bluuebunny/crossref_metadata_2025 huggingface dataset:
Rate and duration of grain filling in five spring wheat (Triticum aestivum L.) genotypes
Authors: Duguid S. D. , Brûlé-Babel A. L.
Published: April 2011

Final grain dry weight, a component of yield in spring wheat, is determined by the rate and duration of grain filling. The objective of this study was to compare grain dry weight and rate and duration of grain filling amongst five spring wheat genotypes (Triticum aestivum L.) that differed in time to maturity. Glenlea, Katepwa, PT516, Roblin, and Wildcat were sown in replicated trials on four seeding dates in 1988 and 1989 at Winnipeg, Manitoba. Mean grain dry weight was measured at various intervals from anthesis to maturity. A logistic equation was used to characterize grain filling and estimate final grain dry weight, and the duration and maximum rate of grain filling. Stepwise multivariate analysis indicated that final grain dry weight was the most important variable characterizing the grain filling curves, followed by duration and then maximum rate of grain filling. The highest grain dry weights were produced by Glenlea (40.4 mg) and Wildcat (36.9 mg). Roblin (34.9 mg) was intermediate in grain dry weight while Katepwa (32.4 mg) and PT516 (30.3 mg) produced the smallest grains. Genotypes with the highest grain dry weights had shorter durations and higher maximum rates of grain filling. Key words:Triticum aestivum L., grain filling, duration, rate, phenological development, yield
Persistence of cool-season grasses under grazing using the mob-grazing technique
Authors: McCartney D. H. , Bittman S.
Published: April 2011

Evaluation of grass germplasms for pasture is usually done in trials which are harvested mechanically. This study evaluated the persistence of 13 cool-season grass species and germplasms under 4 yr of grazing in northeast Saskatchewan, using the mob-grazing technique. Thirteen grass germplasms were contained within each paddock, and the paddocks were grazed by large groups of cattle so that all the herbage was consumed evenly in 1–2 d. Three grazing intensities (light, moderate and intense) were established by varying the rest period between grazings. Ground cover declined more rapidly under intense than under light grazing, but no interaction was found between grazing intensity and grass germplasm. The ground cover of the seeded grasses generally declined but at different rates during the trial, giving a significant grass × year interaction. Parkway crested wheatgrass [Agropyron cristatum (L.) Beauv. ssp. pectination (Bieb.) Tzvel.] declined less than Carlton smooth bromegrass (Bromus inermis Leyss.) and the meadow bromegrass (Bromus biebersteinii Roem & Schult.) cultivars. The most rapid stand decline was observed in intermediate wheatgrass [Elytrigia intermedia (Host) Nevski], northern wheatgrass (Elymus lanceoiatus Scribn. & Smith), and hybrid wheatgrass [Elytrigia repens (L.) Nevski × E. spicata (Pursh) D. R. Dewey]. Seeded grasses were replaced mainly by bluegrass (Poa spp.). The results suggest that mob grazing is a useful technique for evaluating new species and germplasms intended for long-term pastures. Key words: Grazing tolerance, temperate grasses, pasture, ground cover, bromegrass, wheatgrass, wildrye, bluegrass
Direct seeding of alfalfa in grain stubble and bromegrass sod
Authors: Rioux Romain
Published: April 2011

Direct seeding of alfalfa (Medicago sativa L.) is a valuable alternative to conventional seeding. However, yield and nutritive value of forage obtained in the seeding year by direct seeding are not documented for Eastern Canadian conditions. The objective of this study was to assess the forage potential of alfalfa direct seeded into a grain stubble and a bromegrass sod. In the grain stubble, alfalfa development was slower and dandelion (Taraxacum officinale L. Weber) density was higher under direct than under conventional seeding. Forage DM yields were similar under direct and conventional seeding. Crude protein concentration and in vitro dry matter digestibility, however, were higher under conventional seeding than under direct seeding. In the bromegrass sod, the existing stand fertilized with N had higher DM yield than any of the renovated plots. Direct-seeded alfalfa had lower DM yield than conventionally seeded alfalfa. Direct seeded alfalfa with glyphosate applied in band did not establish successfully. In the post-seeding year, DM yields, crude protein concentration and in vitro dry matter digestibility were similar for all seeding systems. Key words:Medicago sativa L., no-till, legume establishment, sod renovation, zero tillage
AC McDuff flax
Authors: Kenaschuk E. O. , Rashid K. Y.
Published: April 2011

AC McDuff, a late-maturing oilseed flax (Linum usitatissimum L.) with very high oil content, was released by Agriculture Canada, Research Station, Morden, Manitoba, in 1993. The cultivar has very good lodging resistance and is high yielding in the Black Soil zone of the prairies. It is immune to North American races of rust caused by Melampsora lini and is moderately resistant to wilt caused by Fusarium oxysporum f. sp. lini. Key words: Flax, oilseed, Linum usitatissimum L., cultivar description
Effect of wounding and jasmonates on the physico-chemical properties and flea beetle defence responses of canola seedlings, Brassica napus L.
Authors: Bodnaryk R. P. , Rymerson R. T.
Published: April 2011

