bluuebunny/crossref_metadata_2025 huggingface dataset:
The biology of Canadian weeds. 127. Panicum capillare L.
Authors: Clements David R. , Stephen J. Darbyshire Antonio DiTommaso, , Cavers Paul B. , Sartonov Alison D.
Published: April 2011

Panicum capillare L., witch grass, is an annual grass native to North America that infests field crops, small grains, grasslands, and a variety of other habitats. High seed production, a persistent seed bank, a tumble-weed seed-dispersing mechanism, and the ability to tolerate some herbicides contribute to the success of P. capillare in these habitats. Despite the widespread presence of P. capillare in crops, its actual impact on crop yield is not well documented. It is an additional host for several insect pests (e.g., cereal aphids) and diseases attacking crop species. Key words: Panicum capillare, witch grass, panic capillaire, weed biology, native weed species
Leaf development in two-row spring barley under long-day and short-day field conditions
Authors: Paynter B. H. , Juskiw P. E. , Helm J. H.
Published: April 2011

To gain an understanding of the adaptation of Australian and Canadian barley (Hordeum vulgare L.) cultivars to the environments of western Canada and Western Australia, phyllochron and number of leaves on the mainstem in eight cultivars of two-row, spring barley were examined when sown at two dates in two locations. The locations were a short-day environment at Northam, Western Australia, Australia in 1997 and a long-day environment at Lacombe, Alberta, Canada in 1998. At each location highly significant relationships between leaf number on the mainstem and thermal time were found (r2 > 0.94). Using linear estimates, the phyllochron of barley under short days was longer than under long days and was correlated to time to awn emergence. Later sowing shortened phyllochron under short days, but generally not under long days. Error messages from the linear regression analysis suggested that residuals were not random for all cultivars. Bilinear models were fitted to those datasets. Bilineal responses were observed under both short and long days, being independent of cultivar, date of seeding, final leaf number, phenological development pattern and time to awn emergence. The occurrence of a bilinear response was also independent of any ontogenetic events. The change in phyllochron occurred between leaves 4–7 at Northam and between leaves 6–9 at Lacombe. The leaf number at which the phyllochron change occurred was positively related to final leaf number and time to awn emergence. The phyllochron of early forming leaves was positively related to time to awn emergence and shorter than later forming leaves. Leaf emergence patterns in spring barley under both long-day and short-day conditions may therefore be linear or bilinear. Key words: barley (spring), Hordeum vulgare L., phyllochron, leaf emergence, daylength
Comparative performance of the L* a* b* colour space and North American colour charts for determining chipping quality in tubers of potato (Solanum tuberosum L.)
Authors: Coleman W. K.
Published: April 2011

Differences in North American standard charts for the characterization of colour quality of potato chips have contributed to an inability to accurately define the colour of the processed product. Consequently, individual colour standard cards for potato chips from the Snack Food Association (USA) and Agriculture and Agri- Food Canada (AAFC) were analyzed for their reflectance characteristics in the visible spectrum (400 nm-700 nm). In addition, several cultivars were chipped and analyzed for comparison purposes. An objective colour criteria was provided by a visually uniform, three-dimensional colour scale developed by the Commission Internationale de l’Eclairage (International Commission on Illumination) and defined by the L* a* b* colour space. When colour values of the AAFC chipping chart, calculated from L* a* b* values, were plotted against assumed card values, high card variability led to the inability to separate these cards when based on objective analysis by reflectance colorimetry. Although strongly influenced by tuber glucose content, chroma plots (a* vs. b*) revealed that the AAFC colour standards were comparable to processed potato chips from a range of cultivars grown and stored under a range of different conditions. The three colour quality levels of the Snack Food Association were restricted in their colour range and demonstrated unacceptable reflected spectral differences. Plotting L* values (y-axis) against a*/b* values (x-axis) gave a linear relationship regardless of data source, i.e., standard curve origin, cultivar, production area, storage temperature, duration in storage. Based on the above analysis, a standardized and more objective colour standard based upon the L* a* b* colour space is suggested. Key words: Potato, Solanum tuberosum, chip colour, quality standards
Physiological characteristics of recent Canada Western Red Spring wheat cultivars: Components of grain nitrogen yield
Authors: Wang H. , McCaig T. N. , DePauw R. M. , Clarke F. R. , Clarke J. M.
Published: April 2011

Genetic yield gains have been difficult to achieve within the Canada Western Red Spring (CWRS) wheat (Triticum aestivum L.) class, partially because of the requirement for high protein concentration. A previous study indicated that four newer, high-yield CWRS cultivars (registered 1994–1997) also had higher protein yields. The objective of the present study was to determine if the increase in grain nitrogen (protein) yield of the four newer wheat cultivars, relative to two older cultivars, Neepawa (registered in 1969) and Marquis (introduced in 1909), resulted from increased plant nitrogen uptake, more efficient utilization of nitrogen, or a combination of these factors. The higher nitrogen yields were primarily attributed to more efficient utilization and redistribution of the nitrogen rather than increased uptake of soil nitrogen. The nitrogen harvest index (NHI) of the new cultivars, considered as a group, was higher than the NHI of Neepawa, which in turn was higher than that of the much older cultivar Marquis. The NHI of each of the new cultivars was higher than that of Marquis. The nitrogen concentration in the non-grain tissue at maturity (NGNCM) of the new cultivars, considered as a group, was lower than that of Neepawa, which in turn was lower than the NGNCM of Marquis. At maturity, all five tissues (leaf blade, stem plus sheath, peduncle, glume, and rachis) for the new cultivars and Neepawa had lower nitrogen concentrations than for the corresponding tissues of Marquis. The nitrogen concentration of the peduncle and leaf-blade tissues of the new cultivars, as a group, were also lower at maturity than the corresponding nitrogen concentrations for Neepawa. The results suggest that low non-grain nitrogen concentration at harvest is associated with improved NHI and grain nitrogen yield in CWRS wheat. This information may improve our understanding of the higher protein yields that have been achieved within this class, and assist in the selection of future parents. Key words: Nitrogen harvest index, nitrogen uptake, nitrogen yield, protein, remobilization, Triticum aestivum
Journey hard red spring wheat
Authors: Graf R. J. , Potts D. A. , Hanson K. M.
Published: April 2011

