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.

In western Canada, more money is spent on wild oat herbicides than on any other weed species, and wild oat resistance to herbicides is the most widespread resistance issue. A direct-seeded field experiment was conducted from 2010 to 2014 at eight Canadian sites to determine crop life cycle, crop species, crop seeding rate, crop usage, and herbicide rate combination effects on wild oat management and canola yield. Combining 2× seeding rates of early-cut barley silage with 2× seeding rates of winter cereals and excluding wild oat herbicides for 3 of 5 yr (2011 to 2013) often led to similar wild oat density, aboveground wild oat biomass, wild oat seed density in the soil, and canola yield as a repeated canola–wheat rotation under a full wild oat herbicide rate regime. Wild oat was similarly well managed after 3 yr of perennial alfalfa without wild oat herbicides. Forgoing wild oat herbicides in only 2 of 5 yr from exclusively summer annual crop rotations resulted in higher wild oat density, biomass, and seed banks. Management systems that effectively combine diverse and optimal cultural practices against weeds, and limit herbicide use, reduce selection pressure for weed resistance to herbicides and prolong the utility of threatened herbicide tools.

Forages with increased total nonstructural carbohydrate (TNC) concentrations improve the N-use effi ciency of dairy cows. Th is study determined the eff ect of time of cutting (0700 vs. 1500 h), stage of development (heading and anthesis), and N fertilization (30, 50, 70, 90, and 110 kg N ha −1 as NH 4 NO 3 ) on the fermentable carbohydrate concentration of timothy (Phleum pratense L.) grown in northern Ontario, Canada. Forage dry matter (DM) yield and concentrations of N, starch, sucrose, glucose, fructose, and fructans were determined. Concentration of soluble carbohydrates (SC) was estimated by the sum of sucrose, glucose, and fructose, while TNC was obtained by adding SC and starch. Nitrogen fertilization did not aff ect forage carbohydrate concentrations, but slightly increased DM yield. Forage had higher TNC, starch, sucrose, and fructose concentrations (+9 to 63%) but lower glucose concentration (-27%) when harvested at anthesis compared with heading. Concentration of high degree of polymerization (HDP) fructans was close to 0 at heading and increased to 64.3 mg g −1 DM at anthesis. Th e aft ernoon-cut forage had higher TNC (+53%), SC (+60%), and sucrose (+87%) concentrations than the morning-cut forage; this positive eff ect was greater when timothy was harvested at heading compared with anthesis. Starch and HDP fructan concentrations were similar for both times of cutting, whereas results for glucose and fructose were inconsistent. Delayed cutting during the day and an extended growth period increased timothy TNC and HDP fructan concentrations to an extent likely to improve the N use effi ciency of dairy cows.

The effect of five harvesting times on the incidence of seed-borne Fusarium spp. was examined using three spring wheat cultivars grown at two locations in eastern Ontario in 1999 and 2000. Twelve Fusarium spp. were isolated from 3831 of the 24 000 seeds, which were surface disinfected and plated onto modified potato dextrose agar. Fusarium sporotrichioides Sherb., F. graminearum Schwabe, F. poae (Peck) Wollenw., F. equiseti (Corda) Sacc., and F. avenaceum (Fr.) Sacc. were the most frequently isolated species and were isolated from 6.8, 3.7, 2.8, 1.8, and 0.6% of total seeds, respectively. The remaining species, F. acuminatum Ellis & Everh., F. crookwellense Burgess, Nelson & Toussoun, F. culmorum (W.G. Sm.) Sacc., F. oxysporum Schlecht., F. sambucinum Fuckel, F. solani (Mart.) Sacc., and F. tricinctum (Corda) Sacc., collectively infected only 0.3% of total seeds. The incidence of F. graminearum, F. sporotrichioides, and total Fusarium spp. increased about twofold, from 1.7, 3.9, and 9.5% in seed harvested very early to 5.5, 8.7 , and 19.8%, respectively, after delayed harvest. Also, F. poae had a significantly lower incidence at very early and early harvest times compared to normal or later harvest dates. Incidence of total other Fusarium spp., percentage of fusarium damaged kernels (FDK), and deoxynivalenol (DON) concentration were relatively low in the harvested grain and not affected by harvesting time. Of the three cultivars used, AC Barrie had the lowest incidence of Fusarium spp., FDK, and DON concentration in the grain; Quantum was intermediate; and Celtic had the highest. Variations in the incidence of Fusarium spp. for location and year were observed and likely related to levels of inoculum and weather conditions before and during harvesting times. Key words: Wheat, grain quality, farinograph, protein concentration, N management, cultivar selection and marketing

Orchardgrass (Dactylis glomerata L.) is a major component of many pastures in temperate North America. Early and profuse flowering in pastures is problematic, because livestock refuse to consume flowering stems, prompting many graziers to simply avoid using this species. The objective of this research was to determine the impact of reduced flowering on the quality of harvested forage under two harvest managements of orchardgrass. Six cultivars, three normal cultivars and three sparse‐flowering cultivars (mean panicle density of 141 vs. 61 panicles m⁻2, respectively), were evaluated in field experiments at 21 locations in North America under a 3‐cut harvest management. These cultivars were also evaluated at seven locations under a 5‐cut harvest management. Sparse‐flowering cultivars averaged 9% greater crude protein (CP), 3% lower neutral detergent fiber (NDF), 2% greater NDF digestibility, and 2% greater in vitro dry matter digestibility (IVDMD) than normal cultivars. For the two digestibility measures, differential panicle density between the cultivar groups explained a significant portion of variability, indicating that the increase in forage quality was proportional to the decrease in panicle density below a threshold of about 50 panicles m⁻2. Lastly, differences in regrowth forage quality between cultivar groups were smaller, less consistent, and of lesser statistical significance than for first harvest. While selection for sparse flowering in orchardgrass resulted in significant cause‐and‐effect increases in first‐harvest forage quality, these effects were too small to offset the reduced forage yield associated with the sparse‐flowering trait.

