis Leyss.), smooth bromegrass (Bromus inermis Leyss.), crested wheatgrass [Agropyron cristatum (L.) Gaertn], intermediate wheatgrass [Agropyron intermedium (Host.) Beauv.] and alfalfa (Medicago sativa L.); simple mixtures of each of these individual grass species with alfalfa; a more complex mixture of all these grass species and alfalfa, and a very complex mixture consisting of the complex mixture plus meadow bromegrass (Bromus riparius Rehm.), orchardgrass (Dactylis glomerata L.), tall fescue [Festuca arundinacea (Schreb.) Wimm.], timothy (Phleum pratense L.) and slender wheatgrass [Elymus trachycaulus (Link) Gould ex Shinners]. The alfalfa was inoculated with rhizobium, and no fertilizer was added to any treatment during the course of the study. The two-cut system yielded higher than the three-cut system in all years. In 2009, the first cutting year, all treatments, especially under the two-cut system, produced similar forage DMY, with monoculture grasses yielding as much as that of their mixture with alfalfa. In 2010, 2011 and 2012, however, monoculture alfalfa and grass–alfalfa treatments had higher DMY than the monoculture grasses. Monoculture alfalfa also showed superior DMY than most grass–alfalfa mixtures, especially during the last 2 yr of the study. In conclusion, the inclusion of alfalfa in forage mixtures, grown in unfertilized soil, significantly increased forage yield, especially after the first production year, and these grass–alfalfa mixtures yielded almost as much as monoculture alfalfa. Also, the inclusion of alfalfa significantly increased the forage protein content over the grass alone treatments. Hybrid bromegrass, grown alone or in mixture with alfalfa, yielded similar to the other grasses tested, while crested wheatgrass did not compete as well as other main grasses, grown alone or in mixture with alfalfa. In this study, the use of complex or very complex mixtures of introduced grasses with alfalfa did not increase DMY over the simple grass–alfalfa mixtures.

Vera, C. L., Irvine, R. B., Duguid, S. D., Rashid, K. Y., Clarke, F. R. and Slaski, J. J. 2014. Pasmo disease and lodging in flax as affected by pyraclostrobin fungicide, N fertility and year. Can. J. Plant Sci. 94: 119–126. Severe infection of the fungal disease known as pasmo, caused by Septoria linicola (Speg.) Garassini, reduces seed yield of flax (Linum usitatissimum L.) in western Canada. Pasmo may also indirectly affect seed yield by predisposing flax plants, under favorable weather and soil fertility conditions, to lodge. With the objective of studying the possible association of this disease with the occurrence of lodging and their effect on seed yield, a study was conducted at Melfort, Saskatchewan, Canada, during 4 consecutive years (2009, 2010, 2011 and 2012), with two fungicide regimes (application and no application) and five rates of nitrogen (N) fertilization (0, 33, 66, 100 and 133% of recommended). The application of pyraclostrobin fungicide reduced disease severity and increased seed yield of flax in the 3 yr (2010, 2011 and 2012) that pasmo infection was detected, and prevented or reduced the occurrence of lodging in the 2 yr (2010 and 2012) with favorable weather conditions for the occurrence of lodging. Increasing rates of N resulted in increased seed yield in 2009 and 2012, regardless of whether fungicide was used or not. Increasing rates of N also increased the severity of pasmo disease in 2010, 2011 and 2012, and of lodging severity in 2010 and 2012. The increase in disease severity due to N occurred in the absence of fungicide in 2011 and when fungicide was applied in 2012, while in 2010 just the effect of N on the two fungicide treatments combined was significant. Only low levels of disease severity (near 20%) were observed when fungicide was applied in 2011, while extreme disease severity (near 100%) occurred in 2012 at all levels of N when fungicide was not applied. The increase in lodging, as N rates increased, was observed only in the absence of fungicide, in both years. The occurrence of lodging took place late in the development of flax.