bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathogenicity of Pratylenchus penetrans to American Ginseng (Panax quinquefolium) and to Kiwi (Actinidia chinensis)
Authors: Vrain Thierry C.
Published: April 2011

The host status and susceptibility of American ginseng and kiwi to the root-lesion nematode were studied in greenhouse experiments. Two-year-old ginseng roots were transplanted into 2.5-L. pots containing 0, 2000, 6000, 10 000, or 15 000 nematodes. After 100 d tap root growth was not significantly affected at the low inoculum densities but it decreased by 32% at the highest inoculum density. The nematodes did not multiply in ginseng roots. One-year-old Kiwi roots were transplanted into 2.5-L. pots containing 0, 2000, 5000, 10 000, and 15 000 nematodes. After 120 d the weight of kiwi vines and roots grown in nematode-infested soil decreased by 15 and 25%, respectively, when compared to plants grown in nematode-free soil. The nematode population barely maintained itself at the lowest inoculum density and declined at the higher inoculum densities. Key words: Nematode, root-lesion, resistance, host status
Cropping systems for spring and winter cereals under simulated pasture: Sward structure
Authors: Baron V. S. , Dick A. C. , Najda H. G. , Salmon D. F. , Pearen J. R.
Published: April 2011

The feasibility of using mixtures of spring-planted spring and winter cereals for pasture in central and southern Alberta was demonstrated previously. In the current study cropping system treatments consisting of: spring cereal monocrops (SMC), either oats (Avenu sativa L.) or barley (Hordeum vulgare L.); winter cereal monocrops (WMC), either winter wheat (Triticum aestivum L.) or winter triticale (× Triticosecale Wittmack); binary mixtures of the spring and winter cereals planted together as intercrops (IC) in the spring at the same time; and a doublecrop (DC) system where the winter cereal was planted into the spring cereal after one clipping were grown during 2 yr at Lacombe, Alberta. Pasture was simulated by clipping the stands five times, beginning at the joint stage of the spring cereal and four times subsequently at about 4-wk intervals. Prior to each clip, tiller weight, tiller density, tiller height and leaf area index (LAI) were measured in each sward. Differences for yield among treatments within systems did not occur, so small differences in sward structure were considered to be due to a compensatory interaction of yield components which stabilized yield and were ignored. Sward structure appeared to explain differences among systems for yield distribution. Tiller density and LAI of the SMC and spring component of the IC and DC became relatively small as the season advanced, especially after cut 2. Tiller density and LAI of the WMC were maintained at high levels throughout the season after cut 1. After cut 2 the winter cereal components of the IC and DC were responsible for the maintenance of total tiller density and LAI in their respective swards. Average seasonal total LAI were 3.36, 3.02, 1.87 and 1.17 cm2 cm−2 in the WMC, IC, DC and SMC. Late planting and competition for light from the taller spring cereal component delayed tillering of the winter cereal component in the DC compared with the IC during midsummer (cuts 2 and 3) resulting in the low average LAI. In contrast, planting the spring and winter cereal components at the same time (IC) resulted in a relatively stable total tiller density, high average LAI and yield. Thus the superior yield distribution of the IC, shown previously, was due to the complementary way in which spring and winter cereal tillers responded to clipping when planting occurred at the same time. Key words: Monocrop, intercrop, double-crop, yield components
Hydroponic culture of wild rice (Zizania palustris L.) and its application to studies of silicon nutrition and fungal brown spot disease
Authors: Malvick D. K. , Percich J. A.
Published: April 2011

The mineral nutrient requirements of wild rice (Z. palustris var. interior L.) grown on flooded soils in Minnesota are poorly understood. A hydroponics culture system was developed to study the effects of silicon on the growth and fungal brown spot disease (FBS) resistance of wild rice. Wild rice was grown to maturity using a modified Hoagland’s solution. Plants attained a height of 1.4 m and had healthy roots, leaves and inflorescences containing viable seeds. Plant height and biomass were approximately 80 and 46%, respectively, of plants grown in cultivated paddies. A method was developed to reliably infect leaves and stems of hydroponically grown wild rice with Bipolaris oryzae, the pathogen causing FBS. Silicon amendments did not significantly increase growth and had no apparent effect on resistance to FBS. Key words: Bipolaris oryzae, hydroponic culture, plant nutrition, silicon, wild rice, Zizania palustris
Evaluation of the SDS-sedimentation test for the assessment of eastern Canadian bread wheat quality
Authors: Ayoub M. , Smith D. L. , Fregeau-Reid J.
Published: April 2011