Inducible defence responses of seedlings of Brassica napus were investigated after cotyledons were mechanically wounded or treated topically with methyl jasmonate (MeJA). Flea beetles (Phyllotreta cruciferae Goeze) fed less (twofold) on wounded or jasmonate-treated seedlings, probably because their cotyledons were tougher (1.4-fold), the protein content was lower (by half), and the level of cysteine proteinase inhibitor was higher (twofold) than in untreated controls. Wound-induced defences in the cotyledons of B. napus appear to be based on multiple mechanisms (all relatively weak) that may be mediated by jasmonates.Remarkable increases (up to 25-fold) were observed in the viscosity of cotyledon extracts after wounding or treatment with MeJA. Altered tissue water content, DNA, sugars or sugar alcohols did not account for the increase in viscosity. Heating extracts at 100 °C, trichloroacetic acid precipitation, chloroform extraction, and anion–cation–exchange chromatography removed protein and greatly lowered viscosity, indicating that jasmonate-induced proteins may be responsible for elevated viscosity. It is uncertain whether the high viscosity of extracts reflects actual physico-chemical conditions within cotyledons or reflects stress, defence or hydraulic responses to wounding and jasmonates. Key words: Wounding, jasmonate, resistance, Insecta, Brassica napus, Phyllotreta cruciferae, plant defence
Impacts on Canadian agriculture of the Convention on Biological Diversity
Authors: Harvey Bryan L. , Fraleigh Brad
Published: April 2011

Canada was among the first nations to sign and ratify the Convention on Biological Diversity. With strong support from the federal government, the Canadian delegation played a key role in its negotiation. The Convention has three major elements: (1) the conservation of biodiversity; (2) the sustainable use of biodiversity; and (3) the equitable sharing of benefits derived from the use of biodiversity. Canada has developed a draft strategy to meet our obligations as a signatory nation. This strategy was developed with input from various levels of government and from a wide range of individuals and organizations. The benefits to agriculture are increased resources for the conservation of biodiversity, which is vital to this industry, and continued access to germplasm. The costs are the funds necessary to conserve, an obligation to share knowledge and benefits from genetic resources and greater regulation of germplasm exchange. Key words: Biodiversity, conservation, germplasm, convention, genetic resources
Canadian wild plant germplasm of economic significance
Authors: Davidson Campbell G.
Published: April 2011

Canada is a large country with a great diversity of native plant material. Many of the native genera and species are related to crop plants. A review of different crop groupings revealed that over 30% of native plant material is related to crop species at the generic level. Fruit crops (111 species) and forage and turfgrass (138 species) crops had the highest number of related wild species. Nut crop species had relatively few native representatives (11 species) as did cereal, oilseed and other field crops (18 species). Special and minor acreage crops were represented by 86 species while landscape plants were represented by 137 genera. Forest trees are an important economic resource. Over 70 species of coniferous and deciduous trees are native to Canada. Many species, particularly in the fruit crop grouping, could be identified as world resources (e.g. Amelanchier) with the major part of their distribution occurring on Canadian soil. A concerted effort is needed to identify which species are endangered so that they can be preserved on a long-term basis. More research is needed to identify other long-term conservation goals coupled with crop development programs. Key words: Genetic conservation, Canada, wild plants, biodiversity
AC Michael hard red spring wheat
Authors: Kibite Solomon
Published: April 2011

AC Michael is a hard red spring wheat cultivar adapted to Alberta and western Saskatchewan. It combines high grain yield with a maturity about 1 and 2 d earlier than Neepawa and Laura, respectively, and has superior resistance to common bunt and loose smut compared to Laura. Key words:Triticum aestivum, spring wheat, cultivar description
Apollo low linolenic summer rape
Authors: Scarth R. , Rimmer S. R. , McVetty P. B. E.
Published: April 2011

Apollo is a low-linolenic acid canola cultivar which produces seed oil with an average linolenic acid content of 1.7%. The low-linolenic oil has a shorter hydrogenation time and greater stability than standard canola oil. Apollo has a significant yield advantage over the low-linolenic cultivar Stellar with higher seed oil and lower seed protein content than Stellar. Apollo is adapted to the southern B. napus canola growing areas of western Canada. Key words: Rape (summer), low linolenic, cultivar description
Influence of phosphorus nutrition and vesicular–arbuscular mycorrhizal fungi on growth and yield of greenhouse cucumber (Cucumis sativus L.)
Authors: Trimble M. Rae , Knowles N. Richard
Published: April 2011

This study determined whether beneficial effects obtained with infection by vesicular–arbuscular mycorrhizal (VAM) fungi during early growth of cucumber are maintained through to maturity. Greenhouse cucumbers (Cucumis sativus L. 'Corona' and 'Carmen') were grown in VAM-inoculated (Glomus intraradices Schenck & Smith) or noninoculated autclaved sandy soil with supplemental phosphorus (P) ranging from 90 to 720 mg P plant−1 wk−1. These P treatments resulted in leaf P levels that spanned the range from deficient to sufficient, based on published data for mature cucumber plants. Leaf and mainstem development, number of fruit per plant, and harvest index were enhanced by increasing P levels in all studies. Low levels of P nutrition resulted in deficiency symptoms that were well correlated with deficient concentrations of leaf P. Mature plants maintained a relatively high level of infection by G. intraradices at low and moderate levels of P nutrition; however, depending on the cultivar, VAM infection either had no effect, or slightly depressed leaf and stem growth. The VAM infection stimulated earlier flowering and fruit production, but a longer fruit abortion period precluded increases in final fruit yield. The reduced shoot development and longer interval of fruit abortion characteristic for VAM-infected plants may be due to increased stress imposed by the collective sink requirements of the fungus and developing fruit. Key words:Cucumis sativus L., growth, phosphorus, vesicular-arbuscular mycorrhizal fungi, yield
Changes with time in the germination of buried scentless chamomile (Matricaria perforata Mérat) seeds
Authors: Bowes G. G. , Thomas A. G. , Lefkovitch L. P.
Published: April 2011