Journey hard red spring wheat is adapted to the wheat-growing regions of the Canadian prairies. Evaluation occurred in Central Bread Wheat Cooperative registration tests in 1997, 1999 and 2000 relative to Neepawa, Roblin, AC Majestic, McKenzie and AC Barrie. Journey displayed high grain yield, mid- to late - season maturity, reduced height, very strong straw, high test weight, high protein content and improved pre-harvest sprouting resistance. It exhibited resistance to the prevalent races of stem rust, leaf rust and common bunt, and intermediate resistance to loose smut and Fusarium head blight. Journey is eligible for all grades of Canada Western Red Spring (CWRS) wheat. Key words: Triticum aestivum L., cultivar description, red spring wheat, strong straw, grain protein, test weight, preharvest sprouting resistance, disease resistance
Prodigy hard red spring wheat
Authors: Graf R. J. , Potts D. A. , Hucl P. , Hanson K. M.
Published: April 2011

Prodigy hard red spring wheat (Triticum aestivum L.) is adapted to the wheat growing regions of western Canada. Evaluation in the Central Bread Wheat Cooperative registration tests from 1995 to 1997 was relative to Neepawa, Roblin, AC Majestic and McKenzie. Prodigy displayed high grain yield, mid-season maturity, strong straw, high protein content and high test weight. It exhibited resistance to the prevalent races of stem rust, leaf rust, and common bunt, moderate susceptibility to loose smut and susceptibility to Fusarium head blight. Prodigy is eligible for all grades of Canada Western Red Spring (CWRS) wheat. Key words: Triticum aestivum L., cultivar description, red spring wheat, grain protein, test weight, disease resistance
CDC Mons flax
Authors: Rowland G. G. , Hormis Y. A. , Rashid K. Y.
Published: April 2011

CDC Mons, a mediumlate maturing oilseed flax (Linum usitatissimum L.) was released in 2002 by the Crop Development Centre, University of Saskatchewan, Saskatoon, Saskatchewan. This cultivar has medium oil content, medium oil quality, small seed size, good lodging resistance and high yield when seeded early in the Black Soil zones of the prairies. It is immune to North American races of rust caused by Melampsora lini, moderately resistant to wilt caused by Fusarium oxysporum f. sp. lini and moderately resistant to powdery mildew caused by Oidium lini. Key words: Flax, oilseed, Linum usitatissimum L., cultivar description
Chemical maturation and storage performance of eleven Russet Burbank clones
Authors: Coleman Warren K. , Li Xin-Qing , Tremblay-Deveau Esther , Coleman Shirlyn
Published: April 2011

Although introduced as a cultivar from a somaclonal mutation of smooth Burbank in the 19th century, the subsequent identification and commercial selection of distinct Russet Burbank clones or strains has not been evident in the scientific literature. The present study examined chemical maturity of tubers (sucrose rating values and glucose content) and subsequent storage performance over a 3-yr period (1999–2001) of eleven Russet Burbank clones collected from across North America in order to determine if subtle quality traits could be associated consistently with specific clones. Although considered a late maturity cultivar (140 d), all clones were chemically mature (sucrose rating values of approximately 1) at the New Brunswick growing site by 125 d. Exploratory cluster analyses using hierarchical or nonhierarchical methods applied to pre-harvest and harvest sucrose and glucose levels in tubers during the 3-yr study allowed the North American clones to be separated into clusters that reflected geographical biases and this hypothesis was supported by canonical discriminant analysis. Exploratory cluster analysis of post-harvest data, however, did not find any consistent structure in the clones based on sucrose or glucose levels during storage at 4 or 10°C for up to 8 mo or after reconditioning from 4°C. Polymerase chain reaction analysis of 10 selected simple sequence repeat (SSR) regions confirmed that the 11 clones belonged to the cultivar Russet Burbank. The limited geographically featured clustering based on pre-harvest sugar changes observed among the clones may have their origins in cultural practices with somaclonal variation leading to geographical strains of the cultivar. Key words: Potato, Solanum tuberosum, cluster analysis, microsatellite DNA markers
Zinc responses of dry beans in Manitoba
Authors: Goh T. B. , Karamanos R. E.
Published: April 2011

