bluuebunny/crossref_metadata_2025 huggingface dataset:
Seeding ratios and rates that maximize annual forage production in Black soil zones of central Saskatchewan
Authors: McCartney D. , Townley-Smith L. , Stevenson F. C. , Pearen J. R.
Published: April 2011

Three different seeding densities and four seeding ratios of spring and fall crop components for annual forage production were evaluated for maximizing silage and fall regrowth yield in a 3-yr study at Melfort, Saskatchewan. Binary mixtures of a spring cereal, barley (Hordeum vulgare L.) or oat (Avena sativa L.), and a fall crop, fall rye (Secale cereale L.) or Italian ryegrass (Lolium multiflorum Lam.), were seeded at three total stand seed densities (150, 275 and 400 seeds m-2), which consequently resulted in the following spring:fall seeding crop component ratios: 1:0, 2:1, 1:2 and 0:1. Both spring and fall crops were harvested when the spring cereals were at the soft-dough stage (silage cut) and late in the autumn (fall regrowth cut). Average spring crop component yield was greater for the silage cut (4806 kg ha-1) than for the fall regrowth cut (329 kg ha-1), and total sward yield was greater for the silage cut (5995 kg ha-1) than for the fall regrowth cut (1261 kg ha-1). Productivity of the fall component was 1173 and 929 kg ha-1 for the silage and fall regrowth cuts, respectively. Total crop yield was often maximized with seeding ratios of 60% spring:fall crop component or greater for the different combinations. Fall regrowth cut yields were always maximized by seeding 100% fall crop component. The spring crop component yield, especially for the oat mixtures, contributed very little to fall regrowth yields. Stand seeding rate frequently affected spring component and total crop yield, but not fall crop yield. Silage and annual yield for the spring crop and total sward increased with increase in stand seeding rate. Fall crop yield was not affected by stand seeding rate or its effect was of questionable practical importance. Italian ryegrass produced the most fall regrowth yield. Weed management was identified as a possible area for future research with regard to seeding ratios and rates for annual forage stands. Key words: Monocrop, intercrop, annual forage, seeding rates, seeding ratio
An assessment of variation in Idaho fescue [Festuca idahoensis (Elmer)] in southern Alberta
Authors: May K. W. , Willms W. D. , Mengli Z. , Lysyk T. J.
Published: April 2011

Idaho fescue (Festuca idahoensis Elmer) is a native grass species that has attracted interest for use in revegetation, reclamation and other applications. However, there is a serious shortage of commercially available seed and concern that germplasm used will not be adapted to the site. A component of adaptation is genetic variability that allows a species to occupy a greater range of environments. Field trials were conducted in southern Alberta to determine the genetic variability of phenotypic and performance characteristics among genotypes of Idaho fescue. Since grazing pressure may contribute to genetic selection and may therefore affect the variability within a population, we also compared genotypes taken from a heavily grazed paddock with those taken from a lightly grazed paddock. Forty-nine genotypes from three populations were randomly sampled in 1992, propagated vegetatively to produce plants for replicated trials and planted in four locations in 1993. Nine plant characteristics were observed from 1993 to 1997. Since the genotypes were grown in common environments, variation among them was assumed to be caused by genetic differences. All variables were affected (P < 0.05) by population, test location and year, while the effect of population was also influenced by test location and year for a few variables. While the Idaho fescue plants expressed differences (P < 0.05) among populations for all selected traits, they displayed considerable overlap in the range of values for all variables both within and among test locations. Therefore, while the populations may be different, individuals within populations exhibit common attributes over a large range. This suggests that sufficient genetic variability exists in all populations to allow successful establishment over a large range of environmental variability. Results from a secondary test suggest that selection pressure, induced by grazing, resulted in genotypes that were smaller in crown circumference, had less spring vigor, had shorter flowering tillers and produced less seed. However, this observation needs further validation with a more robust test. Key words: Morphology, genotypes, seed yield, winter kill, grazing response
A new yellow-seeded canola genotype originating from double low black-seeded Brassica napus cultivars
Authors: Burbulis N. , Kott L. S.
Published: April 2011

A new source of yellow-seeded Brassica napus canola has been identified in doubled haploid progeny, from a cross between the two black-seeded spring cultivars, Star and Bolero. Six yellow-seeded doubled haploid lines were extracted from the F1 generation of this cross. The yellow-seeded doubled haploid lines and some of their progeny showed differences in yellow seed colour expression in different temperature environments, among the 11 lines investigated. Similar populations of plants grown in daily maximum temperatures of 20, 28 and over 30°C showed increasing seed yellowness in the hot temperature and were darker in colour in the cool environments. Oil quality and fatty acid profiles were compared between yellow and dark seeded pairs. Although percent oil showed no overall trend in direction of change, oleic acid increased on average by 10%, while linolenic acid decreased by 5% under warmer growing conditions. Glucosinolate levels were stable between the yellow-seeded and dark-seeded pairs grown in either hot or cool temperatures. The yellow-seeded inbreds retained canola quality. Preliminary inheritance ratios suggest that this trait might be governed by fewer than three genes, and PCR analysis indicates that different genes may be involved here than those for the yellow-seeded genotypes previously published, which were derived from interspecific crosses. Key words: Brassica napus, yellow seed, temperature, oil quality
Detection of yield-independent forage quality differences among timothy genotypes
Authors: Kobayashi S. , Deguchi K. , Nakashima H.
Published: April 2011