Change with time in the germination of scentless chamomile (Matricaria perforata Mérat) seeds was investigated. Seeds were placed in nylon net bags, buried 7 cm deep in soil, exhumed at monthly intervals for 2 yr and allowed to germinate in temperature regimes of 10/2 °C, 20/5 °C, 25/10 °C and 35/20 °C (16/8 h), simulating temperatures found during early spring or late fall, spring or fall, summer and mid-summer on the soil surface, respectively. Exhumed and refrigerator-stored (2 °C) check seeds exhibited no yearly dormancy/nondormancy germination cycle, but mortality of buried seed increased to 36%, after 10 mo in contrast with that of the check seeds which remained low for two years. Light was required for germination during the first year but was not required for a portion of the seed during the second year. The retention of viability in buried seed explains the persistent seed bank and seedling emergence throughout the growing season when moisture and temperature are nonlimiting. Key words: Seed burial, germination, Matricaria perforata Mérat
Agronomic response to seeding rate of two- and six-rowed barley cultivars in central Alberta
Authors: Jedel P. E. , Helm J. H.
Published: April 2011

Little information is available on the response of two-rowed barley (Hordeum vulgare L.) cultivars to seeding rate in central Alberta. The objective of this research was to compare the effects of seeding rates of 129–344 seeds m−2 (50–140 kg ha−1) on the agronomic response of two- and six-rowed barley grown in central Alberta. Grain yields of 5.8–6.1 t ha−1 were not affected by seeding rates in 1990 and 1991 at Lacombe. As seeding rates increased in 1992, grain yields at Lacombe increased from 6.4 to 7.8 t ha−1; at Olds, from 3.5 to 4.0 t ha−1; and at Botha for the 129 seeds m−2 treatment, yields were only 5.5 t ha−1, compared with 5.8 to 6.0 t ha−1 for the other treatments. Effects of seeding rate on test and kernel weights varied between location–years. Tiller numbers m−2 were found to increase at higher seeding rates for the two-rowed cultivars, Abee and Harrington, while for the six-rowed cultivars, Noble and Virden, these numbers remained constant. Node numbers spike−1 decreased with higher seeding rates for both two- and six-rowed cultivars. There was little effect of seeding rate on kernel number spike−1 for the two-rowed cultivars, while for the six-rowed cultivars this number decreased. Although the two- and six-rowed cultivars differed in their partitioning of yield and the effects of seeding rates on these components, their yield responses to seeding rate did not differ. Recommended seeding rates for barley in central Alberta should be above 129 seeds m−2 (50 kg ha−1). To maintain high kernel and test weights, seeding rates for barley grown in central Alberta for malt quality should range from 172 to 258 seeds m−2. When conditions warrant accelerated development, seeding rates of 300 or more seeds m−2 should be used. Key words:Hordeum vulgare, management, yield components
Effects of plant age and late-season hardening on development of resistance to winter crown rot in first-year alfalfa
Authors: Hwang S. F. , Gaudet D. A.
Published: April 2011

The effect of plant age and autumn growth on development of resistance in first-year alfalfa seedlings to winter crown rot caused by the low-temperature basidiomycete (LTB) was evaluated under field and controlled-environment conditions during 1991 and 1992. Early-seeded alfalfa exhibited greater survival and had greater dry shoot weights than late-seeded treatments. Alfalfa plants, seeded in May of 1991 and 1992, were sampled from the field on three dates between September and November, which represented three different levels of cold hardiness in the first-year alfalfa. Plants exposed to the longest hardening conditions prior to inoculation exhibited the highest percentage survival and shoot dry weight and the lowest crown-rot rating. These results demonstrated that early planting and exposure of plants to prolonged hardening conditions in the autumn reduce injury due to winter crown rot in first-year alfalfa. Key words:Medicago sativa, alfalfa, low temperature, winter crown rot, Coprinus psychromorbidus, cold hardening
Outcrossing in two faba bean cultivars under dryland conditions in Spain
Authors: Suso M. J. , Cubero J. I. , Moreno M. T.
Published: April 2011

Field outcrossing rates were estimated for two faba bean (Vicia faba L.) cultivars in 3 yr in Spain using isozyme markers and the mixed mating model for the determination of single and multilocus rates. Out-crossing rates were stable during the years for the local cultivar and higher than previously thought for the Mediterranean region. Key words:Vicia faba, outcrossing rates, isozyme marker
Residual effects of harvested and green-manured legumes on a subsequent barley crop in a subarctic environment
Authors: Sparrow Stephen D. , Cochran Verlan L. , Sparrow Elena B.
Published: April 2011

Experiments were conducted at two locations in Alaska to determine effects of incorporating and harvesting forage legumes on subsequent barley crops. Barley (Hordeum vulgare L.) following forage legume crops and fallow had higher yields and plant N than barley following non-N2-fixing crops. Incorporating, as opposed to harvesting, legume crops sometimes resulted in positive response of barley. Key words: Residual legume effects, green manure, Alaska, subarctic
AC Albright barley
Authors: Wolfe R. I. , Dofing S. M. , Davidson J. G. N. , Clarke P. J.
Published: April 2011