Close to 80% of dry beans in western Canada are grown in southern Manitoba. A need was identified to develop soil-testing criteria based on local conditions as well as derive an optimum fertilizer rate to alleviate Zn deficiency. Two experiments with a number of dry bean (Phaseolus vulgaris L.) cultivars were carried out between 2000 and 2002 at a number of locations in Manitoba. Each experiment included two trials per year. The first experiment consisted of two foliar application rates of Zn (0 and 0.33 kg ha-1) as main plots and five rates of broadcast and incorporated soil Zn (0, 2.8, 5.6, 8.4 and 11.2 kg Zn ha-1) as sub-plots. The second experiment also included two rates of foliar Zn (0 and 0.33 kg Zn ha-1) as the main plots; however, sub-plots included a control and four Zn products that were broadcast and incorporated at a rate of 5.6 kg Zn ha-1. Soil DTPA-extractable Zn levels varied from 0.38 to 1.14 mg Zn kg-1 soil. Soil Zn applications resulted in a significant increase of Zn in plant tissue levels at 1/10 bloom growth stage, however, actual levels varied, thus, suggesting that a plant tissue critical level will have to be derived separately for each cultivar. Significant seed yield responses were obtained only when DTPA-Zn levels were equal to, or less than, 0.5 mg Zn kg-1. Optimum yields at responsive sites were obtained with 5 kg Zn ha-1 broadcast and incorporated. All products used (Zn mono- and heptasulphate or oxysulphate) performed equally well, except in one case when ZnSO4.H2O exhibited superior performance. Foliar application of a sulphonic acid based Zn product was not always as effective as soil applied Zn products. Key words: Dry bean, Phaseolus vulgaris L., DTPA extraction, foliar, soil, Zn products
Identification of a quantitatively inherited source of Hordeum bulbosum derived scald resistance from barley line 926K2/11/1/5/1
Authors: Singh A. K. , Rossnagel B. G. , Scoles G. J. , Pickering R. A.
Published: April 2011

Scald resistance breeding requires identification and incorporation of novel resistance sources into local breeding populations. A New Zealand barley Hordeum vulgare L.) line (926K2/11/1/5/1) was evaluated in scald [Rhynchosporium secalis (Oud.) J.J. Davis] nurseries at Lacombe and Edmonton, Alberta, Canada, as a potential source of scald resistance derived from H. bulbosum. Primary objectives were to evaluate the level of resistance in 926K2/11/1/5/1 under Canadian conditions and determine its mode of inheritance. In western Canadian nurseries, 926K2/11/1/5/1 exhibited moderate resistance. 926K2/11/1/5/1 was crossed with the scald-susceptible cultivar CDC McGwire and resulting progeny (F2 and F4:5 recombinant inbred lines) were tested for normality of disease reaction distribution, and were used to estimate the number of effective factors controlling the resistance. F1 plants expressed an intermediate scald reaction compared with the parents. F2 and F4:5 data were normally distributed. Estimation of the number of effective factors using the Castle-Wright formula indicated that resistance from 926K2/11/1/5/1 is quantitatively inherited, but controlled by relatively few genes. The moderate scald resistance in 926K2/11/1/5/1 is an additional resistance source plant breeders can utilize. Key words: Barley, scald, quantitative resistance, Hordeum bulbosum
Method and time of alfalfa termination affects cereal growth and weed populations
Authors: Moyer J. R. , Clapperton M. J. , Boswall A. L.
Published: April 2011

Experiments were established on irrigated land at Lethbridge, Alberta, to determine the effect of timing and method of alfalfa (Medicago sativa L.) termination on weed abundance, soil moisture and N content, cereal yield and colonization of roots by vesicular arbuscular mycorrhizal (VAM) fungi. Alfalfa growth was terminated using no, minimum, and conventional tillage in either late summer, early fall, or spring. Herbicide was applied or tillage was used to control volunteer alfalfa, dandelion (Taraxacum officinale Weber), stinkweed (Thlaspi arvense L.), and kochia [Kochia scoparia (L.) Schrader] before seeding cereals. Dandelion and volunteer alfalfa density tended to be greatest after no-tillage treatments, and poor in-crop alfalfa control likely reduced cereal yields in no-tillage plots. In contrast, the major in-crop broadleaf weed, redroot pigweed (Amaranthus retroflexus L.), was most dense (7 plants m-2) in tilled plots. Both wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) yields were reduced 9 to 12% after alfalfa termination with no-tillage treatments compared with minimum or conventional tillage. In spring, after seeding, available soil N content averaged 138, 101 and 79 kg ha-1 for conventional-, minimum-and no-tillage plots, respectively; however, fall no-tillage treatments seemed to supply sufficient N for wheat and barley. Soil moisture content tended to be similar after all termination treatments. Wheat and barley responded differently to time and method of termination in terms of seedling root length and colonization by VAM fungi. The percentage of root colonized by VAM fungi was greater on both barley and wheat in no-tillage compared to cultivated treatments. It may be possible to have similar wheat and barley yields after no tillage and tilled alfalfa termination if no-tillage termination is initiated in fall and effective incrop herbicides are used for volunteer alfalfa and dandelion control. Key words: Alfalfa termination, no-tillage, N, vesicular arbuscular mycorrhizal fungi, weed density
Plastic mulches and row covers for early and midseason crisphead lettuce produced on organic soils
Authors: Jenni S. , Dubuc J. -F. , Stewart K. A.
Published: April 2011

