bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal changes in net carbon dioxide exchange rates of Autumn Bliss, a primocane-fruiting red raspberry (Rubus idaeus L.)
Authors: Privé Jean-Pierre , Sullivan J. A. , Proctor J. T. A.
Published: April 2011

Seasonal changes in leaf net carbon exchange rate (NCER), stomatal conductance (gs), and intercellular CO2 (ci) were determined for 2-yr-old potted Autumn Bliss (Rubus idaeus L.) plants grown under field conditions. NCER varied inconsistently between leaves which subtended fruiting lateral branches (laterals) and those that did not. In leaves with fruiting laterals, it was lower on three dates, similar on three other dates and once greater than in leaves without fruiting laterals. Evidence of nonstomatal inhibition of photosynthesis was also apparent as leaf NCER and gs fluctuated during the season while ci remained relatively constant. The leaf chlorophyll content increased when fruiting laterals were present, but this did not produce a consistently higher leaf NCER. The SPAD-501 meter provided a rapid and accurate, nondestructive estimate of leaf chlorophyll content for Autumn Bliss red raspberry leaves. Under uniform environmental conditions, all healthy, fully expanded leaves along the primocane had the same photosynthetic potential. Also, leaf age did not influence leaf gas exchange until the leaves started to senesce. Therefore, good light interception throughout the canopy is needed to optimize dry matter production in primocane-fruiting red raspberries. Key words: Rubus idaeus L., primocane-fruiting, leaf gas exchange
Évaluation de la tolérance de Betula pendula et de Betula nigra aux conditions climatiques du nord-est canadien
Authors: Richer-Leclerc C. , Rioux J. A. , Végiard S. , Côté J. , Guillemette L.
Published: April 2011

A 5-yr study was conducted to evaluate the winter hardiness and growth potential of seedlings of Betulapendula and Betulanigra in order to provide adequate recommendations regarding their adaptation to different climatic conditions. Plants were grown at nine sites of the Réseau d'Essais des Plantes Ligneuses Ornementales du Québec. Betulapendula and B. nigra were not severely affected by winter conditions at any sites and could be used in zones 2 and 2a, respectively. Although, B. pendula could be successfully grown in all tested area, B. nigra could be better produced in zone 5. Key words: Betulapendula, Betulanigra, birch, hardiness, winter damage, growth potential, evaluation
TNS soybean
Authors: Voldeng H. D. , Frégeau-Reid J. A. , Guillemette R. J. D. , Leonard D. A. , Cober E. R.
Published: April 2011

TNS is a 2600 crop heat unit natto type soybean (Glycine max [L.] Merr.) cultivar. Key words: Natto type soybean, cultivar description
Effects of including dry polyacrylamide gel with seed on establishment of alfalfa and Russian wildrye
Authors: Waddington John
Published: April 2011

To examine the possible benefits of crosslinked polyacrylamide gel when establishing forages in a semiarid environment, applications of dry gel in fine, medium and coarse granular forms were made at rates from 0.25 to 4.00 g m−1 of row with seed of alfalfa (Medicago sativa L.) and Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski] in each year 1992–1994 at Swift Current, Saskatchewan. The gel had no effect on seedling year establishment or first year forage production on a sandy-loam soil. On a nearby sandy-clay loam soil, in one of 3 yr with alfalfa, and 2 of 3 yr with Russian wildrye, the lowest gel rate decreased establishment compared with the check, with a further reduction as the rate of gel increased. Alfalfa forage yields were not affected. Gel application decreased Russian wildrye forage yield in 1 of 3 yr. Key words: Medicago sativa, Psathyrostachys juncea, forage yield, soil texture
Proximate and mineral composition of field peas
Authors: Warkentin T. D. , Sloan A. G. , Ali-Khan S. T.
Published: April 2011

Field pea seeds from 10 cultivars grown at two locations in Manitoba in 1986 and 1987 were analyzed for proximate and mineral profiles. Cultivars differed significantly in their level of total protein, crude fat, ADF, and all minerals tested. However, differences were not extremely large and were comparable to European reports. Location-year also had a significant effect on the levels of total protein, ADF, and all minerals tested. In most cases, the warmest location-year produced relatively higher levels of minerals, ash, and total protein, and lower seed yield than the coolest location-year. Key words: Field pea, Pisum sativum L., mineral
AC Harosprout mungbean
Authors: Park S. J. , Anderson T. R.
Published: April 2011

AC Harosprout is a medium to full-season-maturing and high-yielding mungbean [Vigna radiata (L.) Wilczek] cultivar. It is adapted to southwestern Ontario for the production of green beans for sprouting and other human uses. It was purified from an introduction VC1973A from the Asian Vegetable Research and Development Centre (AVRDC). Key words: Vigna radiata, mungbean, green bean, green gram, bean sprout, cultivar description
Water use patterns of eastern black nightshade (Solanum ptycanthum) and hairy nightshade (Solanum sarrachoides) in response to shading and water stress
Authors: Tan C. S. , Weaver S. E.
Published: April 2011

