bluuebunny/crossref_metadata_2025 huggingface dataset:
Seeding rate and row spacing affect flax yields and weed interference
Authors: Stevenson F. C. , Wright A. T.
Published: April 2011

Seeding rate and row spacing are management practices that affect flax seed yield. Two experiments were conducted from 1988 to 1990 to determine the influence of flax seeding rates (300, 600, and 900 seeds m−2) and row spacings (9, 18, and 27 cm). One was a flax-weed interference study (three sites) and the other was a weed-free study (13 sites). In the presence of weeds, increasing seeding rate from 300 to 900 seeds m−2 improved flax seed yield by 180 kg ha−1, and reduced broadleaf weed yields by 300 kg ha−1 and grassy weed yields by 180 kg ha−1. In weed-free conditions, seed yield was not affected by seeding rate. Row spacing did not affect flax yield and had minor effects on weed yields when weeds were not controlled. When weeds were controlled, seed yield in the 9-cm row spacing was 9% (15% in the flax-weed interference study) greater than in the two wider row spacings. Seeding rate and row spacing independently influenced flax yield, and their effect was consistent among sites with weeds present, but was not consistent when weeds were controlled. Our results showed that flax seeding rate was an important component of integrated weed management. Key words: Flax, seeding rate, row spacing, weed interference
Rhizome growth of Calamagrostis canadensis in response to soil nutrients and bulk density
Authors: Landhäusser S. M. , Stadt K. J. , Lieffers V. J. , McNabb D. H.
Published: April 2011

In a series of experiments, we investigated rhizome spread and the growth of C. canadensis, as governed by changes in soil bulk density and nutrient availability. The ability of rhizomes originating from vigorous Calamagrostis canadensis plants to penetrate mineral soil with different bulk densities and their response to various nutrient conditions were assessed in a split container experiment. Decreasing biomass and length of rhizomes with increasing soil bulk density showed that clonal expansion of C. canadensis onto areas of exposed mineral soil from adjacent swards was limited mainly by soil bulk density. No nutrient effect on rhizome growth was detectable; the rhizomes were probably well supplied with nutrients by translocation from the mother plant. Results of a second split container experiment indicated that rhizome growth was better in organic than in mineral soils. In a third experiment, entire C. canadensis plants were grown in mineral soil at different levels of soil bulk density and nutrient condition. Here, rhizome biomass and expansion were limited mainly by nutrient availability; however, once the nutritional needs of the plants were met, increasing bulk density reduced the amount of rhizome spread. These results could be useful in reforestation, e.g. selecting those methods of site preparation which reduce the growth and competitive ability of C. canadensis relative to tree seedlings. Key words: Compaction, rhizome, litter, mineral soil, yield, Calamagrostis canadensis
Impact of crop residues on nutrient availability in conservation tillage systems
Authors: Schoenau Jeff J. , Campbell Constantine A.
Published: April 2011

Crop residue management is a key consideration when attempting to optimize fertility in conservation tillage systems. Major factors affecting the impact of crop residues on nutrient availability include the chemical composition of the residue [e.g. carbon (C) to nitrogen (N) ratio], residue placement, fertilizer placement in relation to residue and time. Greater surface accumulation of crop residues in reduced and no-till systems tends to slow decomposition of N-poor residues such as cereal straw, and crop N supply during the current year can be reduced by immobilization if the straw is incorporated close to the time of high crop demand. Similarly, placement of fertilizer directly in the surface straw residue can reduce fertilizer use efficiency due to greater immobilization. Greater immobilization in reduced and no-till systems can enhance the conservation of soil and fertilizer N in the long term, with higher initial N fertilizer requirements decreasing over time because of 1) reduced losses by erosion and 2) the build-up of a larger pool of readily mineralizable organic N. For N-rich residues, such as legumes, volatilization losses may be greater when these residues are left on the surface than when incorporated into soil. Leaching of soluble phosphorus and sulfur compounds from standing and surface-placed crop residues into the mineral soil below may be a significant pathway for recycling of these elements in no-till systems. Greater coverage of the soil surface by crop residues can increase soil moisture and affect soil biological activity related to nutrient turnover. Future research should address how above- and below-ground decomposition processes differ for a wider range of crop residues and nutrients, emphasizing both short and long-term nutrient recycling. Key words: Crop residue, no-till, nutrient availability, nutrient cycling
Influence of changing tillage practices on crop production
Authors: Lafond G. P. , Boyetchko S. M. , Brandt S. A. , Clayton G. W. , Entz M. H.
Published: April 2011

The most efficient and practical way of protecting the soil against wind and water erosion is with surface and anchored crop residues. The rate and extent of crop establishment is not adversely affected by conservation tillage provided shallow seeding is used and adequate seed-to-soil contact is achieved. Soil water conservation can be enhanced with conservation tillage systems and the amount conserved is directly influenced by the type and amount of crop residues present and the agro-ecological zone. Crop residue decomposition is 1.5× slower on the surface than when buried and the rate of decomposition can be explained almost entirely by the location and nitrogen content of the residues and growing degree days. Grain yield can be improved with conservation tillage and is directly related to the amount of extra water conserved, regardless of the crop. Crop establishment, which is critical in forage production, can be improved with conservation tillage. Removing forage stands with herbicides as opposed to tillage favoured subsequent crops. Further research is required on the manipulation of stubble height and row spacing to enhance water conservation and to determine the impact of such changes on crop growth and development, weeds and plant diseases. There is need to develop crop-specific conservation production practices for each agro-ecological zone. Key words: Residue decomposition, grain yield, water conservation, forage production, conservation tillage
Sustainability and economic issues for cereal crop residue export
Authors: Stumborg Mark , Townley-Smith Lawrence , Coxworth Ewen
Published: April 2011