Plastic mulches and row covers for early and midseason crisphead lettuce (Lactuca sativa L. ‘Ithaca’) grown on organic soils were investigated over 2 yr. For early production, four mulch treatments (infrared transmitting, silver-on-black co-extruded polyethylene, white-on-black co-extruded polyethylene and a bare soil control) with and without an agrotextile low tunnel were tested. For midseason production, the same mulch treatments were evaluated in combination with normal and high planting densities (54 400 plants ha-1 and 65 200 plants ha-1). Low tunnels combined with mulches accelerated early growth and maturity by 10 d for infrared-transmitting mulch, 7–8 d for silver mulch and 3–5 d for white mulch, relative to production on bare soil control without a low tunnel. Infrared-transmitting mulch alone increased plant biomass early in the season and produced a lettuce head of heavier or similar weight relative to that from bare soil, even if harvested 3–4 d earlier. Lettuce heads grown on silver and white mulches were harvested 1–3 d earlier, and were 22% heavier in the first year and 29% heavier in the second year than when grown on bare soil. Head weights of lettuce under the low tunnels were higher than those from control plots in the first year only, and head size was similar in both years. For midseason production, infrared-transmitting and silver mulches accelerated the early growth of lettuce, but resulted in heads with long cores at maturity, particularly with infrared-transmitting mulch. Silver mulch increased the percentage of marketable heads in the first year and head weight and size at maturity in the second year, and reduced the incidence of aphids in both years, relative to plots without mulch. White mulch resulted in larger and heavier heads than those produced without mulch in the second year, and produced heads with shorter cores than those produced with other mulches in both years, even during particularly hot growing conditions. The percentage of marketable heads was similar for both the high- and low-density plantings and, as a result, the former produced more marketable heads per hectare. However, lettuce plants grown at the higher density were smaller in the second year. During conditions conducive to disease development in the first year, higher density plantings were more susceptible to downy mildew. Key words: Lactuca sativa, iceberg lettuce, muck soils, plasticulture, mini-tunnel, physiological disorder, planting densities
Impact of simulated acid rain on photochemistry, morphology, and yield of the wild blueberry (Vaccinium angustifolium Ait.)
Authors: Murray Angela M. , Percival David C. , Stratton Glenn W.
Published: April 2011

The effects of simulated acid rain (SAR) on the photochemistry, net photosynthesis (Pn), morphological damage, and crop yield were studied on Vaccinium angustifolium Ait. Although there was an 8% decrease in fluorescence origin with the pH 1.5 SAR treatment when compared to the control, no effects on the quantum efficiency of photosystem II (PSII) photochemistry, Pn, leaf and berry wax deposition were detected. There was no SAR effect on crop yield or the physiological components studied. Key words: Vaccinium angustifolium Ait., acid rain, blueberry
CDC Plato lentil
Authors: Vandenberg A. , Vera C. , Buchwaldt L. , Dueck S. , Morrall R. A.A. , Warkentin T. D. , Banniza S. , Slinkard A. E.
Published: April 2011

CDC Plato is a high-yielding, yellow cotyledon lentil (Lens culinaris Medik.) cultivar developed by the Crop Development Centre, University of Saskatchewan, Saskatoon, Saskatchewan. It is suitable for the large green market class of lentil and is intended for cultivation in all lentil-growing areas of western Canada. CDC Plato was issued registration #5554 on November 1, 2002 by the Variety Section, Plant Health and Plant Products Division, Canadian Food Inspection Agency. Key words: Lentil, cultivar description, Lens culinaris
Nitrogen use efficiency characteristics of commercial potato cultivars
Authors: Zebarth B. J. , Tai G. , Tarn R. , de Jong H. , Milburn P. H.
Published: April 2011

One approach for reducing the contribution of potato (Solanum tuberosum L.) production to nitrate contamination of groundwater is to develop cultivars which utilize N more efficiently. In this study, variation in N use efficiency (NUE; dry matter production per unit crop N supply) characteristics of 20 commercial potato cultivars of North American and European origin were evaluated in 2 yr. Cultivars were grown with or without application of 100 kg N ha-1 as ammonium nitrate banded at planting. The recommended within-row spacing was used for each cultivar and no irrigation was applied. Plant dry matter and N accumulation were determined prior to significant leaf senescence. Crop N supply was estimated as fertilizer N applied plus soil inorganic N measured at planting plus apparent net soil N mineralization. Nitrogen use efficiency decreased curvilinearly with increasing crop N supply. Nitrogen use efficiency was lower for early-maturing cultivars compared to mid-season and late-maturing cultivars. A curvilinear relationship was obtained between plant dry matter accumulation and plant N accumulation using data for all cultivars. Deviations from this relationship were interpreted as variation in N utilization efficiency (NUtE; dry matter accumulation per unit N accumulation). Significant differences in NUtE were measured among cultivars of similar maturity. Nitrogen uptake efficiency (NUpE; plant N content per unit crop N supply) and soil nitrate concentration measured at plant harvest were uniformly low for all cultivars when crop N supply was limited, but varied among cultivars when N was more abundant. This suggests that potato cultivars vary more in terms of N uptake capacity (plant N accumulation in the presence of an abundant N supply) than in terms of NUpE. Key words: Solanum tuberosum, N mineralization, dry matter accumulation, N accumulation, N utilization efficiency
The Biology of Invasive Alien Plants in Canada. 2. Cynanchum rossicum (Kleopow) Borhidi [= Vincetoxicum rossicum (Kleopow) Barbar.] and Cynanchum louiseae (L.) Kartesz & Gandhi [= Vincetoxicum nigrum (L.) Moench]
Authors: DiTommaso Antonio , Lawlor Frances M. , Darbyshire Stephen J.
Published: April 2011