AC Albright (Hordeum vulgare L.) is an early maturing, six-row feed barley cultivar. It was selected from the cultivar Otal at the Northern Agriculture Research Centre, Agriculture and Agri-Food Canada, Beaverlodge, Alberta Canada. It has demonstrated adaptation to north-central and western Alberta and the Peace River region of British Columbia. Key words:Hordeum vulgare, barley, early maturity, cultivar description
Incidence of pod and seed infection in two soybean lines differing in resistance to Phomopsis seed decay
Authors: Anderson T. R. , Buzzell R. I. , Buttery B. R. , Dirks V. A.
Published: April 2011

Two soybean (Glycine max) lines differing in resistance to Phomopsis seed decay were evaluated in field trials, over 3 yr, for time and incidence of pod and seed infection caused by Phomopsis longicolla, Diaporthe phaseolorum var. caulivora and D. p. var. sojae. Pod infection increased linearly with time but OX615 averaged 15% less than Coles at each sample date. Seed infection increased curvilinearly in conjunction with decreasing seed moisture with marked increases between the fifth and seventh weeks after flowering. At maturity, average seed infection was 69% in Coles and 28% in OX615. Key words:Glycine max, soybean, resistance to Phomopsis seed decay
Carbon-13 isotope discrimination at several growth stages in lentil, spring wheat and canola
Authors: Matus A. , Slinkard A. E. , Kessel C. van
Published: April 2011

CID has been proposed to indirectly select for transpiration efficiency and seed yield in C3 plants. Before using CID as an indirect selection criterion it is important for plant breeders to determine the best growth stage at which to sample for CID. Consequently, to determine the most effective growth stage to select for CID we measured: (i) several growth stages to determine the one that provides the maximum differential for CID, (ii) the magnitude of the genotype by growth stage interaction for CID, and (iii) the variability for CID within and among genotypes of two divergent genotypes of lentil (Lens culinaris Medikus), spring wheat (Triticum aestivum L.) and canola (Brassica napus L.). Three plants per pot were grown hydroponically in a glasshouse using a RCBD replicated four times. Three samples were collected at four growth stages: early vegetative, late vegetative, flowering and maturity. The variability for CID among plants within genotypes was small. The two lentil genotypes differed significantly in CID; whereas, no significant differences were observed for the wheat or canola genotypes. In all three crops the genotype by growth stage interaction for CID was not significant, and the best differential for CID among lentil genotypes was mature seed. The ranking of genotypes remained constant across growth stages; therefore, sampling for CID may be done at any stage of plant development. Key words: Carbon isotope discrimination, lentil, spring wheat, canola, growth stages.
Using transpiration to characterize plant height in winter wheat in different environments: A simulation study
Authors: Weiss A. , Budak N. , Baenziger P. S.
Published: April 2011

Winter wheat (Triticum aestivum L.) plant height is an important trait for the diverse environmental conditions found in the Great Plains. It has been related to seedling emergence, lodging, soil erosion, ease of harvest, crop residue and weed control. The hypothesis that transpiration, which integrates atmosphere, soil, and plant processes, could be used to characterize environmental effects on wheat plant height was tested in this research. Data from four commercial winter wheat cultivars (Arapahoe, TAM107, Vista, and Siouxland) and nine environments in Nebraska in 1992 and 1993 were used. The climatic regions represented in this study ranged from sub-humid to semiarid. To test our hypothesis, a spring wheat growth and yield model was modified to predict plant height development (modeled as a sigmoidal function of time) in winter wheat. Daily height increment was based on the ratio of actual to potential transpiration. The model was run for these four cultivars in eight environments. Data from the ninth environment was used to estimate maximum plant height for each cultivar; a necessary input into the model. Modeled plant height predictions were in good agreement with actual measurements for all environments (R2 = 0.80). Based on these results, we conclude that transpiration was a good indicator of environment for plant height development in winter wheat. Key words:Triticum aestivum L., plant height, transpiration, modeling
The possible role of embryo sac degeneration in yield reduction of summer turnip rape cultivar Candle
Authors: Tian Xiuying , Caeseele L. Van , Sumner M. J.
Published: April 2011

When pollination occurred within 24 h after anthesis, 69.2% of the pods of Brassica rapa cultivar Candle contained at least 50% fertilized ovules. If pollination occurred later than 4 d after anthesis, an occasional ovule near the base of the pistil was fertilized; however, no significant seed set was observed. Pollen tubes were observed entering the locules of the ovary from pollinations carried out as late as 5 d after anthesis. At 3 d after anthesis, in unpollinated flowers, a general deterioration of the embryo-sac contents began and gradually increased to include integumentary cells by 6 d after anthesis. Some ovules swelled as though they were fertilized, but no embryos were present. The results suggest that yield reductions in this species may occur because of the reduction of fertilization potential through rapid degeneration of embryo sacs following anthesis. Key words:Brassica rapa, embryo sac, yield
Influence of protein segregation on the quality characteristics of Biggar and Genesis Canada Prairie Spring Wheat
Authors: Preston K. R. , Morgan B. C. , Dexter J. E.
Published: April 2011

