A report of poor kochia (Kochia scoparia) control with glyphosate was received in August, 2011 and we subsequently investigated suspected glyphosate-resistant (GR) kochia in three chemfallow fields (each farmed by a different grower) in southern Alberta. In greenhouse dose-response experiments, the three kochia populations exhibited a resistance factor ranging from 4 to 6 based on shoot biomass response (GR₅₀ ratios) and 5 to 7 based on survival response (LD₅₀ ratios). A field confirmation dose-response experiment at Lethbridge in 2012 indicated a resistance factor of 6.2 (GR₅₀ ratios). An additional 46 fields within a 20-km radius of the original three fields were surveyed in October, 2011 and 7 of 46 populations were found to be glyphosate-resistant. In the spring of 2012, another kochia population >100 km away from the original site was also confirmed to be glyphosate-resistant. Greenhouse studies indicated that all GR kochia populations are Group 2 (thifensulfuron/tribenuron) resistant but Group 4 (dicamba) susceptible. A field experiment at Lethbridge evaluating alternative herbicides for GR kochia control in the absence of crop competition found that 2,4-D ester, bromoxynil, and bromoxynil/MCPA only provided moderate growth suppression. In contrast, excellent GR kochia control was attained with fluroxypyr, dicamba, dicamba/diflufenzopyr, sulfentrazone, and MCPA/dichlorprop/mecoprop-P. These findings will be utilized to provide growers with advice on management of GR kochia.

Site-specific wild oat (Avena fatua L.) management. Beckie H.J., Shirriff S.W. Agriculture and Agri-Food Canada, Saskatoon, SK

Variation in soil properties, such as soil moisture, across a hummocky landscape may influence wild oat emergence and growth. To evaluate wild oat emergence, growth, and management according to landscape position, a study was conducted from 2006 to 2010 in a hummocky field in the semiarid Moist Mixed Grassland ecoregion of Saskatchewan. The hypothesis tested was that wild oat emergence and growth would be greater in lower than upper slope positions under normal or dry early growing season conditions. Three herbicide treatments were imposed on the same plots each year of a two-yr canola (Brassica napus L.) – wheat (Triticum aestivum L.) sequence: (1) nontreated (weedy) control; (2) herbicide application to upper and lower slope positions (i.e., full or blanket application); and (3) herbicide application to lower slope position only. Slope position affected crop and weed densities before in-crop herbicide application in years with dry spring growing conditions. Site-specific wild oat herbicide application in hummocky fields in semiarid regions may be justified based on results of wild oat control averaged across slope position. In year 2 of the crop sequence (wheat), overall (i.e., lower and upper slope) wild oat control based on density, biomass, and dockage (i.e., seed return) was similar between site-specific and full herbicide treatment in 2 of 3 yr. Because economic thresholds have not been widely adopted by growers in managing wild oat, site-specific treatment in years when conditions warrant may be an appropriate compromise between no application and blanket herbicide application.

Pod-drop and seed shatter in canola are important issues related to harvest loss, yield, profitability, and the problem of volunteer canola.  Traditional methods tend to be time consuming and no universal method to measure these has been developed.  To facilitate canola breeders and reduce harvest losses and seedbank additions, efficient methods for the evaluation of pod-drop and seed shatter need to be developed.  In these studies, different methods to evaluate seed shatter and pod drop in canola including catch trays, soil vacuum, pod retention resistance and visual ratings were evaluated and compared.  Eight varieties of canola (four hybrids and four open pollinated), have been tested two locations over the past two years.  The research is also evaluating whether there is a trade-off between pod drop and seed shatter.  Preliminary result indicate that total harvest losses measured using catch trays were similar to total harvest losses determined using the vacuum method.  Visual estimates of seed shatter agreed best with the amount of shattered seeds retrieved from catch trays.

Effect of crop management, glufosinate rate, and application parameters on weed control and yield of Liberty-Link canola. E. N. Johnson¹ and T. M. Wolf². ¹Agriculture and Agri-Food Canada, Scott, SK; ²Agriculture and Agri-Food Canada, Saskatoon, SK.

The efficacy of contact herbicides such as glufosinate can be sensitive to application parameters such as carrier volume and spray quality.  Many growers prefer to apply at low carrier volumes and relatively coarse spray quality to increase efficiency and reduce drift, which may have a negative effect on efficacy.   A 3-year study was conducted at the Scott Research Farm from 2007 to 2009 to determine if optimum input management (seeding rate, hybrid vs OP cultivar, soil fertility) could offset reductions in efficacy from low volume, coarse sprays.  The 4 factor experiment include input level [high (hybrid cultivar, 150 seeds m^-2 planting density, fertility at 100% target yield) vs low (OP cultivar, 75 seeds m^-2, fertility at 50% target yield)], glufosinate rate (400 g ai ha^-1 vs 200 g ai ha^-1), carrier volume (125, 85, and 45 L/ha), and spray quality (medium, coarse, and very coarse).  The 2 input levels were arranged in a split-block design, with the other 3 factors arranged in a RCBD within the blocks.  When combined over 3 years, there was a rate X carrier volume X spray quality interaction for weed biomass.  When 0.5 X rate glufosinate was applied, weed biomass was significantly higher with very coarse qualities and 125 l ha^-1 carrier volume compared to medium and coarse spray qualities at the same volume; whereas, at 1.0 X rate, the very coarse quality and 125 l ha^-1 had similar weed biomass to the medium and coarse spray qualities.  For canola seed yield, there was a rate X carrier volume interaction.  At 0.5X rate, increasing carrier volume did not increase yield; however, a linear yield increase resulted with increasing carrier volume at 1X rate.  The absence of an input level by application parameter interaction for seed yield indicated that reductions in efficacy from low volume, coarse sprays could not be overcome with input management; however, the overall impact of application parameters on weed biomass and yield were small relative to the impact of glufosinate rate and low vs high inputs.  Growers should consider application parameters such as spray quality and carrier volume as fine-tuning their herbicide application, but they should not expect that they will provide compensatory weed control for poorly managed crops.    

A study was initiated in 2001at four locations in western Canada to investigate an integrated approach to managing wild oat, the region’s worst annual weed. The study examined the effects of combining short or tall barley cultivars with normal or twice normal barley seeding rates in either continuous barley or a barley-canola-barley-field pea-barley rotation. Herbicides were applied at 25, 50 and 100% of recommended rates. The first phase of the study was completed in 2005. This paper reports on the second phase which in 2006 was continued for four more years at two of the original locations, Beaverlodge and Fort Vermilion, Alberta. The primary objective was to determine the long-term impact of the treatments on wild oat seed in the soil seed bank. The diverse rotation combined with the higher barley seeding rate (optimal cultural practice) mostly resulted in higher barley yields and reduced wild oat biomass in 2009. In contrast to the first phase of the study, barley yield was generally higher with the short cultivar, and cultivar had no effect on wild oat management. Wild oat seed in the soil seed bank decreased with increasing herbicide rate, but the amounts were often considerably lower with the optimal cultural practice. The results were especially compelling at Beaverlodge where the combination of the recommended herbicide rate and optimal cultural practice drove the wild oat seed in the soil seed bank to virtual extinction. The results indicate that combining optimal cultural practices with herbicides will reduce the long-term accumulation of wild oat seed in the soil seed bank, and result in higher barley yields. The results have implications for mitigating the evolution of herbicide resistance in wild oat.

In Ontario, the occurrence of pigweed populations resistant to herbicides is a significant threat to carrot producers on muck and mineral soils. Linuron and prometryne are the only broad-spectrum herbicides registered in carrots. Alternative herbicides were evaluated for efficacy on redroot pigweed and crop tolerance in carrots grown on muck and mineral soil. Trials were conducted at 3 sites in Ontario: on muck soil at MCRS (70-80% O.M) near Bradford; and mineral soils at Ridgetown (82.4% sand; 10.5% silt; 7.1% clay; 4.1% O.M.); and Harrow (82.5% sand; 5% silt; 12.5% clay; 2% O.M.). Preemergence treatments of pendimethalin (ME formulation), ethofumesate, pyroxasulfone, flufenacet, and s-metolachlor were applied at 1X the proposed use rate:  3000, 3960, 89, 450, and 1373 g ai ha^-1, respectively, for control of redroot pigweed. Herbicide efficacy and crop tolerance was influenced by soil type. At MCRS all herbicides gave <50% control of pigweed at 2 WAT (weeks after treatment) compared to 75-90% control at 5 WAT (weeks after treatment) on mineral soils except for reduced control with flufenacet and s-metolachlor at Harrow. When applied PRE to carrots at 2X, herbicide tolerance was excellent at MCRS and Ridgetown. At Harrow, however, all herbicides except pendimethalin caused injury and yields were reduced except with pendimethalin and ethofumesate. When applied POST to carrots at the 2-3 leaf stage, tolerance was excellent and no yield loss incurred at all locations with 2X rates of pendimethalin (ME formulation), pyroxasulfone, flufenacet, and s-metolachlor. Below label treatments of oxyfluorfen (EC formulation), acifluorfen, fluthiacet-methyl, and fomesafen, at doses of 60, 18.75, 1.875, and 5 g ai ha^-1, respectively, gave postemergence control of 2-4 leaf redroot pigweed. Carrot tolerance to 2X rates of these herbicides applied when carrots were at the 2-3 and 4-5 leaf stage was commercially acceptable, and did not reduce total or marketable carrot yield.

Mikania micrantha, known as “mile-a-minute” (Asteraceae), is a perennial creeping vine capable of both rapid growth and rapid geographic spread through seed dispersal and vegetative propagation. It readily colonizes a wide variety of agricultural and natural habitats, severely impacting growth of other plants through shading or smothering. Native to Central and South America, mile-a-minute reached Asia about 1910 and was subsequently introduced throughout the Indo-Pacific region. I have witnessed mile-a-minute’s rapid spread in Yunnan Province, China, with an increasing level of infestation on an annual basis. This rapid spread follows the same pattern seen in other Chinese provinces such as Guangdong.  Given this rapid invasion potential, it is imperative that we develop methods of forecasting further spread. CLIMEX models have been applied to the spread of mile-a-minute in Papua New Guinea and Australia utilizing climate data from its world distribution. As well as climate matching, other factors need to be considered such as which habitats are most invasible, factors impacting dispersal mode (e.g., fragmentation vs. seed), relationship of spread to land use patterns, evolutionary adaptation or ecotype variation, and the impact of emerging management strategies. I will describe our present state of understanding of these factors with respect to mile-a-minute. A more proactive approach to its management across Asia and the South Pacific will require a thorough understanding of the biology of this invader and collaboration among jurisdictions threatened by new invasions and further spread.

Common ragweed (Ambrosia artemisiifolia L.), a monoecious  indigenous weed, is responsible for seasonal rhinoconjunctivitis (“hay fever”) . A four year study (2007 – 2010) was carried out in July of each year in two municipalities south of Montréal, Quebec to survey ragweed density in different urban habitats and associate their presence with edaphic and environmental characteristics of each habitat. Each municipal territory was divided into sectors of 1.5 km², Salaberry-de-Valleyfield (SV) with 13 sectors and Saint-Jean-sur-Richelieu (SJR) with 18 sectors.  Four habitat types were identified within each municipality: residential (street, boulevard), industrial (industrial sites, train yard, quarry), landscaped (park, golf, green area) and disturbed (construction site, snow deposit site, railroad & hydro land). Ragweed plants were counted in quadrats (50 X 50 cm) randomly positioned in each habitat per sector along roadside (for a total of 312 to 432 quadrats per municipality). Visual assessment of overall soil components, % weed cover and soil component under ragweed canopy were also collected. A mixed model ANOVA was carried out on transformed (ln (√ (x+0.5) + 1) values. At the onset of the project in 2007, both municipalities had similar ragweed populations (7.8 ± 0.5 plants/m² in SJR and 8.0 ± 0.5 plants/m² in SV). Ragweed density was statistically lower in residential areas than in any other habitat (landscaped, industrial or disturbed) in both municipalities throughout the study. The importance of ragweed densities varied with urban habitats and ragweed densities can be ranked as follows: Residential << landscaped <= industrial < disturbed. Industrial and disturbed habitats were identified as the most problematic habitats within municipalities for ragweed management.