Cynanchum rossicum (dog-strangling vine) and C. louiseae (black dog-strangling vine) are introduced, perennial herbs or small twining vines in the Milkweed family (Asclepiadaceae). Generic placement of these two species has been problematic, but are here treated as members of Cynanchum subgenus Vincetoxicum. The species occur primarily in natural upland areas, including understories of woodlands, pastures, old fields, shores, flood plains and ruderal areas of southern Ontario and Quebec and the northeastern United States. Ecosystems on well-drained, stony soils are often densely colonized, but both species can tolerate a wide moisture regime. Plants establish in full sun or under forest canopies and may form monospecific stands in all light conditions. They often form dense colonies which smother other vegetation and reduce invertebrate and vertebrate biodiversity. Reproduction is by polyembryonic, wind-dispersed seeds. Effective control is primarily by herbicides, since mechanical control is difficult and no biological control agents have been developed. A third European species, C. vincetoxicum, has been reported as an occasional garden escape in southern Ontario and the northeastern United States, but has not yet become naturalized. Information on this species is included because of its close relationship with C. rossicum and its better known biology. Key words: Dog-strangling vine, swallow-wort, Cynanchum, Vincetoxicum, CYKNI, invasive plant, weed biology
Optimal time for remote sensing to relate to crop grain yield on the Canadian prairies
Authors: Brian McConkey Prakash Basnyat, , Lafond Guy P. , Moulin Alan , Pelcat Yann
Published: April 2011

The optimal time to acquire remote sensing imagery to relate to grain yield has not been thoroughly investigated for the Canadian prairies. Remotely sensed data collected when there is the best relationship with yield should provide useful information on the in-field spatial variability of biophysical factors affecting crop productivity relevant to site-specific management. The correlations of normalized difference vegetation index (NDVI) with grain yield for three dates in 2000 at Indian Head and Swift Current, SK, for field pea, canola, and spring wheat were compared. No single date consistently had the highest NDVI-yield correlation for all crops. The period between Jul. 10 to 30 was optimal to obtain NDVI to relate to grain yield for springseeded crops that typically mature in August. Significant NDVI-yield correlations for this period were confirmed in three additional site-years. In a further site-year, however, NDVI-yield correlation was significant for wheat and pea, but not for canola. Occasional problems relating the NDVI to canola yield were attributed to characteristics of the canola canopy, namely, the highly reflective flowers and the dropping of leaves after flowering. In terms of both magnitude and temporal stability of the NDVI-yield correlation, we ranked the crops as: spring wheat, then pea, and then canola. Key words: Remote sensing; grain yield, field pea, canola, wheat, normalized difference vegetation index
Agronomic characteristics and nutritive value of 11 grasses grown with irrigation on a saline soil in southwestern Saskatchewan
Authors: Glover D. E. , Kielly G. A. , Jefferson P. G. , Cohen R. D. H.
Published: April 2011

Agronomic and nutritive characteristics of 11 grasses were studied at Swift Current, Saskatchewan on a moderately saline irrigated soil: [smooth bromegrass (Bromus inermis Leyss.), meadow bromegrass (Bromus riparius Rehmann), tall wheatgrass (Elytrigia elongata (Host) Nevski), crested wheatgrass (Agropyron desertorum (Fisch. ex Link) Schult.), intermediate wheatgrass (Elytrigia intermedia (Host) Nevski), slender wheatgrass (Elymus trachycaulus (Linke) Gould ex Shinners), Altai wild ryegrass (Leymus angustus (Trin. Pilger), Russian wild ryegrass (Psathyrostachys junceus (Fisch.) Nevski), Dahurian wild ryegrass (Elymus dahuricus Turcz ex Grieseb), reed canarygrass (Phalaris arudinaceae L.) and creeping foxtail (Alopecurus arundinaceus Poir.)]. Grasses were clipped at threeleaf, heading and seed set. Yield, leaf-to-stem ratio (LSR), botanical composition (BC), crude protein (CP), phosphorus, fibre and in vitro dry matter digestibility (IVDMD) were determined. There were differences (P < 0.05) between the grasses in yield at each growth stage with smooth bromegrass and creeping foxtail having high yields and meadow bromegrass low yields at all growth stages. The BC of most target grasses was greater than 60%. Exceptions were Dahurian wild ryegrass, crested wheatgrass, tall wheatgrass and meadow bromegrass. There were few significant differences between the grasses for LSR, except that Russian and Altai wild ryegrasses and meadow bromegrass had higher LSR (P < 0.05) than the other grasses. Differences in CP, P, neutral (NDF) and acid (ADF) detergent fibres were inconsistent and small at each growth stage but CP and P declined (P < 0.05) while NDF and ADF increased (P < 0.05) with plant maturation. There were differences (P < 0.05) between years and cuts for all traits except between years for yield, BC and LSR at seed set (P > 0.05). Dry matter intake (DMI) NDF and in vivo dry matter digestibility (DMD) were determined for hay cut from each plot using sheep. The relationship between forage NDF and DMI:

DMI g kg BW-1 d-1 = 86.5 – 0.09 NDF (r2 = 0.87; RSD = 1.16; P < 0.001)]
Endophytic rhizobia in barley, wheat and canola roots
Authors: Lupwayi N. Z. , Clayton G. W. , Hanson K. G. , Rice W. A. , Biederbeck V. O.
Published: April 2011

Endophytic rhizobia have been shown to improve the nutrition of nonlegume crops. The objective of this work was to investigate the effects of field pea (Pisum sativum)-based crop rotations on endophytic rhizobia in roots of cereal and oilseed crops. Barley (Hordeum vulgare), wheat (Triticum aestivum) and canola (Brassica rapa) were each grown (a) following inoculated peas, (b) following uninoculated peas or (c) in monoculture. At flag-leaf or flowering growth stage, populations of endophytic rhizobia were usually in the order: crop following uninoculated peas (up to 7244 cells g-1 root DM) > crop following inoculated peas (up to 1660 cells g-1 root DM) > crop grown in monoculture (< 10 cells g-1 root DM). At one of three sites, there were significant positive correlations between endophytic rhizobia and crop N and yield. Populations of rhizobia in bulk soil, rhizosphere, or rhizoplane of nonlegume roots were greater where nonlegume crops were preceded by peas (inoculated or uninoculated) than where they were grown in monoculture. Significant positive correlations between populations of these rhizobia outside roots and crop N or yields were observed at each site. Key words: Crop rotation, inoculation, nitrogen fixation, plant growth-promoting rhizobacteria (PGPR), rhizosphere
Impacts of using polyethylene sleeves and wavelength selective mulch in vineyards. I. Effects on air and soil temperatures and degree day accumulation
Authors: Bowen P. A. , Bogdanoff C. P. , Estergaard B.
Published: April 2011