Soil conservation and sustainability concerns, and a lack of markets for crop residues, have left producers with few alternatives for cereal residue export beyond cattle feed or livestock bedding. With the increasing producer use of minimum and zero-tillage systems, the management of crop residues has become an important issue. Opportunities for residue removal may exist provided markets are developed for the material and long-term soil sustainability concerns are addressed.Recent research on the effect of residue removal in Saskatchewan has shown that there is little or no impact on soil organic matter provided adequate fertilization is practised and tillage is reduced. Assuming that 750 kg ha−1 of retained residue is adequate for erosion protection in reduced tillage systems, significant quantities of residues may be available for export from the Black Soil zone. The economic returns to producers are such that residue export is an attractive diversification option. Key words: Crop residues, economics, residue export, soil erosion, soil nutrients, soil carbon
Agronomic comparison of Minnesota-adapted dwarf oat with semi-dwarf, intermediate, and tall oat lines adapted to northern growing conditions
Authors: Mäkelä Pirjo , Väärälä Leena , Peltonen-Sainio Pirjo
Published: April 2011

Development of a dwarf oat (Avena sativa L.) for northern growing conditions may further improve many important agronomic features of the oat crop including lodging resistance, yield stability, yield potential, grain-straw ratio, and fertile tillering. Our objective in this study was to assess the performance of a Minnesota-adapted dwarf line at high latitudes, through measurement of several traits that characterize duration of pre- and post-anthesis growth and plant stand structure, with special reference to tiller growth and tiller productivity. Response of the dwarf line to seeding rate (250, 500, and 750 viable seeds m−2) and nitrogen fertilizer application rates (80, 120, and 160 kg N ha−1) was compared with that of a semi-dwarf line, a conventional height cultivar, and a landrace cultivar, all of which are adapted to long-day conditions. The experiments were conducted in Finland (60°13′N) in 1993 and 1994. The dwarf line produced less grain (≤ 30%) than the other lines but out-yielded the lodging-sensitive landrace in 1994 at a high seeding rate and high rate of nitrogen fertilizer application. As for the semi-dwarf line and conventional height line, the dwarf line produced the highest grain yield at 500 seeds m−2 which is the standard planting density for oat in Finland. The particularly short duration of the generative phase and associated low number of grains per main shoot panicle are likely to be principal contributors to low mean panicle-filling rate, panicle weight, and grain yield of the dwarf line. However it was better able to tiller and produce head-bearing tillers than the other lines. This increased number of tillers was, however, unable to compensate for yield reduction resulting from low yield potential of the main shoot. Key words:Avena sativa L., oat (dwarf), grain yield, landrace, partitioning, straw length, yield components
Yield and growth responses of asparagus to between-row spacing and planting depth
Authors: Loughton Arthur , Baker Randy , Allen O. Brian
Published: April 2011

Recommendations for commercial production of green asparagus, Asparagus officinalis L., advocate planting crowns as deep as 30 cm in rows as wide as 1.8 m. The studies reported were designed to test the individual and interactive nature of these two variables and their effects on crop yield, quality and ultimate position of the crowns in the soil relative to the original planting depths. Five between-row spacings of asparagus, ranging from 60 to 120 cm were combined with five planting depths ranging from 15 to 30 cm, in a central composite rotatable design. After seven harvest seasons, the accumulated yields declined linearly by 756 (± 126.1) kg ha−1 for each increase of 1 cm depth. Accumulated yield also declined linearly by 46.5 (± 31.5) kg ha−1 with each increase of 1 cm between rows. Effects of treatment on early yield (first one-third of the harvest season) paralleled the effects on total yield. Effects of the treatments on average spear weight were negligible. Depth and row width did not interact. Based on economic analysis, the cost of the extra plants was more than offset by the greater yields obtained from the higher populations. Nine years after planting, the final depth of all crowns, regardless of original planting depth, had floated to about 11.3 (± 0.18) cm. Key words: Green asparagus, Asparagus officinalis L., spacing, crown depth, yield, quality
Linked morphological and molecular markers associated with common root rot reaction in barley
Authors: Kutcher H. R. , Bailey K. L. , Rossnagel B. G. , Franckowiak J. D.
Published: April 2011

Selection of common root rot [Cochliobolus sativus (Ito & Kurib.) Drechsl. ex Dastur] resistant barley germplasm is difficult due to the influence of environment on disease expression and the quantitative nature of resistance. Morphological and molecular markers associated with common root rot resistance could be used to increase the efficiency of selection of resistant germplasm and facilitate transfer to desirable barley genotypes Forty-five morphological marker sets consisting of four to six backcross-derived lines for each marker in a common background (cultivar Bowman) were planted in disease nurseries at two locations in each of 3 yr. Disease reactions of the back-cross-derived lines were tested for a difference from the disease reaction of Bowman, which indicated a putative association between the marker and common root rot reaction. An association was obtained between common root rot reaction and one set of backcross-derived lines that contained two linked markers: glossy-sheath (gs4) and orange lemma (o). A RAPD marker closely linked to gs4 and o was also associated with common root rot reaction. The RAPD marker was associated with the allele for resistance, while gs4 and o were associated with the allele for susceptibility. The RAPD marker would be most useful in the selection of common root rot resistant germplasm and the transfer of this resistance to other genotypes. Key words: Common root rot, Cochliobolus sativus, barley, morphological markers, molecular markers
Wild mustard (Sinapis arvensis) response to field pea (Pisum sativum) cultivar and seeding rate
Authors: Wall D. A. , Townley-Smith L.
Published: April 2011