Demography of red sorrel (Rumex acetosella L.) in lowbush blueberry (Vaccinium angustifolium Ait.) fields in Nova Scotia, Canada. White, S.N.¹, Boyd N.S.², Van Acker R.C.¹, Swanton C.J.¹, and Newmaster S.³. ¹Department of Plant Agriculture, University of Guelph, Guelph, Ontario; ²Department of Environmental Sciences, Dalhousie Faculty of Agriculture, Truro, Nova Scotia; ³Department of Integrative Biology, University of Guelph, Guelph, Ontario. 

Seasonal patterns of red sorrel ramet emergence, mortality, and phenological development were determined in three sprout year and three crop year lowbush blueberry fields in Nova Scotia between 2009 and 2011. Ramet data were collected weekly or bi-weekly from May until December in four 0.09m² quadrats located within blueberry clones and four 0.09m² quadrats located within bare soil patches between blueberry clones at each site. New ramets were marked with colored elastics to keep cohorts separate, and flowering was related to time of ramet emergence based on the elastic color associated with each flowering ramet. Emergence of new ramets in the sprout year was season-long with the density of new ramets emerging generally higher in blueberry than in bare soil patches. Sprout year ramet mortality was lower in blueberry than in bare soil patches, resulting in a large net gain to ramet populations in blueberry patches at all sprout year sites. Approximately 88% of the final net ramet population in the sprout year survived over winter into the crop year. Crop year ramet emergence was also season-long, but mortality was high (>60%) in both blueberry and bare soil patches. As a result, little net gain to ramet populations was observed at crop year sites. The majority of flowering ramets (>70%) were from the overwintering cohort, with the remaining percentage comprised of ramets emerging early in the season. No plants established from seed or root fragments under controlled conditions flowered when grown under constant 8 or 16-hour photoperiods. Less than 20% of plants established from seed flowered after vernalization for 5 weeks at 4^oC. Vernalization for 10 or 15 weeks at 4^oC resulted in an average of 60 and 80% flowering, respectively. Field and greenhouse data have been used to develop a life-cycle model of red sorrel for the 2-year lowbush blueberry production cycle.

Sightline- A New Herbicide for Control of ALS Resistant Kochia in Non-Crop Areas in Canada. Hare, D.D. Dow AgroSciences Canada Inc.  Calgary Alberta Canada.

Dow AgroSciences has recently received registration of Sightline™ Herbicide Tank-Mix, a new selective post-emergent herbicide that will provide kochia control, including ALS resistant biotypes, for vegetation managers across Canada. Sightline combines highly effective kochia control with broad-spectrum control of annual and perennial broadleaf weeds, invasive plants and shrubs – resulting in a wide spectrum of control.  Sightline is designed for controlling vegetation on rights-of-way, industrial areas, roadsides and other non-crop areas.  Sightline offers low use rates and a favourable environmental and user safety profile compared to current industry standards. It combines three active ingredients and two herbicide groups for effective control of kochia including ALS and glyphosate resistant bio-types. Sightline controls an extensive list of weeds, but also controls kochia, which continues to be a problem species for vegetation managers in many areas of Canada. Sightline is designed from Dow AgroSciences Reduced Risk Aminopyralid chemistry. Sightline is easy to use, and has a favourable environmental and user safety profile. Sightline can be applied alone or tank-mixed with Vantage™ XRT for bare ground applications in areas such as oil and gas sites, electrical sub stations, and rail lines.

™Trademark of Dow AgroSciences LLC

Within agricultural systems, weeds are a source of plant diversity.  Soil function is mediated by soil microbes and these are influenced by the surrounding plant community.   Weeds, therefore, may influence below ground function in agricultural systems.  A 10 year old field study with different equilibrium weed seedbank densities was sampled to evaluate the effect of weed seedbank density relative to previous crop on functional soil microbes.  Soils were sampled after a canola and a flax crop in these rotations with three different levels of weed seedbank densities that, with the exception of different in-crop herbicide use in some crops, have been otherwise managed identically.  Soil functional microbe responses that were investigated included denitrification and arbuscular mycorrhizal fungi in a durum trap crop.  Increasing weed densities increased early above ground dry matter production, root length accumulation and root length colonized by AMF in durum wheat.  Weed seedbank densities were more influential to these responses than previous crop.  The intraradicle AMF community structure was also affected by weed seedbank density, previous crop, and durum developmental stage.  Potential denitrification was lower at higher weed densities suggesting differences in nutrient cycling and nutrient pools in response to weed seedbank densities.  Initial results indicate that weeds play an important role in soil function that warrants further investigation. 

In production agriculture, it is not uncommon for a crop seedling to experience both intra- and inter-specific interference during the normal course of growth and development.  Although the interference between crop seedlings (intraspecifc) is often considered independently of that among crop and weeds (interspecific), the physiological mechanisms through which yields are reduced may be common to both.  In this study, we will compare and contrast the impacts of intra and interspecific interference on the growth and development, stand uniformity in maize and examine their impact on yield determination. Specifically, we will review literature pertaining to the two widely recognized critical periods of maize development: 1) the critical period for weed control, lasting from the 4^th to the 13^th leaf tip stage of development, and 2) the critical period for kernel set, lasting from around 1 week before to 2 weeks after silking. While the acquisition of light, water and nutrients is critical during the early stages of crop establishment, little is known regarding the differences/commonalities of early physiological responses to stresses occurring during this period and their impact on grain yield at maturity. We hypothesize that early stressors will differentially impact the advancement of developmental stages (i.e., leaf appearance and ear development), coupled with changes in biomass accumulation.  Secondly, the degree of association between growth and development may change depending on the stress considered. Overall, the comprehensive study of early factors influencing stand uniformity and competitiveness will bring to light new opportunities to improve general stress tolerance and yield in maize.

Canada fleabane is a genetically diverse weed which adapts to no till and Roundup Ready soybean agricultural practices, disbursing easily via windblown seed.  In 2010, populations of Canada fleabane were confirmed to be resistant to glyphosate at 8 locations in Essex County in Ontario.  Seeds from Canada fleabane were collected in the fall of 2011 and an additional 76 resistant populations were identified as glyphosate resistant (GR) within the counties of Essex (48), Kent (19), Elgin (7), Lambton (1), and Niagara (1).  Four field trials in Roundup Ready soybeans were conducted in 2011 and 2012 at sites with confirmed GR Canada fleabane.  The objectives of these trials were a) to determine the biologically effective rate of glyphosate on these resistant populations, b) to evaluate glyphosate tankmixes for the control of GR Canada fleabane, and c) to determine the efficacy of dicamba for the control of GR Canada fleabane in dicamba-resistant soybean (Roundup Ready 2 Extend soybean).  Saflufenacil, saflufenacil/dimethenamid-p, metribuzin, and flumetsulam tankmixed with glyphosate provided greater than 90% control of GR Canada fleabane.  None of the post-emergence tankmixes provided acceptable control of GR Canada fleabane.  Dicamba was found to be a very effective herbicide for control for of GR Canada fleabane in a fifth trial established in confined trials with Roundup Ready 2 Extend soybean.

Seed loss in canola leads to a considerable yield loss and dispersal of canola seeds into the soil seedbank. The volunteer canola can then create weed problems in the subsequent crops and result in crop yield loss. Gene dispersal in time particularly from genetically modified volunteer canola can be another undesirable consequence. A study was conducted in Saskatchewan in 2010 and 2011 to determine seed loss in canola from windrowing and direct harvesting operations and to determine factors that contribute to canola seed loss in western Canada. A total of 66 canola fields were surveyed within 3 weeks of harvest. Three random samples were taken from each field using a vacuum cleaner and seed loss per unit area was determined for each field. Data concerning agronomic and harvest specific information were collected for each field using short survey questionnaires. The average seed loss was found to be 184 kg ha^-1, which is equivalent to 7.3% of the total yield and resulted in seedbank addition of approximately 5821 viable seeds m^-2. Seed loss among producers ranged from 4.9 to 9% of the total yield and resulted in seedbank addition which is many times more than the normal seeding rate of canola. There was no difference in yield and seed loss between windrowed and direct harvested canola. This indicates that direct harvesting can be a viable option to harvest canola in western Canada.

Domestication is the process by which a wild plant undergo several modifications such as morphological, physiological, biochemical and molecular. These evolutionary changes are often used to understand the domestication trend from wild to cultivated plant. To understand the domestication status of cow cockle, we compared fifteen lines for phenotypic variability, seed dormancy and seed persistence in both field and laboratory experiments. Several morphological and agronomic traits were recorded to estimate the phenotypic variability. Seed dormancy was measured based on their response to temperature and photoperiod treatments. Artificial ageing technique was followed to quantify the seed persistence. Most lines obtained from Saskatchewan and Manitoba had weedy characteristics including early maturity, small seeds with a wider window of seed germination. White beauty and Florist rose were found to have ornamental traits as well as greater dormancy, which suggests the role of artificial selection. Though Mongolia registered wild characters such as poor emergence and late maturity, it was found to be completely non-dormant. This study emphasized the importance of selection pressures and organ of interest during the process of evolution. In most of the genotypes, natural selection pressures were observed to have been imposed to adapt the native or non-native habitat conditions.

Hexazinone Alternatives and Resistance for Wild Blueberry Production

Li Z.Y.¹, Boyd N.S.², McLean N.³, Pruski K.⁴.^1,2, Department of Environmental Sciences, Dalhousie Agricultural Campus, Truro, N.S.; ^3,4Department of Plant and Animal Sciences, Dalhousie Agricultural Campus, Truro, N.S.

Weeds compete for resources with blueberries and lower yields and reduce berry quality. Hexazinone is the most commonly used herbicide in wild blueberry fields, and may have the potential to create herbicide-resistant weeds. It is important to evaluate new herbicides that can be applied before blueberry emergence (PRE) and after blueberry emergence (POST) that have modes of action different than hexazinone. Herbicides, including Velpar, Ultim, Sinbar and other tank mixes, were applied to experimental plots to determine their effect on blueberries, weeds, and grass biomass. Herbicides were applied in early May (PRE) and mid June (POST). Preliminary results show Sinbar WDG has the best grass control in the general weedy trial. Red sorrel seeds were collected at 4 different sites to evaluate herbicide resistance. Seeds were collected from old blueberry fields, new blueberry fields and none-blueberry areas. All plants were treated with 6 different rates of hexazinone: 0, 0.25x, 0.5x, x, 2x and 4x. Preliminary results show red sorrel seeds were resistant to hexazinone in blueberry fields where hexazinone had been sprayed for several years. In most cases, triazine resistance is caused by a Ser₂₆₄ to Gly mutation in psbA gene that alters the conformation of the Q_B and herbicide binding niche. After sequencing 16 resistant and 16 non-resistant red sorrel plant leaves, preliminary results show the triazine-resistance in red sorrel was not caused by Ser₂₆₄ to Gly mutation.