Greenhouse and growth room experiments were conducted to determine the effects of shading and water stress on transpiration of eastern black nightshade (Solanum ptycanthum) and hairy nightshade (S. sarrachoides). Transpiration rates were estimated using heat balance stem flow gauges. Eastern black nightshade transpired significantly more water than hairy nightshade given ample water and light. Eastern black nightshade also transpired more water than hairy nightshade when shaded. Transpiration of both species increased with light intensity and was relatively insensitive to changes in soil volumetric water content above 0.10 m3 m−3, but declined sharply below that level. Eastern black nightshade had significantly more stomata than hairy nightshade, particularly on the lower leaf surface. Key words: Sap flow, stomata
Long-term effects of burn-pruning on lowbush blueberry (Vaccinium angustifolium Ait.) production
Authors: Penney B. G. , McRae K. B. , Rayment A. F.
Published: April 2011

Burning is a pruning technique used to improve productivity of lowbush blueberry fields. Growers, however, are concerned that continuing and frequent burning might reduce production and eventually destroy blueberry fields. To assess the effect of long-term spring burn-pruning on blueberry production and the surface organic layer, 2-, 3- and 4-yr burning cycles were studied for 24 yr on a previously unfertilized natural stand of lowbush blueberry. Mean annual yield (averaged over burn and crop years) decreased with increases in the interval between burning due to decreased production in the second and third crop years following burning. Yield in the third crop year was similar to that from the unburned check plots. There was no significant yield decrease between the first 12 yr (period 1) and the second 12 yr (period 2) of production for the 2-yr cycle, but there were declines for the 3- and 4-yr cycles due mainly to lower yields in the second crop. Lower second-crop yields in the second period was attributed to damage by the blueberry leaftier (Croesia curvalana Kft.). Mean annual ripe fruit yields for the 2-, 3- and 4-yr cycles and unburned check were 473, 458, 335 and 109 kg ha−1, respectively, in period 1 and 478, 340, 277 and 38 kg ha−1, respectively, in period 2. Burning did not decrease the depth of the surface organic layer. Key words: Lowbush blueberry, Vaccinium angustifolium, burning, pruning, organic matter, yield, berry weight, flower buds, residual maximum likelihood
AC Langille birdsfoot trefoil
Authors: Papadopoulos Y. A. , Choo T. M. , Christie B. R. , Thomas W. G. , McKenzie D. B. , Bélanger G. , Sutherland K. , McRae K. B. , Fillmore S. A. E.
Published: April 2011

AC Langille is a birdsfoot trefoil (Lotus corniculatus L.) cultivar developed by the Nappan Research Farm, Agriculture and Agri-Food Canada. It was developed through two cycles of mass selection for winterhardiness and one cycle of mass selection for seedling vigor. The original material was six distinct germplasms selected from the cultivar Leo and released from the Crop Science Department of the University of Guelph. AC Langille is superior to the check cultivar Leo in forage yield and seedling vigor in Atlantic Canada. Key words: Birdsfoot trefoil, Lotus corniculatus, cultivar description, seedling vigor
AC Sunbeam summer turnip rape
Authors: Woods D. L.
Published: April 2011

AC Sunbeam summer turnip rape (Brassica rapa L.) is a canola-quality cultivar. It is well adapted to the short and mid-season growing areas of western Canada. It is higher yielding than AC Parkland, and has a higher oil and protein content than Tobin. AC Sunbeam has a good level of resistance to white rust, and has a very low meal glucosinolate content. Key words: Rape, canola, Brassica rapa, cultivar description
Evaluation of field and laboratory predictors of drought and heat tolerance in winter cereals
Authors: Gavuzzi P. , Rizza F. , Palumbo M. , Campanile R. G. , Ricciardi G. L. , Borghi B.
Published: April 2011

In Mediterranean regions, plant breeding programs are being conducted to select genotypes having high and stable yields. Screening techniques that are able to identify desirable genotypes based on the evaluation of physiological traits related to stress tolerance could be useful, particularly if they are rapid, simple and inexpensive. The objectives of this study were: i) to evaluate the validity of four laboratory screening tests to discriminate among bread wheat (Triticum aestivum L.), durum wheat (Triticum turgidum L.) and barley (Hordeum vulgare L.) cultivars differing in adaptation to the Mediterranean climate; ii) to evaluate the repeatability of determinations performed on cultivars grown in different locations and years, and iii) to evaluate relationships among the tests and yield performance under stress. The tests were: cellular membrane stability after heat (CMS-HS) and drought stress (CMS-DS), tolerance to leaf water loss (LWL), and translocation capacity after the chemical desiccation (CD) of the photosynthetic apparatus. The CMS-HS and CMS-DS tests revealed genetic variability in all the three species. The LWL test did not differentiate genotypes at some sites. Genetic differences for grain yield, kernel weight and harvest index after chemical desiccation were evident for wheat genotypes but the test did not differentiate barley genotypes. The test performed under laboratory controlled conditions (CMS-HS, CMS-DS and LWL) was less affected by environment compared with the test based on the evaluation of the translocation capacity after chemical desiccation carried out in the field. We concluded that, when good standardization of procedures are obtained, the tests investigated can be regarded as possible tools in breeding programs for tolerance to heat and drought stress. Key words: Wheat, barley, drought screening
Mitochondrial and nuclear DNA variation, genotype fingerprinting and genetic relationships in lentil (Lens culinaris Medik.)
Authors: Rajora Om P. , Mahon John D.
Published: April 2011