The trade-off between forage yield and quality would be minimized by selecting a genotype that produces high-quality forage regardless of yield. This paper attempts to detect forage quality differences among timothy (Phleum pratense L.) genotypes that are independent of yield. Two separate field experiments were conducted from 1993 to 1995 on an Ando loamy sand in Hokkaido, Japan. For exp. 1, timothy plants (cv. Nosap) were harvested at various maturity stages for the first, second, and third cuts in 1994 and 1995 to evaluate the relationships of crude protein (CP) and neutral detergent fibre (NDF) yields with dry matter (DM) yield. The relationship between NDF and DM yields was positive and linear across different cuts (r2 =  0.98–0.99), and was slightly affected by year. In contrast, the relationship between CP and DM yields depended on the cuts (r2 = 0.01–0.98). In exp. 2, four genotypes were evaluated in 1994 to compare the coefficients of the NDF vs. DM yield regressions using ANCOVA. The comparison showed that the NDF yields of Kitami 20, Kitami 21, and Hokuo were less than that of Nosap (P < 0.01) for a wide range of DM yields (150–700 g m-2). Thus, NDF concentrations were lower in the former genotypes across varying forage yields. Using the regression lines as indices could facilitate selection of timothy genotypes that reduce the trade-off between yield and quality, although further experiments are needed to confirm the usefulness of this method. Key words: Acid detergent fibre, crude protein, forage yield, neutral detergent fibre, timothy
Legume cover crops with winter cereals in southern Manitoba: Fertilizer replacement values for oat
Authors: Thiessen Martens J. R. , Entz M. H. , Hoeppner J. W.
Published: April 2011

Yield benefits of legume cover crops in winter/spring cereal systems have not been well documented in the Canadian prairies. The objective of this study was to evaluate the fertilizer replacement values (FRV) of relay-cropped alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) and double-cropped chickling vetch (Lathryus sativus L.) and black lentil (Lens culinaris Medik. subsp. culinaris) to a subsequent oat (Avena sativa L.) crop. Field experiments were conducted in Manitoba on a clay soil at Winnipeg and a sandy loam at Carman. Alfalfa provided the highest FRV at Winnipeg (51–62 kg N ha-1), followed by chickling vetch (29–43 kg N ha-1), lentil (23–39 kg N ha-1), and red clover (24–26 kg N ha-1). FRV could not be established at Carman, where course-textured soil and low rainfall limited legume growth. Key words: Relay cropping, double cropping, cover crops
Comparative forage yield, water use, and water use efficiency of alfalfa, crested wheatgrass and spring wheat in a semiarid climate in southern Saskatchewan
Authors: Jefferson Paul G. , Cutforth Herb W.
Published: April 2011

Crested wheatgrass (Agropyron cristatum L. Gaertn.) and alfalfa (Medicago sativa L.) are introduced forage species used for hay and grazing by cattle across western Canada. These species are well adapted to the semiarid region but their long-term responses to water stress have not been previously compared. Two alfalfa cultivars with contrasting root morphology (tap-rooted vs. creeping-rooted) and two crested wheatgrass (CWG) cultivars with different ploidy level (diploid vs. tetraploid) were compared with continuously cropped spring wheat (Triticum aestivum L.) for 6 yr at a semiarid location in western Canada. Soil water depletion, forage yield, water use efficiency, leaf water potential, osmotic potential and turgor were compared. There were no consistent differences between cultivars within alfalfa or CWG for variables measured. However, these two species exhibit different water stress response strategies. Leaf water potential of CWG was lower during midday stress period than that of alfalfa or wheat. Alfalfa apparently had greater capacity to osmotically adjust to avoid midday water stress and maintain higher turgor. Soil water use patterns changed as the stands aged. In the initial years of the trial, forage crops used soil water from upper layers of the profile. In later years, soil water was depleted down to 3 m by alfalfa and to 2 m by crested wheatgrass. Alfalfa was able to deplete soil water to lower concentrations than crested wheatgrass or wheat. Soil water depletion by wheat during the non-active growth season (after harvest to fall freeze-up) was much less than for CWG or alfalfa as expected for annual vs. perennial crops. As a result, more soil water was available to wheat during its active growth period. In the last 3 yr, the three species depleted all available soil water. Forage yield responses also changed over time. In the initial 3 yr, crested wheatgrass yielded as much as or more than alfalfa. For the last 3 yr of the experiment, alfalfa yielded more forage than crested wheatgrass. Forage crops deplete much more soil water during periods of aboveground growth dormancy than wheat. Water use efficiency of crested wheatgrass declined with stand age compared with fertilized continuous spring wheat. Alfalfa exhibited deep soil water extraction and apparent osmotic adjustment in response to water stress while CWG exhibited tolerance of low water potential during stress. Key words: forage yield, soil water, water potential, water use, water use efficiency, drought
Bud-autogamy in the velvet-leaf blueberry, Vaccinium myrtilloides Michx.
Authors: Noormets Merrit , Olson A. Randall
Published: April 2011