Demographic analysis using field based experiments as a method of quantifying the relative invasiveness potential of plants with novel traits (PNT) from a regulatory perspective has not been evaluated. Common garden sites were established in 5 ecological regions of Canada in disturbed, ruderal and natural areas, and compared 6 species at 2 densities. Experiments were initiated twice a year, fall to assess overwintering seed viability and emergence, spring to measure plant survival, growth and fecundity. Data collection included weekly survival counts, height and staging, and a measure of fecundity in the fall. Projected population growth rate (λ) and the sensitivity/elasticity of λ to vital rates were derived using a matrix modeling approach. λ values vary considerably between disturbance regimes and environments, high λ values are generally associated with the high disturbance regimes and low λ values are generally associated with low disturbance regimes. Preliminary data shows higher sensitivity/elasticity of λ to the seed-to-seedling overwintering vital rate compared to the fecundity vital rates. Demographic analysis provides a simple metric based on field data for determining the relative invasiveness of a plant that could be used by regulators in addition to the current apriori trait-based methods.

Small seeded Brassicaceae crop camelina, is being developed as a genetically engineered (GE) bioproduct crop for the Canadian Prairies. Seed-mediated gene flow from GE camelina could impact the ability to co-exist with conventional agriculture and thus is a significant hurdle towards unconfined environmental release. Field experiments were conducted 2008 to 2011 to quantify aspects of camelina seed bank dynamics through a three part study that looked at seed lost at the time of harvest (seed bank inputs), persistence of camelina seed in the soil (seed bank longevity) and emergence of volunteer populations from the seed bank. Harvest losses were variable and ranged from 1,202 to 43,430 seeds m^-2; the respective weights were 12.0 to 434.3 kg ha^-1, approximately 0.7 to 25.5 % of total yield losses. Artificial seed banks were established to test for differences in seed persistence on soil surface (0 cm) and buried (3 and 10 cm) for two cultivars (Calena and CN101985). There were no significant differences between cultivar and seed on the soil surface persisted the longest. Buried samples were 99 % non-viable after 8 mo whist surface persisted up to 15 mo. Lastly, 11 commercial fields, one year post-camelina cultivation, were surveyed for the emergence of volunteer populations. Initial surveys showed variable high densities (9 to 4839 plants m^-2) however populations sharply declined over time and were near extinct after 2 yrs. Results from this study report that camelina forms transient seed banks and volunteer populations can be extinguished within 2 yrs by employing herbicide application.

 Red Fescue (Festuca rubra) Management in Wild Blueberry

Submitted By- Sunil Sikoriya

Red fescue is a common, cool season, sod forming grass that spreads via seeds and rhizomes. Its recent spread into agricultural fields has made it an emerging weed, especially in blueberry. This unwanted vegetation inhibits rhizome growth, reduces yield, and hinders harvest operations. Field studies will be conducted in 2012 and 2013 to evaluate efficacy of different herbicides and their application timings on red fescue suppression as well as blueberry tolerance. Recent findings have shown that pre-emergence application of Casaron and Glyphosate show significant damage on red fescue in approximately 5 weeks. There was no significant loss in biomass of either blueberry or red fescue. The present study is continued until next summer, with an insight to find control measures including potential herbicide selection based on their temporal efficacy.

Weed management options for organic wild blueberry production

Goutam Kuwar

Dalhousie University, Halifax, NS

 Weeds are considered a major problem for organic wild blueberry (Vaccinium angustifolium Ait.) production due to their excessive growth and limited management options available. Therefore, the main objective of this study was to investigate burning in combination with sulphur application as a weed management option for organic blueberry production. Experiments were conducted in two commercial blueberry fields in Collingwood and Earltown, Nova Scotia. A 2 x 2 factorial design with four blocks was established after harvesting blueberry in 2009. Treatments included pruning method (burning versus mowing) and soil pH modification (sulfur versus no-sulfur). The Results showed that the burned plots and sulphur application plots had higher blueberry stem density, blueberry cover and yield as compared to mowed and no-sulphur plots, respectively. Similarly, soil moisture and mycorrhizal colonization, NPK and soil moisture were higher in burned plots.

Field pea breeding programs have been very successful at improving plant standabiltiy and disease resistance; however, limited success has been achieved in improving the competitive ability of field pea. Finding a practical solution that improves field pea competitive ability could lead to a substantial increase in the crop’s profitability and acreage in western Canada. We conducted a study to determine whether growing field pea in two-way genotypic mixtures could improve the crop’s yield and competitive ability. We were also interested in whether genetic relatedness had any effect on the mixing ability of genotypes and thus, genotypes were chosen on the basis of pedigree and included two sister lines (CDC 1987-3 and CDC 1897-14), their common parent (Eclipse), and a distantly related genotype (Midas). The four genotypes were grown as monocultures and as all possible two-way mixtures in field experiments conducted at two locations in Alberta from 2010 to 2011. The results of this study revealed that CDC1897-3 x Eclipse (the common parent) was found to suppress the pseudo-weed (barley); it reduced seed production by 47% (442 kg ha^-1) and 61% (391 kg ha^-1) compared to the respective components monocultures at Lethbridge 2010 and Lethbridge 2011, respectively. However, for field pea grain yield and thousand seed weight (TSW), mixtures were not different than monocultures both in the presence or absence of weed competition. In general, field pea mixtures had inconsistent performance throughout different site-years of this study and they had provided no evidence of higher ecosystem functions compared to monocultures.

Gareth Davis & Francois Tardif , University of Guelph                                                                                                                                 

                                                                                ABSTRACT

A survey of linuron-resistant Amaranthus sp. in Southern Ontario

Carrot is an important fresh market and processing vegetable crop in southern Ontario. Yield losses of 92 to 100% can result from weed competition. This makes weed control a crucial part of this industry. Linuron and prometryn are two photosystem 2 inhibiting herbicides that are widely used by carrot growers. Overreliance on herbicides, especially linuron, has lead to the development of resistance in pigweeds (Amaranthus sp.) which was first confirmed in 1999. Lack of alternatives meant that producers still rely on linuron. Recent field observations suggest resistance has continued to evolve in many carrot fields. Our aim is to survey carrot fields in Ontario and collect samples of pigweeds in order to confirm resistance to linuron and other herbicides. Each suspected accession will be grown from seed and sprayed with a diagnostic herbicide dose. Upon confirmation of resistance status, DNA will be extracted and the target site gene (psbA) will be sequenced. Resistance status will be correlated with herbicide use history from each field. This project will reveal the extent of resistance to linuron in Ontario and will confirm its molecular basis. It is hoped that this will help growers decide on more sustainable production practices.

Investigation into the Molecular and Biochemical Mechanisms of Resistance to Glyphosate in Two Populations of Giant Ragweed (Ambrosia trifida)

Jeffery, T., Hall, C., Lawton, M., Sikkema, P., Tardif, F.

There are two phenotypes associated with resistance to glyphosate in giant ragweed (Ambrosia trifida). The most common in Canada is the “rapid necrosis response” which shows treated leaves rapidly reacting to glyphosate while the growing point remains unaffected. Plants with the “slow recovery response” stop growing for about 14 days and turn slightly chlorotic before resuming growth. Our aim is to examine the genetic and biochemical factors that confer resistance. The target site of glyphosate has been PCR amplified and sequencing analysis is being conducted. We are also examining the role free radicals play in the rapid response plants. Using spectrophotometry we are examining free radical production in response to glyphosate application. In addition semi-quantitative PCR we will be used to investigate changes in expression of genes associated with free radical control. Finally crosses have been made between resistant and susceptible plants, as well as between resistant plants with the two phenotypes. We will determine the inheritance and dominance of the resistant traits. Results from this study will provide insight on new resistance mechanisms that will lead to a better understanding of the selection process leading to resistance.

Resistance Weed Management in Carrot Production. Roy-Fortin, V. and Leroux, G.D. Department of Plant Science, Laval University, Quebec, QC. Benoit, D.L. Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu, QC

Carrots (Daucus carota) are an important fresh market and processing vegetable crop is grown on a wide range of soil types, from light sand to clay loam soils and high organic muck soils, primarily in Ontario and Quebec. Weed control in carrots is important as this crop is a poor competitor and in the absence of control, yields are often reduced by more than 90 per cent. However, herbicide options are limited for weed control in carrots, especially in organic soils, where a typical herbicide weed management program includes Lorox (Linuron) – the only available for broadleaf weed control - applied preemergent followed by a postemergent application of this herbicide. This practice has led to problems of resistance in some species such as common ragweed (Ambrosia artemissifolia L.) in Quebec and redroot pigweed (Amaranthus retroflexus L.) in Ontario. Lower risk options and integrated approaches were needed. Carrots have basal leaves with compact internodes forming a rosette compared to most weeds which have longer internode length. The mechanical control technique evaluated in this project takes advantage of the morphological difference between carrots and weeds to develop a selective mowing method to achieve maximum damage to weeds with minimal impact to carrots. A precision cutting weeder was used in a two year trial (2011 & 2012) in organic soil in Quebec. A randomized complete block design with four repetitions was set up for treatments combining pre and/or post herbicide applications with cutting at approximately 6 cm height at 3 or 4-leaves carrot stage. Although being cost effective, the use of precision cutting tool results in partial control of weeds since cutting stimulates regrowth and secondary branching of common ragweed. Consequently, carfentrazone (Aim) applied at two rates (14 & 28 g ai/ha) was evaluated, as an interrow banding treatments to complement the proposed weed control program. Even if the broadcast linuron application was superior to all other treatments providing the highest weed control and carrot yield at the lowest cost, the combination of linuron applied prior to carrot emergence, followed by a single cutting at three leaves stage of carrots and an interrow application of carfentrazone four days later seems to be an interesting approach for producers.

            Plants perceive their neighbours through changes in light quality. This change in light quality is brought about by alterations in the red/far-red ratio detected by plant phytochrome, which in turn will induce a shade avoidance response. The shade avoidance response has been reported to be an important variable defining the critical period for weed control. Previous work has shown that this period occurred from the first to third trifoliate of soybean development. No work, however, has been done to quantify how early a soybean seedling can detect the presence of neighbouring weeds. We hypothesized that a soybean seedling can detect the presence of aboveground neighbouring weeds upon emergence and this detection will be evident through changes in seedling morphology. Growth chamber studies were conducted using the soybean cultivar OAC Wallace grown in the presence of ryegrass. Seedling measurements were recorded at 72 hours after planting, VE, VC, unifoliate, first trifoliate, and second trifoliate stage of growth. Morphological changes in stem height were observed upon seedling emergence. This alteration in carbon allocation between weedy and weed free treatments persisted throughout all growth stages sampled. The results of this study suggest that detection of changes in light quality induced by aboveground neighbouring weeds occurs at time of seedling emergence. The ability of soybean seedlings to detect changes in light quality at such an early stage of development further suggests that molecular and physiological changes were occurring prior to seedling emergence.

Within Saskatchewan’s organic industry there is a need for improved tools to minimize yield losses due to weeds.  Cultivar mixtures may improve the ability of organic pulse crops to suppress weeds and maintain yields in the presence of weeds.  While semi-leafless peas are known for their lodging resistance and high yield potential in the absence of weeds, conventional “leafed” peas may provide better weed suppression and yield stability in the presence of weeds.  A replicated field experiment was conducted on organic land over four site-years to test the hypothesis that cultivar mixtures of semi-leafless and leafed field pea would improve weed suppression and yields compared with single-cultivar crops.  The experiment tested factorial combinations of five ratios of semi-leafless pea cultivar CDC Dakota and leafed cultivar CDC Sonata (0:100, 25:75, 50:50, 75:25, and 100:0, respectively), and two seeding rates (conventional and organic recommended).  Plots were monitored for crop and weed emergence, biomass, and yields.  Weed suppression and yield benefits were seen in pure stands of the semi-leafless cultivar compared with the leafed.  As the canopy composition progressed from a pure leafed canopy towards increasing percentages of semi-leafless pea, weed biomass decreased.  The semi-leafless cultivar out-yielded the leafed by approximately 148%.  A highly significant quadratic effect indicated that yields were maximized in the mixture dominated by the semi-leafless cultivar, an effect observed in three of four site-years.  Results indicate that mixtures of semi-leafless and leafed cultivars can be used as an organic tool to increase crop productivity.  Additionally, this study calls into question the notion that leafed peas have a competitive edge over semi-leafless under weedy conditions.   