Effects on soil and air temperatures of wavelength-selective polyethylene mulch applied in planted rows, and clear polyethylene enclosures (sleeves) applied around vine canes or cordons for 7 wk in the spring were determined in three Merlot vineyards in the Okanagan Valley, British Columbia. Three sleeve configurations were studied: single-layer and closed at bottom; single-layer with bottom ventilation added after 5 wk; and double-layer with bottom ventilation added after 5 wk. All sleeves were perforated at the top between two supporting trellis catch wires, and were stapled closed at the bottom under the cordon or cane. Sleeve removal was either all at once or in two stages by first opening the top then removing the sides 6 d later. The sleeves increased mean air temperatures by ca. 1 to 2°C and maximum temperatures by ca. 5 to 8°C, and decreased minimum temperatures by ca. 1 to 2 °C, depending on the vineyard, measurement period, and sleeve configuration. Adding bottom ventilation to sleeves increased the mean minimum nighttime temperature by ca. 1°C at one vineyard but had no effect at the other two sites. Degree day (base 10°C) accumulati on inside sleeves was 1.5 to 2 times that of ambient, depending on the site, which increased total degree day accumulations for the season by 4.1 to 7.9%. The polyethylene mulch increased soil temperatures by ca. 2°C continuously over the diurnal period at two of the vineyards, but at the third where there was significant weed growth under the mulch the increase was less and only at night. Key words: Wine grapes, plasticulture
Response of glufosinate-resistant Bt sweet corn (Zea mays) cultivars to glufosinate and residual herbicides
Authors: O’Sullivan J. , Sikkema P. H.
Published: April 2011

Field studies were conducted in 1999 and 2000 at Simcoe and Exeter, Ontario to determine the effect of glufosinate, applied alone or in combination with s-metolachlor/atrazine, on weed control and crop safety on six glufosinate-resistant Bt sweet corn cultivars. A single application of glufosinate at 0.5 or 1.0 kg ha-1 gave 89% or better control of redroot pigweed, common ragweed, wild buckwheat and lady’s-thumb in 1999 and pale smartweed and redroot pigweed in 2000. Glufosinate applied alone gave reduced control of wild buckwheat and barnyard grass in 2000 and reduced control of crab grass in 1999 and 2000 at Simcoe. S-metolachlor/atrazine applied preemergence, followed by glufosinate postemergence, improved control of these species. In the untreated control, yield of all cultivars, except Bonus Bt at Exeter, was reduced at all locations. Yield of Cupola Bt and SS Jubilee Bt was reduced when glufosinate was applied alone at 0.5 kg ha-1. Yield of Cupola Bt, Empire Bt and SS Jubilee Bt was reduced with s-metolachlor/atrazine used alone. Maximum yields were obtained with a sequential treatment of s-metolachlor/atrazine followed by glufosinate. Glufosinate did not cause any injury, plant height reduction or delayed maturity of any glufosinate-resistant Bt sweet corn cultivars. Key words: Cultivar, sensitivity, herbicide injury, glufosinate, Zea mays
Establishing winterfat in prairie restorations in Saskatchewan
Authors: Romo J. T.
Published: April 2011

The importance of native shrubs in the Northern Mixed Prairie of Canada has generally been overlooked; however, restoration specialists have recognized the importance of including shrubs in prairie restorations. Emergence and establishment of winterfat (Krascheninnikovia lanata (Pursh) A. D. J. Meeuse & Smit), a palatable and long-lived shrub, was evaluated in relation to planting time and seedbed preparation in swards of native grasses that had been seeded on previously cultivated cropland in the prairie ecozone of southern Saskatchewan. Diaspores of winterfat were broadcast at 20 m-2 in autumn or spring on upland and lowland sites in seedbed treatments including (1) a control or undisturbed sward, (2) mowing the sward to a 15-cm height, (3) haying, (4) glyphosate application after haying and, (5) tillage. Emergence of winterfat on upland and lowland sites was about three-fold greater with autumn than with spring planting (P < 0.01). Winterfat establishment on upland sites was affected by the interacting influences of planting times and seedbed treatments (P = 0.01), with most winterfat establishing from autumn sowing in the glyphosate and tillage treatments (2.1 and 2.2 plants m-2, respectively). Establishment of 0.9 plants m-2 from autumn planting was greater (P < 0.01) than the 0.1 plants m-2 establishing from spring sowing on lowland sites. The interaction of planting date and seedbed treatment on lowland sites did not influence winterfat establishment (P = 0.06) nor did seedbed treatments (P = 0.07). Winterfat should be planted in late autumn as opposed to spring. Key words: Ceratoides lanata, Eurotia lanata, Krascheninnikovia lanata, Northern Mixed Prairie, restoration
Genotypic and environmental effects on saturated fatty acid concentration of canola grown in Manitoba
Authors: McCartney C. A. , Scarth R. , McVetty P. B. E. , Daun J. K.
Published: April 2011