In velvet-leaf blueberry, Vaccinium myrtilloides Michx., flower buds at different stages of development were collected from managed, lowbush blueberry populations and examined microscopically for evidence of autodeposition of selfpollen. During late bud development, anther pores opened for pollen tetrad release and remained relatively close to the stigma. Just prior to full bloom, at petal separation, 18% of the flower buds were pollinated. Self-pollination prior to anthesis may either ensure some reproductive success or enhance the seed set from subsequent cross pollinations. Key words: Vaccinium, autogamy, self-pollination
Herbage yield and composition of Kentucky bluegrass (Poa pratensis L.) cultivars under two harvest systems
Authors: Dürr G. H. , Kunelius H. T. , Drapeau R. , McRae K. B. , Fillmore S. A. E.
Published: April 2011

Although Kentucky bluegrass (Poa pratensis L.) is a naturalized species commonly found in the permanent grasslands of eastern Canada, its contribution to sward output is not well defined. Six Kentucky bluegrass cultivars originating from Norway, Germany and North America, and a timothy (Phleum pratense L.) cultivar, were grown under two harvest systems at two locations to determine yield and herbage composition. All cultivars persisted over 3 production years. Dry matter yields of bluegrass cultivars were similar to those of timothy, ranging from 7.87 to 9.76 t ha-1 in Charlottetown, Prince Edward Island, and from 3.64 to 4.79 t ha-1 in Normandin, Quebec. Yields of broadleafed genotypes from Europe were superior in year 1. However, the warm and dry growing conditions of year 3 favoured the narrow-leafed genotypes. Mean tiller density of Kentucky bluegrass was 6440 m-2; timothy had a mean tiller density of 3040 m-2. Forage quality attributes of Kentucky bluegrass were similar to those of timothy. Cultivar differences in fibre and mineral concentrations were consistent across years and locations and may provide selection criteria in breeding programs. Greater harvest frequency increased the total nitrogen concentration of herbage and tiller density but had no effect on yield. Kentucky bluegrass is a persistent, valuable forage grass species with good potential for use in pasture and as conserved forage in eastern Canada. Key words: Herbage composition, herbage yield, Kentucky bluegrass, Poa pratensis, Phleum pratense, tiller, timothy
Influence of leaf scorch on vegetative growth and yield of three strawberry (Fragaria × ananassa Duch.) cultivars with differing levels of resistance
Authors: Mutisya J. M. , Sullivan J. A. , Sutton J. C. , Zheng J. , Couling S.
Published: April 2011

Three strawberry cultivars, Kent, Jewel and Blomidon, were evaluated for their reaction to leaf scorch (Diplocarpon earlianum) disease. The three cultivars are considered to be susceptible, moderately resistant and resistant to leaf scorch, respectively. Plants were grown in the field in a runnerless culture system and inoculated with conidial suspensions at one of five concentrations to generate a range of disease severities. The control plants were not innoculated. Disease severity was monitored during the establishment year and these data were used to calculate area under the disease progress curves (AUDPC) for each cultivar. At dormancy, vegetative growth analysis was performed on a sample of plants from each plot. The remaining plants were overwintered and data were collected on yield and yield components the following season. The difference in AUDPC values between control and highest levels of the disease for Kent, Jewel and Blomidon were 31.6, 26.0 and 25.2 units, respectively. Leaf scorch reduced photosynthetically active leaf area in all three cultivars, which reduced dry matter accumulation. The vegetative characters most affected were leaf area and number, crown number and dry weight and root dry weight. At the highest level of disease attained total yield declined 58, 41 and 31 g plant-1 corresponding with disease severities of 44.5, 36.4 and 32.4 units AUDPC for Kent, Jewel and Blomidon, respectively. This represented a 20–21% yield reduction in each cultivar. Fruit number was the yield component most sensitive to the leaf scorch disease. A strong relationship was established between highest disease severity during late summer and fall (which includes the time of flower bud initiation) and yield the following season. Key words: Diplocarpon earlianum, foliar disease, June-bearing
Germination of common bean under constant and alternating cool temperatures
Authors: Nleya T. , Ball R. A. , Vandenberg A.
Published: April 2011

In western Canada, common bean is often sown in cool soils, which causes poor germination and uneven stand establishment. A major goal in bean breeding is to find and assess cold-tolerant parental material. Seed germination and emergence of 12 diverse common bean genotypes, which included adapted Prairie cultivars, were evaluated in petri dishes under 15 alternating and five constant temperature regimes. Cumulative heat hours to maximum germination were calculated for all 12 genotypes using a base temperature of 9°C. Six genotypes were tested for emergence in soil in growth chambers at two temperature and three soil moisture regimes. In petri tests, optimal temperatures for bean germination were 16/16°C (day/night temperature) or higher. G8823, G9345 and AC Polaris germinated below 10°C, and all genotypes germinated at 12°C or higher. Rapid germinating genotypes with >0.09 cumulative heat hours per percentage germination were G8823, G9345 and AC Polaris, which took the least number of cumulative heat hours to germinate (<1100 heat hours). CDC Pinnacle was the highest representative of the medium germination rate group, having 1170 heat hours to germination. Emergence and plant development in soil were decreased by low moisture availability or cooler temperatures. Genotypes with >80% emergence in soil were CDC Crocus, CDC Nighthawk, CDC Pinnacle and CDC Polar Bear. Differing genotype rankings in soil versus petri dishes demonstrated that germination in controlled cool conditions may still be complicated by dormancy, moisture availability, seed coat thickness, imbibition rate and differing viabilities of seed lots. G8823, G9345 and AC Polaris are promising genotypes for developing cultivars that can germinate under cool temperatures (<10°C) at the highest rate. Key words: Phaseolus vulgaris, common bean, germination, temperature
Effects of relative time of emergence and density of wild oat (Avena fatua L.) on oat quality
Authors: Willenborg C. J. , Rossnagel B. G. , May W. E. , Lafond G. P. , Shirtliffe S. J.
Published: April 2011