Giant ragweed (Ambrosia trifidia) was the first glyphosate resistant weed in Canada.  Giant ragweed interference in soybean has resulted in yield losses of greater than 90%; therefore, control of this competitive weed is essential.  The objectives of this research were; a) to conduct an expanded field survey to document the distribution of glyphosate resistant giant ragweed in Ontario, b) to determine effective control options for glyphosate resistant giant ragweed in soybean, and c) to ascertain the biologically effective rate of 2,4-D for the control of glyphosate resistant giant ragweed.  In 2011, giant ragweed seed was collected from 51 sites in Essex (16), Kent (20), Lambton (10), Middlesex (2), Elgin (2) and Lennox & Addington (1) counties.  Glyphosate was applied to giant ragweed seedlings at 1800 g ae/ha and resistant or susceptible ratings were taken at 1,7,14 and 28 days after application.  Results from the 2011 survey concluded that there were 23 additional sites with glyphosate resistant giant ragweed in Ontario.  An additional survey will be conducted in the fall of 2012.  Field trials were conducted at 5 sites in 2011 and 2012 to determine the most effective control options.  Based on these experiments, glyphosate tankmixes with 2,4-D or amitrole provide the most effective control.  These two tankmixes provided greater than 90% control.  The minimum dose of 2,4-D required for acceptable control of glyphosate resistant giant ragweed is 500 g/ha. 

No-till field crop production without herbicide. Halde, C.¹, Gulden, R.H.¹, Hammermeister, A.M.², Ominski, K.H.³, Tenuta, M.⁴, and Entz, M.H.^{1 1}Department of Plant Science, University of Manitoba, Winnipeg, MB; ²Organic Agriculture Centre of Canada, Truro, NS; ³Department of Animal Science, University of Manitoba, Winnipeg, MB; ⁴Department of Soil Science, University of Manitoba, Winnipeg, MB.

In recent years, efforts have been invested in developing ways to reduce tillage and herbicide use on grain farms while maintaining good weed control. The objective of the research project was to examine the possibilities of implementing no-till practices in herbicide-free field crop production systems in Manitoba. A 2-year field study was conducted twice in Carman, MB. In year 1 (Y1), ten different combinations of various green manures (GM) species were seeded in the spring and rolled using a roller-crimper in mid-summer, at the flowering stage. The GM species tested included barley, hairy vetch, pea, oilseed radish, and sunflower. These rolled mulches were then left on the soil surface over the fall and the winter. In year 2 (Y2), spring wheat was seeded directly into these mulches (no-till). Mulches with hairy vetch (Vicia villosa) showed the most promising results. GM treatments with hairy vetch had the highest mulch biomass in September Y1 (9.1-11.5 t ha^-1), and in the spring Y2 (6.0-7.6 t ha^-1). Green manure mulches with hairy vetch were effective at reducing weeds biomass by 50% to 90% in the no-till spring wheat, in 2011 and 2012, compared to other mulches and a tilled control treatment. Spring wheat yields reached 2.4-2.7 and 3.9 t ha^-1 in 2011 and 2012, respectively, in herbicide-free no-till production with mulches containing hairy vetch. Yields obtained in these research plots were comparable to the average regional yields of 2.8 t ha^-1 (2011) and 3.4-4.7 bu ac^-1 (2012). Spring wheat in plots with mulches without hairy vetch yielded poorly both years, yielding 21 to 92% less than in plots with hairy vetch mulches. In conclusion, the use of mulches (in particular those including hairy vetch) in no-till field crop production is an option for farmers interested in reducing tillage and herbicide use on their farms.

        Canada fleabane (Conyza canadensis (L.) Cronq. var. canadensis) is a surface-germinating ruderal facultative winter annual with recruitment that is highly susceptible to changes in microsite conditions.  Temperature and light play the largest roles in germination and emergence timing of this species.  Base germination temperatures for Canada fleabane are unknown and have only been estimated at 13⁰C in a Knoxville, Tennessee population.  In this experiment the germination of Canada fleabane seed was investigated using the Thermo-gradient Plate (TGP) at the University of Saskatchewan in Saskatoon, SK, Canada in January and February of 2012. The TGP machines consist of 96 and 176 individually controlled cells that are accurate within 0.1⁰C.  An international collection of seed from varying climatic zones was used.  Seed sources included populations from San Joaquin Valley, CA, Hertfordshire, UK, Shiraz, Iran, and Southern Ontario, Canada. Seeds from each of the 4 populations were counted and counted and placed into 40 petri dishes with wet filter paper within the Thermo-gradient Plate cells. The seeds were subjected to temperatures from 6.5-20⁰C at 1.5⁰C increments. Cumulative daily germination counts for 30 days were recorded.  Results indicated that temperature and source have a significant effect on germination.  Base germination temperatures were significantly different between all populations (Ontario (~9.5⁰C), Iran (~11⁰C), Spain (~14⁰C), UK (~12.5⁰C)) as well as literature values.  The results suggest a genetic difference between these international populations and suggest rapid evolutionary change since the introduction of Canada fleabane 200-300 years ago to Europe and the Middle East.   The results also have implications for management especially in no-till situations where Canada fleabane populations are the most problematic.  Germination at such low temperatures may require altered approaches to controlling this species.

In 2012 glyphosate-resistant (GR) kochia populations were confirmed in chemical fallow fields in southern Alberta. Pre-seeding and post harvest trials were conduced on susceptible kochia to evaluate the effectiveness of commercially available herbicides to supplement or replacement glyphosate. In 6 pre-seeding trials conducted in 2011 and 2012, 2,4-D ester, pyrasulfotole/bromoxynil, dicamba, gluphosinate ammonium, diflufenzopyr/dicamba, diquat and bromoxynil/2,4-D were less effective than glyphosate alone; carfentrazone-ethyl and saflufenacil provided similar control; and fluroxypyr/MCPA ester enhanced control when applied after kochia emergence and before wheat seeding. In the 4 post harvest trials eight herbicides, pyrasulfotole/bromoxynil, dicamba, saflufenacil, carfentrazone-ethyl, fluroxypyr/MCPA ester, glufosinate ammonium, diquat, and diflufenzopyr/dicamba were applied at two different intervals after the planted crop was harvested. While biomass was not affected at these late applications, seed production and viability are being examined to determine if late herbicide application effect could affect fecundity and spread of resistance.  

Wild chervil (Anthriscus sylvestris (L.) Hoffm.) management on Nova Scotia dykes. Beaton E.F.¹, Boyd N.S.², Hoyle J.³, and McLean N.⁴. ^1,2,3Department of Environmental Sciences, Dalhousie Agricultural Campus, Truro, N.S.; ⁴Department of Plant and Animal Sciences, Dalhousie Agricultural Campus, Truro, N.S. 

Wild chervil is an invasive weed that frequently occurs on Nova Scotia dykes causing soil erosion and destabilization.  New management methods are being explored for this weed because current practices, such as mowing in late summer and spot herbicide applications, are no longer effective.  A field screening experiment was conducted in 2011-2012 on a dyke in Masstown, Nova Scotia where herbicide products recommended by DuPont were evaluated for efficacy including the tank mixes: MAT 50 SG (aminocyclopyrachlor)/Escort 60 WG and MAT 50 SG/ Telar 75 DF along with the following herbicides: Milestone, Clearview and Overdrive.  Herbicide treatments were applied once to both trials when plants were in full bloom.  Ground cover measurements and damage ratings were taken throughout the experiment and were used to evaluate the efficacy of these products.  The data collected supports that MAT 50 SG (aminocyclopyrachlor)/Escort 60 WG and Clearview are the most effective herbicides to manage wild chervil on dykes.  Another field experiment was conducted in 2011-2012 on another dyke in Masstown, Nova Scotia where MAT 50 SG (aminocyclopyrachlor)/Escort 60 WG was applied at four different times throughout the summer and fall in 2011.  These times include: when wild chervil was in full bloom, at seed maturity, in early fall, along with an early fall application and a single mowing at full bloom.  Ground cover, damage ratings, and biomass were collected throughout the experiment and were used to evaluate the efficacy of each application time.  Preliminary results suggest that spraying at full bloom is the optimal time to apply MAT 50 SG (aminocyclopyrachlor)/Escort 60 WG.

Japanese knotweed (Fallopia japonica) management: Aminopyralid vs imazapyr applications at various phenological stages. Larsen T.G., Boyd N.S., Nams V.O., and Brewster G. Department of Environmental Science, Faculty of Agriculture, Dalhousie University, Truro, NS

Japanese knotweed is a non-native invasive weed in North America where it readily establishes in riparian areas, dump sites, and along roadways. Its rapid growth causes mono-specific stands of knotweed to proliferate in the newly established range. Management options include pulling, cutting, covering with tarps, and herbicide application, however all methods require a long-term integrated management plan. For this project, herbicide application was studied in terms of type and timing of application. Herbicide was applied at various times throughout the 2011 growing season: early emergence (May); maximum plant growth (July); flowering (August); and prior to senescence (October). All possible combinations of these treatment stages were tested, for a total of 16 different 4 m² plots with three blocks at two sites.  Aminopyralid (Milestone) was applied at early emergence, and imazapyr (Arsenal) was applied to the three other stages. Herbicide efficacy was evaluated over time by measuring damage ratings, height, density, and leaf area index (LAI) at 2, 4, and 8 weeks after treatment. A final damage assessment was conducted the following growing season (June 2012) with the same variables, as well as biomass of each plot. Results suggest that aminopyralid alone did not provide effective control against knotweed the following year, whereas all treatments with imazapyr gave significant control. Furthermore, imazapyr application when the plant was at its maximum growth (July) expressed the most significant damage the following year with reduced density, height, leaf area index, and biomass when compared with other application timings. At the two sites in Nova Scotia, untreated knotweed reached maximum growth (205 cm) in early July, density of 17 shoots per m², and fresh weight of 8.28 kg per m². This biological information allows weed management teams to create effective plans for knotweed control.

Does lentil seeding rate influence mustard response to fluthiacet-methyl?

Colleen Redlick, S.J. Shirtliffe, and C.J. Willenborg

Department of Plant Sciences, University of Saskatchewan, Saskatoon Sk.

In recent years concern over the development of herbicide resistant weeds has lead to interest in integrated weed management systems. These systems seek to relieve selection pressure for herbicide resistance by utilizing mechanical and cultural controls in addition to herbicides. The cultural practice of increasing crop seeding rate has been identified as having potential to provide non-chemical weed control and enhance the effects of herbicide application. The objective of this study was to examine the interaction between increasing seeding rate and the dose response relationship of weeds to herbicide application. Lentil was chosen to represent the crop, with wild mustard as the weed, and fluthiacet-methyl the herbicide. The experiment was a factorial design with four levels of seeding rate (70, 140, 280, and 560 seeds m^-2) and seven levels of herbicide application rate (0, 0.94, 1.87, 3.75, 7.5, 15, and 30 g ai ha^-1). The study was conducted at two locations near Saskatoon, Sk. in 2012. Results of the experiment show that increasing lentil seeding rate decreased the total mustard biomass when herbicides were not applied or were applied at low rates. In addition increasing lentil seeding rate lowered the herbicide dose required to result in a 50% reduction in mustard biomass. These results suggest that the practice of increasing seeding rate can work with herbicide application to increase herbicide efficacy.