Mitochondrial DNA (mtDNA) and nuclear DNA (nuDNA) variations were examined in six cultivars of Lens culinaris ssp. culinaris and two (mtDNA) or one (nuDNA) accession(s) of L. culinaris ssp. orientalis. Total leaf DNA was digested with up to 15 restriction endonucleases, separated by agarose gel electrophoresis and trasferred to nylon membranes. To examine mtDNA variation, blots were probed with mtDNA coding for cytochrome c oxidase I (coxI) and ATPase 6 (atp6) of both wheat and maize as well as apocytochrome b (cob) and Orf25 (orf25) of wheat. Sixteen combinations of mtDNA probes and restriction enzymes revealed 34 fragments that discriminated between at least two lentil accessions. For nuDNA analysis, probes from cDNA and genomic DNA clones of lentil were used to probe the same blots, and identified 46 diagnostic fragments from 19 probe/enzyme combinations. Each lentil accession could be unequivocably distinguished from all others on the basis of both mitochondrial and nuclear DNA fragment patterns. The mitochondrial restriction fragment similarities ranged from 0.944 to 0.989, with a mean of 0.970 but nuclear restriction fragment similarities varied from 0.582 to 0.987, with a mean of 0.743. The apparent genetic relationships among accessions differed according to the source of DNA examined, although the commercial varieties Laird, Brewer and Redchief showed similarly high levels of mean similarity with both nuclear (0.982) and mitochondrial DNA (0.983). Key words: Lens culinaris Medik., genetic variation, mitochondrial, nuclear, DNA, lentil
The conversion of cellulose to electrons: The future of scientific journals from a scientist's perspective
Authors: Vessey J. Kevin
Published: April 2011

Rapidly increasing costs of print-on-paper scientific journals are largely driving the move to electronic publishing. Current electronic scientific journals range in format from non-peer reviewed, bulletin-board types that are free to users, through to expensive, user-friendly, multimedia types established by new or traditional scientific publishers. Potential advantages of electronic publishing scientific journals include faster and wider access, cost-savings (up to 75–80%), greater speed of publication, and colour and multimedia presentation of data. Problems to be faced in electronic publishing of scientific journals include limitations in monitor technology, "traffic" on the Internet, resolution of fine detail in electronic graphic images, and the method of payment. It is concluded that the advantages of electronic scientific journals will result in a near complete conversion from print-on-paper to electronic publishing in the near future. Key words: Electronic publishing, internet, multimedia, scientific journals
An investigation on linkage between white flower colour and erucic acid in summer rape
Authors: Woods D. L. , Séguin-Swartz G.
Published: April 2011

A dominant gene for white flower colour, derived from Brassica albogabra, is shown to be closely linked to a gene for seed erucic acid in summer rape (Brassica napus). This observation conflicts with a previous report on material of the same origin, where independent inheritance of these characters was reported. Key words: Brassica napus, flower colour, erucic acid, linkage, summer rape
Hysyn111 summer turnip rape
Authors: Stoenescu F. M. , Falk K.C.
Published: April 2011

Hysyn111 summer turnip rape (Brassica rapa L.) is a canola-quality population-synthetic (syn1) cultivar adapted to the short and mid-season growing areas of western Canada. Key words: Turnip rape (summer), synthetic, cultivar description
Genetic variances, heritabilities and genetic correlations of grain yield, harvest index and yield components for common bean (Phaseolus vulgaris L.) in sole crop and in maize/bean intercrop
Authors: Atuahene-Amankwa G. , Michaels T. E.
Published: April 2011

Breeding of common bean (Phaseolus vulgaris L.) for intercropping with maize (Zea mays L.) is usually done in bean sole crop nurseries. However, bean cultivar evaluations have identified significant cultivar × cropping system interactions. The objective of this study was to determine whether intercrop and sole cropping systems have different effects on phenotypic and genetic variance components of bean populations. Unselected F2 and F3 populations of 16 crosses of common bean were evaluated in the two cropping systems at Elora and Woodstock, Ontario, Canada, in 1993 and 1994. Significant population × cropping system interaction was found for grain yield and pods per plant. Genetic correlations between cropping systems were lowest for grain yield and pods per plant and highest for seed weight and seeds per pod. There were few differences between cropping systems for genetic variances. Genotype × location variance was higher in intercrop than in sole crop. Broad-sense heritabilities and narrow-sense heritabilities for most traits were comparable between cropping systems. The exception was pods per plant, which showed greater heritability in sole crop. Realized heritability of grain yield was greater in intercrop. We conclude that single plant selection as done with the pedigree system of breeding should be effective in intercrop. Key words: Genetic variances, heritability, intercrop, Phaseolus vulgaris
Nitrogen, phosphorus and zinc management effects on grain yield and cadmium concentration in two cultivars of durum wheat
Authors: Grant C. A. , Bailey L. D.
Published: April 2011

Cadmium concentration in durum (Triticum turgidum) grain may be influenced by fertilizer management. A 3-yr field study conducted on two Orthic Black Chernozemic soils investigated the effects of banded and broadcast applications of N and P, and applications of Zn fertilizer on the yield and Cd concentration of the grain of two cultivars of durum wheat. Applications of N and P fertilizer increased grain yield of durum wheat when soil nutrient supply was low or yield potential was high, while Zn application generally had little effect on grain yield. Cadmium concentration of durum increased with applications of N and P and was generally unaffected by Zn application. Method of application of N or P did not consistently influence either grain yield or Cd concentration of the grain under the conditions of this study. Where differences due to placement occurred, banded P produced higher grain yield and Cd concentration than application of the same level of P as a broadcast treatment. Cadmium accumulation increased substantially with N and P applications, since both Cd concentration in the grain and grain yield increased with N and P application. Year-to-year variation in Cd concentration in the grain was large, indicating a strong effect of environment on Cd phytoavailability. Key words: Management, banding, nutrient, accumulation
Histochemistry and UV-microspectrometry of cell walls of untreated and ammonia-treated barley straw
Authors: Goto Masakazu , Takabe Keiji , Abe Isao
Published: April 2011