Selective control of wild oat with herbicides is not possible in oat (Avena sativa L.) crops and, consequently, the high quality that is imperative to market success is continually jeopardized. Field experiments were conducted to determine the effects of relative time of emergence and density of wild oat on oat kernel size and weight. Thousand-kernel weight and percentage plump kernels were generally reduced, and percentage thin kernels were generally increased with increasing wild oat densities and earlier wild oat emergence. However, reductions were generally small and occurred only at the highest wild oat densities, which are not commonly observed in commercial fields. These findings suggest that oat growers should not control wild oat based on perceived reductions in oat physical grain quality. Key words: Competition, emergence, physical grain quality, test weight, 1000-kernel weight
Timing of partial defoliation affects carbohydrate concentration of vegetative tissues and concentration of phenolics in berries of potted De Chaunac (Vitis sp.) grapevines
Authors: Vanden Heuvel Justine E , Robidoux Jessica L , Autio Wesley R , Neto Catherine C
Published: April 2011

Partial defoliation of grapevines often increases fruit phenolic content; however, improved light interception by fruit and possible improved photosynthetic efficiency of leaves are confounding factors. In this study, potted De Chaunac grapevines were partially defoliated at three phenological stages, but cluster light environment was unaffected. Partial defoliation at berry set significantly reduced glucose and fructose concentrations in the leaf/shoot tissue, and also reduced total flavonols and total phenolics in the fruit. Vines partially defoliated pre-harvest had increased sucrose concentration in the leaves and roots, increased glucose in the roots, and produced fruit with improved total anthocyanins compared to the control. Key words: Grapevines (French hybrid), carbohydrates, phenolics
Inheritance of resistance to covered smut [Ustilago hordei (Pers.) Lagerh.] in barley
Authors: Grewal T. S. , Rossnagel B. G. , Scoles G. J.
Published: April 2011

Covered smut of barley, caused by Ustilago hordei, has the potential to cause significant losses under organic production systems, particularly for hulless barley. The objectives of this investigation were to identify sources of resistance to covered smut and to study the inheritance of resistance and allelic relations between resistant barley lines. Hulled barley breeding lines and cultivars TR640, Q21861, TR244, and CDC Helgason were identified as sources of resistance to covered smut based on screening for 3–5 yr in the field and twice in the greenhouse. No hulless sources with strong resistance were identified indicating that there is a need to transfer resistance to hulless barley. Inheritance of covered smut resistance in the hulled barley line TR244 was studied using a hulless × hulled barley population screened with a mixture of U. hordei isolates. A single major resistance gene was identified in TR244. Many hulless lines in this population showed good resistance to covered smut indicating that resistance can be transferred to hulless lines. Allelic studies indicated that the resistance gene in TR244 is different from that in the resistant lines Q21861 and TR640. Key words: Barley, Ustilago hordei, resistance, hulless, covered smut
Quantification of the yield and protein response to N and water availability by two wheat classes in the semiarid prairies
Authors: Selles F. , Clarke J. M. , DePauw R. M.
Published: April 2011

Genetic improvements have increased grain yield of newer wheat (Triticum spp.) cultivars relative to older benchmark cultivars. However, the improvements have been larger in the Canada Western Amber Durum wheat class (CWAD) [Triticum turgidum L. var. durum (T. durum)] than the Canada Western Red Spring class (CWRS) (Triticum aestivum L.). Thus, it is necessary to determine if N fertilizer recommendations for these two wheat classes need to be segregated. We conducted fertility trials for four CWAD and seven CWRS cultivars during 4 yr, in two soils in southwestern Saskatchewan, under fallow- and stubble-cropping to determine if there were differences in the N response of the two wheat classes under various water availability conditions. Grain yields of CWAD were consistently higher than those of CWRS, while protein concentrations were higher for CWRS than for CWAD. A regression model consisting of available water (W) plus the interactions of W with fertilizer N (NF), NF2, soil NO3-N in the 0- to 60-cm depth (NS), NS2, and with the NF × NS interaction explained 76% of the yield variability of all cultivars and site years. Inclusion of wheat class as an indicator variable increased the proportion of the explained variability to 80%, and determined that both classes of wheat had similar response to N availability, and that CWAD had a larger response to available water than CWRS. A regression model consisting of a quadratic function of N and a linear term for W with wheat class as an indicator variable explained 58% of the variability in grain protein of all varieties, and indicated that both classes had the same protein response to N availability, but that the protein of CWAD decreased faster than that of CWRS as water availability increased. Inclusion of wheat cultivars as indicator variable, instead of wheat class, did not increase the resolution of the regression model for either yield or protein responses. Results of these analyses indicate that the amount of N required for maximum yield is the same for both wheat classes. Key words: Durum wheat, hard red spring wheat, grain yield, grain protein, fertilizer N, soil N, available water
Canopy growth and biomass partitioning to yield in short-season lentil
Authors: Hanlan T. G. , Ball R. A. , Vandenberg A.
Published: April 2011