Early season weed control in maize is essential to protect yield potential. The presence of uncontrolled weed seedlings is known to trigger a shade avoidance response in maize seedlings. This response has been observed to delay in reproductive development and a subsequent decline in kernel number. Such changes in reproductive development and kernel number may limit the ability of a maize hybrid to express novel traits such as drought tolerance. In this study, we hypothesized that if weed control was delayed, an increase in the anthesis-to-silking interval (ASI) would occur in both a drought tolerant and non-drought tolerant maize hybrid compared to these hybrids growing under weed free conditions. In order to test this hypothesis, we compared a drought tolerant hybrid with its non-drought tolerant isoline. Field studies were conducted over two years at the Ridgetown Campus (2011 and 2012) and one year at the Woodstock Research Station (2012).Weed control treatments included a season long weedy and weed-free treatment, and weed removal at the 1^st, 3^rd, 5^th, 7^th and 10^th leaf tip stage of maize development. No differences were observed in height or rate of leaf appearance in either of the two years of study. ASI was found to be shorter in the drought tolerant hybrid when compared to the non-drought tolerant hybrid across all treatments. A delay in weed control, however, increased ASI and kernel number loss for both hybrids. No difference in final yield was observed between hybrids in 2011. The lengthening of ASI caused by delayed weed control may limit the effectiveness of the drought tolerant trait. Further studies are required to confirm this result.

Germination behaviors of common ragweed (Ambrosia artemisiifolia L.) and other roadside ground cover species subjected to a range of heavy metal levels. Jichul Bae¹, Diane L. Benoit², Alan K. Watson¹. ¹ Department of Plant Science, McGill University (Macdonald Campus), Ste. Anne de Bellevue, QC; ² Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu, QC

Common ragweed (Ambrosia artemisiifolia L.) is not only a noxious agricultural weed, but also the most prevalent allergenic weed in Canada. As one of the most common invasive species along roadside, A. artemisiifolia particularly forms dense linear populations within the first few meters of a roadside. The roadside population of common ragweed serves as the means of entry into urban settings and agriculture fields. Identifying potential mechanisms to explain the prevalence of common ragweed along roadside can help in controlling this problematic weed and preventing its dispersal. Roadside environments often receive deposits of anthropogenic sources of heavy metals at concentrations toxic to plants via atmospheric fallouts and road runoff. Given that seed germination and seedling growth occur on the surface soil, the successful establishment and colonization along roadsides are probably dependent on species’ capacity to tolerate heavy metal contamination. Such ability may afford the species a competitive advantage over other neighboring species. A research project was set up to investigate germination behaviors of common ragweed (Ambrosia artemisiifolia L.), and common roadside ground cover legume species (Coronilla varia L., Lotus corniculatus L., and Trifolium arvense L.) exposed to a range of heavy metal levels. Lead (Pb), copper (Cu), nickel (Ni), zinc (Zn), and cadmium (Cd) were evaluated because they are the most common metal elements found in roadside soils. The concentrations of heavy metal were determined based on the background values in soils in southern Québec (0 – 50 – 100 – 200 ppm for Zn, Pb, Ni, and Cu, and 0 – 5 – 10 ppm for Cd). Single seeds of each species were germinated on agar media with selected heavy metal treatments in the growth chamber (6 replicates of 25 seeds/replicate/species-heavy metal combination). Germination behaviors (T₅₀: germination rate and TG: final germination percentage) were monitored over 2 weeks. All heavy metal treatments did not induce any inhibitory effects on TG of A. artemisiifolia. There was no significant delay in germination of A. artemisiifolia by heavy metal exposures except for Cu treatment. The degree to delay in germination by Cu was the lowest in A. artemisiifolia, suggesting the species was more tolerant to Cu than other test species. The germination rate (T₅₀) of A. artemisiifolia was promoted by Pb (at 50 and 200 ppm) and Ni (at 50 ppm), suggesting its adaptation to contaminated environments. As heavy metal concentration increases, decreases in TG and increases in T₅₀ of other species were observed with varying threshold level for each species and heavy metal types. The degree of tolerance to the selected heavy metals was as follow: A. artemisiifolia > L. corniculatus ≥ C. varia > T. arvense. Given that seed stage is very sensitive to external environmental stress, the present research is of value to outline the potential mechanisms that may drive the successful establishment of A. artemisiifolia along roadside. It provides insight on appropriate roadside vegetation and soil management practices for controlling common ragweed.

To meet a current production goal of 15 million tonnes by the year 2015, canola will have to be grown on a greater amount of land and at a higher frequency in the rotation. Historically, both the frequency of canola in the rotation and the land base that it is grown on have been increasing. It is unclear if and how these changes to western Canadian crop rotations have affected the weed community. Therefore, the objective of this study was to look at the effects of herbicide system and frequency of canola (in the rotation) on weed communities found in the canola producing regions of western Canada. Data was collected from the Prairie Weed Survey in 1990’s and 2000’s, Manitoba canola frequency survey (1998-2003), and Alberta irrigation survey (2009). Data was evaluated based on cropping history, canola variety and herbicide usage. Fields were surveyed after in-crop weed control had occurred to represent residual weed populations. Data was also collected in a field trial at Lethbridge and Lacombe in the summer of 2011 and 2012. Weed counts were performed both pre and post herbicide application, which was then used to compare against the weed survey results. Treatments in the field trial consisted of two different canola varieties (LL150, RR73-45) and three rotations using canola, wheat, peas and barley (C-C, C-W, C-B-P). Redundancy analysis (RDA) was used to determine whether weed species were significantly correlated with management systems. Results from the weed survey data showed an association of chickweed (Stellaria media (L.) Yill), green foxtail (Setaria viridis (L.) Beauv), wild oat (Avena fatua (L.)) and wheat (Triticum aestivum (L.)) with different management systems. Results from the field trial showed that volunteer canola was, not surprisingly, the most common weed associated with continuous canola. Interestingly, the majority of weed species were actually associated with the C-W rotation. 

Evaluating the competitive ability of semi-leafless field pea cultivars. Jacob, C.E.¹, Lawless, M.E.¹, Dyck, M.², Shirtliffe, S.J.¹, Warkentin, T.¹, and Willenborg, C.J.^{1 1}Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK; ²Department of Renewable Resources, University of Alberta, Edmonton, AB

Field pea (Pisum sativum L.) is an important grain legume in Western Canada. Growers can, however, be reluctant to include pulse crops in their rotation because they are poor competitors with weeds. Developing more competitive field pea cultivars is important to ameliorate weed competition. The identification of competitive cultivars and the traits conferring competitive ability should lead to the development of more competitive field pea cultivars. The objective of this research was to evaluate the ability of semi-leafless field pea cultivars to suppress and withstand weed competition and to identify traits that may confer competitive ability in field pea. Field experiments were conducted in 2012 at Floral, Saskatchewan and St. Albert, Alberta. Fourteen semi-leafless field pea cultivars with divergent pedigree, vine length, seed size, and market classes were seeded at a target density of 75 plants m^-2 under weedy and weed-free conditions. Imidazolinone-tolerant wheat (c.v. CDC Imagine) and canola (c.v. 45H73) were planted as pseudo weeds at a target density of 20 plants m^-2 in the weedy plots. Variables measured were leaf area index, plant height, pea biomass, weed biomass, pea yield, and weed seed production. Data were subjected to ANOVA using the mixed model procedure in SAS. There was a cultivar by treatment interaction for pea yield at Floral with Striker producing the greatest pea yield under weed competition and CDC Dakota producing the greatest pea yield under no weed competition. CDC Dakota produced the greatest pea biomass at Floral and was among the best at St. Albert; Striker followed with the next greatest pea biomass at both sites. However, Striker and CDC Dakota were among the best and intermediate in their weed suppressive ability compared to CDC Mozart, SW Midas, and CDC Sage, which were among the best for weed suppressive ability across both sites.

Field trials were conducted over a three-year period (2010 - 2012) at various locations in Southwestern Ontario, Canada to compare various two-pass weed management strategies in glyphosate-tolerant corn for weed control, crop injury, corn yield, environmental impact and profit margin. No visible injury resulted from the herbicide treatments evaluated.  One early postemergence application of glyphosate provided good full season control of pigweed species and lady’s thumb and fair control of velvetleaf, common ragweed, lambsquarters, barnyard grass and green foxtail. Glyphosate (LPOST) provided excellent control of all the weed species evaluated but corn yield was reduced due to early weed interference. The sequential application of glyphosate (EPOST fb LPOST) provided excellent control of all weed species evaluated with no adverse effect on corn yield. The sequential application of a preemergence herbicide followed by an application of glyphosate LPOST (at 6-8 leaf stage) provided excellent full season control of all the weed species evaluated and corn yield was equal to the weed free control. Among the sequential programs the lowest environmental impact was glyphosate EPOST fb LPOST and saflufenacil/dimethenamid-p, isoxaflutole + atrazine and rimsulfuron + s-metolachlor + dicamba applied PRE fb glyphosate LPOST. Based on this study, the most efficacious and profitable weed management programs in glyphosate-resistant corn are a sequential application of glyphosate or a two-pass program of a preemergence herbicide followed by glyphosate LPOST. The two-pass programs have glyphosate stewardship benefits.

Early physiological mechanisms that occur in crop plants in response to neighboring weeds are not well understood. In this experiment, it was hypothesized that, in the absence of direct competition for resources, low red to far red ratio (R:FR) reflected from neighboring weeds will modulate the phenylpropanoid pathway, increase hydrogen peroxide (H₂O₂)_, and up-regulate the expression of ethylene biosynthesis and auxin transport genes. Laboratory experiments were conducted under conditions of non-limiting resources using perennial ryegrass as a model weed species. We discovered that the detection by phytochrome of low R:FR signals reflected from both biological and non-biological sources triggered an up-regulation of ethylene biosynthesis genes and stimulated an auxin transport gene. The low R:FR also modulated the phenylpropanoid pathway resulting in a reduction in anthocyanin content and an enhancement of lignin synthesis. The presence of neighboring weeds also caused an accumulation of H₂O₂ in the first leaf and crown root tissues of the maize seedling. Stomata were observed to be closed as H₂O₂ accumulated in leaf tissue. This is the first study to report the modulation of phenylpropanoid pathway and the accumulation of H₂O₂ attributed to low R:FR. We further suggest that these physiological changes which occur in response to early weed competition, result in a physiological cost to the crop plant, which contributes to the rapid loss in yield observed in weed competition studies conducted under field conditions.

Thiamethoxam, is a broad-spectrum neonicotinoid insecticide which when applied to seed, has been observed to enhance seedling vigour under environmental stress conditions. Stress created by the presence of neighbouring weeds is known to trigger the accumulation of hydrogen peroxide (H₂O₂) in maize seedling tissue. No previous work has explored the effect of thiamethoixam as a seed treatment on the physiological response of maize seedlings emerging in the presence of neighbouring weeds.  In this study, we hypothesized that the enhancement in seedlings vigour reported in seedlings emerging from seeds treated with thiamethoxam is the result of a reduction in H₂O₂ accumulation. We further hypothesized that the mode of action of thiamethoxam involves the alteration of gene expression linked to anthocyanin biosynthesis pathway and antioxidant scavenging genes. In this study, thiamethoxam was found to enhance seedling vigour and to overcome the expression of typical shade avoidance characteristics in the presence of neighbouring weeds. These results were attributed to an increase in seed germination, the maintenance of anthocayanin content, and the activation of scavenging genes which reduced the accumulation of H₂O₂ in maize seedling tissues. These results suggest the possibility of new chemistries and modes of action be explored as novel seed treatments to up-regulate free radical scavenging genes and to maintain the antioxidant system within plants. Such an approach may provide an opportunity to enhance crop competitiveness with weeds.