Histochemical staining reactions with acid phloroglucinol and ultraviolet (UV) absorption spectra of the individual cell walls in spring barley straw (Hordeum vulgare L.) were investigated in combination with spectrometric measurements of the dioxane-water soluble lignin. Changes in lignin structure of barley straw with ammonia treatment were also investigated. Parenchyma and metaxylem vessel walls in untreated straw stained red with acid phloroglucinol and had higher absorbances around 550 nm than did epidermis and sclerenchyma cell walls, being consistent with the λmax of coniferylaldehyde. Following a reductive treatment, the lignins isolated from untreated barley straw showed an increase in UV absorbance at 280 nm and a decrease in that around 320 nm. These regions in UV and IR absorption spectra are assigned to conjugated carbonyl groups as shown by the narrowing of the IR absorption band at 1660 cm−1, and this was consistent with the staining observation of the specific tissue walls. UV microspectrometry indicated that parenchyma cell walls were much less lignified tissues than metaxylem and protoxylem vessel walls and probably epidermal cell walls. The lignins isolated from untreated and ammonia-treated straw had similar values for empirical formulae of the C9 units, phenolic hydroxyl and methoxyl group contents, and molecular weight, although the lignin of ammonia-treated straw had a slightly higher contents of nitrogen and hydrogen. The IR bands of 1730–1680 cm−1 in ammonia-treated straw lignin also disappeared. Therefore, ammonia appeared to react with the carbon atoms of the propane side-chain. Key words: Ammonia treatment, barley straw, lignin distribution, lignin structure, staining with acid phloroglucinol, ultraviolet microspectrometry
Shearing force of alfalfa stems: effects of cultivar and shearing site
Authors: Iwaasa A. D. , Beauchemin K. A. , Acharya S. N. , Buchanan-Smith J. G.
Published: April 2011

A 3-yr study was conducted to investigate the effect of shearing position on shearing force characteristics in alfalfa (Medicago sativa L.) stems and to evaluate the relationship between cell wall (CW) chemical constituents and stem shearing force. Stems from plots of 24 alfalfa cultivars were harvested from the second, third and fourth production years. Each stem was divided into three 16-cm segments: top, middle and bottom, and the force required to shear each segment was measured using a modified Ottawa Texture Measuring System. Cultivar by stem segment interactions were significant (P < 0.05) for stem diameter, weight and shearing force. The middle and bottom stem segments were the best sampling site to detect cultivar differences for shearing force. Stem diameter and weight were generally the variables most associated with shearing force for all three stem segments. However, shearing force characteristics for certain cultivars could not be entirely explained by stem diameter or weight and may be affected by CW chemical constituents and/or structural tissues. The ADL concentrations were not consistently correlated to shearing force at the top and bottom segments over the 3 yr. For the bottom stem segment a negative relationship (r = −0.42, P < 0.001) resulted between shearing force and hemicellulose, while a positive relationship (r = 0.40, P < 0.001) resulted between shearing force and cellulose. Key words: Cultivar, environment, shearing force, cell wall chemical constituents
Effects of sowing date, photoperiod and nitrogen on variation in main culm leaf dimensions in field-grown wheat
Authors: Hotsonyame G. K. , Hunt L. A.
Published: April 2011

In some cereal simulation models, canopy leaf area development is calculated using relationships that summarize how leaf size changes with position. The nature and extent to which various environmental factors interact with ontogenetic variations in leaf size, however, is not clearly understood. This study was undertaken, therefore, to evaluate how temperature, photoperiod and nitrogen impact on leaf to leaf relationships in wheat grown under field conditions. Four contrasting genotypes of wheat comprising two spring and two unvernalized winter types were sown on five dates, supplied with one of two levels of nitrogen (150 kg N ha−1 and 0 kg N ha−1), and grown under natural and extended photoperiod conditions. For the spring wheats, individual mature leaf area increased along with leaf number up to leaf 5 (a stage that coincided with rapid stem elongation) but varied for subsequent leaves in a manner that was dependent on genotype and environment.In the period prior to the expansion of the fifth leaf, neither nitrogen nor photoperiod significantly influenced the pattern of change in leaf size. Thereafter, leaves under low nitrogen and extended photoperiod progressively became smaller, an effect that was due primarily to changes in length rather than in width. For the winter genotypes, which did not reach the stage of rapid stem elongation, mature leaf dimensions increased along with leaf number during the whole period of study and were not markedly affected by photoperiod but, after leaf 5, were smaller for the low nitrogen level. For all genotypes, the size of the first leaf and the coefficients derived by regressing the area of successive leaves on the area of the previous leaf during the vegetative phase varied among sowing dates due partly to the temperature environment under which the leaves at each node developed. The results, however, indicated that the potential leaf size at any of the lowermost leaf positions can be obtained by using a logarithmic function that relates the potential size of one leaf to its predecessor. Such relationship can be used to calculate actual leaf size if account is taken of environmental and assimilate supply factors that operate during leaf expansion. Key words: Wheat, sowing date, leaf area, temperature, photoperiod
The effect of soybean variety on corn-soybean intercrop biomass and protein yields
Authors: Martin R. C. , Astatkie T. , Cooper J. M.
Published: April 2011