Lentil (Lens culinaris L.) cultivars in the large green market class in Western Canada have late-season bushy growth, low harvest index (HI), and lodge readily. The aim of this study was to compare a range of genotypes for canopy traits such as rapid growth, light interception, HI, lodging, and yield. Four stiff-stem unadapted genotypes varying in leaf size and canopy openness were compared with two large green market class and other locally adapted cultivars at three population densities in the field in 2001 and 2002. Canopy measurements included biomass and light interception at weekly intervals, lodging score, end of season HI and yield. Adapted cultivars had high biomass (525 to 700 g m-2), high seed yield (96 to 130 g m-2), high maximum light interception (61 to 80%), high final branch number (17 to 19), and greatest overall plant height (0.3 to 0.44 m), but large green cultivars were prone to lodging. Unadapted genotypes produced less biomass and lodged the least. Genotypes that accumulated most above-ground biomass yielded the highest, grew the tallest, branched the most, but lodged the most. Unadapted genotypes FLIP 2000-7L (tallest, highest yielding of the unadapted types) and FLIP 96-7L (most lodging resistant (2001) and most brittle stemmed (2002) were promising parents for improving lodging resistance, on the basis of lodging resistance and yield or stem stiffness, respectively. CDC Milestone had the best canopy characteristics of moderate biomass and high harvest index for Western Canada. Key words: Lentil, Lens culinaris, biomass, harvest index, yield, lodging
Genetic analysis infers Dt loci underlie resistance to Fusarium solani f. sp. glycines in indeterminate soybeans
Authors: Njiti V. N. , Lightfoot D. A.
Published: April 2011

Improved resistant cultivars are being developed to better withstand the sudden death syndrome (SDS) of soybean (Glycine max L. Merr.) caused by Fusarium solani (Mart.) Sacc. f. sp. glycines (Fsg) (renamed F. virguliforme). Field trials to identify and select SDS-resistant cultivars take several years and are expensive. Selection of seedlings in the greenhouse and marker assisted selection are faster and cheaper. Selection for loci contributing SDS is well established for southern US germplasm sources (Forrest, Pyramid) but untested in northern germplasm. The aim was to find DNA markers associated with loci contributing seedling resistance to F. solani in the northern germplasm cultivars Minsoy and Noir. The greenhouse assay used plants grown for 3 wk in F.solani inoculated soil. Disease severity (DS) was recorded for 2000 recombinant inbred lines (RIL) from Minsoy × Noir1 (M×N) after F. solani infestation and compared to the DS of non-infested controls. Minsoy was partially resistant and Noir1 was relatively susceptible to F. solani. The heritability of DS was 48%. Comparison of alleles at 247 loci with the DS trait identified three regions associated with DS. Two regions within a 16 cM region of linkage group L (U14) were identified by markers SAT99 (P = 0.0006, R2 = 7%) and SATT6 (P = 0.0013, R2 = 5%). One region on linkage group C1 (U10b_ was identified by A063_1 (P = 0.0011, R2 = 5%). Interacting loci explained an additional 12% (A280 and SAT99) and 10% (R28 and SATT6) of the variability in DS, mainly by increasing resistance in susceptible class at each quantitative trait loci (QTL). These loci jointly explain the major portion (34%) of heritable resistance to F.solani. The QTL did not correspond with the known loci that condition resistance in the field in southern US germplasm. The QTL were in regions of the genome that were previously determined to alter determinacy, plant morphology, leaf shape, stem thickness, plant height, maturity and water use. Here Minsoy was taller, had thicker stems, produced more root mass and more shoot mass than Noir 1 during Fsg infestati on. Height (r = 0.15, P = 0.03), root weight (r = 0.3, P = 0.0002) and shoot weight r = 0.4, P = 0.0001) were significantly negatively correlated with resistance to SDS. Therefore, we conclude the SDS resistance is a pleiotropic effect of shoot and root characters in Minsoy and Noir that may confound selection for resistance to SDS in North American germplasm. Key words: Determinacy, genetic map, soil borne disease, Fusarium solani f. sp. glycines, soybean, Fusarium virguliforme
Competitive ability of wheat in conventional and organic management systems: A review of the literature
Authors: Mason H. E. , Spaner D.
Published: April 2011

Wheat (Triticum aestivum L.) is the world’s most widely grown crop, cultivated in over 115 nations. Organic agriculture, a production system based on reducing external inputs in order to promote ecosystem health, can be defined as a system that prohibits the use of synthetic fertilizers, chemical pesticides and genetically modified organisms. Organic agriculture is increasing in popularity, with a 60% increase in the global acreage of organically managed land from the year 2000 to 2004. Constraints that may be associated with organic grain production include reduced yields due to soil nutrient deficiencies and competition from weeds. Global wheat breeding efforts over the past 50 yr have concentrated on improving yield and quality parameters; in Canada, disease resistance and grain quality have been major foci. Wheat varieties selected before the advent of chemical fertilizers and pesticides may perform differently in organic, low-input management systems than in conventional, high-input systems. Height, early-season growth, tillering capacity, and leaf area are plant traits that may confer competitive ability in wheat grown in organic systems. Wheat root characteristics may also affect competitive ability, especially in low-input systems, and more research in this area is needed. The identification of a competitive crop ideotype may assist wheat breeders inthe development of competitive wheat varieties. Wheat varieties with superior performance in low-input systems, and/or increased competitive ability against weeds, could assist organic producers in overcoming some of the constraints associated with organic wheat production. Key words: Triticum aestivum L., wheat breeding, low-input agriculture, plant height, early-season growth, tillering capacity, leaf area index
Somatic hybridization between Solanum tuberosum and S. cardiophyllum
Authors: Shi Y. Z. , Chen Q. , Li H. Y. , Beasley D. , Lynch D. R.
Published: April 2011