Decreasing the particle size of herbicides can influence biological activity in several ways including improved cuticular penetration and stomatal uptake.  Decreased particle size can also result in improved coverage on the leaf surface.  The combination of these effects can improve efficacy of herbicides at lower rates.  The objective of this research was to compare the standard (Excel Super, 80.5 gai/L EC) and nano (37% WP) formulations of fenoxaprop-p-ethyl for the control of selected annual monocot species.  Species selected included green foxtail (Setaria viridis) , corn (Zea mays)) and oat (Avena sativa).  These species were selected based on known susceptibility to fenoxaprop-p-ethyl with green foxtail the most susceptible, corn, (moderate susceptibility) and oat being the most tolerant of the three species tested.  The nano formulation of fenoxaprop-p-ethyl had greater efficacy consistently on green foxtail and corn than the standard formulation. For green foxtail and corn, the dose required of the nano formulation to reduce plant biomass by 50 % (GR₅₀) was approximately 50% of the commercial formulation of fenoxaprop-p-ethyl.   In addition, the nano-formulated fenoxaprop-p-methyl was equal to or better for the control of the more tolerant oat species compared to the standard commercial formulation.

 
Development of the Enlist Weed Control System for corn and soybean. McFadden, A.G. Dow AgroSciences Canada Inc. Guelph, ON
The Enlist Weed Control System provides effective broader spectrum weed control of hard-to-control and glyphosate resistant weeds in corn and soybeans. This system will give growers the tools to maintain current tillage systems by combining the power of 2,4-D with other leading weed control programs.  The Enlist Weed Control System exhibits robust crop tolerance in both corn and soybean. The system will be introduced with a comprehensive Product Stewardship Program.

New Brunswick Report to the CWSS/SMC

Gavin Graham

New Brunswick Department of Agriculture, Aquaculture and Fisheries

gavin.graham@gnb.ca

November 2012 

Legislation

Plant Health Act - http://laws.gnb.ca/en/ShowPdf/cs/2011-C.204.pdf

No pests named and no plans on naming any weeds as pests at this time.

Invasive Plants

New Brunswick Invasive Species Council (www.nbisc.ca) was active in 2012 through volunteer time. One project was the creation of a field guide for the identification of invasive plants during the annual highway cleanup program. Guides were printed and available on the website (www.nbisc.ca/images/field_guide_en.pdf), although no formal training offered to groups yet. New reports of dog strangling vine in Northern region of province in addition to increased public awareness to giant hogweed and angelica.

Weather/Crop Reports

In 2012, New Brunswick experienced an early start to spring, with twice the growing degree days from January-April as compared to the 30 year average. This resulted in advanced development of horticultural crops and early planting for field crops. Good growing conditions in May resulted in adequate application windows for early pesticide applications. Drier than normal conditions were common in the summer, although most crops received timely rains. Drier weather contributed to increased reports of herbicide injury, especially within soybean and wild blueberry crop. Overall, crop yields were considered good, aside from a yield reduction in the Southern potato crop due to the dry conditions. 

Potatoes: Sow thistle, lamb’s quarters, pigweeds, chickweed and marsh hedge-nettle reported issues. Poor weed control in general due to poor timing, reduction in top growth due to drought and early crop senescence permitting late season weed development. In need of new chemistry as industry relies on metribuzin and linuron for weed control. One-pass hilling is becoming more common, with more pressure on PRE herbicide. Control of volunteer plants within rotation and potential for herbicide resistance are grower concerns.

Wild blueberry: Concern with increasing populations of hawkweed, spreading dogbane and fescue species. Tank mixing becoming more popular with more questions on safety of non-labelled tank mixes. In need of crop year weed management tools.

Cranberry: Dewberry, burnweed and common reed are reported issues. Growers are rapidly adopting mesotrione as base weed control treatment, with favourable overall performance. Need for alternative weed control products for resistance management.

Field Corn: Acreage increasing. Most RR growers using a residual tank mix or second application for improved control. Application timings remain problematic for some growers.

Soybean: Acreage increasing, growers still learning best practices for this crop. Commercial interest for non-GM types but there are weed control challenges.

Cereals: Sow thistle, volunteer potato and ragweed reported as issues. Options for weed management in underseeded crops required. White cockle starting to increase.

Pastures/hay: Smooth bedstraw largest issue, although triclopyr use can help with control. White cockle becoming more prevalent in some areas.

Strawberries: Groundsel and toadflax remain largest concerns. Need for new herbicide options, especially for the planting year. Handweeding labour becoming harder to access.

Vegetables: Vegetable production static, in need of new herbicide options especially with uncertainty surrounding linuron. Increased interest in CSA programs and more diverse crop variety.

Minor Use

NBDAAF conducted 25 herbicide trials in 2012, mostly in support of Minor Use crops. Specific needs addressed included foramsulfuron in wild blueberry, hawkweed control in wild blueberry, fall glyphosate for lambkill control in wild blueberry, rate/timing for mesotrione in cranberry and screening herbicides for use in potato.

Current minor use gaps include crop year herbicides for wild blueberry production, broadleaf control in cranberry and alternative herbicides for potato production.

New URMULE for fall application of glyphosate for lambkill control in wild blueberry approved in 2012. Proposal to Amend Blueberry Use Pattern for Callisto 480 SC.

Branch/Department and Personnel Updates

Government of NB going through on-going Performance Excellence Process, where the effect on DAAF is still to be determined. Not expecting any reduction in staff in short-term, although replacement of retiring positions is on a case-by-case basis. Website will be undergoing revision in late 2012/early 2013 and web addresses for all material will change. Reduced presence of weed science expertise within the Atlantic region is a challenge.

New/revised fact sheets:

Callisto Use in Cranberry, Strawberry IPM Weed Management Guide, Fall Glyphosate Use for Lambkill Control, Wild Blueberry IPM Weed Management Guide,

Challenges/Research Needs

Additional herbicide screening required in wild blueberry industry, with weed control in the crop year a major need. New herbicide tools are helping weed control within sprout year, but crop year management an increasing gap. Concerns over ticklegrass canopy causing other production issues like increased insect injury and reduced fungicide performance.

Additional weed control tools are required within cranberry industry, especially for broadleaf weeds.

Additional weed control tools for potato production required. Industry is rapidly adopting one-pass hilling system, which places additional pressure on late season weed control with reduced mechanical weed control.

Reduction in weed science expertise within Atlantic region a great concern. Loss of AAFC research station in Bouchtouche further reduces agricultural research capacity in NB.

Plenary Session Topic – Evolution in Action: Changes in Weeds from Crop Domestication to Glyphosate Resistance

Increased industry interest in new crops, especially within bio-energy (grasses) and health benefits (sea buckthorn). Environmental Impact Assessments required for introduction of any new species to New Brunswick. Limited knowledge on new crop introductions can be a barrier on this introduction process. Weed resistance suspected within Group 5 in multiple crops, but no Group 9 resistance suspected at this time.

Ontario Report to the CWSS/SCM

Kristen Callow, M.Sc., Weed Management Program Lead, Horticulture Crops -OMAFRA, kristen.callow@ontario.ca

Mike Cowbrough, Weed Management Program Lead, Field Crops – OMAFRA

mike.cowbrough@ontario.ca

October 10, 2012

Legislation

Weed Control Act – Mike Cowbrough, Chief Inspector  

• Revising noxious weed list (same since 1991)
• Guidelines for Inclusion:
  • Species that negatively affect agricultural production and are difficult to remove once established.
  • Species that are hosts for insect and/or diseases that negatively affect agricultural crop productivity and/or quality.
  • Weeds poisonous to livestock and/or agricultural workers.
• Weed inspectors want a shorter list.  Includes species that clients have asked to be included.  It is complaint driven legislation.
• Short List:

Poison Ivy (Toxicodendron radicans)

Giant Hogweed (Heracleum mantegazzianum)

Wild Parsnip (Pastinaca sativa)

Kudzu (Pueraria lobata)

Dog Strangling Vine (Vincetoxicum nigrum (L.) Moench)

Tansy Ragwort (Senecio jacobeae)

Barberry, Common (Berberis vulgaris)

Buckthorn, European (Rhamnus cathartica L.)

Knapweed spp. (Centaurea spp.)

Sowthistle spp. (Sonchus spp.)

Canada Thistle (Cirsium arvense)

Wild Chervil (Anthriscus sylvestris)

Smooth Bedstraw (Galium mollugo L.)

Ragweed spp. (Ambrosia spp.)

Common Crupina (Crupina vulgaris Cass.)

Jointed goatgrass (Aegilops cylindrical Host)

Serrated Tussock (Nassella trichotoma)

Wolly cup grass (Eriochloa villosa (Thunb.) Kunth)

A meeting is scheduled with the Minister’s office in October to review the proposed list and hopefully give the okay to move forward.  The next step is to present the changes to the Act to cabinet.  The change in legislation may come by 2013.

http://www.search.e-laws.gov.on.ca/en/isysquery/512ce64e-b6e9-4db5-9b3e-3d16d4de741f/1/doc/?search=browseStatutes&context=#hit1

Invasive Plants

The Ontario Invasive Plant Council (OIPC) http://www.ontarioinvasiveplants.ca/ is currently completing best management practices (BMP) for dog strangling vine, garlic mustard and Japanese knotweed.  The OIPC has made available a giant hogweed managers list and a Grow Me Instead guide providing home owners with plant options that look similar to certain invasive species that have been sold at garden centres.  This guide was completed in cooperation with Landscape Ontario in hopes to reduce the number of invasive plants being sold by garden centers and landscape supply companies.   The MNR has released a BMP for invasive Phragmites (common reed).  The Ontario Invasive Species Strategic Plan has been released.  This plan commits to improve coordination within government and seeks stronger collaboration with non-government partners like OIPC to protect our economy and our natural biodiviersity from invasive plant species. Ontario already has more invasive species than any other province and we will continue to see new invasive arrivals in the coming years. A very significant strength of this Plan is that it addresses all invasive species and that it seeks to integrate the government effort.

Kudzu is only known in one location in Canada, near Leamington, Ontario on the shores of Lake Erie.  A Critical Plant Pest Management Committee was developed and is currently determining the feasibility of a removal strategy.  The steering committee includes OMAFRA, OMNR, MTO and CFIA.  There have been no further developments since May 2010.

Efficacy Trials

-          Wild Parsnip - Gilles Quesnel and Mike Cowbrough (OMAFRA)

-          Giant Hogweed – Dr. Francois Tardif and Peter Smith (University of Guelph)        

Minor Use

URMULE registrations to September 12, 2012 – weed management

• Dual Magnum – sweet potatoes; fresh market tomatoes, peanuts [pending final label]
• Goal – Brassica vegetables, SRIC poplar
• Frontier Max – green onions, outdoor ornamentals
• Trophy A + B – winter wheat in Ontario (ragweed, atriplex)
• Ultim + Marksman – field corn E. Can. (horsenettle)
• Aim – grapes, pome fruit, stone fruit, ornamentals (weeds and sucker control)
• Converge Pro – prairie carnation E. Can., seed corn [pending final label]
• Betamix B – strawberries
• Chateau – celery, spearmint, peppermint, tree nuts
• Ignite – tree nuts
• Prowl – snap, lima, adzuki beans
• Distinct – field corn (4 new weed species)
• Poast Ultra – celery
• Aatrex – sorghum
• Muster – rutabaga; Ethiopian mustard [pending final label]
• Sencor – fresh market tomatoes
• Prism – field tomatoes, rate increase
• Callisto – sod turf, cranberries [rate increase]
• Marksman – field corn E. Can. (3 new weed species)
• Gesagard – celeriac
• Roundup - camelina
• Garlon – xmas trees
• Assure – crop group 9, field cucurbits; Ethiopian mustard, clover for seed
• Command – peppers [pending final label]
• Frontline – timothy for hay and seed [pending final label]
• Simplicity – wheatgrass [pending final label]