Field studies were conducted at Morden, Manitoba from 1992 to 1995 and Wadena, Saskatchewan in 1995 to investigate the effect of cultivar selection and seeding rate on field pea competitiveness with wild mustard. Cultivars that had both long vines and rapid canopy development (leaf area index) were more competitive with wild mustard than those with short vines and slow canopy development. Cultivars differed markedly in their ability to suppress weed growth. Wild mustard density was affected in 2 of 4 yr by cultivar selection, while weed biomass was affected in 3 of 4 yr. Field pea yield losses under weedy conditions differed among cultivars and those cultivars that more effectively reduced wild mustard density or biomass had the lowest yield losses. Yield losses from wild mustard competition did not differ among cultivars when weed pressure was high and weeds emerged 1 wk before the crop. Seeding rate of Titan, a cultivar with long vine length, affected wild mustard biomass more than Trump, a cultivar with a short vine length. Key words: Competitiveness, leaf area index, yield
Effet de la dose de semis et de l'écartement entre les rangs de l'orge sur la répression du chiendent
Authors: Pageau D.
Published: April 2011

A 4-yr study (1989–1992) was conducted to evaluate the effect of two row spacings (10 and 20 cm) and five seeding rates (100, 200, 300, 400 and 500 viable seeds m−2) of barley (Hordeum vulgare L. 'Cadette') on the control of quackgrass (Elytrigia repens (L.) Nevski). A control treatment consisted of quackgrass grown in the absence of the cereal. The productivity of quackgrass was measured at cereal harvest during the first year and in the following year. Compared with the control, increasing seeding rates from 100 to 500 seeds m−2, reduced dry weight of quackgrass aerial shoots by 43 to 76%, respectively. The presence of barley also reduced the number of quackgras shoots. The year following the cereal harvest of 1989, 1990 and 1992, the presence of barely during the seeding year caused a reduction in quackgrass aerial shoot dry weight of 32, 37 and 13% respectively. This reduction was only 5% in 1991. On average, the total number of quackgrass shoots was reduced by 23% in the year following the harvest of barley. Row spacing did not influence the number or dry weight of quackgrass aerial shoots during the seeding year or the following year. However, high seeding rates reduced the productivity of quackgrass during both the seeding year and the following year. Nevertheless, quackgrass numbers and aboveground biomass remain relatively high the year following cereal seeding.
Predicting a ceiling for soil carbon sequestration on variable landscapes under no-till in eastern Canada
Authors: Chan C. , Kay B D , Gregorich E G
Published: April 2011

Much of the crop production in eastern Canada occurs on landscapes where erosion/deposition has occurred. The potential to sequester C by reducing tillage will be greatest in those parts of landscapes where the organic carbon (OC) stocks are below a ceiling (OCc). However, the physical/biochemical basis for OCc is not understood and therefore it is difficult to predict where C sequestration will occur in landscapes with variable topography. In this research we tested two hypotheses proposed as the physical/biochemical basis for OCc: (1) OCc coincides with the steady state OC (OCss) stocks on non-eroded sites and (2) OCc coincides with a critical proportion of the capacity of the clay and silt fraction to absorb and retain OC (i.e., a critical saturation ratio). Comparison of data from sites with level and variable topography disproved the first hypothesis; OC stocks on level sites were, on average, 14 Mg ha-1 larger than OCc 15 yr after implementing no-till (NT) on variable landscapes. Further analyses of data from sites with variable topography indicated the saturation ratio in the surface 10 cm of soil must be less than 0.45 before NT results in C sequestration in the profile. Although the analyses are not incompatible with the second hypothesis, the critical saturation ratio is surprisingly small compared with values obtained from level sites. Additional tests of the second hypothesis are warranted on sites with variable topography in which C sequestration has been documented. Key words: Erosion, C capacity, saturation ratio, spatial variability, C sequestration
Apparent fertilizer nitrogen recovery and residual soil nitrate under continuous potato cropping: Effect of N fertilization rate and timing
Authors: Cambouris A N , Zebarth B J , Nolin M C , Laverdière M R
Published: April 2011