The wild diploid Mexican species, Solanum cardiophyllum Lindl. (2n = 2x = 24), is resistant to important potato diseases. However, introgression of resistance to the tetraploid cultivated potato (S. tuberosum L.) (2n = 4x = 48) by conventional crossing is not feasible due to the difference in their endosperm balance number between these species. Somatic hybrids between S. cardiophyllum and S. tuberosum were produced for the first time by electrofusion of protoplasts isolated from young leaves of each parental line. The hybrid nature of the regenerated plants was confirmed based on morphology, chromosome number and DNA species-specific RAPD markers. All the somatic hybrids produced a violet pigmentation on their stems and petioles, which resembled the wild partner. Most of the hybrid plants had 2n = 72 chromosomes and exhibited a morphology intermediate between the two fusion parents, but with a tendency towards cultivated potato. These plants flowered and set fruit when backcrossed with their S. tuberosum fusion parent. Key words: Potato (Solanum tuberosum), S. cardiophyllum, protoplast fusion, RAPD marker
Chilliwack-VR orchardgrass
Authors: Bittman S. , Acharya S. N. , Hunt D. E.
Published: April 2011

Chilliwack-VR is a medium-maturing orchardgrass (Dactylis glomerata L.) population with high levels of resistance to Cocksfoot Mottle Virus (CfMV) suited to silage and hay production in regions with a moderate temperate climate. The population was developed at the Pacific Agri-Food Research Centre (PARC), Agriculture and Agri-Food Canada (AAFC), Agassiz, BC, in collaboration with AAFC Research Centre, Lethbridge, AB. In BC trials, Chilliwack-VR yielded 5% more than the check cultivar Potomac without inoculation with CfMV and 23% better than the check when inoculated with the virus. In a southern Alberta trial, Chilliwack-VR survived for 3 yr and yielded as much biomass as a winterhardy check cultivar, Kay. Key words: Orchardgrass, Cocksfoot Mottle Virus resistance, Dactylis glomerata
Cheam-VR orchardgrass
Authors: Bittman S. , Acharya S. N. , Hunt D. E.
Published: April 2011

Cheam-VR is an early-maturing orchardgrass (Dactylis glomerata L.) cultivar with high levels of resistance to Cocksfoot Mottle Virus (CfMV) suited to silage and hay production in regions with moderate temperate climate. The population was developed at the Pacific Agri-Food Research Centre (PARC), Agriculture and Agri-Food Canada (AAFC), Agassiz, BC, in collaboration with AAFC Research Centre, Lethbridge, AB. In BC trials, Cheam-VR yielded 6% better than the check cultivar Potomac without inoculation with CfMV and 15% more than the check when inoculated with the virus. In a southern Alberta trial, Cheam-VR survived for 3 yr and yielded 6% more than a winterhardy check cultivar, Kay. Key words: Orchardgrass, Cocksfoot Mottle Virus resistance, Dactylis glomerata
Arbuscular mycorrhizal fungi in field crop production: Potential and new direction
Authors: Hamel Chantal , Strullu Désiré-Georges
Published: April 2011

Arbuscular mycorrhizal fungi (AMF) are multipurpose organisms with complex ecological ramifications in the soil system that have been difficult to study and understand. The phytocentric concept of AMF that has prevailed since the naming of these organisms is being replaced by a holistic vision recognizing that AMF are a key element of soil functioning and health rather than a plant root component. Recent advances in knowledge brought about by new techniques for soil microbiology research open the way to AMF management in crop production. Arbuscular mycorrhizal fungi may influence crop development, even in phosphorus-rich soils. However, growing crops in soil with lower fertility would optimize the expression of the multiple beneficial effects of AMF in agro-ecosystem and reduce nutrient seepage to the environment. The consideration of the soil mycorrhizal potential within the framework of soil testing and fertilization recommendations, the development of improved inoculants and signal molecules to manipulate AMF and the development of cultivars with improved symbiotic qualities would insure the production of good crop yields while improving agroecosystems’ sustainability. Key words: Arbuscular mycorrhizal fungi management, field crop production, agriculture, soil quality, arbuscular mycorrhizal effect
CDC Sage field pea
Authors: Warkentin Tom , Vandenberg Albert , Banniza Sabine , Barlow Brent , Ife Scott
Published: April 2011

CDC Sage, a green cotyledon field pea (Pisum sativum L.) cultivar, was released in 2005 by the Crop Development Centre, University of Saskatchewan for distribution to select seed growers in Saskatchewan and Alberta through the Variety Release Program of the Saskatchewan Pulse Growers. CDC Sage is a semileafless type, with powdery mildew (caused by Erysiphe pisi DC.) resistance, good lodging resistance, medium-sized, round seeds, and good yield potential. CDC Sage is adapted to the field pea growing region of western Canada. Key words: Field pea, Pisum sativum L., cultivar description
Effect of seeding date and rate on desi chickpea in southern Alberta
Authors: McKenzie R. H. , Middleton A. B. , Bremer E.
Published: April 2011