The sodium dodecyl sulphate (SDS) was applied to six sets of composite eastern Canadian wheats, four from regional registration tests and two from a nitrogen fertility study, both from the 1990 and 1991 seasons. Correlations existed between SDS sedimentation volume and remix bread loaf volume (cm3) only in three of the six sets tested. These correlations were improved when calculated independently from the grain protein concentration. There were no significant correlations among variables for the spring wheat sets from the registration tests. In conclusion, the SDS sedimentation method seems unable to differentiate between eastern Canadian wheats of different remix loaf volumes especially when they have a high grain protein concentration (GPC), and is thus not suitable for use in predicting wheat strength. Key words: Breadmaking quality, sodium dodecyl sulphate sedimentation
Seedling growth analysis of Russian wildrye
Authors: Jefferson Paul G.
Published: April 2011

Tetracan, a recently released tetraploid cultivar of Russian wildrye (Psathyrostachys juncea (Fisch.) Nevski), has larger seed mass and better emergence from seeding depth than diploid cultivars. The objective of this research was to compare the seedling growth of Russian wildrye with crested wheatgrass (Agropyron desertorum (Fisch. ex Link) Schultes), Nordan and second to compare Tetracan Russian wildrye with two diploid Russian wildrye cultivars, Mayak and Swift. Seedlings were destructively harvested at 28, 42, 56, and 70 d after planting (DAP) in the greenhouse. Crested wheatgrass had greater seedling biomass in shoot and root, higher tiller number, and a more efficient root system than the Russian wildrye. Tetracan had fewer, larger tillers with larger leaves and greater root length than the two diploid cultivars. These results document that the tetraploid cultivar Tetracan has a different pattern of tiller initiation and growth than the diploid cultivars. Seedling growth rate and biomass yield (seedling vigor) of tetraploid Russian wildrye could be improved through polyploidization with high tillering diploid breeding lines as parents and selection for large tiller size (similar to Tetracan) while maintaining high tillering capacity. Key words: Specific root length, leaf area, tillering, carbon allocation
The effect of temperature on quality characteristics in timothy (Phleum pratense L.) genotypes
Authors: Ames N. , McElroy A. R. , Erfle J.
Published: April 2011

Improving the nutritive value of timothy (Phleum pratense L.) through breeding is dependent on selecting for genetic traits which directly contribute to ruminant digestibility. The identification of these traits is the goal of many forage researchers. The objectives of this research were to evaluate the leaf and stem digestibility of six timothy genotypes under different temperature conditions using two methods of estimating digestibility. Correlations between leaf and stem digestibility were not significant, suggesting that separation of these components is nessessary to clearly evaluate genotypic differences. Temperature had an important effect on digestibility, particularly for the stem fraction. Isolating leaf from stem and evaluating genotypes individually across temperatures may permit the identification of more simple genetic factors which control digestibility in timothy. Genotypic differences were observed at all temperatures. The rumen fluid digestion resulted in a much greater range within and among genotypes for both stem and leaf fractions. Genotypes tended to follow the same trends with respect to temperature using both techniques suggesting that only a portion of the dry matter digested by rumen fluid is available to the cellulases used in these experiments. Lignin content was measured for two of the most variable genotypes and the results showed that while levels increased with higher growth temperature, differences between genotypes are more pronounced at 10 °C for both leaf and stem. Key words: Digestibility, forage quality, lignin, temperature, timothy, Phleum pratense L.
AC Stephen barley
Authors: Ho K. M. , Seaman W. L. , Choo T. M. , Martin R. A.
Published: April 2011

AC Stephen is a six-rowed spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Canada Barley Breeding Group, Agriculture Canada, and is adapted to Eastern Canada. It was selected from an OAC Kippen/Léger cross. AC Stephen has high yield, good test weight and is resistant to powdery mildew (Erysiphe graminis DC. ex Merat. f. sp. hordei Em. Marchal). Key words: Hordeum vulgare L., six-rowed barley, feed barley, high yield, powdery mildew
AC Hunter oat
Authors: Burrows V. D. , McDiarmid G.
Published: April 2011

AC Hunter is a high yielding, white-hulled, daylength-sensitive, spring oat (Avena sativa L.) cultivar suitable for the feed industry in Quebec and Ontario. Its hull percentage is higher than is desirable for milling purposes but most of its yield and agronomic characteristics compare favourably with the check cultivars. AC Hunter is resistant to victoria blight (Bipolaris victoriae (Meehan and Murphy) Shoem.), loose smut (Ustilago avenae (Pers.) Rostr.) and to races CR13 and CR36 of crown rust (Puccinia coronata f. sp. avenae Eriks. and E. Henn.). It is susceptible to septoria blotch (Septoria avenae Frank, f. sp. avenae), red leaf (barley yellow dwarf virus) and stem rust (Puccinia graminis Pers. f. sp. avenae Eriks and E. Henn.) but shows field reactions similar to the better checks. Key words: Avena sativa L., rust, smut, cultivar description, oat
Evaluation of low temperature hardiness of strawberry plants under field and controlled conditions
Authors: Turner J. M. , Tanino K. K. , Stushnoff C.
Published: April 2011