Soybean intercropped with corn can produce a high-quality silage, but pods of early maturing soybean varieties usually shatter when harvested, thus reducing the silage protein potential. In 1991 and 1992, an experiment was conducted in Truro, Nova Scotia, and Sussex, New Brunswick, to determine whether later soybean varieties can provide sufficient biomass and protein in intercrops and escape pod losses at harvest. Early, early high protein, medium, late and very late maturing varieties of soybean were grown as monocrops and intercrops with corn. Eight response variables were measured: soybean shoot biomass yield, intercrop shoot biomass yield, soybean shoot protein concentration, intercrop shoot protein concentration, soybean shoot protein yield, intercrop shoot protein yield, soybean seed biomass yield and soybean seed protein concentration. The two later soybean varieties had higher yields than the two early varieties, contributing to higher protein yields in the later varieties than in the early varieties, under both monocropping and intercropping. In contrast to the corn monocrop, intercrops with all soybean varieties produced higher protein concentrations. Under intercropping, only the late variety produced significantly higher protein yields than the corn monocrop; however, none of the varieties resulted in significantly lower biomass yields than the corn monocrop. With the late soybean variety, land equivalent ratios of the intercrop shoot biomass yield and the intercrop shoot protein yield revealed yield advantages of intercrops over monocrops of 21% and 10%, respectively. The late variety resulted in an increased intercrop shoot protein concentration without reducing the intercrop shoot biomass yield, because it was still green enough to be harvested with minimal pod shattering. Key words: Soybean variety, corn-soybean intercrop, biomass, silage protein
Use of planting depth and budding height to modify vigour control of Ottawa 3 apple rootstock
Authors: Quamme H. A. , Hampson C. R. , Brownlee R. T.
Published: April 2011

The dwarfing apple rootstock Ottawa 3 (O.3) produces trees slightly too large for high density plantings on fertile soils, but it is more cold hardy and better anchored than Malling 9. Our objective was to reduce the vigour of trees on O.3 by budding scions higher or planting the trees more shallowly. Summerland McIntosh was budded at 15 cm onto O.3 and planted such that 6 to 14 cm of the rootstock shank was above ground. Planting depth did not affect tree size, yield or yield efficiency. Increasing budding height from 5 to 25 cm increased vigour control, yield efficiency and the production of root suckers on O.3. Higher budding may be an effective way to reduce the vigour of trees on O.3 in areas where the greater root suckering is not a fireblight hazard. Key words: Malus domestica Borkh., dwarfing rootstock
Time of application and winter wheat genotype affect production of large seed after fungicide application
Authors: Bockus W. W. , Bowden R. L. , Claassen M. M. , Gordon W. B. , Heer W. F. , Shroyer J. P.
Published: April 2011

Two field experiments were established to compare four times of fungicide application (flag leaf emergence, boot, fully headed, and milky ripe) for improving production of large seed. Quadratic models fit the data when large-seed (≥0.238-cm diameter) yields were regressed against time of fungicide application. The optimum time to apply foliar fungicides was between boot and fully headed. Four other field experiments were established to compare large-seed yields after fungicide application on 12 cultivars differing in susceptibility to foliar diseases. With moderate foliar disease pressure, linear models fit the data when increases in large seed due to fungicide were regressed against Kansas Cooperative Extension Service disease ratings. In conjunction with the expected price of seed wheat, these models can be used to help decide whether foliar fungicide is warranted. Key words: Pyrenophora tritici-repentis, Puccinia recondita, Septoria tritici, Stagonospora nodorum, seed cleanout, tebuconazole, propiconazole, foliar disease control
Early generation testing of common bean (Phaseolus vulgaris L.) populations in sole crop and in maize/bean intercrop
Authors: Atuahene-Amankwa G. , Falk D. E. , Beattie A. D. , Michaels T. E.
Published: April 2011

Few plant-breeding studies have examined methodology for improving common bean (Phaseolus vulgaris L.) yields by selecting in an intercrop situation. We hypothesized that early-generation testing would be as useful in a maize (Zea mays L.)/bean intercrop as in sole crop for identifying superior bean populations for yield. F2 to F5 bulks of six selected crosses and their F5-derived advanced lines were evaluated in sole crop or intercrop. The F2 and F5 bulks were evaluated together in a preliminary trial in one location, while the advanced lines were evaluated with the F3s in one location, and with the F4s in two locations. Within sole crop, selection of the best three populations, based on F2 performance, provided 67% of the top advanced lines. The rank correlation between average bulk yield across generations and the average line yield was positive and significant. Within intercrop, selection of the best three populations provided 56% of the top advanced lines. The rank correlation between advanced line yield and bulk yield across generations was positive but not significant. Also, the top three F2 populations selected in sole crop produced 89% of the top advanced lines in intercrop. Advanced line performance showed a positive significant correlation with mean F4 bulk performance for grain yield, 100-seed weight and seeds per pod within sole crop, while positive significant correlation was seen with pods per plant and seeds per pod in intercrop. Results indicate that F2 bulk yields can be used to discard the least promising crosses in both cropping systems. Key words: Early generation testing, Phaseolus vulgaris, intercropping
Kernel colour varies with cultivars and environments in barley
Authors: Edney M. J. , Choo T. M. , Kong D. , Ferguson T. , Ho K. M. , May K. W. , Martin R. A.
Published: April 2011