The influence of protein segregation on the quality characteristics of Biggar, a Canada Prairie Spring Red wheat cultivar, and Genesis, a Canada Prairie Spring White wheat cultivar has been evaluated using 1989, 1990 and 1991 harvest survey samples. Protein segregation had a strong influence on most physical parameters and processing characteristics all three years. However, the slopes of the regression equations of protein content to values for each quality test exhibited heterogeneity between years. For both wheat cultivars, test weight and kernel weight gave consistently high negative correlations to protein content, indicative of less kernel plumpness at high protein content. The resulting lower endosperm content of the higher protein segregates was reflected by higher wheat ash content, and lower flour yield in 2 of the 3 yr. The milling performance of the higher protein segregates was further diminished by consistently high positive correlations of flour grade color to protein content, indicative of diminishing flour brightness. Flour ash content was not related to protein content for either cultivar, indicating that endosperm ash content was not related to protein content. Flour starch damage, which is directly related to kernel hardness, decreased in response to protein content for both cultivars, with the effect being more pronounced for Genesis. Farinograph dough development time, stability and water absorption increased with increasing protein content. Baking water absorption and loaf volume snowed highly significant positive correlations with protein content. However, baking strength index, a measure of loaf volume on a constant protein basis, decreased with increasing protein content for both cultivars in 2 of the 3 yr. These data demonstrate that marketing Canada Prairie Spring wheat at specified protein levels would facilitate specific customer requirements by optimizing particular quality attributes and improving uniformity between commercial shipments. Key words: Wheat, milling, baking, protein, wheat quality
Effet du chiendent sur l'orge ensemencée à différents écartements entre les rangs et doses de semis
Authors: Pageau D. , Tremblay G. F.
Published: April 2011

A 4-yr study was conducted to evaluate the effect of two row spacings (10 and 20 cm) and five seeding rates of the cereal (100, 200, 300, 400 and 500 viable seeds m−2) on the interference between quackgrass [Elymus repens (L.) Nevski] and barley (Hordeum vulgare L. 'Cadette'). Narrow row spacings had no effect on the yield of barley in presence or absence of quackgrass. However, seeding rates influenced the productivity and development of barley when quackgrass was present. At a seeding rate of 100 seeds m−2, the yield reduction caused by the presence of quackgrass was 41%. When barley was seeded at 500 seeds m−2, the yield reduction was 19%. These yield reductions were mainly attributed to a decrease of spike density. In presence of quackgrass, the specific weight, number of kernels per spike, number of spikes per plant, 1000-kernel weight, harvest index and N concentration of grain were reduced. In contrast to a decrease of the row spacing, increasing seeding rate can be used to reduce interference between quackgrass and barley. Key words: Barley, quackgrass, interference, row spacing, seeding rate
HR46 white bean germplasm
Authors: Park S. J. , Hamill A. S.
Published: April 2011

A germplasm line, HR46, of white (navy/pea) bean (Phaseolus vulgaris L.) has been released for its insensitivity to foliar application of the herbicide metobromuron. This line is a full-season white bean in southwestern Ontario with high yield potential and acceptable canning quality. It is resistant to delta race of anthracnose and races 1 and 15 of bean common mosaic virus. Key words: Germplasm, white, bean (navy/pea), herbicide insensitivity, metobromuron
A comparison of first and second cropping years of Nova Scotia lowbush blueberries (Vaccinium angustifolium) Ait.
Authors: Jordan W. Christopher , Eaton Leonard J.
Published: April 2011

Traditional lowbush blueberry (Vaccinium angustifolium Ait.) production is based on a biennial management system with vegetative growth occurring the first year and fruit development and harvest in the second. An alternative to this management system is the 3-yr system (second-cropping) which is characterized by 2 cropping years/cycle. This study was initiated to quantify differences in vegetative and reproductive development between first and second cropping years of the lowbush blueberry and to determine why there are lower second crop yields. Second crops averaged 70% of first crop yields. Second crop plants had longer stems and higher branch numbers than first crop plants. Although both cropping years produced equal numbers of flower buds/stem, second crops had fewer blossoms/bud, blossoms/stem, set fruit, and berries/stem, resulting in lower fresh and dry weights of fruit/stem in second crop fields. Slower growth rate, fewer blossoms/bud, smaller leaf area/stem, and lower productivity of the second cropping year suggest that second crop stems have fewer resources available to achieve the same production level as first crop stems. Key words: Lowbush blueberry, Vaccinium angustifolium, 3-year management, second-cropping
Variations interpopulations de la longueur des aigrettes et des caractéristiques des follicules de l'asclépiade commune
Authors: Prince René D. , Benoit Diane L.
Published: April 2011

A study was carried out in 1987 on five populations of common milkweed (Asclepias syriaca L.) from the Montréal region, Québec, Canada, to determine if differences between pappus length, and length and weight of follicles existed and could be due to early or late flower pollination and to populations. Pollination date had no effect at harvest on pappus length and follicle length and weight. Significant differences of pappus length, follicle length and weight were found. Key words:Asclepias syriaca, intraspecific variation, follicle, pappus
Crop production under alternate rotations on a Dark Brown Chernozemic soil at Scott, Saskatchewan
Authors: Brandt S. A. , Zentner R. P.
Published: April 2011