When acclimated strawberry plants (Fragaria × ananassa Duch. ’Redcoat’) from the field were placed in a programmable freezer, mother strawberry crowns were as hardy or hardier than daughter crowns when frozen to −11 °C. However, under field conditions, daughter plants expressed consistently greater hardiness than mother plants. Mulching had no effect on daughter plant survival, whereas enhanced mother plant survival was observed. Field-growth habit of mother crowns may be the important factor for consistent winter survival under prairie conditions. A simple scoring system was developed to predict survival of strawberry plants. Key words. Fragaria × ananassa Duch., strawberry, crowns, low temperature hardiness
Photosynthèse de la primevère (Primula obconica Hance): Effets du gaz carbonique et de l’éclairement
Authors: Combe Laurette , Bertolini Jean-Michel , Quétin Philippe
Published: April 2011

Net CO2 exchange rates were measured on a 1 m2 crop of Primula obconica placed in a closed loop growing chamber as a function of irradiation and CO2 concentration. Greenhouse cultivation with CO2 enrichment (700 ppm) or without (350 ppm) had only very little effect on dry weight or on flowering rate and did not modify photosynthetic capacity of primrose. Productivity differences between horticultural techniques, such as supplemental lighting and/of CO2 enrichment, can be partly explained by study of photosynthesis curves: light increase is more efficient than carbon dioxide increase, the latter giving the best results with young primroses under strong irradiation. Key words: Primula obconica, net assimilation, carbon dioxide air concentration, light intensity, carbon fertilization
Assessment of tolerance in wheat and barley to common root rot (Cochliobolus sativus)
Authors: Duczek L. J. , Wildermuth G. B.
Published: April 2011

Field tests at Saskatoon, Saskatchewan, Canada indicated no evidence of tolerance to common root rot in four spring wheat cultivars. There was a relationship between increased yield losses and increasing disease. In barley, the relationship was inconsistent in four cultivars and there was evidence of tolerance or recovery in Melvin with the number of seeds per head increasing with the level of disease. In Queensland, Australia there was evidence of tolerance in the wheat cultivar Banks across two locations, but the response was not consistent in all cultivars. Dry matter loss at immature growth stages was not related to grain yield loss. The inconsistent expression of tolerance in wheat, the difficulty of assessing it, and the difficulty of distinguishing tolerance from recovery suggest that the assessment of tolerance is not a reliable method of determining the reaction to common root rot. The relationship between loss in dry matter and grain yield, as disease increased, indicates that disease assessment should continue to be based on severity of symptoms. The evidence of tolerance to common root rot in barley suggests research on tolerance should concentrate on barley instead of wheat. Key words: Cochliobolus sativus, common root rot, tolerance, wheat, barley
Potential of an organosilicone surfactant to improve soil wettability and ameliorate fairy ring symptoms caused by Marasmius oreades
Authors: Nadeau L. B. , Blenis P. V. , Knowles N. R.
Published: April 2011

Currently, chemical control of fairy ring caused by Marasmius oreades is not feasible, in part because colonized soil is very repellent to pesticidal solutions. Fungicidal control, however, might be successful if a surfactant was used to increase soil wettability. Of 13 surfactants screened for ability to enhance solution uptake by infested soil cores, the organosilicone, Silwet L-77, was most effective, followed by Citowett Plus and Agsurf. In a second, similar experiment, Silwet L-77 was more effective than the other two surfactants in increasing water uptake by both infested and uninfested soil cores. Silwet L-77 concentrations of 0.98–3% were equally effective in increasing grass production, relative to the water control, on colonized and uncolonized turf, under greenhouse conditions. At concentrations of 2% or higher, but not at concentrations of 0.016% to 1.0%, Silwet L-77, Citowett Plus, and Agsurf prevented M. oreades growth in liquid culture. Silwet L-77, and perhaps other organosilicone surfactants, seemingly have considerable potential for the management of fairy ring by improving uptake of water, or as carriers of biological or chemical control agents. Key words: Wetting agents, Silwet L-77
The biology of Canadian weeds. 102. Gaultheria shallon Pursh.
Authors: Fraser Lauchlan , Turkington Roy , Chanway C. P.
Published: April 2011

Gaultheria shallon Pursh., salal (Ericaceae), is a densely growing perennial evergreen shrub occurring only from the panhandle of Alaska along the entire coast of British Columbia to southern California; it is of native origin. Salal grows on a wide range of soil types and textures, and is abundant in open habitats near the coast particularly on rocky knolls and along bluffs. It is a persistent, pervasive woody perennial and is a serious competitor with coniferous species. The plant produces numerous seeds but the most significant and effective form of colonization is through vegetative spread. Several herbicides are recommended for control of the the weed but it is both resistant and resilient to many herbicides. This contribution summarizes the known biological data for this species. Key words: Gaultheria shallon, salal, evergreen shrub, weed biology, competition
Effect of initial quackgrass density on control with glyphosate prior to spring wheat
Authors: Leroux Gilles D.
Published: April 2011