Adequate nitrogen (N) fertilization is crucial to optimize yield and quality of potato and also to minimize N environmental losses. Effects of rates and timing of N fertilizer on residual soil nitrate (RSN) [NO3-N, 0-0.7 m], soil solution nitrate (SWN) concentrations and apparent fertilizer nitrogen recovery (Nrec) by potato (Solanum tuberosum L.) tubers were evaluated from 1999 to 2001. Two sites representative of the management zones (MZ) previously delineated by apparent soil electrical conductivity and differing in soil water availability were selected. The MZ differed primarily with depth to a clayey substratum, with average values of 1.06 m and 1.34 m in the shallow MZ (SMZ) and in the deep MZ (DMZ), respectively. At each site, a trial with 21 treatments including five rates of ammonium nitrate (0–200 kg N ha-1 in 1999; 0–240 kg N ha-1 in 2000 and 2001) was conducted. Each N rate was applied according to five application timings (100, 75, 50, 25 or 0% of N applied at planting with the remainder at hilling). The effects of N rates and timing on Nrec, RSN and SWN sometimes differed between sites. The Nrec was less responsive to N rates and timing in the SMZ site compared with the DMZ site. Application of the same rate of fertilizer N generally resulted in higher values of RSN at harvest in the SMZ site compared with the DMZ site. Measured SWN was higher in the DMZ than in the SMZ on several occasions in 1999 and 2001, indicating greater nitrate (NO3) leaching in the DMZ site compared with the SMZ site. Different site-specific N management regimes could thus be used at the two sites to improve N use efficiency and to limit the risk of NO3 leaching. However, the temporal variability in the measured parameters, influenced mainly by climatic conditions, was greater than the spatial N variability and this emphasizes the fact that a dynamic model of the N status based on the soil and/or the plant is a prerequisite to help growers to adjust the N fertilizer application within fields and seasons. Key words: Solanum tuberosum, apparent soil electrical conductivity, suction lysimeter
A framework for evaluating sustainable land management
Authors: Smyth A. J. , Dumanski J.
Published: April 2011

Concerns for the effects of global environmental change, caused primarily by the interrelated issues of environmental degradation and population growth, have prompted a consortium of international and national agencies to develop a Framework for Evaluation of Sustainable Land Management (FESLM). The FESLM, based on logical pathway analyses, provides a systematic procedure for identification and development of indicators and thresholds of sustainability. An assessment of sustainability is achieved by comparing the performance of a given land use with the objectives of the five pillars of sustainable land management: productivity, security, protection, viability and acceptability. A classification for sustainability is proposed, and plans for future development of the FESLM are described. Key words: Sustainability, land management, indicators, thresholds, environment, agriculture
Watershed responses to clear-cutting: Effects on soil solutions and stream water discharge in central New Brunswick
Authors: Jewett Kevin , Daugharty David , Krause Helmut H. , Arp Paul A.
Published: April 2011

Elemental concentrations (H, Ca, Mg, K, Na, NH4-N, NO3-N, P) and water flux data for precipitation and stream discharge as well as ion concentration data for soil solutions were collected and summarized for the Hayden Brook (HB) and Narrows Mountain Brook (NMB) watersheds of the Nashwaak Experimental Watershed Project (NEWP) in Central New Brunswick. Elemental concentrations, fluxes and stream discharge from both watersheds were compared for pre- and post-harvest periods (1972–1978 and 1978–1984, respectively). For soil and streamwater solutions, elemental concentrations were typically highest in late summer to fall, and continued to be high throughout the dormant season. For the soil solution, concentrations of NO3-N, NH4-N, Ca and K peaked in midsummer. Highest NO3-N concentrations were found in post-harvest soil solutions taken from hardwood sites. Nitrate levels were low in soil solutions taken from conifer sites, with post-harvest levels slightly higher than pre-harvest levels. Soil solution concentrations were found to vary with soil depth: pH values were lowest at the surface, and increased uniformly with depth; bases (Ca, Mg, K, Na) and NO3-N tended to be lowest at intermediate soil depth. Seasonally divergent trends were observed for post-harvest NO3-N in soil solutions and in streamwater: midsummer levels were high in the former, but low for the latter. Several aspects likely contributed to this divergence: (1) enhanced rates of N mineralization and nitrification in upland soils during post-harvest midsummers, (2) reduced post-harvest vegetational N uptake, (3) possibly accelerated N absorption by microbes and vegetation in the wet areas of the cut watershed. Altogether, post-harvest effects on stream discharge and streamwater chemistry were short-term: differences for elemental concentrations and stream discharge became insignificant after about 5 and 10–12 yr, respectively. Vegetation, especially tolerant hardwoods, recovered rapidly from stump and root sprouts. Key words: Clearcutting, stream discharge, soil solution, pH, Ca, Mg, K, Na, P, NO3-N, NH4-N, seasonal trends
Species, herbicide and tillage effects on surface crop residue cover during fallow
Authors: Blackshaw R. E. , Lindwall C. W.
Published: April 2011

Fallow continues to be a common agronomic practice on the Canadian prairies but it has been associated with increased soil erosion. Risk of fallow erosion can be reduced by maintaining adequate levels of crop residue on the soil surface. Field experiments were conducted at Lethbridge, Alberta from 1991 to 1993 to determine if commonly grown prairie crops differ in their rates of crop residue degradation during fallow and to assess the effect of herbicides and wide-blade tillage on loss of crop residues. The ranking of crop residue losses during fallow was lentil > canola > rye > barley > wheat > flax. High N content in residues usually increased the rate of biomass loss. Flax straw, perhaps because of its high lignin content, did not follow this pattern and was the most persistent of all crop residues. Up to three applications of the herbicides, glyphosate, paraquat, and 2,4-D, at recommended rates did not alter field degradation of any of these crops. These herbicides maintained greater amounts of anchored and total surface crop residues than wide-blade tillage during both fallow seasons. Results are discussed in terms of crops grown before fallow, weed control during fallow, and maintenance of sufficient surface plant residues to reduce the risk of soil erosion. Key words: Glyphosate, paraquat, 2,4-D, reduced tillage, soil erosion, stubble retention
Yield component variation in winter wheat grown under drought stress
Authors: Duggan B. L. , Domitruk D. R. , Fowler D. B.
Published: April 2011