Active URMULE projects underway – weed management

• 2, 4-D – highbush blueberries, giant ragweed on soybeans
• Aim - hops
• Alion - raspberry
• Ally – dandelion on timothy
• Assert – borage
• Assure – hemp, Saskatoon berries, faba beans
• Basagran + Solo – dry beans, dry peas (W. Canada)
• Blazer – carrots
• Buctril M - switchgrass
• Callisto – rhubarb, sorghum, millet, grapes, asparagus, flax (E. Can)
• Casoran – berry crop group
• Chateau – caneberries, broccoli, sweet potatoes
• Command – asparagus
• Dacthal – ginseng
• Dual II Magnum – grapes, pearl millet, leaf lettuce, celery, parsnip, Asian radish
• Eptam – dry beans
• Eragon – giant ragweed on oats in E. Cda & soybeans; resistant weeds on labelled crops
• Etho – sod turf (Poa annua control)
• Everest – caraway
• Express – timothy, bromegrass, fescue
• First Rate – giant ragweed on soybeans
• Florel – Poa annua on golf green turf, GH tomatoes
• Frontier Max – Brassica crop group, grapes
• Gallery - grapes
• Gesagard – parsley
• Goal – highbush blueberries, seedling conifers
• Heat – chickpeas, alfalfa, clover (dessicant), bromegrass
• Ignite - strawberries
• Infinity – durum wheat (E. Cda)
• Lontrel – durum wheat (E. Cda), willow [SRIC]         
• Lorox – leeks, poplar [SRIC]
• Nortron – carrots, red beets
• Odyssey – faba beans
• Option – lowbush blueberries
• Peak + Pardner – wild carrot on winter wheat
• Poast Ultra – grapes, fenugreek, blueberries (reduce PHI), potato (reduce PHI)
• Prestige – foxtail millet
• Princep Nine-T – tree nuts
• Prism – highbush blueberry
• Prowl – ornamentals, leeks, green onions, dry beans, pearl millet, carrots, shallots, garlic
• Puma Advance – perennial ryegrass, durum wheat (E. Cda)
• Pursuit – fenugreek
• Reflex – cucumber, potatoes
• Sandea – caneberries
• Scythe – outdoor ornamentals (liverwort)
• Select/Centurion – red beets, parsnips, herb crop group, buckwheat, safflower, cranberry, prairie carnation, cherries
• Sencor – carrots, potato (reduce PHI)
• Sulfentrazone – chickpeas, strawberries, asparagus, oilseed mustard
• TopFlor – GH ornamentals (growth regulation)
• Venture – lettuce

For summaries of minor use crop registrations, priorities and active projects visit:  http://www.omafra.gov.on.ca/english/crops/minoruse/index.html

A number of new potential joint with U.S. IR-4 minor use projects for weed science were nominated for review at the 2012 IR-4 food use workshop.  The problem is that the PMC may only be able to do 10 joint projects, last year they did 23.  There was a concern that with the change to Crop Groupings from Discipline based prioritizing that weed science priorities would be minimized; however, this was not the case.  Weed science had the most priorities at the IR-4 meeting.

OMAFRA submitted a response to the PMRA proposed re-evaluation decision documents on amitrol and linuron.

Minor Use Projects

1. Tree nut nursery (Hazelnut) established at Harrow AAFC to conduct herbicide tolerance and efficacy work (New Directions Funding).
2. Sweet potato / chateau herbicide tolerance and efficacy work completed.  This information has been provided for URMULE D.3.1: 2011-0060 (Farm Innovation Program).
3. Determining the Extent and Mechanism of Resistant Weed Species in Ontario and Quebec Carrot and Onion Producing Regions.  This project is 70% complete with an A priority achieved a the National Minor Use Prioritizing meeting in March 2012 for solutions Blazer and Goal 2XL (CAAP Funding).
4. Management and Prevention of Herbicide Resistant Weeds in Vegetables with Alternate Modes of Action.  This project evaluated candidate herbicides for either a) control of herbicide-resistant weeds, or b) prevention of development of herbicide resistance through adoption of alternative modes-of-action in carrot and tomato.  The specific intent of this research is to find alternate modes-of-action to control Group 1 resistant crabgrass (Farm Innovation Program Funding).

Branch/Department and Personnel Updates

Personnel Updates:

OMAFRA, Agriculture Development Branch has a new Director, Scott Duff and a new Deputy Minister, Karen Chan.

Website Updates:

Ontario Crop IPM – (Callow)

• New herbicide injury photos added
• Twelve new weed species added

Ontarioweeds.com and weedpro75.com – (Cowbrough)

• Mobile versions updated in 2012
• Efficacy data and photos updated in 2012

Guide to Weed Control: Publication 75 (Callow/Cowbrough)

• Updates will be provided directly on the online pdf.  Changes and additions will be made very apparent to the viewer.

Challenges/Research Needs

With the increasingly complex issues surrounding herbicide resistant weed species, new genetically engineered crops with staked genes for multiple herbicide resistance, the cosmetic pesticide ban and invasive species there is an immense need for a great deal more publicly funded weed related research.

Given the constraints on the registration of herbicides in horticulture / specialty / minor crops, the increasing limits on the use of fumigants, the impact of herbicide resistant crops on the development of herbicide resistant weeds and drift to highly sensitive horticulture crops, what are the options for weed scientists to pursue, in order to create, develop and manage new weed control tools?  Should research focus on development of competition models and decision thresholds?  As energy and labour costs continue to rise should scientists focus on weed removal tools such as robotics? Should more work be done with conventional breeding for herbicide tolerance in horticulture crops? Given that horticulture / specialty / minor crops are worth more than half of the total value of all Ontario agriculture why are weed management programs for these crops far less efficient than for field crops?  What funding sources are available for horticulture / specialty / minor crop weed scientists?

Plenary Session Topic: Evolution in Action: Changes in Weeds from Crop Domestication to Glyphosate Resistance

Newest Case of Resistance: Large crabgrass from onion and carrot fields has been found to be cross resistant to all Group 1 grass herbicides (fops and dims): quizalofop (Assure), fenoxaprop (Acclaim, Excel), fluazifop (Venture), clethodim (Select), sethoxydim (Poast).  There are no immediate solutions to this problem.  This is the first case in Canada.  There are other cases of crabgrass resistance to group 1 in the USA and Australia.

Linuron Resistant Pigweed Project: 85% of carrot fields sampled in 2011 had resistant populations.  Further testing is underway to test for cross resistance [metribuzin (Sencor), bentazon (Basagran), flumioxazin (Chateau)].

Glyphosate Resistance (GR): There are three species with resistance to glyphosate in Ontario, giant ragweed since 2008 (71 location), Canada fleabane since 2010 (84 total locations) and common ragweed (1 location).

• Glyphosate resistant giant ragweed has been confirmed in Essex, Kent, Lambton and Lennox Addington counties.  Three of these sites have confirmed multiple resistance to Group 9 and Group 2 (cloransulam).
• Glyphosate resistant Canada fleabane has been confirmed in Essex, Kent, Lambton, Elgin and Niagara counties.  Five of these sites have confirmed multiple resistance to Group 9 and Group 2 (cloransulam).
• Glyphosate resistant common ragweed has been confirmed in Essex county.

Complete Listing of Herbicide Resistant Weeds in Ontario

            Download table here or click on the link below:

http://fieldcropnews.com/wp-content/uploads/2012/10/Herbicide-Resistant-Weeds-in-Ontario-2012.pdf

Provincial/Regulatory Report for British Columbia

CWSS/SMC

November 14^th, 2012 Winnipeg, MB

Respectfully Submitted by

David Ralph, Invasive Plant Program,

Ministry of Forests, Lands and Natural Resource Operations,

David.Ralph@gov.bc.ca

Legislation

The BC Weed Control Act has not undergone any revisions for many years and there are no immediate plans for such.

http://www.bclaws.ca/EPLibraries/bclaws_new/document/ID/freeside/00_96487_01

The BC Weed Control Act Regulations was revised July 21, 2011 with the addition of 20 species to Schedule A, Part I, Provincial Weeds. http://www.bclaws.ca/EPLibraries/bclaws_new/document/ID/freeside/10_66_85

Since 2010, a Regulations review has been underway to develop new updated weed lists proposing three weed list categories. The current Regulation has two categories, Provincial and Regional, while the revisions propose three categories, Prohibited, Restricted Provincial and Restricted regional. The list revisions are almost complete.

Revisions to the content portion of the Regulations, such as: Definitions, Designation, Notice to Control, Transportation restrictions, etc, are currently being developed and revised with completion expected in 2013.

In addition to the Weed Control Act and Regulation other provincial legislation pertaining to weed or invasive plant legislation currently exists in BC.

The Forest, Range and Protection Act, Sec 47:

http://www.bclaws.ca/EPLibraries/bclaws_new/document/ID/freeside/00_02069_01

The Forest and Range Practices Act, Invasive Plants Regulation:

http://www.bclaws.ca/EPLibraries/bclaws_new/document/ID/freeside/18_18_2004

The Community Charter, Spheres of Concurrent Jurisdiction, Environmental and Wildlife Regulation:  

http://www.bclaws.ca/EPLibraries/bclaws_new/document/ID/freeside/41_144_2004

Planning is underway to harmonize the lists species lists of all invasive plants legislation in BC to reference the Weed Control Act Regulation.

In addition, BC is investigating harmonization of BC legislation that pertains to all invasive species.

Invasive Plants

Invasive Plant Program, Ministry Forests, Lands & Natural Resource Operations (FLNRO): is responsible for the Weed Control Act and Forest and Range Practices Act.

FLNRO initiated a provincial Early Detection Rapid Response (EDRR) Program in 2012 along with the appointment of a Provincial EDRR Coordinator. In 2012 historical and current reports of listed EDRR species in BC were acted on to verify species and site reports. Verification of sites is ongoing and accomplished by FLNRO Invasive Plant Specialists and Coordinators and staff from Regional Weed Committees across BC. Follow-up to confirmation of species is immediate management (chemical, cultural, mechanical) by occupier, with assistance available from FLNRO and local IP programs with the goal of eradication. These EDRR species and sites are of the highest priority in BC.

All invasive plant site records and information, including management applications and monitoring, are entered into the provincial Invasive Alien Plant Database, which houses all IP records for BC.

Approximately 90% of lands in BC are Crown lands and are the responsibility of FLNRO. Crown land IP management by FLNRO is accomplished through contracts to private contractors to carry out management which is predominately herbicide applications. Regional Weed Committees (RC’s) or local governments are also contracted to manage IP’s on crown land through Operational Grants. In addition, RC’s and local governments involved in a weed function are eligible for administrative grants to assist in operational costs. In 2012, FLNRO distributed $1.72 million in Operational and Administrative Grants to RC’s and local governments. This does not include the cost of other contracts for crown land management.

BC Inter-Ministry Invasive Species Working Group (IMISWG) is responsible for developing a strategic and collaborative approach to invasive species management among government and other partners in BC.

http://www.for.gov.bc.ca/hra/invasive-species/index.htm

Member Ministries include: Agriculture, FLNRO, Transportation and Infrastructure, Energy and Mines, Environment and other Provincial Authorities.

Regional Weed Committees (RWC) and Local Governments (LG)  

http://www.bcinvasives.ca/general/regional-committees

Twenty eight regional committees or local government programs ultimately offer coverage of the entire province. RC and LG programs carry out a variety of functions from merely education and awareness to partnership delivery which can encompass education, coordination, inventory, mapping, addressing complaints, on-ground management of public lands. Many RC’s only carry out a few of these functions and only LG’s are empowered to implement the WCA or local IP by-law legislation. Some RC’s are changing their name and diversifying their focus to invasive species over the past year. This seems the trend in BC.

