The presence of volunteer canola is becoming a significant agro-ecological concern, given the large-scale use of herbicide-tolerant varieties in some areas. Our goal was to estimate the frequency and persistence of volunteer canola in Québec cropping systems by surveying fields that included a single canola crop since 1995. A survey was conducted in 131 fields in the main canola-growing areas of Québec: in the Saguenay-Lac Saint-Jean region and the Québec City–La Pocatière area. Volunteer canola plants were counted in 0.25-m2 quadrats every 10 m along a W pattern, and every 15 m along the margins of 88 fields. Volunteer canola plants were found in 90% of the fields surveyed and in a wide range of crops, including cereal, corn, and soybean. Average densities of 4.9 and 3.9 plants/m2 were found 1 yr after canola production in fields and field margins, respectively. Volunteer canola densities decreased significantly over time. However, volunteer plants were still present at low densities 4 and 5 yr after production. Dense stands of volunteer canola were found before postemergence herbicide application in no-till fields (9.8 ± 4.1 plants/m2), suggesting that, contrary to what was suggested in the literature, seeds could become dormant in no-till as well as in tilled systems. A small proportion of the volunteer canola plants observed in no-till fields near Québec City and Ottawa included plants that had overwintered, either originating from fall-germinated seedlings, harvested adult plants that had grown new leaves before the onset of winter, or spring regrowth from the base of unharvested adult plants from experimental plots. The presence and persistence of low densities of volunteer canola may not have been a cause of concern until now. However, producers should be made more aware of the potential short-and long-term problems associated with potential gene flow between different herbicide-tolerant canola (HT canola) varieties and also between HT canola and related weed species.

The oat (Avena sativa L.) breeding program at the Eastern Cereal and Oilseed Research Centre of Agriculture & Agri‐Food Canada has the responsibility to breed new oat cultivars for producers in eastern Canada, which includes Ontario, Quebec, and the Atlantic provinces. A 3‐yr multilocation test was conducted to understand the genotype × location interaction patterns and the relationships among test locations in eastern Canada. A genotype + genotype × environment interaction biplot analysis of yield data revealed three distinct oat mega‐environments in eastern Canada: (i) northern Ontario, (ii) southern and eastern Ontario, and (iii) Quebec and Atlantic Canada. To breed for all mega‐environments, initial yield screening must be conducted at locations representing each of these mega‐environments. Based on the relationships among test locations, six essential test locations were identified: three in Ontario, two in Quebec, and one in Atlantic Canada. Testing at all six locations appeared to provide a good coverage of the whole oat‐growing area in eastern Canada. Based on these findings, a breeding and test strategy was developed. This includes conducting initial yield screening at three locations in Ontario, Quebec, and Atlantic Canada, followed by a formal yield test at all six essential test locations. Specifically adapted genotypes selected from this test will then be tested in the Registration Tests in their respectively adapted subregions.

Core Ideas Mixtures of alfalfa with meadow fescue, tall fescue, or meadow bromegrass have comparable yields and persistence to alfalfa‐timothy. Mixtures with festulolium or perennial ryegrass had lower total seasonal DM yields than the alfalfa‐timothy mixture. Harvesting mixtures at the alfalfa early flower stage maximizes the estimated milk production per ha. Timothy (Phleum pratense L.) is the main forage grass species cultivated with alfalfa (Medicago sativa L.) in eastern Canada, yet its regrowth under dry and warm conditions is poor. Air temperature and water stress are predicted to increase in the near future, which could further reduce timothy’s regrowth. We evaluated six alfalfa–grass binary mixtures at three contrasted sites in eastern Canada to find potential alternatives to the alfalfa–timothy mixture under current climatic conditions. Timothy, tall fescue (Schedonorus arundinaceus [Schreb.] Dumort.), meadow fescue (Schedonorus pratensis [Huds.] P. Beauv.), festulolium (× Festulolium Asch. & Graebn), perennial ryegrass (Lolium perenne L.), and meadow bromegrass (Bromus biebersteinii Roem. & Schult.) were evaluated with harvests either at the early bud or early flower stage of alfalfa. Dry matter yield, nutritive attributes, and the yield contribution of each species were determined. Alfalfa mixtures with festulolium (cv. Spring Green) and perennial ryegrass (cv. Remington) had inferior grass yield contributions due to winter damages, as well as inferior forage yield and estimated milk production per hectare; these cultivars are not currently viable alternatives to timothy in eastern Canada. In contrast, alfalfa–meadow fescue and alfalfa–meadow bromegrass mixtures produced comparable yields, nutritive value, and estimated milk production per hectare and they are, therefore, possible alternatives to the alfalfa‐timothy mixture. The alfalfa–tall fescue mixture also represents a possible alternative; its lower nutritive value was compensated by its slightly greater yield. Timothy, tall fescue, meadow fescue, and meadow bromegrass remained productive over the first three production years when cultivated in mixture with alfalfa.

Recent investigations in northern Europe and western Canada suggested that mycotoxins caused by Fusarium head blight (FHB) could be a potential problem for oat (Avena sativa L.) production and oat food safety. Here we report studies conducted in eastern Canada to address this issue. In one study, oat genotypes of diverse origin were evaluated for grain and groat deoxynivalenol (DON) contamination owing to artificial FHB inoculation at Ottawa, ON, in 2006 and 2007. In a separate study, oat genotypes tested in the yearly Quebec Oat Registration and Recommendation Trials were evaluated for DON contamination due to artificial inoculation in Quebec from 2003 to 2008. Deoxynivalenol was detected in all tested genotypes, and up to 43 μg g−1 of DON was observed in the oat grain. Up to 86% of the DON in the oat grain was removed by dehulling. However, some genotypes still retained up to 9 μg g−1 of DON in the groat. Genotype ranking in DON content was relatively consistent across years, planting dates, and experiments, and genotypes with consistently low and high DON levels were identified. It was concluded that FHB is a potential problem for oat production and oat food safety under high FHB pressures; however, the severity of this problem needs to be further assessed by extensive monitoring of the DON level under natural conditions. The most susceptible genotypes identified in this study can be useful for this purpose.

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