Nine rotations of fallow (F), wheat (W), barley (B), canola (C) and alfalfa hay (H) were evaluated to determine whether alternating crops in rotation on Dark Brown soils increases yield or reduces yield variability. Enhanced yield could increase economic returns, while reduced yield variability could reduce risk of economic loss in individual years. Rotations used in the study were F–W, F–C, F–W–W, F–C–W, F–W–B, F–C–B, F–C–B–H, F–C–W–B–H–H, and continuous wheat. Rotation did not affect yield of wheat or canola grown on summerfallow. Yield and quality of wheat and barley grown on stubble were influenced by rotation. Wheat yield on wheat stubble averaged 1980 and 2160 kg ha−1 in the continuous wheat and F–W–W rotations, respectively, while wheat on canola stubble averaged 2340 and 2290 kg ha−1 in the F–C–W and F–C–W–B–H–H rotations. Most of the yield reduction with wheat on wheat stubble occurred during 1987–1991, when pre-seeding tillage on stubble was minimized. Leaf disease (tan spot and septoria) increased noticeably on wheat stubble during 1987–1991 compared with 1980–1986 or with wheat on canola stubble. Presumably, reduced tillage during 1987–1991 left more infected residue on the soil surface, where it could infect a succeeding wheat crop. Yield of canola relative to wheat during 1980–1991 was much higher than reported for this study during 1972–1979; this was likely due to better seedbed preparation and more effective weed control. Coefficients of variability (CV) for yield over years were 20–25% for canola; 27–30% for wheat on fallow; 24–31% for wheat on stubble; 23–34% for barley on stubble; and 51–63% for alfalfa hay. Calculated on a rotation basis, CV tended to be high in wheat monoculture rotations, particularly where summerfallow was eliminated, but tended to be lower where a mix of crops was grown. Implications for more widespread acceptance of extended cropping are discussed. Key words: Crop rotation, wheat, barley, canola, alfalfa, rotation effect, yield variability
Potential of wild common bean for seed yield improvement of cultivars in the tropics
Authors: Singh Shree P. , Molina Albeiro , Gepts Paul
Published: April 2011

Thirty nine wild or weedy common bean (Phaseolus vulgaris L.) accessions, representing the two extremes of geographical range of distribution and domestication of cultigens in the Americas, were crossed to a high-yielding, small-seeded cultivar, ICA Pijao. The resulting F1, F2, and F3 population bulks, along with ICA Pijao, were evaluated for seed yield, days to maturity, and 100-seed weight under favorable growing conditions at two locations in Colombia. The F3 and F4 bulks were tested separately under soil-fertility and moisture stresses. Thirty random F5-derived F8 lines from the highest yielding population involving both Andean and Middle American wild beans, along with the parents and a control cultivar, were also evaluated for 2 yr, under favorable conditions. No F1 hybrid, population bulk, or F5-derived F8 line significantly outyielded ICA Pijao in any test environment. The mean yield of F1 hybrids, population bulks, and F5-derived F8 lines involving wild and weedy beans of Middle America was higher than that involving Andean South American wild beans. Heritability for seed yield, seed weight, and days to maturity, as well as gains from selection were comparable to those obtained in crosses among cultivars. The small seed of the progenies and the positive correlation between seed size and seed yield suggest that alternative mating schemes that increase the recovery of progenies with a cultivated phenotype should be investigated. Until this research is done, it would be premature to draw conclusions about the yield improvement potential of wild beans. Key words:Phaseolus vulgaris, common bean (wild), yield, heterosis, heritability, selection gain
AC Karma white spring wheat
Authors: Knox R. E. , Pauw R. M. De , McCaig T. N. , Clarke J. M. , McLeod J. G. , Fernandez M. R.
Published: April 2011

AC Karma, white seeded spring wheat (Triticum aestivum L.), combines high grain yield with resistance to common bunt [caused by Tilletia laevis Kuhn in Rabenh. and T. caries (DC.) Tul. & C. Tul.] and loose smut [caused by Ustilago tritici (Pers.) Rostr.] in a semidwarf, photoperiod insensitive background. AC Karma has improved leaf rust (caused by Puccinia recondita Roberg ex Desmaz.) and stem rust (caused by P. graminis Pers.:Pers.) resistance, stronger straw and earlier maturity compared to Genesis. AC Karma is eligible for grades of the Canada Prairie Spring (white) wheat class. Key words:Triticum aestivum L., cultivar description, loose smut resistance, common bunt resistance, high yield, white kernel, spring wheat
Herbicide reduction in metribuzin-based weed control programs in corn
Authors: Hamill Allan S. , Zhang Jianhua
Published: April 2011

The relative effectiveness of 13 metribuzin-based weed control programs in field corn was investigated in a 3-yr study. Reduction in herbicide rates was made by modifying some commonly used metribuzin-based herbicide programs for weed control in corn. Satisfactory weed control, corn yield and economic return were obtained under each herbicide treatment, suggesting that reduction in herbicide use to reduce environmental hazard and enhance the economical benefit is achievable. Among the various herbicide programs, banded herbicide application at reduced rates plus one cultivation was observed to be the most economic weed management practice. Herbicides applied early (2–3 leaves) showed better results than those applied later (6–7 leaves) in the development stage of corn, although both times of application are within the critical period of weed control for corn. Key words: Corn (Zea mays), economic return, herbicides, weed control
Physical and chemical defences of pods and seeds of white mustard (Sinapis alba L.) against tarnished plant bugs, Lygus lineolaris (Palisot de Beauvois) (Heteroptera: Miridae)
Authors: Bodnaryk Robert P.
Published: April 2011