Invasive Plant Council of BC formally changed its’ name to the Invasive Species Council of BC (ISCBC) http://www.bcinvasives.ca/  at their AGM in January 2012. The ISCBC is involved in province wide programs that are predominately rolled out through RC’s or LG’s in a partnership approach. In 2012, the ISCBC received $3 million from the Province of BC to carry out a “Take Action Program”. http://www.bcinvasives.ca/programs/take-action

This is a two-year employment program that will apply the principles of social marketing to encourage behaviour change related to invasive species in BC. The key focus for Take Action teams is to work with local community members to stop the introduction and spread of invasive species. The first phase of this program in 2012 is focused on aquatic environments working with boaters and outdoor recreationists to "CLEAN-DRAIN-DRY" boats and equipment to prevent the spread of aquatic invasive species in BC.

Phase Two will be a “Horticulture Program” which is currently in the development phase and will be implemented in 2013.

Primary invasive species in BC are the proposed BC Prohibited Noxious Weed List, and candidates for the BC EDRR Program:

http://www.for.gov.bc.ca/hra/invasive-species/Proposed_Prohibited_Noxious_weeds_Feb2012.pdf

Weather/Crop Reports

Weather

After a wetter than normal spring and early summer across most of British Columbia, dry conditions have prevailed since early to mid-July. Cumulative rainfall since August has been very limited across most of the province, with record dry conditions through August and September in a number of areas. Regions with particularly dry conditions include the South Coast, Vancouver Island, and Peace regions.

Due to large snowpack’s and heavy rain through the snow melt period this year, larger rivers and rivers draining high elevation terrain are generally flowing at near normal levels for this time of year. This includes the Kootenay, Columbia, Central Coast and most areas in the Central Interior.

With on-going extreme dry conditions and historic low flows, areas of the East Peace Region are currently at a Level 4 Drought (Extremely Dry).  Level 2 Drought (Dry) conditions are present in the remainder of the Peace Region, the Middle Fraser, Nicola, South Coast & Vancouver Island. Other areas of the province remain at Drought Level 1.

Information on Drought in BC is available at:  http://www.livingwatersmart.ca/drought/.

Cool, wet spring in most areas of the province held up weed control opportunities in the earlier parts of the growing season.

Crop Production

South Coastal Region

A cold and wet spring and summer resulted in late planting and slow growth on vegetable and silage corn crops. August through early October was dry providing good harvest conditions for root crops and silage corn. Strawberry and raspberry production suffered from a late growing season. Blueberries production was not as impacted by weather, but Drosophila fly is an increasing problem.

Vancouver Island

Slower growing and less competitive forage crops, as a result from the spring weather, resulted in increased weed growth resulting in increased crop competition. Non-native, invasive horticultural species (Daphne, Lamium, Spurge) escapes (deliberate and accidental) are a concern in Vancouver Islands’ natural areas. Japanese and other knotweed species, along with yellow flag Iris, are concerns in riparian areas,

Central and Thompson Okanagan Regions

Tree fruit, vegetable and vine crop production was impacted by the wet spring and early summer from increased fungal and disease infections resulting in increased crop culls, especially with tree fruits. Drosophila fly is increasing this region.

Kootenay Region

Wetter, cooler spring and early summer brought similar crop growing conditions as was seen in the rest of the central and southern provincial regions. Late seeding, reduced opportunity for weed control windows and increased weed competition in crops early in the season with forage yields reaching normal after a drier, warmer summer and fall.

Peace Region

Unlike most of BC this year, this region received optimum spring weather followed by a wet June. Warm and dry July to September resulted in good seeding weather and growth season, drought stress in August with harvest conditions and yields normal to good in fall.

Minor Use

In early March 2012 the B.C. Ministry of Environment submitted two emergency registration applications to PMRA for the purpose of controlling and eradicating invasive Spartina (cordgrass) located in tidal areas along the B.C. Coast. The applications were for glyphosate (Rodeo) and imazapyr (Habitat). Since application submission, additional information was provided on request, including pre-submission applications for Habitat and Rodeo, clarification as to the emergency of the application and intended use, and a well documented timeline of our engagement with PMRA and other federal and provincial agencies to determine the appropriate registration approach and provide project notification. Letters of acknowledgement and/or support were provided by all involved federal and provincial land managers in the original applications. Two pre-submission requests were submitted late March 2012 and received early April. As of Sept. 25, no response on the applications had been received. Delay of application approval has set back treatment of Spartina to 2013. Treatment sites are projected to increase 10 fold by 2013.

This is a collaborative project with FLNRO, Ducks Unlimited, MoE and the Spartina Working Group.

Branch/Department and Personnel Updates

The FLNRO Invasive Plant Program is in the Range Branch with staffing of: Program Manager, 5 IP Specialists (1 vacant), EDRR Coordinator, GIS/Mapping Technician, Inter-Ministry Coordinator, BioControl Specialist and 2 Biocontrol Technicians.

http://www.for.gov.bc.ca/hra/Plants/index.htm  

EDRR program and WCA Regulations revision are the highest priority for BC in 2012/13. This program team is responsible for crown lands IP management in the entire province, which encompass approximately 90% of BC’s land base.

The FLNRO IP Program also administers the Invasive Alien Plant Program (IAPP)

http://www.for.gov.bc.ca/hra/plants/application.htm

The IAPP is the database for invasive plant data in BC. It is intended to co-ordinate/share information generated by various agencies and non-government organizations involved in invasive plant management.

The IP Biological Control Program also resides in the FLNRO IP Program.

http://www.for.gov.bc.ca/hra/plants/biocontrol/index.htm

Extension is primarily carried out by Regional Weed Committees and the Invasive Species Council in the form of Best Management Practices, Factsheets and Weed Alerts. Provincial IP Specialists assist in their development through technical advice and editing of publications and information.

Challenges/Research Needs

Stable, consistent funding for IP management programs is an ongoing need in all of BC’s IP Programs. The ISCBC is working to develop a Trust Fund for invasive plant projects to assist in the costs of IP education and awareness program materials, as well as, other initiatives.

On – ground management of IP’s in BC is the responsibility of the land occupier, so provincial funding for management is the prime source for funds on crown land, which encompasses most of BC’s land base. Therefore, it is the province that funds the vast majority of on-ground management in BC.

For the majority of invasive plant species in BC, research needs are typically in the form of new or improved methods of control. Long term management methods are a necessity for IP management in BC, as many of our priority species are perennial, aggressive in nature, found in very remote locations, difficult to access and expensive to tend to each year.

More work is required in tank-mix options that result in residual control, for a variety of species that are proving difficult to control for longer periods.

Knotweed species are a major concern in riparian areas, especially in the coastal, wet zones and regions of BC. Lack of effective management options along water edges and in riparian zones is a hurdle to reducing and eliminating knotweed sites in these areas. It is expensive to continually suppress knotweed in these areas, with no effective eradication possible and the concern over these un-treatable sites becoming a source of further spread to surrounding areas.

Plenary Session Topic

Weed resistance is a growing concern in the Peace and other regions of pulse, oilseed and cereal crop production. Increased awareness and education is necessary to: outline the management techniques that result in resistance; identify the signs of potential or established resistance and imparting management techniques to producers that help them to prevent or eliminate resistance. More workshops and field days would assist in resistance management and would be of benefit to agricultural producers.

Alberta Report to the CWSS/SMC

Chris Neeser, Alberta Agriculture and Rural Development, chris.neeser@gov.ab.ca

Oct. 2012

Legislation

Two years after the proclamation of the new Alberta Weed Control Act we now have broad awareness of the species listed. The Department will continue to provide weed identification training at the beginning of the season, as many weed inspectors are hired on seasonal basis and are often new to the job.  There are still issues insofar as the consistency of enforcement between jurisdictions is concerned, but progress is being made.

We continue to assist municipalities with weed identification at no charge.  Plans are in the works to establish a diagnostic center that will take care of such requests in the future.

The species of greatest concern at this time are the non-native hawkweeds (orange, yellow, and mouse-ear hawkweeds), which are regulated under the prohibited noxious category, but are now far more widespread than originally estimated.  Furthermore, a number of infestations of yellow devil hawkweed (Hieracium glomeratum) and tall hawkweed (Hieracium piloselloides) have been found in Alberta for the first time this year.  These species are considered as much a threat as the ones currently regulated. Therefore discussions are underway to determine the most appropriate course of action.

Alberta Invasive Plants Council

The Alberta Invasive Plants Council, which was created in 2004 and has played a major role in promoting awareness of threats posed by invasive plants, has had a very difficult year following the termination of the Invasive Alien Species Partnership Program last April.  Efforts are underway to secure funding to resume activities, including the completion of a project to set up EDDMaps (www.EDDMaps.org/Alberta) for Alberta, to collaborate on Ox-eye daisy and tansy bio-control, and to further coordinate the development of Cooperative Weed Management Groups.

Government of Alberta Interdepartmental Invasive Alien Species Working Group

The Interdepartmental Alien Species Working Group has put forward proposals to senior management to create a position for an Early Detection Rapid Response Coordinator and to establish an Invasive Species Sustainable Trust Fund along the lines of what the State of Montana has put in place.

Weather/Crop Reports

Harvest was virtually complete by early October. Yields were average to slightly above average, which was somewhat of a disappointment given the very promising conditions in June and early July.  It appears that the relatively hot weather in later on in July and August, caused significantly more damage than what was originally anticipated, possibly due to crops being shallow rooted. Crop quality was generally good with 94% of the HRS wheat and 99% of the durum grading in the top 3 grades, 80% of the barley should grade 1 CW or higher and 70% of the field pea crop should be of food quality. The exception is canola with only 81% grading 1-Canada, primarily due to green seed. The complete version of the October Crop Report is available here:

http://www1.agric.gov.ab.ca/$Department/deptdocs.nsf/All/webdoc14122

Minor Use

Label extensions obtained in 2012

Ongoing projects

Concerns:

Pulse crops: Insufficient post-emergence broadleaf control options.

Mint:   Control of pigweed in established fields. 

Branch/Department and Personnel Updates

The Pest Surveillance Branch is developing a new website dedicated specifically to weeds with the emphasis on mapping and monitoring (www.agriculture.alberta.ca/weeds).  Results from the 2009-2010 weed survey are now posted.  Plans for this site include interactive maps of regulated weeds on a township grid, which we hope to have ready by the fall of 2013. 

We published a series of four posters to help with the identification of regulated weeds.  These posters can be downloaded from the same website.  There is also a weed identification guide produced by Wheatland County, which has been very popular. 

Challenges/Research Needs

Glyphosate resistant kochia

As glyphosate resistant kochia will continue to spread, it will increasingly limit the usefulness of glyphosate based weed control systems.  Ongoing research led by Agriculture and Agri-Food Canada, is evaluating the extent of the problem. At this time the Department is providing technical advice to growers through the Ag-Info Centre.  However, more needs to be done to address this problem in a coordinated fashion.  A series of meetings on this topic are planned for the first quarter of 2013.

Aquatic weeds

Aquatic weeds pose a problem because aquatic habitats are the responsibility of Alberta Environment & Sustainable Resource Development, but enforcement is the responsibility of the municipalities, or ultimately, Alberta Agriculture and Rural Development.  The weed inspectors hired by municipalities are generally not equipped to carry out inspections for Eurasian water milfoil, which is the only purely aquatic species regulated at this time.  Discussions are underway to develop a solution to this problem that will include all aquatic invasive species and establish an effective inspection system.

Weed evolution

On the topic of weed evolution, I would like to point out that Qixing Zhou from our pathology group in Edmonton found that specimens of flowering rush (Butomus umbellatus) from three locations were diploid (n=13).  This contrasts with reports from the mid-west and Montana, where the triploid form appears to be dominant.  Given that flowering rush is listed as prohibited noxious weed in Alberta we would have preferred to triploid version with its sterile flowers.

Acknowledgments

I would like to thank Nicole Kimmel (ARD/Pest Surveillance Branch) and Ken May (Prairie Pesticide Minor Use Consortium) for their valuable help with this report.