Kernel colour is an important marketing trait for both malting and feed barleys. Therefore a study was initiated to investigate the kernel colour of 75 Canadian barley (Hordeum vulgare L.) cultivars at three locations (Charlottetown, Ottawa and Bentley) across Canada in 1991 and 1992. Kernel colour was measured by an Instrumar Colormet Spectrocolorimeter. Kernel colour was found to be brighter at the two locations in eastern Canada (Charlottetown and Ottawa) than at the location in western Canada (Bentley). Two-row cultivars on average were more discoloured than six-row cultivars; eastern two-row were more discoloured than western two-row. Covered barleys were less discoloured than hulless barleys in five of the six environments, but covered barleys at Bentley in 1992 were more discoloured than hulless barleys. Kernel discolouration appeared to be associated with susceptibility to net blotch for six-row cultivars. More studies are needed on kernel discolouration of barley. Key words: Barley, Hordeum vulgare, kernel colour
Colombe soybean AC
Authors: Voldeng H. D. , Frégeau-Reid J. A. , Guillemette R. J. D. , Leonard D. A. , Cober E. R.
Published: April 2011

AC Colombe is a 2300 crop heat unit soybean (Glycine max [L.] Merr.) cultivar developed for natto soy-food production. Key words: Soybean, cultivar description, natto
The utilization of heterosis for seed yield in hybrid and synthetic cultivars of summer turnip rape
Authors: Falk K. C. , Rakow G. F. W. , Downey R. K.
Published: April 2011

Hybrids of summer turnip rape (Brassica rapa L. syn. B. campestris L.) have been shown to exhibit high levels of heterosis. This study was undertaken to determine whether the heterosis for seed yield observed in hybrids could be captured by synthetic cultivars of turnip rape. The agronomic performance of reciprocal inter-cultivar hybrids and their corresponding two-component synthetics was studied using four turnip rape cultivars. Hybrid seed was produced by hand pollination in the greenhouse and Syn1 seed was produced by mixing equal proportions of each parent to form the base seed (Syn0) of each synthetic, and planting these in isolation in the field. The seed yield of hybrids, synthetics and parents were similar in 1985 while in 1986, hybrids yielded 25% and synthetics 23% more than parents. Actual versus predicted synthetic yields were similar except for one synthetic, Echo-Torch in 1986, where the actual yield exceeded the predicted value. Hybrid yields may have been underestimated by the chosen prediction method and therefore the yield potential of hybrids would be greater than for synthetics in turnip rape. However, until a suitable pollination control system is developed in this species, synthetic cultivars are a viable alternative to hybrids. Key words: Turnip rape (summer), synthetic, hybrids, Brassica rapa, B. campestris
The biology of Canadian weeds. 109. Cytisus scoparius (L.) Link
Authors: Peterson David J. , Prasad Raj
Published: April 2011

Scotch broom (Cytisus scoparius [L.] Link.) is an exotic perennial, leguminous, deciduous shrub, which during the past century has greatly expanded its range along the Pacific and Atlantic coasts of North America, and in Australia, New Zealand, South Africa, Chile, Iran, and India. This shrub rapidly invades disturbed areas, forming dense thickets, which can suppress and inhibit native vegetation, including economically important conifer seedlings. The developmental characteristics whereby Scotch broom invades new sites include specialized stem photosynthesis, prolific seed production, longevity of seeds in the soil, and nitrogen fixation. Human activities such as planting along highways for beautification and prevention of soil erosion have accelerated the problem of rapid geographical dispersal. Various methods of control (chemical, manual, and biological) together with habitat, morphology, reproductive biology, growth and development are discussed. Key words: Cytisus scoparius, Ulex europaeus, Scotch broom, invasive weeds, bioherbicides, Fusarium tumidu
Levels of allozymic diversity in diploid and tetraploid Vaccinium sect. Cyanococcus (blueberries)
Authors: Hokanson Karen , Hancock Jim
Published: April 2011

Levels of allozymic diversity were examined in native Michigan populations of diploid Vaccinium myrtilloides, and the tetraploids, V. angustifolium and V. corymbosum. Plants from three populations of each species were included in the analysis. Levels of heterozygosity and the number of alleles were averaged over seven polymorphic isozyme loci within both populations and species. As has been found in other studies that compared closely related diploid and tetraploid species, the level of heterozygosity and number of alleles per locus were noticeably lower in the diploid V. myrtilloides (21.7%; 2.9) than in the tetraploids, V. angustifolium (57.1%; 3.4) and V. corymbosum (75.6%; 3.6). The average level of heterozygosity was almost 20% higher in V. corymbosum than V. angustifolium. These two tetraploid species may face distinct selective pressures or have differences in outcrossing rates. Key words: Vaccinium myrtilloides, Vaccinium corymbosum, Vaccinium angustifolium, autotetraploidy
Comparison of four organic amendments with a chemical fertilizer applied to three vegetables in rotation
Authors: Blatt C. R. , McRae K. B.
Published: April 2011