Adult tarnished plant bugs (Lygus lineolaris) fed 5–10 times less frequently on seeds within pods of white mustard (Sinapis alba L.) than on seeds within pods of canola (Barssica napus L.) in no-choice feeding tests in the laboratory. The presence of long, sharp spines (trichomes) on pods of S. alba did not account for all of the difference in feeding on this mustard and on the smooth pods of canola because the feeding rate on shaved pods of S. alba was only twofold higher than on unshaved controls. Lygus lineolaris fed four times less frequently on seeds within pods of a commercial cultivar than on seeds of a near-isogenic low-glucosinolate line of S. alba, suggesting that it is the high concentration of the glucosinolate "sinalbin" in seeds that largely determines the low rate of feeding of L. lineolaris on this species.Plant breeders are currently developing low-glucosinolate lines of mustards such as S. alba for the oilseed market. Seed damage by L. lineolaris in an oilseed S. alba likely will be considerably higher than currently occurs in the mustard S. alba. Key words:Brassica, Sinapis, Lygus, trichome, glucosinolate, feeding damage, antixenosis
Effect of seed size on seedling vigor and forage production of winter wheat
Authors: Bockus W. W. , Shroyer J. P.
Published: April 2011

There are numerous reports of increased wheat (Triticum aestivum L.) grain yields with large seed compared with small, but these do not relate to use of wheat for grazing purposes. Field experiments were conducted over 3 yr to measure the effect of seed size on stands, percentage ground cover, and fall and spring forage production. Other variables included sowing plots by seed number or volume per unit area. When sown at the same number of seed per square metre (220), large (> 0.24-cm diameter) seed resulted in 16–74% more plants per area than small (< 0.20-cm) diameter seed. When sown by volume (8.7 mL m−2), stands from small seed were similar to or more dense than those from large seed. When sown by seed number, large seed increased fall ground cover by 58–100% over small seed; however, even when sown by volume, large seed increased ground cover by 13–26%. Similarly, when seeded on an equal-number basis, large seed increased fall and spring forage 23–214% over that produced by small seed. Although sowing on an equal-volume basis resulted in fewer significant differences among seed sizes, large seed produced 35% more fall forage one year and 44% more spring forage another year. Therefore, sowing large seed should help reduce soil erosion by producing plants with greater ground cover. Similarly, large seed should increase the amount of forage for producers who sow winter wheat early as a prelude to grazing livestock. Key words:Triticum aestivum, forage, seed size, soil erosion control, seedling vigor
Sweetheart sweet cherry
Authors: Lane W. D. , MacDonald R. A.
Published: April 2011

Sweetheart is a very late maturing self-fertile sweet cherry (Prunus avium L.) with large firm fruit which are moderately resistant to rain induced splitting. It has performed well in British Columbia, Washington State and France. Key words: sweet cherry, cultivar description
The effect of seeding date and plant density on infestations of root maggots, Delia spp. (Diptera: Anthomyiidae), in canola
Authors: Dosdall L. M. , Herbut M. J. , Cowle N. T. , Micklich T. M.
Published: April 2011

Five seeding dates and four plant densities were evaluated in 1991 and 1992 for reducing infestations of root maggots, Delia radicum (L.) and Delia floralis (Fallén) (Diptera: Anthomyiidae), in both species of canola (Brassica rapa L. and Brassica napus L.), under field conditions in central Alberta, Canada. Infestations were assessed by numbers of eggs laid throughout the season and by degree of damage to taproots at the end of the season. Root maggot infestations were reduced by seeding in late May rather than in early or mid-May, but because seed yield also declined with late-May plantings, delaying canola seeding is not an appropriate cultural control strategy. Increasing plant density, however, resulted in reduced infestations and increased seed yield and so is considered an acceptable control practice. Increases in plant density caused corresponding and statistically significant decreases in basal stem diameter of canola. Moreover, increases in basal stem diameter resulted in corresponding and significant increases in Delia spp. egg populations and damage to taproots from larval feeding. These data suggest that ovipositing females of Delia spp. select larger canola plants, i.e., those seeded earlier or at lower densities, and these are consequently damaged to a greater degree than smaller plants. Key words:Brassica napus, Brassica rapa, Delia radicum, Delia floralis, seeding date, plant density, Insecta, cultural control
Field evaluation of the suitability of four Brassica and two Sinapis species (Brassicaceae) as host plants of Lygus lineolaris (Palisot de Beauvois) (Heteroptera: Miridae)
Authors: Gerber G. H.
Published: April 2011

The relative suitability of Sinapis alba L., Sinapis arvensis L., Brassica carinata A. Braun, Brassica juncea (L.) Czern, Brassica napus L., and Brassica rapa L. as host plants for Lygus lineolaris (Palisot de Beauvois) was measured by comparing the numbers of colonizing adults (first generation), nymphs (second generation), and new-generation adults (second generation) on these species in field plots during flowering and seed development in July and August 1994. The mean numbers of first-generation adults and second-generation nymphs were not significantly different on the six species of Brassica and Sinapis. The mean number of second-generation adults differed significantly on these species, but the differences were relatively small. The results indicate that the six species of Brassica and Sinapis tested are suitable host plants of L. lineolaris and have similar levels of suitability. Key words: Insecta, Miridae, Lygus lineolaris, host plants, Brassica, Sinapis
AC Barrie hard red spring wheat
Authors: McCaig T. N. , DePauw R. M. , Clarke J. M. , McLeod J. G. , Fernandez M. R. , Knox R. E.
Published: April 2011

AC Barrie hard red spring wheat is adapted to the Canadian prairies. It combines high grain yield with high protein content. It is slightly shorter with stronger straw than Katepwa and Laura, and has resistance to leaf and stem rust, common bunt, and loose smut. Key words:Triticum aestivum, spring wheat, cultivar description
AEC Hillcrest awned slender wheatgrass
Authors: Darroch B. A. , Acharya S. N.
Published: April 2011