Orchardgrass (Dactylis glomerata L.) is a major component of many pastures in temperate North America. Early and profuse flowering in pastures is problematic due to livestock refusal to consume flowering stems. The objective of this research was to determine the stability and agronomic impact of recently developed sparse‐flowering orchardgrass populations across temperate North America. Six cultivars, three sparse flowering and three normal flowering, were grown at 21 locations in temperate North America and evaluated for panicle density, heading date, and forage yield. Sparse‐flowering cultivars had 57% fewer panicles than normal‐flowering cultivars, but this effect was highly dependent on mean winter temperature, with normal‐flowering cultivars showing twice as much temperature sensitivity compared to sparse‐flowering cultivars. Forage yield of sparse‐flowering cultivars was reduced by approximately 24 to 32% for first harvest and 2 to 9% for regrowth harvests compared to normal‐flowering cultivars and this reduction in forage yield was independent of mean winter temperature. The forage yield reduction associated with sparse flowering is most likely due to a combination of physiological load (loss of stems) and opportunity cost (lack of selection pressure for yield), suggesting an opportunity to improve forage yield potential of this sparse‐flowering germplasm pool.

The effect of harvest date on the incidence of seed-borne Fusarium spp. and deoxynivalenol (DON) concentration in barley (Hordeum vulgare L.) was studied using three cultivars at three locations in Ontario in both 2004 and 2005. The profile of seed-borne Fusarium spp. was dominated by F. equiseti (Corda) Sacc., F. sporotrichioides Sherb., and F. poae (Peck) Wollenw., isolated from 4.4%, 3.3%, and 1.6% of the kernels, representing 39.3%, 29.4%, and 14.2% of the Fusarium pathogen population, respectively. Fusarium graminearum Schwabe and F. avenaceum (Fr.) Sacc. were each recovered from <1% of the kernels and represented 8.3% and 6.6% of the pathogen population, respectively. Other species, including F. acuminatum Ellis & Everh., F. culmorum (W.G. Sm.) Sacc., and F. semitectum Berk. & Rav., collectively occurred only on 0.2% of all kernels and represented <2% of the population. The incidence level of all Fusarium spp. increased from 6.9 to 13.9% when harvest was delayed. Of the commonly recovered species, only F. avenaceum and F. sporotrichioides levels increased with the delayed harvest, while other species did not follow a clear pattern. DON concentration in the harvested grain ranged from 0.20 to 0.28 mg kg‑1 with the five harvest dates, and was not statistically different. Significant differences in the incidence of all Fusarium spp. and in DON concentration were observed among cultivars, locations, and between the 2 yr of the study. The highest DON concentration observed in this study was 0.5 mg kg‑1, which is below the Canadian tolerance level of 1.0 mg kg‑1.L’effet de la date de récolte sur l’incidence des concentrations aéroportées de Fusarium spp. et de désoxynivalénol (DON) chez l’orge (Hordeum vulgare L.) a été étudié à l’aide de trois cultivars dans trois sites en Ontario en 2004 et 2005. Le profil des Fusarium spp. aéroportées était dominé par F. equiseti (Corda) Sacc., F. sporotrichioides Sherb. et F. poae (Peck) Wollenw., retrouvées dans 4,4 %, 3,3 % et 1,6 % des grains et représentant 39,3 %, 29,4 % et 14,2 % de la population pathogène de Fusarium, respectivement. Fusarium graminearum Schwabe et F. avenaceum (Fr.) Sacc. ont été retrouvées dans <1 % des grains et représentaient 8,3 % et 6,6 % de la population pathogène, respectivement. D’autres espèces, y compris F. acuminatum Ellis & Everh., F. culmorum (W.G. Sm.) Sacc. et F. semitectum Berk. & Rav., étaient présentes dans seulement 0,2 % des grains et représentaient <2 % de la population. Le taux d’incidence de toutes les espèces de Fusarium augmentait de 6,9 à 13,9 % lorsque la récolte était retardée. Chez les espèces les plus souvent retrouvées, seuls les taux de F. avenaceum et F. sporotrichioides ont augmenté lorsqu’on retardait la récolte, alors que les autres espèces n’ont pas suivi de tendance claire. Les concentrations de DON dans les grains récoltés variaient entre 0,20 et 0,28 mg kg‑1 selon les cinq dates de récolte et n’étaient pas statistiquement différentes. Des différences significatives dans l’incidence de toutes les espèces de Fusar...

AC Legend is a six-rowed spring feed barley (Hordeum vulgare L.) cultivar bred at the Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, and evaluated by the Easter Canada Barley Breeding Group. It was selected from a Chapais/CIMMYT-6 cross and is suitable for growing in eastern Canada, where it out-yielded the check cultivars AC Stephen, Chapais, Myriam, ACCA and AC Westech. AC Legend is resistant to scald. Key words: Hordeum vulgare L., six-rowed barley, feed barley, high yield, scald resistance