The low saturated fatty acid concentration of canola oil relative to other vegetable oils has resulted in a favourable market share for canola. Understanding the effects of genotype and environment on saturated fatty acid concentration will facilitate Brassica napus breeding efforts aimed at maintaining or reducing saturate levels in the seed oil. Canola-quality B. napus samples from the Manitoba Crop Variety Evaluation Team (MCVET) trials in 1999, 2000 and 2001 were tested for fatty acid composition, oil concentration and protein concentration. Weather data were obtained from nearby weather stations. The majority of the variation in total saturates for the cultivars studied was attributed to variation in palmitic acid (C16:0) due to the genotype main effect and variation in stearic acid (C18:0) due to the genotype and environment main effects. The variation due to the genotype × environment interaction was small relative to the main effects for the individual saturated fatty acids. C18:0 and arachidic (C20:0) acid concentrations were correlated between genotypes, suggesting pleiotropy or that these traits are controlled by linked genes in the cultivars tested. The data also suggested that C16:0 and C18:0 acid concentrations are controlled by different genes. C18:0, C20:0 and behenic (C22:0) acid concentrations were correlated across environments, but did not correlate with C16:0 concentration. Relationships between weather variables and fatty acid composition, oil concentration and protein concentration were not established. Additive Main effects and Multiplicative Interaction (AMMI) analysis revealed that some canola cultivars were more stable than others with regard to total saturates over environments. Key words: Genotype, environment, seed quality, saturated fatty acids, canola, Brassica napus
Quantitative and qualitative responses of an established Kentucky bluegrass (Poa pratensis L.) turf to N, P, and K additions
Authors: Badra Abdo , Parent Léon-Etienne , Desjardins Yves , Allard Guy , Tremblay Nicolas
Published: April 2011

Kentucky bluegrass is a common turf species used on golf courses, sports fields, municipal parks, sod farms, road banks, as well as residential and school yards. Our objective was to determine the effects of N, P, K rates on turfgrass quantitative response (clipping yield and underground turf biomass) and qualitative response (shoot density and foliage colour) under a continuous clipping removal. A 3-yr field study was conducted on two sites, a sand that met the specifications of the United States Golf Association (USGA) and a loam. The factorial experiment was arranged in a randomized complete block design with four replicates and different levels of three nutrients, N (0 or 50 to 300 kg ha-1 yr-1), P (0 or 21.8 to 87.3 kg P ha-1 yr-1), and K (0 or 41.7 to 250 kg K ha-1 yr-1). The maximum clipping yield was produced at the rate of 200 kg N ha-1 yr-1 in the loam and 300 kg N ha-1 yr-1 in the sand. Increasing N rates linearly reduced underground turf biomass. Added P and K had no effect on clipping yield and underground turf biomass. Nitrogen significantly improved shoot density and foliage colour. However, equivalent shoot density and colour ratings required 40 to 80 kg more N ha-1 yr-1 in the sand compared to the loam. Phosphorus and K had no significant effect on shoot density and colour in the loam. Colour response to P and K depended on N rates in the sand. Fertilizer units needed to increase soil test P averaged 6 kg added P ha-1 mg-1 PM-III kg-1 across soil types. To replenish soil K, 7 kg K ha-1 per mg KM-III kg-1 were required in the sand, and 3 kg K ha-1 per mg KM-III kg-1 in the loam. Phosphorus and K fertilizer programmes should account for P and K removals to maintain low to medium fertility levels for P, and medium for K when conditions are similar to those in this research. Key words: Turfgrass clipping yield, underground turf biomass, turfgrass shoot density, turfgrass foliage colour, Kentucky bluegrass fertilization
Rate and timing of nitrogen fertilization of Russet Burbank potato: Nitrogen use efficiency
Authors: Zebarth B. J. , Leclerc Y. , Moreau G.
Published: April 2011

This study evaluated rate and timing of N fertilization effects on the N use efficiency characteristics of rain-fed Russet Burbank potato. Trials conducted in 1999–2001 included different rates of fertili zer N (0–160 kg N ha-1 in 1999 and 0–200 kg N ha-1 in 2000 and 2001) applied either at planting according to normal grower practice, or at hilling, the latest time that granular fertilizer can practically be applied. Whole-plant dry matter and N accumulation were determined at topkill. Soil inorganic N content was measured to 30-cm depth at planting and at tuber harvest. Soil N supply (plant N accumulation plus soil inorganic N content at harvest with no fertilizer N applied) varied from 77 to 146 kg N ha-1 depending on the year. Crop N supply (soil N supply plus fertilizer N applied) was a better predictor of plant N accumulation than fertilizer N rate, and was used to remove the confounding effect of variation in soil N supply when making among-year comparisons for N use efficiency characteristics. Nitrogen uptake efficiency (NUpE; plant N accumulation/crop N supply) decreased with increasing rates of N applied at hilling N rate in 1999, which was a dry year, but was not influenced by at-hilling N rate in 2000 and 2001, or by at-planting N rate in any year. Nitrogen use efficiency (NUE; dry matter accumulation/crop N supply) and N utilization efficiency (NUtE; dry matter accumulation/plant N accumulation) decreased curvilinearly with increasing crop N supply in each year. Similar relationships between NUE and crop N supply, and between NUtE and plant N accumulation, among the 3 yr of the study suggest that these relationships are largely independent of seasonal climatic variation, and are primarily genetically controlled. Timing of N fertilization had no effect on any N use efficiency parameter, with the exception of reduced NUpE associated with split N application in 1999. This suggests that under rain-fed potato production in Atlantic Canada, timing of N fertilization has no significant effect on N use efficiency of Russet Burbank potato in years of adequate soil moisture, but NUpE may be decreased by split application of N in dry years. Key words: Solanum tuberosum, soil inorganic N, apparent fertilizer N recovery
Number of check rows required to select summer turnip rape for resistance to brown girdling root rot
Authors: Klein-Gebbinck H. W. , Woods D. L.
Published: April 2011