Field trials were conducted at 12 location-years (sites) over a 4-yr period (2000–2003) to determine the response of desi chickpea (Cicer arietinum L.) to seeding date and rate in southern Alberta. Desi chickpea, cv. Myles, was planted on three dates at approximately 10-d intervals at target plant densities of 20, 40, 60, 80 and 100 plants m-2. Seed yields were close to maximum at seeding dates ranging from late April till mid-May, but further delays in seeding resulted in modest yield declines at two sites during the drought years and large yield declines at two sites in the wet year. The economic optimum plant density for desi chickpea increased with moisture availability, from 26 to 79 plants m-2. Under typical conditions in southern Alberta, optimum yields of chickpea were obtained with seeding dates prior to May 15 and seeding rates of 30 to 40 plants m-2. Key words: Cicer arietinum, yield, planting, sowing
Effectiveness of three Bt corn events against feeding damage by the true armyworm (Pseudaletia unipuncta Haworth)
Authors: Schaafsma A. W. , Holmes M. L. , Whistlecraft J. , Dudley S. A.
Published: April 2011

A 3-yr study (2002-2004) was conducted to evaluate the resistance of three Bt corn events to herbivory damage by the armyworm, Pseudaletia unipuncta (Haworth). Resistance was assessed by damage ratings and fresh mass measurements. Greenhouse studies were run in 2002 and 2004, and a field study was conducted in 2003. Hybrids expressing the Cry1A(b) insecticidal protein, Mon810 and Bt176 events, and their near isolines, as well as the TC1507 event, which expresses the Cry1F protein, were evaluated. Bt hybrids suffered less damage in all 3 yr and had higher fresh masses in 2002 and 2003 than the non-transgenic isolines. In 2002 and 2003, hybrids expressing the Cry1A(b) protein were significantly less damaged than the hybrid expressing Cry1F. In both 2002 and 2004, the Mon810 event suffered less damage than the Bt176 event, despite expressing the same Cry1A(b) protein. Bt corn, especially the Mon810 event may be used as an effective method of preventing P. unipuncta herbivory damage in corn. Key words: True armyworm, Pseudaletia unipuncta, Bt corn, Cry1A(b), Cry1F, epistasis
Comparison of the vegetation and seedbanks of soybean fields, adjacent boundaries, and hedgerows in Ontario
Authors: Boutin Céline
Published: April 2011

Patterns of plant assemblages in habitats located within agroecosystems are poorly understood. A study of the seedbank and standing vegetation in 10 soybean [Glycine max (L.) Merr.] fields, their adjacent boundaries, and adjoining woody hedgerows was undertaken in Ontario. The objective was to examine the composition of plants of conservation value and weedy species in these habitats. The seedbank of each habitat was determined from soil cores in quadrats located at regular intervals along transects, using the seedling emergence method in the greenhouse. The vegetation was surveyed in plots adjacent to the seedbank sampling areas. There was no significant difference in total species richness of vegetation or the seedbank among habitat types. However, there was a marked difference in species composition. In the seedbank, no difference in weed species richness among habitats was observed. In vegetation, however, fields harboured significantly more weedy species than adjacent boundaries and hedgerows. The dissimilarity between the seedbank and the vegetation was confirmed in detrended correspondence analyses, which showed that hedgerow vegetation, and to a lesser extent boundary vegetation, differed from field vegetation and all the habitats of the seedbank. The analysis of soil properties indicated that organic matter and nutrient levels were often higher in hedgerows than in fields. It can be concluded that hedgerows are valuable habitats for plant diversity and that weed species represent a minor component of their overall vegetation composition. Key words: Agroecosystems, field boundaries, hedgerows, soil seedbank, vegetation composition
The effect of container size on overwintering survival and growth of herbaceous perennials
Authors: Svendsen E. , Tanino K. K.
Published: April 2011

The effect of container size on the growth and survival of herbaceous perennials (Artemesia, Lamium, Thymus, Echinacea Monarda, Gentiana, Penstemon, Stachys) overwintered over two seasons at two commercial nurseries was evaluated. Results indicate: (1) For most species, container size does not affect survival; (2) Container size was a significant factor in plant growth and in almost all cases, a larger container resulted in a larger plant compared with a smaller container. Plug-grown perennials may be fall planted in their final container size to maximize growth potential by the following spring. Key words: Low temperature, overwintering, storage, perennial plants
Response of adzuki bean to pre-emergence herbicides
Authors: Sikkema P. H. , Soltani N. , Shropshire C. , Robinson D. E.
Published: April 2011