Field studies were initiated in 1985 and 1986 at two sites near Quebec City to evaluate the population response of three quackgrass (Elytrigia repens (L.) Nevski.) infestation levels of 13, 72, and 180 shoots m−2 treated with glyphosate at 0, 0.45, 0.90, and 1.80 kg a.i. ha−1 prior to seeding wheat. During year 1, almost complete shoot and rhizome control was achieved by the 0.90 kg a.i. ha−1 + ethylan and the 1.80 kg a.i. ha−1 glyphosate treatments, regardless of the initial quackgrass infestation levels. Quackgrass control was less for the 0.45 kg a.i. ha−1 rate applied to the high infestation. During year 2, this trend was similar. Shoot density and biomass varied more than rhizome biomass in the glyphosate-treated plots. In the absence of wheat competition during year 3, glyphosate still had a significant impact on quackgrass infestations, although rhizomes had built up to a considerable level by mid-July. Reduction in rhizome biomass in the low, medium, and high quackgrass infestation by glyphosate averaged 56, 53, and 34%, respectively, but no further difference in control existed among glyphosate treatments. The data indicate that a reduced rate (0.45 kg a.i. ha−1) of glyphosate can be used effectively when the density of quackgrass shoots is below ca. 70 shoots m−2 at time of treatment. Key words: Glyphosate, quackgrass control, quackgrass density, rhizome, Elytrigia repens (L.) Nevski.
Influence of interference from a mixed weed species stand on soybean (Glycine max (L.) Merr.) growth
Authors: Acker Rene C. Van , Weise Stephan F. , Swanton Clarence J.
Published: April 2011

Field experiments were conducted to examine soybean-weed interactions under Ontario conditions. Trials were conducted at Elora, Ontario in 1990 and 1991 using comparative growth analysis to investigate the aboveground response of soybean to weed interference from a mixed weed species stand. Although season-long weed interference caused a significant decrease in soybean grain yield, weeds could remain in the crop up to 40 d after emergence, between R1 and beginning pod development stage (R3), in 1990 and up to 16 d after emergence, 3rd node development stage (V3), in 1991 without causing more than a 5% yield loss. These critical times of weed removal coincided with the timing of significant effects of weed interference on soybean LAI. Weed interference also significantly reduced total aboveground soybean dry weight and crop growth rate. Pods m−2 was the yield component most affected by season-long weed interference. Although there was no consistent effect of weed interference upon net assimilation rate and leaf weight ratio, weed interference resulted in a decrease in dry weight distribution to branch stems, causing as much as a fivefold reduction in allocation to branch stems. It may be useful to develop early branching soybean varieties, or use narrower row spacing, to enhance soybean competitiveness against weeds. Key words: Soybean (Glycine max), weed interference, growth analysis, leaf area, yield components
The effect of KCl, KNO3, and CaCl2 fertilization under conventional- and zero-till systems on common root rot, dry matter yield and grain yield of Heartland barley
Authors: Grant C. A. , Bailey L D.
Published: April 2011

Field studies were conducted on two soil types testing low in Clover a 4-yr period to assess the influence of K and Cl fertilization under zero (ZT) and conventional tillage (CT) management on common root rot, dry matter yield at heading, and grain yield of Heartland barley. Tillage did not influence incidence of common root rot in the 4 site-yr where assessments could be taken. Common root rot incidence was reduced by KCl applications in 1 out of 4 site-yr. Dry matter yield at heading and grain yields were consistently higher with ZT than with CT on the silty clay soil, but only in 1988 on the fine sandy loam soil. The higher yields with ZT than with CT may be due to greater moisture conservation under the ZT management system. Response to K or Cl applications was generally not influenced by tillage treatment. Applications of Cl had little influence on either dry matter yield at heading or grain yield, despite the low initial Cl levels in the soils. Application of fertilizers containing Cl, therefore, may not be consistently beneficial, even on soils testing low in Cl. Key words: Potassium, chloride, tillage, barley, common root rot
Response of eight Canadian spring wheat (Triticum aestivum L.) cultivars to copper: Pollen viability, grain yield plant−1 and yield components
Authors: Owuoche J. O. , Briggs K. G. , Taylor G. J. , Penney D. C.
Published: April 2011