Field research, conducted for six seasons (1991–1996) on one soil type, compared organic amendments (three formulations of fish bone meal (FBM) and a marine sediment enriched with fish, lobster, and crab meal) with an NPK chemical fertilizer (17–17–17) and a zero-N control (0–17–17). Each fertilizer material was applied pre-plant at 80 kg N ha−1 to the same plot for six seasons that spanned two cycles of a three-crop rotation of seeded carrots, green beans, and transplanted cabbage. In plots receiving the organic amendments, soil pH and Ca increased over time compared with those plots receiving 17–17–17. The increase of soil Mg was greatest in plots receiving the fortified marine sediment treatment. Soil and leaf K values were lowest with the FBM treatment, reflecting its low K composition (6–10–1). Soil and foliar P values from the organic amendment plots were higher than those from the 17–17–17 plots. Foliar N, Ca, Mg, Fe, and B were not consistently affected by 17–17–17 or the organic amendments, but foliar Mn was higher in crops receiving 17–17–17. Marketable yields of cabbage and carrots in plots receiving the organic amendments were comparable with those from 17–17–17, but marketable yields of green beans were consistently higher in plots receiving 17–17–17. Soil and foliar results indicate that the cumulative effect of repeated application of these organic amendments is not detrimental to plant growth, and that these amendments produce marketable yields of cabbage and carrot equivalent to those of the chemical fertilizer. Key words: Fish bone meal, marine sediment, organic amendments, vegetables
Perennial sowthistle control with sequential herbicide treatments applied under minimum and zero tillage systems
Authors: Darwent A. L. , Harker K. N. , Clayton G. W.
Published: April 2011

Perennial sowthistle (Sonchus arvensis L.) control under minimum and zero tillage systems, and following several sequential in-crop herbicide treatments applied in a crop rotation of canola (Brassica rapa L.) followed by 3 yr of barley (Hordeum vulgare L.), was evaluated in two field experiments near Grande Prairie, Alberta. Under zero tillage, in-crop applications of clopyralid at 0.1 to 0.3 kg active ingredient (a.i.) ha−1 to canola, followed by annual in-crop applications of clopyralid at 0.15 kg a.i. ha−1 plus MCPA at 0.42 kg a.i ha−1 to barley in the next 2 yr, reduced perennial sowthistle from a mean initial density of 3.9 shoots m−2 to ≤0.5 shoots m−2 in the fourth year. Glyphosate at 0.45 kg acid equivalent (a.e.) ha−1 plus dicamba at 0.14 kg a.i. ha−1 was applied annually before seeding barley in these plots. In the second experiment, the same herbicide treatments, except for an additional preseeding application of glyphosate at 0.9 kg a.e. ha−1 in the first year, reduced perennial sowthistle density from 9.2 shoots m−2 to ≤0.1 shoots m−2 Increasing the rate of clopyralid in the first year resulted in decreases in perennial sowthistle density in the second and third years following application but not in the fourth year. In unweeded zero tillage check plots of the two experiments, perennial sowthistle increased to 41.8 and 36.0 shoots m–2, respectively, over the same period. Applying metsulfuron at 0.0045 kg a.i. ha–1 in the second year and dicamba plus the potassium salt of MCPA (1:4) at 0.54 kg a.i. ha−1 in the third year, in place of clopyralid plus MCPA, produced similar reductions in perennial sowthistle density. Under minimum tillage, where tillage was limited to a single preseeding discing before seeding and a single mid-to-late October deep tillage cultivation, reductions in perennial sowthistle density following in-crop applications of clopyralid in the first year and clopyralid plus MCPA in the next 2 yr were similar to those following application of the same in-crop herbicides under zero tillage. However, in minimum tillage plots where metsulfuron and dicamba plus MCPA were applied in the second and third years, perennial sowthistle density was not reduced or declined at a slower rate than in other sprayed plots. Canola and barley yields increased as a result of reductions in perennial sowthistle density. Key words: Perennial sowthistle, Sonchus arvensis L., tillage, clopyralid, metsulfuron, dicamba
Blackjack 21 Soybean
Authors: Ablett G.R. , Stirling B. T. , Fischer J. D.
Published: April 2011

Blackjack 21 is a late Maturity Group I soybean (Glycine max [L.] Merr.) cultivar with excellent yield potential, good lodging resistance and with average levels of oil and protein in the seed. Key words: Soybean, cultivar description
Effects of seed inoculation with a strain of Pseudomonas fluorescens on root growth and activity of wheat in well-watered and drought-stressed glass-fronted rhizotrons
Authors: Volkmar K. M. , Bremer E.
Published: April 2011

Identification of mechanisms by which plant growth-promoting rhizobacteria (PGPR) affect plants is required to obtain consistent or predictable increases in crop yields using PGPR. We conducted an outdoor lysimeter study using 12 glass-fronted rhizotrons to determine if inoculation with a strain of Pseudomonas fluorescens (G20-18) might benefit spring wheat (Triticum aestivum L.) (cv. Katepwa) yield by altering root growth. Inoculated and uninoculated treatments were either well watered or subjected to terminal drought with just one surface irrigation at anthesis. The only significant effect of G20-18 inoculation was a reduction in root growth in the well-watered rhizotrons after about 40 d. Inoculation did not significantly affect depth of rooting, soil moisture depletion, seed yield or uptake of 15N-labelled fertilizer. Watering regime did not affect overall root growth, although there were significant differences within specific depths. Final yields in well-watered treatments were double those of the drought-stressed treatments. Variability in yields within the drought-stressed treatments occurred due to accidental flooding of several rhizotrons early in the experiment, and demonstrated the value of deeply placed available moisture under drought conditions. We conclude that inoculation with G20-18 has minor effects on root growth that are unlikely to affect wheat yield. Key words: Plant growth-promoting rhizobacteria, rhizobacteria, roots, rooting depth, rhizotrons, N use efficiency, drought
Landscape variables affecting livestock impacts on water quality in the humid temperate zone
Authors: Clark E. Ann
Published: April 2011