Crops produced in the semiarid environment of western Canada are subjected to variable and unpredictable periods of drought stress. The objective of this study was to determine the inter-relationships among yield components and grain yield of winter wheat (Triticum aestivum L) so that guidelines could be established for the production of cultivars with high yield potential and stability. Five hard red winter wheat genotypes were grown in 15 field trials conducted throughout Saskatchewan from 1989–1991. Although this study included genotypes with widely different yield potential and yield component arrangements, only small differences in grain yield occurred within trials under dryland conditions. High kernel number, through greater tillering, was shown to be an adaptation to low-stress conditions. The ability of winter wheat to produce large numbers of tillers was evident in the spring in all trials; however, this early season potential was not maintained due to extensive tiller die-back. Tiller die-back often meant that high yield potential genotypes became sink limiting with reduced ability to respond to subsequent improvements in growing season weather conditions. As tiller number increased under more favourable crop water conditions genetic limits in kernels spike−1 became more identified with yield potential. It is likely then, that tillering capacity per se is less important in winter wheat than the development of vigorous tillers with numerous large kernels spike−1. For example, the highest yielding genotype under dryland conditions was a breeding line, S86-808, which was able to maintain a greater sink capacity as a result of a higher number of larger kernels spike−1. It appears that without yield component compensation, a cultivar can be unresponsive to improved crop water conditions (stable) or it can have a high mean yield, but it cannot possess both characteristics. Key words: Triticum aestivum L., wheat, drought stress, kernel weight, kernel number, spike density, grain yield
MillenniUM 02 summer rape
Authors: McVetty P. B. E. , Scarth R. , Rimmer S. R.
Published: April 2011

MillenniUM 02 summer rape (Brassica napus L.) is a high erucic acid, low glucosinolate (i.e., canola-quality meal) cultivar. It has an average 27% yield advantage over Reston high erucic acid, low glucosinolate summer rape, is 18 g kg−1 higher in seed oil content than Reston, 20 g kg−1 higher in meal protein content than Reston, and is adapted to the southern B. napus growing regions of western Canada. Key words: Rape, erucic acid, glucosinolate, cultivar description
Grazing tolerance of alfalfa (Medicago spp.) under continuous and rotational stocking systems in pure stands and in mixture with meadow bromegrass (Bromus riparius Rehm. syn. B. biebersteinii Roem & Schult)
Authors: Katepa-Mupondwa F. , Singh A. , Smith Jr. S. R. , McCaughey W. P.
Published: April 2011

The continuing development of adapted alfalfa (Medicago sativa L.) cultivars that combine high yield, disease resistance, winterhardiness, and grazing tolerance is of great value to the beef cattle industry in western Canada. This study evaluated alternative management strategies and plant measurements for assessing the grazing tolerance of alfalfa cultivars over 3 yr. Seven hay-type, four pasture-type, and one dual-purpose (hay or graze) cultivars were established in pure stands and in mixture with meadow bromegrass (Bromus riparius Rehm. syn.B. biebersteinii Roem & Schult). Stands were defoliated under continuous or rotational stocking with beef cattle (Bos taurus). Plants we reassessed for winterhardiness, percent alfalfa within row, percent alfalfa cover, basal area and species composition. Continuous stocking resulted in consistent and significant differences between cultivars, whether persistence was measured as percent alfalfa within row, percent cover and basal area, in both pure and mixed stands (P < 0.05). High correlations between measurement techniques (r = 0.74 to 0.99; P < 0.05) confirmed the value of alfalfa within row and alfalfa cover as time and labour efficient methods to evaluate grazing persistence. Competition between alfalfa and meadow bromegrass resulted in a significant confounding effect under rotational stocking (P < 0.05). Winter injury was identified as an important criteria to evaluate for grazing persistence. The most grazing-tolerant genotypes were selected for subsequent breeding efforts to combine winterhardiness, grazing tolerance, and high productivity. This research showed that grazing method, grass competition, and severe winter conditions strongly influence differential survival of alfalfa cultivars under grazing in western Canada. Key words: Alfalfa, grazing tolerance, grazing systems, Medicago sativa L., Medicago falcata L. Arcang, persistence
AC Rebel oat
Authors: Duguid S. D. , Brown P. D. , Chong J. , Harder D. E. , Haber S. , Menzies J. , Noll J. S.
Published: April 2011

AC Rebel is a high-yielding, high-protein, white hulled oat cultivar possessing the crown rust resistance genes Pc38 and Pc39. It has good resistance to loose and covered smut, good resistance to stem rust, and moderate tolerance to Barley Yellow Dwarf Virus (BYDV). AC Rebel has good kernel characteristics including commercially acceptable hull and oil content. AC Rebel is well suited for the oat growing areas of western Canada where crown rust is not a problem, in particular to the Brown soil zone of Saskatchewan and Alberta. Key words: Oat, Avena sativa L., cultivar description
CDC Milestone lentil
Authors: Vandenberg A. , Kiehn F. A. , Vera C. , Gaudiel R. , Buchwaldt L. , Kirkland K. J. , Morrall R. A. A. , Wahab J. , Slinkard A. E.
Published: April 2011