Eight Canadian spring wheat (Triticum aestivum L.) cultivars, Katepwa, Roblin, Park, Laura, Conway, Oslo, Columbus and Biggar, were tested in the field for copper (Cu) use efficiency. The experiment was conducted at Stony Plain, Alberta on an Orthic, Dark Grey, Chernozemic, Cu deficient (0.48 μg g−1) soil. A split-plot experimental design was used with (+Cu) and without (−Cu) copper treatment of 12.2 kg copper sulphate ha−1. Significant (P ≤ 0.05) effects due to cultivar, Cu, season, and cultivar × Cu interaction were observed, indicating differential response of the test cultivars to Cu for yield and yield components. Cu application significantly (P ≤ 0.05) improved the number of grains spike−1, and floret fertility of Roblin, Laura, Park and Oslo, and increased the grain yield of Conway by 10%. Significant (P ≤ 0.05) effects due to cultivar, year and year × cultivar interaction for Cu efficiency indicated that Cu use efficiency varied with both year and cultivar. Biggar showed the highest Cu use efficiency (108%) while Oslo showed the lowest (57%). Key words:Triticum aestivum L., cultivars, copper, pollen viability, copper use efficiency
Pasture production of Russian wild ryegrass alone or in mixtures with Dahurian wild ryegrass or slender wheatgrass
Authors: Holt N. W. , Lawrence T.
Published: April 2011

A 5-yr grazing study at Swift Current, Saskatchewan examined the potential benefits of sowing Russian wild ryegrass (RWR) with a rapidly growing grass to increase production in the early years of new stands. Russian wild ryegrass was sown in alternate rows with Dahurian wild ryegrass (DWR) or slender wheatgrass (SWG) and these two treatments were compared to RWR alone. In the first crop year, 1988, the combination of RWR and DWR was higher yielding (380 kg ha−1) than the other treatments (230 kg ha−1). In 1989, RWR alone or in mixture with SWG was the highest-yielding treatment. Dahurian wild ryegrass was eliminated from the stand by 1990; SWG by 1991. Pasture production and grazing effects were evaluated from 1988 to 1992 (generally May to September) with yearling Hereford steers. Carrying capacity averaged 29 steer grazing days per ha in 1988 and 182, 220, 277 and 99 d ha−1 in the subsequent 4 yr. Carrying capacity was marginally greater for the combinations of grasses in 1988 and 1989, but not different than RWR alone, thereafter. Forage nitrogen and organic matter digestibility declined from May to September. However, forage quality was adequate to maintain season-long weight gains at an average 1.0 kg d−1. There was no benefit of total gain per hectare or additional grazing in the early years or thereafter by combining RWR with another grass. Key words:Psathyrostachys juncea, Elymus dahuricus, Elymus trachycaulus, steers, grazing
Effect of transplanting date on the fatty acid composition, oil content and yield of evening primrose (Oenothera biennis L.) seed
Authors: Roy Robert C. , White Peter H. , More Alex F. , Hendel John G. , Pocs Robert , Court William A.
Published: April 2011

The influence of transplanting time on the growth of evening primrose (Oenothera biennis L.) was investigated for 3 yr. Delaying transplanting reduced the yield of seed in two of these years. The amount of oil in the seed was not influenced by time of transplanting, and only in one year did the γ-linolenic acid content of the oil decrease with delays in transplanting. Key words: Evening primrose, transplanting date, oil content, γ-linolenic acid
Wildcat red spring wheat
Authors: Clarke P. J. , DePauw R. M. , Thomas J. B.
Published: April 2011

Wildcat (Triticum aestivum L.) is an early maturing, extra strong gluten cultivar adapted to the Peace River and Parkland regions of western Canada. Wildcat is shorter and more lodging resistant than Glenlea, it is moderately resistant to leaf and stem rust, resistant to loose smut but susceptible to common bunt. Key words:Triticum aestivum, wheat (spring), early maturity, cultivar description
OAC Talbot soybean
Authors: Beversdorf W. D. , Tanner J. W. , Gostovic P. , Montminy W. , Hume D. J.
Published: April 2011

OAC Talbot is an early Maturity Group II soybean (Glycine max [L.] Men.) cultivar with equivalent yield, slightly earlier maturity, more height and better lodging resistance than the best check cultivars with which it was compared. Key words: Soybean, cultivar description
OAC Eclipse soybean
Authors: Beversdorf W. D. , Tanner J. W. , Montminy W. , Gostovic P. , Hume D. J.
Published: April 2011

OAC Eclipse is a mid-Maturity Group 0 soybean (Glycine max [L.] Merr.) cultivar with excellent yield potential and high seed oil content. Key words: Soybean, cultivar description
Efficacy of downy brome herbicides as influenced by soil properties
Authors: Blackshaw R. E. , Moyer J. R. , Kozub G. C.
Published: April 2011

Controlled environment experiments were conducted to determine the effect of various edaphic factors on the efficacy of metribuzin, BAY SMY 1500, cinmethylin, and napropamide to control downy brome (Bromus tectorum L.). Experiment 1 determined the effects of soil organic matter, pH and texture and experiment 2 determined the effect of soil water contents ranging from −0.03 to −1.5 MPa on herbicide efficacy on downy brome. Metribuzin, BAY SMY 1500, cinmethylin, and napropamide efficacy on downy brome was highly correlated with soil organic matter and soil water content. Phytotoxicity of these herbicides was decreased up to two- to threefold as organic matter increased and soil water content decreased. Metribuzin and BAY SMY 1500 efficacy on downy brome increased as soil pH increased. Cinmethylin was more efficacious in sandy soils. This information may aid in determination of precise herbicide rates for various soil types to allow growers to achieve consistent control of downy brome without injuring winter cereals. Key words: Edaphic factors, cinmethylin, BAY SMY 1500, metribuzin, napropamide, Bromus tectorum L.
Using small tubes to measure root elongation of newly germinated alfalfa seedlings in relation to moisture
Authors: Waddington John , Snoop Marvin C.
Published: April 2011