AEC Hillcrest awned slender wheatgrass [Elymus trachycaulus subsp. subsecundus (Link) Gould] is a reclamation variety developed for use in reclaiming and revegetating disturbed sites in the mountains and foothills of Alberta. It is the first variety of awned slender wheatgrass available in Canada. Key words: Awned wheatgrass, slender wheatgrass, Elymus trachycaulus, cultivar description, reclamation
Agronomic performance and seed quality of Ethiopian mustard in Saskatchewan
Authors: Getinet A. , Rakow G. , Downey R. K.
Published: April 2011

Ethiopian mustard (Brassica carinata A. Braun) is grown as an oilseed crop in Ethiopia. The agronomic performance and seed quality of 11 B. carinata lines were evaluated for 2 yr in field tests at Saskatoon, Saskatchewan, to asses the potential of Ethiopian mustard as an oilseed crop for the Canadian prairies. The B. carinata accessions were 5 d later flowering and 19 d later maturing than the B. napus cultivar Westar. Seed yields of B. carinata were comparable to those of B. napus in 1984, but were much lower than those of B. napus and B. juncea in 1985. Seed of B. carinata had higher protein and lower oil and crude fibre contents than that of B. napus and B. rapa. The fatty acid composition of the oil of B. carinata seed was typical for that of a high erucic acid Brassica oil. Allyl glucosinolate was the only alkenyl glucosinolate found in B. carinata seed meal. A comparison of near isogenic yellow and brown B. carinata lines indicated that, on average, yellow lines produced heavier seed (+ 0.4 g), higher oil (+ 23 g kg−1) and protein (+ 21 g kg−1) and lower crude fibre (− 12 g kg−1) contents than brown lines. Correlation studies showed that seed weight was positively correlated with oil and protein and negatively correlated with fibre content. The results of this study indicated that none of the 11 lines of B. carinata tested was adapted for immediate production on the Canadian prairies. Earlier-maturing, higher-oil-content lines of B. carinata that produce low erucic acid and low glucosinolate seed must be developed before this species can be grown as an oilseed crop in Canada. Key words:Brassica carinata, agronomic performance, seed quality
Out-crossing rates for 10 Canadian spring wheat cultivars
Authors: Hucl P.
Published: April 2011

The genetic purity of pedigreed wheat seed can be compromised by inter-cultivar cross-pollination. Common wheat (Triticum aestivum L.) is assumed to be highly self-pollinated, an assumption that has not been verified for more recent western Canadian spring wheat cultivars. This field study was designed to estimate the outcrossing (OC) rate in three market classes of spring wheat in each of 2 yr and to determine whether OC rates were associated with specific spike characteristics. Highest OC rates were detected for the cultivar Oslo (6.05%) followed by Rongotea (2.30%), Roblin (1.43%), Wildcat (1.35%), Biggar (1.05%) and Glenlea (0.95%). In contrast Katepwa and CDC Makwa had OC rates of 0.38 and 0.30%, respectively. The cultivars Oslo, Columbus, Roblin and Glenlea tended to have lower iodine pollen viabilities. Of those four cultivars, three had higher-than-average OC rates. No single spike characteristic was correlated with OC rate. However, the cultivars Oslo, Wildcat and Glenlea had high OC rates, low pollen staining and spikes which tapered at the extremeties. Furthermore, cultivars with higher OC rates tended to have a greater degree of spikelet opening at anthesis. The high levels of OC observed in this study could result in obvious off-types if morphologically diverse cultivars were grown in adjacent pedigreed seed fields. The current 3 to 10 m isolation distance for pedigreed wheat seed production may not be enough to ensure that OC is minimized. Key words: Cross-pollination, spring wheat, market class
Seed yield and quality of Altai wildrye in populations of contrasting visible glaucousness
Authors: Jefferson Paul G. , Kielly G. Andrew
Published: April 2011

Glaucous Altai wildrye grass, Leymus angustus (Trin.) Pilger, has been reported to exhibit higher seed yield than the normal green phenotype. Seed quality is correlated with successful seedling establishment. Our objective was to determine the seed yield and quality of three half-sib populations of Altai wildrye that differed in visible glaucousness. Seed was harvested from 60 glaucous, 60 non-glaucous, and 60 variably glaucous half-sib lines over 3 yr at a semi-arid location. Seed yield, seed weight and germination was greater from glaucous lines than the nonglaucous lines. Key words: Glaucous, range improvement, seedling establishment, epicuticular wax
AC Emerson flax
Authors: Kenaschuk E. O. , Rashid K. Y. , Gubbels G. H.
Published: April 2011

AC Emerson, a medium-early maturing oilseed flax (Linum usitatissimum L.), was released by Agriculture and Agri-Food Canada, Agri-Food Diversification Research Centre, Morden, Manitoba, in 1994. The cultivar has high oil quality, medium-large seed size and was high yielding in both early and late seeding tests in the Black and the Brown Soil zones of Manitoba and Saskatchewan. Because of its chlorosis tolerance, it is particularly well suited to the calcareous soils of Manitoba. It is immune to North American races of rust caused by Melampsora lini and moderately resistant to wilt caused by Fusarium oxysporum f. sp. lini. Key words: Flax, oilseed, Linum usitatissimum L., cultivar description