CDC Milestone is a high-yielding, yellow cotyledon lentil (Lens culinaris Medik.) cultivar developed by the Crop Development Centre, Saskatoon, Saskatchewan. It is intended for cultivation in all lentil production areas of western Canada. CDC Milestone was evaluated for yield, resistance to ascochyta blight (Ascochyta lentis Vassilievsky) and agronomic performance as breeding line 512-2 in the Lentil Co-operative Yield Trials in 1995 and 1996. It has small seeds with pale green seed coat and is acceptable in the small green market class of lentil. CDC Milestone was granted official registration (#4836) as a cultivar in Canada by the Variety Section, Plant Health and Plant Products Division, Canadian Food Inspection Agency on 8 December 1998. Key words: Lentil, cultivar description, Lens culinaris
Leaves of North American ginseng, Panax quinquefolius L.: A renewable source of certain ginsenosides
Authors: Starratt Alvin N. , Hendel John G. , Reeleder Richard D.
Published: April 2011

Quantities of both malonylated and non-malonylated ginsenosides in mature P. quinquefolius leaves were determined weekly near the end of the growing season (late September–early October). Ginsenosides Rb3, mRb3, Rd, mRd, and Re were the major dammarane glycoside components observed in the leaf extracts. Levels of total ginsenosides remained high throughout the period studied when leaf harvest would be expected to have little effect on the roots. Only ginsenoside PG-F,11 appeared to decrease with the approach of leaf senescence. It is concluded that P. quinquefolius leaves represent an excellent source of certain ginsenosides. Key words: Panax quinquefolius, ginseng, leaf ginsenosides
Comparing weed composition in natural and planted hedgerows and in herbaceous field margins adjacent to crop fields
Authors: Boutin Céline , Jobin Benoît , Bélanger Luc , Choinière Line
Published: April 2011

Hedgerows and field margins are common features of the agricultural landscape in southern Québec. In the last decade, hedgerow establishment has been encouraged primarily for the prevention of soil erosion, though many farmers view them as reservoirs of invasive weeds and pests. In this study, we compared weed assemblages of several hedgerow types and herbaceous field margins. Ranking that takes into consideration weed abundance was clearly demonstrated: planted hedgerows > herbaceous field margins > natural woody hedgerows. The latter harboured many perennial plant species of less weedy propensity than planted hedgerows, which accommodated a larger number of weedy species. In planted hedgerows close to 50% of plants were weeds, even in their central position, although planted and natural hedgerows sheltered similar weed composition in their central parts. Likewise, most species inventoried in adjacent fields were weeds. Weeds characterising the central position of hedgerows/field margins were often species of wet habitats (Lythrum salicaria L., Equisetum arvense L., Cicuta maculata L.). Management practices of hedgerows and perhaps of crop fields adjacent to hedgerows may be mostly responsible for the abundance of weeds in hedgerows and field margins. Key words: Hedgerow, field margins, weed, management practices, pesticide, fertiliser
Alfalfa leafcutting bee (Hymenoptera: Megachilidae) pollination of oilseed rape (Brassica napus L.) under isolation tents for hybrid seed production
Authors: Soroka J. J. , Goerzen D. W. , Falk K. C. , Bett K. E.
Published: April 2011

In this 3-yr field study, the activities of alfalfa leafcutting bees (Megachile rotundata Fabricius) (LCB) at varying stocking levels were monitored in shade cloth isolation tents containing male-sterile and male-fertile rows of oilseed rape Brassica napus L. to determine optimum conditions for hybrid seed production. Bumble bees, Bombus impatiens Cresson, were similarly tested in 1 yr; their pollination activities were minimal, and weight of seed produced on female lines in tents containing bumble bees was similar to that in tents without pollinators. Leafcutting bee activity, as measured by the number of female bees at the entrance to tunnels in the hive, at first increased, then decreased with increasing stocking rate. Duration of time spent visiting flowers did not vary with stocking rate, but was longer on male-fertile than on male-sterile flowers. Production of hybrid seed within tents varied with leafcutting bee stocking rate, with the highest seed yield achieved at stocking rates equivalent to three charges at weekly intervals of 400 000 leafcutting bees per hectare. At optimum LCB stocking rates, the method described provided sufficient seed quantity for small-plot multi-location field evaluation of oilseed rape hybrids. Key words: Megachile rotundata, alfalfa leafcutting bee, Bombus impatiens, Brassica napus, oilseed rape, hybrid seed production, isolation tents
Introgression of long pod genotype from spring rape (Brassica napus L.) into summer turnip rape (Brassica rapa L.)
Authors: Lewis L. J. , Woods D. L. , Cheng B. F.
Published: April 2011

Long pod character from a summer Brassica napus L. line was introgressed into turnip rape B. rapa L. cultivar AC Sunshine resulting in progeny lines with significantly longer pods and larger seed size than those of AC Sunshine, but producing no yield advantage. Key words: Brassica rapa, Brassica napus, pod length, summer turnip rape, spring rape, interspecific hybridisation
Partial resistance to Mycosphaerella pinodes in field pea
Authors: Xue A. G. , Warkentin T. D.
Published: April 2011