A method of growing newly germinated seedlings in small tubes was developed to enable the study of early root elongation. Three newly germinated alfalfa (Medicago sativa L.) seeds were placed in tubes of various diameters and volumes filled with sand at several moisture tensions, and the tubes were sealed to prevent moisture loss. For the first 4 d, roots elongated at approximately 8 mm d−1 in polyvinyl chloride plastic tubes holding 60 mL of sand with a moisture tension of 100 kPa or less. After the initial 4 d, root elongation continued at a slower rate, and branch roots developed before termination of the experiments at 12 d after germination. At a moisture tension of 300 kPa, root elongation was markedly less than at 100 kPa, and was zero at moisture tensions of 500 kPa or greater. In round-bottom glass tubes, root elongation rate was significantly slower in a sand volume of 23 mL than in 65 mL, and there was evidence of slower seedling development as the diameter of the tubes was reduced from 20 to 15 mm. Wax plus masking tape or nylon tape were equally effective in sealing the sides of tubes formed from the two halves of a plastic pipe previously cut lengthwise. A plastic cap plus wax was significantly better than plastic film for sealing the bottom ends of plastic tubes. Neither aeration nor replacement of water with a dilute nutrient solution had an effect on root elongation of young seedlings. Key words: Alfalfa, seedling, root elongation, moisture stress, Medicago sativa
Inheritance of leaf area and hooked trichome density of the first trifoliolate leaf in common bean (Phaseolus vulgaris L.)
Authors: Park S. J. , Timmins P. R. , Quiring D. T. , Jui P. Y.
Published: April 2011

Hooked trichomes on common bean (Phaseolus vulgaris L.) plants are known to function as a plant defence against phytophagous insects and rust disease, and wide genotypic variability exists for trichome density. A bean cross between small-leafed, low-trichome-density cv. Harokent (P1) and broad-leafed, high-trichome-density cv. California Dark Red Kidney (P2) was analyzed to determine the inheritance of leaf area and trichome density of the first trifoliolate leaf under controlled environments. The F1 hybrids had leaf areas similar to those of the broad-leafed parent P2, had a trichome density similar to that of P1, and had fewer trichomes per leaf than the mid-parental value. Frequency distribution of the characteristics for the F2 and backcross P1F1 were skewed toward P1 but displayed continuous variation, with means around the mid-parental values. Generation-means analysis suggested control of the characteristics by additive, dominance and epistatic gene interactions. Low narrow-sense heritability estimates were obtained for these characteristics. Significant correlations between leaf area and trichome abundance and between trichome abundance and density were obtained, but leaf area and trichome density were not correlated. Selecting small leaves with high trichome density may be accomplished, since they are independent. These two characteristics are desired in small white pea bean cultivars. However, several cycles of recurrent selection in large populations may be required to combine these two desired characteristics. Key words: Common bean, Phaseolus vulgaris, inheritance, trichomes, plant defence
The use of bulk F2 and F3 yield tests to predict the performance of durum wheat crosses
Authors: Knott D. R.
Published: April 2011

Bulk F2 and F3 generation yield tests were carried out on 17 durum wheat (Triticum turgidum L.) crosses to determine if they could be used to predict the performance of lines selected from the crosses. The amount of variation for yield within crosses was also measured to see if there were differences among crosses. The crosses differed significantly in yield in both the F2 and the F3 tests, but the correlation between the tests was not significant (r = 0.189). The average yields of F3-derived F4 and F5 lines from the crosses showed no significant correlations with the bulk F2 and F3 yields. All of the crosses showed similar variation in yield, except for one, which had more low-yielding lines. Visual selection among F3 plants had no effect on F4 or F5 yields. At Saskatoon, the weather (particularly temperature and rainfall) varies greatly from year to year and is the main factor in limiting yields. Genotype × environment interactions undoubtedly played a major role in the results obtained in these tests. Different results might be obtained if the weather showed little year-to-year variability. Key words:Triticum turgidum, durum wheat, early-generation yield, yield prediction
Effect of low temperature and seeding depth on the germination and emergence of seven flax (Linum usitatissimum L.) cultivars
Authors: O'Connor B. J. , Gusta L. V.
Published: April 2011