Limited herbicide options are available to adzuki bean growers in southwestern Ontario. Six field trials were conducted in Ontario during 2003 and 2004 to evaluate the tolerance of adzuki bean to dimethenamid (1250 and 2500 g a.i. ha-1), S-metolachlor (1600 and 3200 g a.i. ha-1), clomazone (1000 and 2000 g a.i. ha-1), and imazethapyr (75 and 150 g a.i. ha-1) applied pre-emergence. Dimethenamid caused up to 37% visual injury and reduced plant height, shoot dry weight and yield 27, 59 and 52%, respectively. Seed maturity was also delayed by dimethenamid at 2500 g ha-1. S-metolachlor caused up to 34% visual inj ury and reduced plant height, shoot dry weight and yield 27, 48 and 48%, respectively. Clomazone caused 53% visual injury and reduced plant height, shoot dry weight and yield 47, 84 and 78%, respectively. Imazethapyr caused up to 6% visual injury; however, this injury was transient with no adverse effect on plant height, shoot dry weight, seed moisture content and yield of adzuki bean. Based on these results, dimethenamid, S-metolachlor and clomazone applied pre-emergence (PRE) do not have an adequate margin of crop safety for use in adzuki bean at the doses evaluated. However, imazethapyr applied PRE has an adequate margin of crop safety for weed management in adzuki bean production in Ontario at the doses evaluated. Key words: Clomazone, dimethenamid, imazethapyr, S-metolachlor, tolerance
Size doesn’t matter: The effects of seed size and seeding rate on injury by root maggots (Delia spp., Diptera: Anthomyiidae) to canola (Brassica rapa L. and B. napus L.)
Authors: Soroka J. J. , Elliott R. H.
Published: April 2011

In 16 experiments at two locations over six years, seed size had no effect on feeding levels by crucifer-feeding root maggots (Delia spp.) in Brassica rapa nor in B. napus. Root maggot injury in B. rapa declined as seeding rates increased. Damage to plants grown from small seed increased as root diameter increased. Key words: Canola, Delia spp., root maggot injury, seeding rate, seed size, root diameter
Success hybrid bromegrass
Authors: Coulman Bruce
Published: April 2011

Success hybrid bromegrass was selected from populations produced by backcrossing smooth bromegrass (Bromus inermis Leyss.) with hybrid populations resulting from crosses between meadow bromegrass (Bromus riparius Rehm.) and smooth bromegrass. Success has a unique array of plant characteristics, some similar to meadow bromegrass, and others more similar to smooth bromegrass; overall, it more closely resembles smooth brome. In regional trials in the prairie provinces of western Canada, Success produced forage yields greater than meadow brome, but lower than smooth bromegrass. In the drier brown soil zone of the prairie provinces, Success was superior to both meadow and smooth bromegrass in forage yield. It was superior to smooth bromegrass in regrowth after cutting and had lower concentrations of acid-detergent fiber than meadow bromegrass. Key words: Hybrid bromegrass, Bromus riparius × Bromus inermis, cultivar description
Growth and nutrient response of flax and durum wheat to phosphorus and zinc fertilizers
Authors: Jiao You , Grant Cynthia A , Bailey Loraine D
Published: April 2011

Flax (Linum usitatissimum L.) and durum wheat (Triticum turgidum L.) are important agricultural crops that enter the human food chain. Effective nutrient management considering nutrient interactions is important in order to increase crop yield and improve crop nutrient concentration. The objective of this study was to investigate the effect of P and Zn fertilizers on the yield and nutritional value of flax and durum wheat. A pot culture experiment conducted in a growth chamber using a calcareous clay-loam soil showed that P fertilizers can restrict flax growth due to an antagonistic effect of Zn fertilizer but can increase the seed yield of both crops by enhanced dry matter translocation to the seed/grain. Among the P sources, commercial monoammonium phosphate (CMAP) and commercial triple superphosphate (CTSP) had similar effects on growth and yield, but different impacts on the nutrient concentrations of both crops, indicating the importance of selecting P source to improve crop quality. Zinc addition with reagent grade P decreased the concentrations of P, K, Ca, Mg and Cu in flax but not in durum wheat. We conclude that proper combination of P and Zn fertilizers is necessary to optimize crop yields, but that P had a proportionally greater effect in promoting yield in durum wheat than in flax. In contrast, Zn had a greater impact on mineral composition in flax than in durum wheat, which can affect the nutritional quality of the crop as a component of the human diet. Key words: Flax, durum wheat, P and Zn fertilizers, nutrient, essential trace elements
Grain protein as a post-harvest index of nitrogen status for winter wheat in the northern Great Plains
Authors: Engel Richard E. , Long Dan S. , Carlson Gregg R.
Published: April 2011

The use of grain protein as a post-harvest index of N fertility status has been promoted for spring wheat (Triticum aestivium L.) through the establishment of critical levels for segregating wheat into N deficient vs. N sufficient classes. The objectives of this study were to evaluate this concept for winter wheat in the northern Great Plains; and to estimate the added N requirements necessary to achieve maximum yield when protein concentrations fall below the critical level. A field study consisting of three water regimes, four cultivars, and five fertilizer N levels was conducted near Havre, MT. A consistent relationship between relative yield and grain protein was found and a critical protein concentration of 121 mg g-1 was defined using Cate-Nelson R2 statistics. Protein concentrations below the critical level were associated with yield losses from N deficiency (79% frequency), while protein concentrations ≥ the critical level were associated with N sufficiency (93% frequency). Under conditions of mode rate N deficiency (68–99% of maximum), protein concentration could be used to estimate the amount of additional N that would have been needed to achieve maximum yields. This is accomplished by first calculating the difference between the critical and actual protein concentration (expressed in mg g-1 protein). This protein deficit is then multplied by a fertilizer N equivalent that varied from 20 to 38 kg N ha-1 (according to the precipitation environment) for each 10 mg g-1 rise in protein desired. Key words: N sufficiency, N deficiency, critical protein concentration, plant available N