The responses of 335 field pea lines originating from more than 30 countries to mycosphaerella blight caused by Mycosphaerella pinodes were evaluated in inoculated field plots in 1994 and 1995. Seven lines (Baccara, Carneval, Danto, Majoret, Miko, PI273605, and Yellowhead) with low area under the disease progress curve (AUDPC) scores were identified. These seven lines, along with the resistant check, Radley, and the susceptible check, 89–195, were further examined for components of partial resistance to the disease in 1996 and 1998. Components evaluated were leaf area with symptoms (LAS), stem area with symptoms (SAS), pod area with symptoms (PAS), and percent seed infection (SI). Differences among pea lines were found in all components. Compared with the susceptible check, Carneval had significantly lower LAS, PAS, and SI in both years and was considered partially resistant to leaf, pod, and seed infection; Danto had significantly lower LAS, SAS, and PAS and was partially resistant to leaf, stem, and pod infection; Yellowhead had significantly lower SAS, PAS, and SI and was partially resistant to stem, pod, and seed infection; Majoret had significantly lower LAS and SAS and was partially resistant to leaf and stem infection; Miko had significantly lower SAS and PAS and was partially resistant to stem and pod infection; PI273605 had significantly lower PAS and SI and was partially resistant to pod and seed infection; and Baccara and Radley had significantly lower SAS and were partially resistant to stem infection only. Plots of Baccara and Yellowhead inoculated with M. pinodes-infected stubble had 10 and 17% reduction in yield, respectively, compared with non-inoculated and fungicide-treated plots and, thus, were considered tolerant to the disease. The remaining lines had yield reductions of 30 to 49%. Key words: Mycosphaerella blight, Mycosphaerella pinodes, Pisum sativum, field pea, partial resistance, disease tolerance
Availability of late-season heat and water resources for relay and double cropping with winter wheat in prairie Canada
Authors: Thiessen Martens Joanne R. , Entz Martin H.
Published: April 2011

Long-term weather data for 21 sites across Manitoba, Saskatchewan and Alberta were analyzed to evaluate the availability of late-season heat and water resources between time of winter wheat maturity and freeze-up. Thermal time during this period ranged from 159 to 754 growing degree days; precipitation ranged from 42 to 152 mm. Southern Manitoba appears to be best suited to relay and double cropping. Southern Saskatchewan receives significant thermal energy; however, lack of precipitation may limit late season plant growth. Key words: Legumes, no-till, cropping system intensity
Potential of controlling insect pests of corn using entomopathogenic nematodes
Authors: Riga E. , Whistlecraft J. , Potter J.
Published: April 2011

A series of experiments was performed in the laboratory and in the greenhouse to assess the efficacy of the entomopathogenic nematodes, Steinernema glaseri or S. feltiae in decreasing the numbers of European corn borer, fall armyworm, western corn rootworm and the seedcorn maggot in corn. Both nematode species effectively controlled the four insect pest species. During greenhouse experiments, the number of plants protected with entomopathogenic nematodes against these insect pests was significantly higher than in the untreated controls. Similar results were obtained in a microplot study of corn infected with the European corn borer, the western corn rootworm and the seedcorn maggot. The application of a single nematode species against several insect pests has economic advantages. In addition, both S. glaseri and S. feltiae overwintered and survived in the field until the next growing season. Key words: Entomopathogenic nematodes, sweet corn, European corn borer, fall armyworm, seedcorn maggot, western corn rootworm
CO430, CO431 and CO432 corn inbred lines
Authors: Reid L. M. , McDiarmid G. , Parker A. J. , Woldemariam T. , Hamilton R. I.
Published: April 2011

CO430, CO431 and CO432 are short-season corn inbred lines with improved resistance to silk infection by Fusarium graminearum. These inbreds exhibit average combining ability, average to superior lodging resistance in hybrids and were rated as having excellent emergence and seedling vigour. Key words: Corn, maize, Zea mays, cultivar description, ear rot, Fusarium
Wheat seeding rate for spread and distinct row seed placement with air seeders
Authors: Johnston Adrian M. , Craig Stevenson F.
Published: April 2011

Air (pneumatic) seeding systems that have seed row opener options that spread seed rather than place it in distinct rows may allow producers to uniformly distribute plants and increase seeding rates to improve cereal crop yield. A study was conducted to determine if seed placement configuration influenced hard red spring wheat (Triticum aestivum L.) response to seeding rate. The study was carried out at Melfort, SK, from 1997 to 1999, using three seed configurations (23 cm and 30 cm distinct row with a hoe opener; and a 20 cm spread using a 28 cm sweep on 23 cm row spacing) and four seeding rates (67, 100, 134, and 167 kg ha–1). Grain yield increased 6% when seeding rate was increased from 100 (recommended rate) to 168 kg ha–1 in 1997. Improved grain yield with increased seeding rates was related to greater kernels head–1. In the 2 following years, yield decreased by 9% when seeding rate was increased from 100 to 168 kg ha–1. Yield reductions in these years were associated with high yield potential (high soil N availability) and lodging, that in turn resulted in decreased kernels head–1 and kernel weight with increased seeding rates. Grain yield did not differ between the sweep and distinct rows, regardless of the seeding rate. Furthermore, the similar yields among the three seed configurations occurred despite lodging being less with sweeps compared with 23 or 30 cm row spacing at the highest seeding rate in 1998. The increased distance between wheat plants with sweeps did not improve grain yields as a result of reduced inter-plant competition, regardless of seeding rate. This absence of grain yield differences between the sweep and distinct row placement illustrates the yield stability associated with Canadian hard red spring wheat cultivars through yield component compensation. Key words: Wheat (Triticum aestivum L.), row spacing, seeding rate, lodging, seed placement
Response of Lantana camara L. subsp. camarato paclobutrazol and shading
Authors: Matsoukis A. S. , Chronopoulou-Sereli A. , Dimopoulos I. D. , Kamoutsis A.
Published: April 2011