Cool, moist soils combined with deep seeding can have a dramatic negative effect on percent emergence and the time to emergence of flax seedlings. The effects of temperature (over a range of 5–15 °C) on seed germination, and seedling emergence from a sowing depth of 20 and 40 mm, were determined for seven cultivars of flax. Temperature had no effect on percent germination; however, the time for 50% of the seeds to germinate at 5 °C was on average 160 h compared with 30 h at 15 °C. The time for 50% of the seeds to germinate at temperatures less than 8 °C was the least for Andro and Vimy and the greatest for Dufferin, McGregor and Norlin. Temperatures less than 10 °C had a dramatic effect on seedling emergence from both seeding depths. On average, fewer seedlings emerged from the 40-mm seeding depth than from the 20-mm seeding depth. The time for 50% seedling emergence at 5 °C was on average 450 h for seeds sown 20 mm deep and 600 h for seeds sown 40 mm deep. In contrast at 15 °C, 50% of the seedlings for all seven cultivars emerged after 150 h from 20 mm and 180 h from 40 mm. At the cooler temperatures and 40 mm seeding depth, Vimy and Andro had the highest emergence rates, while Dufferin and Norlin had lowest emergence rates. This study demonstrates the importance of seeding depths when seeding into cool soils. Also genotypes such as Andro and Vimy are more likely to provide uniform stands when soils are cool and moist and when flax is seeded deep. Key words:Linum usitatissimum L., flax, germination, emergence, low temperature, seeding depth
Effects of agronomic practices on free fatty acid levels in the oil of Ontario-grown spring canola
Authors: May W. E. , Hume D. J. , Hale B. A.
Published: April 2011

Spring canola (Brassica napus) seed grown in Ontario frequently exhibits elevated levels of free fatty acids (FFA) in the oil. The objective of this study was to determine the effects of various agronomic practices on FFA levels. Several field experiments were conducted in 1989 and 1990, and one experiment was conducted in 1987. FFA levels in the oil were higher in 1989 than in 1990. Two cultivars, Kristina and Global, were included in most experiments. The cultivar Kristina exhibited consistently lower FFA levels than the cultivar Global, averaging 42% less over years and treatments. Global averaged 1.31 and 0.62% FFA in 1989 and 1990, respectively. Decreasing seeding rates raised FFA levels in both cultivars in 1989 and in Global in 1990. Increasing rates of nitrogen (N) fertilizer increased FFA in Global in 1989. The removal of drought stress by irrigation during seed filling decreased FFA in Global by 46% in 1989. A combination of high N, low seeding rates, and no irrigation increased FFA in both cultivars in 1990. Delays in planting date resulted in higher FFA in 1987. The effect of these agronomic practices on yield and seed oil concentration were also reported. Applications of potassium or boron fertilizers did not affect FFA, nor did weekly applications of the fungicide, benomyl, or dosing plants with elevated levels of atmospheric ozone. The problem of elevated FFA can be diminished by avoiding excessively high nitrogen fertilizer rates and low seeding rates and by selection of low-FFA cultivars. Key words: Canola, free fatty acids, irrigation, ozone, planting date, oil content
Long-term comparison of rock phosphate with superphosphate on crop yield in two cereal-legume rotations
Authors: Choudhary M. , Bailey L. D. , Peck T. R. , Paul L. E.
Published: April 2011

Monocropping and long-term use of highly water soluble commercial fertilizers may reduce crop yields and contaminate surface and ground water. A long-term experiment compared the effectiveness of rock phosphate (RP) with superphosphate (SP) on crop yields, soil tests, and leaf nutrient concentrations in two rotations with or without addition of N or lime in a strip-block design with phosphate as vertical factor and N or lime as horizontal factor applied over P treatments. Crops in rotation A (1952–1967) included oats (Avena sativa L.), alfalfa (Medicago sativa L.), corn (Zea mays L.) 1st yr and corn 2nd yr while crops in rotation B (1968–1983) included corn and soybean (Glycine max L.). Phosphate application as single source, RP and SP in combination, and RP with elemental sulphur ranged from 0 to 40 kg P ha−1 yr−1. In rotation A, RP was applied once every 8 yr at eight times the annual rate; in rotation B it was applied at half the annual rate of rotation A. The SP was applied annually in both rotations. In both rotations, P treatments significantly increased crop yields. In rotation A, crop yields on RP treatments were similar to those on corresponding SP treatments except for oats. Similarly, yields of crops grown with RP alone were similar to those obtained with a mixture of RP with SP or S. But corn grown after alfalfa did not respond to N application nor did crop yields respond to lime application. In rotation B, at low lime, corn and soybean yields were similar on RP treatments to those on corresponding SP treatments, but at high lime, yields were significantly lower with RP than corresponding SP treatments. Further, crop yields on mixture of RP and SP were similar to yields with RP alone, and the RP and S combination produced lower soybean yields and similar corn yields than RP alone. In this long-term cropping sequence study, on acidic soil RP was equally as effective as SP in supplying P to crops. Key words: Rock phosphate, superphosphate, legumes, lime, nitrogen
Selection of environments using simultaneous clustering based on genotype × environment interaction
Authors: Baril C. P. , Denis J-B. , Brabant P.
Published: April 2011