The potential for impact by grazing livestock on unprotected watercourses may vary with climate, with landscape level factors including the landform within which the pasture is located, with the biophysical characteristics of the watercourse itself, and with pasture and grazing management practices. Policies seeking to implement cost-effective measures to protect downstream water quality need to acknowledge large-scale as well as small-scale processes which can moderate or exacerbate potential sources of pollution. Applied and scholarly evidence suggest that unrestricted livestock access accounts for a relatively modest share of watercourse pollution in humid temperate regions, as compared with such watershed-specific factors as leaking septic tanks and confinement feeding systems. A wide variety of evidence suggests that the degree of compatibility of grazing livestock with a healthy riparian ecosystem should be viewed as a hypothesis that is testable on a site-specific basis. Greater understanding of the factors causal to livestock behavior in, and impact on, watercourses may help to better focus preventative and remediation efforts by both producers and policymakers. Key words: Riparian ecosystem; beef cattle; pasture fertility; soil and water conservation
AC Avonlea durum wheat
Authors: Clarke J. M. , McLeod J. G. , McCaig T. N. , DePauw R. M. , Knox R. E. , Fernandez M. R.
Published: April 2011

AC Avonlea durum wheat is adapted to the durum production area of the southern Canadian prairies. It combines high yield with high grain protein concentration. It has shorter, stronger straw than Kyle and Plenty, and has similar maturity and disease resistance. Key words: Triticum turgidum L. var durum, durum wheat, cultivar description, yield, protein, disease resistance
Protein degradation and ensiling characteristics of red clover and alfalfa wilted under varying levels of shade
Authors: Owens V. N. , Albrecht K. A. , Muck R. E.
Published: April 2011

The conversion of protein nitrogen (PN) to nonprotein nitrogen (NPN) in forages occurs rapidly and extensively during wilting and ensiling. The objectives of this study were to determine whether the amount of time between cutting and ensiling affects protein degradation in red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) silage and to document pre- and post-ensiling characteristics of these two species. Forage from the second (24 August 1993), first (27 May 1994), and second (10 July 1995) growth cycles was harvested with hand clippers to a 5-cm stubble height between 09:00 and 10:00 h on each of the three harvest dates. Herbage was allowed to wilt to a targeted dry matter (DM) content of 350 g kg−1 under 0, 30, 73, and 100% shade (wilting treatment) and ensiled in 100-mL polypropylene centrifuge tubes. Time required to reach the desired DM varied each year, with the greatest range in drying times occurring in 1993. Starch was lower and sugar higher in fresh and wilted red clover than in alfalfa. Fresh red clover contained less NPN than alfalfa in 1993 and 1995 (P < 0.05) and similar amounts in 1994 (P > 0.05). Wilting treatment had no effect on NPN in wilted forage in 1994 and 1995, a result of nearly equal wilting times across shade levels. In 1993, however, NPN increased and starch decreased with shade. Within species, further protein hydrolysis during ensiling resulted in similar NPN levels in silage from all wilting treatments in 1993, despite differences in NPN in pre-ensiled wilted forage. Red clover silage consistently contained less NPN than alfalfa. Wilting treatments did not consistently affect sugar and starch concentrations of silage from either species, although there was a tendency for sugar and starch to decrease with longer wilting periods. Key words: alfalfa, red clover, protein degradation, ensiling
Cole crop yield response to reduced nitrogen rates
Authors: Sanderson K. R. , Ivany J. A.
Published: April 2011

Response of cabbage (Brassica oleracea L. var. capitata), Brussels sprouts (Brassica oleracea var. gemmifera) and broccoli (Brassica oleracea L. var italica) to reduced N rates was studied over 4 yr. Treatments were application methods, broadcast, split and banded with two rates of N; 120 and 90 kg ha−1 plus a control of 150 kg ha−1 broadcast N. Marketable yield was lower by 15, 23, and 13%, respectively, compared to the control. Banding lowered yield of cabbage and broccoli. The lower N rate had the lowest yield in all crops. Leaf N concentration varied with N rate. Key words: Broccoli, Brussels sprouts, cabbage, reduced nitrogen, yield
Weed seed return as influenced by the critical weed-free period in corn (Zea mays L.)
Authors: Swanton Clarence J. , Chandler Kevin , Shrestha Anil
Published: April 2011

Seed return from later emerging weeds is a concern in weed management systems based on critical periods of control. A study in Ontario found that estimated weed seed return to the soil surface was influenced by the duration of weed control in corn and the prevailing environmental conditions. Weeds emerging after the 8- to 11-leaf stage of corn growth did not cause an increase in total seed number compared to the residual seed bank in the weed-free control. Key words: Seedbank, weed population dynamics, integrated weed management
AC Proteina soybean
Authors: Voldeng H. D. , Guillemette R. J. D. , Cober E. R.
Published: April 2011

AC Proteina is a 2550 crop heat unit soybean [Glycine max (L.) Merr.] cultivar with seed protein levels about 6% higher than oilseed cultivars. AC Proteina is intended for whole-seed use in livestock rations. Key words: Soybean, cultivar description, high protein cultivar