Brown girdling root rot is a devastating disease of canola (Brassica rapa) in the Peace river region. Breeding for resistance to this disease up to now has relied on field screening, with every alternate row as a check. Examination of the distribution of brown girdling root rot from spaced rows of Brassica rapa ‘Tobin’ revealed that there would be a minimal loss of precision in breeding programs by reducing the frequency of check rows to one in four, which represents a considerable saving in cost compared with the current practice. Key words: Turnip rape, Brassica rapa, brown girdling root rot, resistance, selection technique
Phytophagous arthropods and silvertop levels associated with post-harvest residue treatments in three turfgrass species grown for seed
Authors: Soroka J. J. , Gossen B. D.
Published: April 2011

Silvertop, which is characterized by whitish, completely sterile seed heads produced on green tillers, is a common symptom in many perennial grasses. A 3-yr study of creeping bentgrass (Agrostis palustris), Kentucky bluegrass (Poa pratensis) and creeping red fescue (Festuca rubra subsp. rubra) grown for seed production was conducted at Saskatoon, Saskatchewan, to investigate the cause(s) of silvertop, the impact of residue management strategies on silvertop incidence, and the impact of silvertop on seed yield. Three residue management practices were applied in the fall of the first harvest year and again the next fall, as follows: (i) burned after harvest; (ii) clipped to 1–2 cm in height and the residue removed; or (iii) mowed to 20 cm and the residue retained. Arthropods in each plot were collected weekly from May until July by sweep sampling, counted, and identified to family level or lower, and the incidence of seed heads with and without silvertop were assessed. The majority of arthropods were thrips, leafhoppers, plant bugs, mites, or grass-dwelling flies. Grass species and residue treatment strongly affected the number of reproductive tillers and levels of silvertop. Levels of silvertop were lowest in creeping bentgrass in all 3 yr of the study, while they were similar for Kentucky bluegrass and creeping red fescue. Mown plots had fewer reproductive tillers, fewer heathy seed heads, and higher levels of silvertop than burned or clipped plots. However, arthropod species composition was generally similar across grass species and residue treatments. This indicates that a specific arthropod taxon may not be a critical factor in silvertop expression. The relationship between the number and composition of arthropods found and incidence of silvertop is discussed. Key words: Festuca rubra subsp. rubra, Poa pratensis, Agrostis palustris, seed production, arthropods, silvertop
Forage quality of seeded native grasses in the fall season on the Canadian Prairie Provinces
Authors: Jefferson P. G. , McCaughey W. P. , May K. , Woosaree J. , McFarlane Li.
Published: April 2011

There is renewed interest in re-seeding native grasses in the prairie region of western Canada but there is limited information on their forage quality for fall grazing. We evaluated forage quality in early fall of nine native and one introduced grass species for 2 to 4 yr at five locations. The neutral detergent fiber (NDF) was high due to the advanced growth stage of the plants but varied among grass species at all sites . Western wheatgrass, Pascopyrum smithii, exhibited the lowest NDF and highest in vitro organic matter digestibility (IVOMD). Northern wheatgrass, Elymus lanceolatus, exhibited the highest crude protein while western wheatgrass ranked second highest for crude protein. Indiangrass, Sorghastrum nutans, exhibited the highest P and Ca concentrations, while green needle grass, Nasella viridula, and mammoth wildrye, Leymus racemosus, exhibited the lowest concentrations. Acid detergent fiber (ADF) was not highly correlated to IVOMD, presumably due to the mature phenological stage at sampling. Western wheatgrass forage was nutritionally adequate to maintain a dry beef cow during the second trimester of pregnancy. Other species did not “cure on the stem” as had been previously reported and would require supplementary energy and protein to be utilized for fall pastures. Key words: Forage quality, fiber, protein, P, C4 grasses, C3 grasses
Influence of protein concentration on farinograph absorption, mixing requirements and mixing tolerance
Authors: Fowler D. B. , Kovacs M. I. P.
Published: April 2011

Accurate and precise measurements of grain quality traits are required throughout the wheat (Triticum aestivum L. Em. Thell.) production and marketing chain to ensure that quality standards are maintained. In the present study, spring and winter wheat genotypes representing a wide range of grain quality types and protein concentration (PC) were grown in dry land and irrigated nitrogen fertilizer trials in western Canada to determine the influence of flour PC and quality on farinograph water absorption, mixing requirements and mixing tolerance. As expected, there was a strong linear relationship between PC and water absorption. In contrast, PC had a large nonlinear influence on mixing requirements and tolerance measurements, which made it difficult to make meaningful comparisons among genotypes when flour PC was less than 12%. Consequently, because cultivar grain yield potential, environment, and fertilizer management decisions have a large and variable influence on PC, it is important that cultivar selection procedures and marketing programs based on farinograph measurements include grain quality comparisons made over a wide range of PC and preferably at similar PC. This allows for a more accurate assessment of cultivar genetic potential that is independent of the normally strong negative relationship between PC and grain yield potential. When combined with the ability to segregate grain on the basis of PC at the time of delivery, it also allows producers a greater opportunity to select cultivars and adopt management practices that maximize returns while maintaining effective quality control in grain handling systems. Key words: Wheat, grain quality, farinograph, protein concentration, N management, cultivar selection and marketing