The effects of several shading materials on the response of Lantana camara L. subsp. camara to paclobutrazol were investigated in 1997 and 1998 under greenhouse conditions inAttica (37°48’20”N, 23°57’48”E), Greece. Treatments were shading (0%, 28% and 65%) and paclobutrazol (0, 20, 40, 80 and 160 mg L–1) drenches after pinching of the plants. As paclobutrazol concentration increased, plant growth, expressed by the growth index (GI), decreased, at all shading levels. At the same time, the number of flowers per plant increased to a maximum as paclobutrazol concentration increased to 80 mg L–1. Concentrations above this resulted in a decrease in the number of flowers per plant, at all shading levels. The interaction between shading level and paclobutrazol concentration significantly affected the studied parameters. The growth index increased while the number of flowers per plant decreased as shading increased from 0% to 65%, at all concentration levels examined. Plants treated with paclobutrazol had greener leaves. At higher concentrations, some leaf distortion was noted. The most attractive plants (small with maximum flowering) were obtained with 80 mg L–1 paclobutrazol at 0% shading. Key words: Lantana camara, paclobutrazol, light intensity
OAC EXETER soybean
Authors: Tanner J. W. , Rajcan I. , Luzzi B. M. , Gostovic P. , Montminy W. , Zilka J. , Hume D. J.
Published: April 2011

OAC Exeter is a 2825 crop heat unit soybean [Glycine max (L.) Merr.] cultivar with very good yield potential and above average protein content. Key words: Soybean, cultivar description
AC Maple barley
Authors: Ho K. M. , Choo T. M. , Martin R. A.
Published: April 2011

AC Maple is a six-rowed spring feed barley (Hordeum vulgare L.) cultivar bred at the Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, and evaluated by the Eastern Canada Barley Breeding Group. It was selected from a Chapais/CIMMYT-6 cross and has high yield. AC Maple is suitable for growing in the Maritime Region of Canada. Key words: Hordeum vulgare L., six-rowed barley, feed barley, high yield
Groat yield of naked and covered oat
Authors: Burrows V. D. , Molnar S. J. , Tinker N. A. , Marder T. , Butler G. , Lybaert A.
Published: April 2011

Near-isogenic covered (CN 18941) and naked (CN 18942) lines of the oat (Avena sativa L.) cultivar NO 141-1 were developed to determine if the contrasting spikelet morphologies of the two lines affected groat yields differentially. Molecular markers verified the high level of genetic similarity between the two lines. Their groat yields were not significantly different under field conditions. Key words: Hulless oats, Hulled oats, Avena sativa L., near- isogenic lines, groat yield, amplified fragment polymorphism
AC X790P soybean
Authors: Poysa V. , Buzzell R. I.
Published: April 2011

AC X790P is a large-seeded soybean [Glycine max (L.) Merr.] cultivar with elevated seed protein levels. AC X790P has yellow hila, lacks the a4 protein sub-unit of the 11S glycinin, and has acceptable tofu processing quality for foreign and domestic markets. Key words: Glycine max (L.) Merr. soybean, cultivar description, tofu-type
CDC Glamis lentil
Authors: Vandenberg A. , Kiehn F. A. , Vera C. , Gaudiel R. , Buchwaldt L. , Dueck S. , A. Morrall R. A. , Wahab J. , E Slinkard A.
Published: April 2011

CDC Glamis is a high-yielding, yellow cotyledon lentil (Lens culinaris Medik.) cultivar developed by the Crop Development Centre, University of Saskatchewan. It is intended for cultivation in all lentil production areas of western Canada. It has large seeds with green seed coat and is suitable for the large green market class of lentil. CDC Glamis wa s issued registration #4835 on 8 December 1998 by the Variety Section, Plant Health and Plant Products Division, Canadian Food Inspection Agency. Key words: Lentil, cultivar description, Lens culinaris
CDC Grandora lentil
Authors: Vandenberg A. , Kiehn F. A. , Vera C. , Gaudiel R. , Buchwaldt L. , Dueck S. , A. Morrall R. A. , Wahab J. , E Slinkard A.
Published: April 2011

CDC Grandora is a high-yielding, yellow cotyledon lentil (Lens culinaris Medik.) cultivar developed by the Crop Development Centre, University of Saskatchewan, Saskatoon, Saskatchewan. It has large seeds with green seed coat and is suitable for the large green market class of lentil. CDC Grandora is intended for cultivation in all lentil-growing areas of western Canada. CDC Grandora was issued registration #4993 on October 4, 1999 by the Variety Section, Plant Health and Plant Products Division, Canadian Food Inspection Agency. Key words: Lentil, cultivar description, Lens culinaris
CDC Robin lentil
Authors: Vandenberg A. , Kiehn F. A. , Vera C. , Gaudiel R. , Buchwaldt L. , Dueck S. , Wahab J. , E Slinkard A.
Published: April 2011

CDC Robin is a high-yielding, red cotyledon lentil (Lens culinaris Medik.) cultivar developed by the Crop development Centre, University of Saskatchewan, Saskatoon, Saskatchewan. It has brown seed coat colour suitable for the small red market class of lentil. It is intended for cultivation in all lentil-growing areas of western Canada. CDC Robin was issued registration #4990 on 4 October 1999 by the Variety Section, Plant Health and Plant Products Division, Canadian Food Inspection Agency. Key words: Lentil, cultivar description, Lens culinaris