Cluster analysis is used to classify genotypes and environments to decompose and interpret genotype × environment (GE) interaction. A simultaneous clustering method is applied to wheat-yield data collected over 8 yr in seven locations, with two agronomic treatments per location. This approach evidenced redundancies among the used environments constituting the Institut National de la Recherche Agronomique series of experiments in northern France. The aim is to reduce the number of environments without losing GE interaction. A graphical method based on the decreasing mean square of GE interaction is proposed to provide a cutting criterion of the cluster procedure. The comparison of groupings made independently for successive years suggested the removal of some environments, hence providing rational savings in the breeding program. Lastly, the simultaneous two-way clustering procedure is compared with the common one-way clustering procedure. Key words: Cluster analysis, genotype × environment interaction, pattern analysis, series of experiments, wheat
Effect of frost injury on quality of flax seed
Authors: Gubbels G. H. , Bonner D. M. , Kenaschuk E. O.
Published: April 2011

In field and laboratory studies, flax (Linum usitatissimum L.) was frozen when 40–60% of the capsules were still green. Seed visibly frozen at this stage were of lower weight and density, darker in color, and lower in germinabihty than the fraction of the sample that was not visibly frozen. Also, oil color was darker, oil and protein concentrations and stearic and oleic acid levels were lower, and palmitic, linoleic and linolenic acid levels and iodine values were higher in the frozen than the normal seed. Key words: Flax, Linum usitatissimum, frost damage, seed quality, germination
Comparative yield and evaluation of cultural practices for selected fall-planted garlic lines (Allium sativum L.) in Quebec
Authors: Landry Benoit S. , Khanizadeh Shahrokh
Published: April 2011

From observation trials of 225 garlic lines that exhibited good winter hardiness and yield, five fall-planted lines (California Early, Fructidor, Musik, Roman and Zdreluk) were selected for further study. In replicated experiments, these lines were found to be winterhardy and consistently yielded bulbs larger than 60 mm in diameter. Distance between rows, size of the planting material, and site had significant effects on marketable yield and average size of harvested cloves. The highest yield was obtained with 45–50 cm between rows. Planting cloves smaller than 20 mm produced smaller bulbs, but yield was not effected by clove provenance (internal vs. external part of the bulb). Key words: Breeding, genotype evaluation, distance between rows, clove size, winter survival, garlic
Postemergence control of quackgrass [Elytrigia repens (L) Nevski] with DPX-79406 in corn (Zea mays L)
Authors: Reidy M. E. , Swanton C. J.
Published: April 2011

Laboratory and field experiments were established to determine the optimum dose and timing of postemergence applications of DPX-79406 for quackgrass control. Four node quackgrass rhizome fragments from each biotype were grown under controlled conditions. At the three-to-four-leaf stage, quackgrass plants were sprayed with DPX-79406 and evaluated for control. A significant response of quackgrass biotypes to DPX-79406 was evident only at lower doses. In the field, quackgrass was effectively controlled by all doses of DPX-79406. Significant growth-stage effects were observed for quackgrass shoot and rhizome dry weights in the year of application and in the year following application. There was a significant interaction between year and growth stage. In 1990, quackgrass biomass was greater when DPX-79406 was applied at the two-to-three-leaf stage of quackgrass than at the four-to-five-leaf stage. In 1991, however, the opposite occurred. Within a growth stage, the 6.25 g ha−1 dose was as effective for controlling quackgrass as 18.5 g ha−1, in both years of the study. In 1991, significant decreases in corn yield were observed for DPX-79406 doses of > 12.5 g ha−1 applied at the four-to-five-leaf stage of quackgrass. For all the variables studied, DPX-79406 doses of 6.25–12.5 g ha−1 resulted in consistent control of quackgrass. Key words: DPX-79406, nicosulfuron, rimsulfuron, quackgrass, Elytrigia repens, corn, Zea mays
The effect of varying levels of hybridity on the performance of three pol CMS summer rape hybrid cultivars (Brassica napus L.)
Authors: Pinnisch R. , McVetty P. B. E.
Published: April 2011

The Polima (pol) cytoplasmic male sterility system (CMS) has been developed to facilitate the commercial production of hybrid summer rape cultivars. Polima A-lines usually produce small quantities of viable pollen, and further, they suffer from high-temperature-induced male-fertility reversion at temperatures of 30 °C or higher. This pollen production can result in selfing and sibing of the pol A-lines, substantially reducing the hybridity of the field-produced hybrid seed lots. The effects of 5, 15, 25 and 35% A-line contamination on seed yield, oil content and protein content for three different pol CMS summer rape hybrids grown in seven environments over 3 yr were found to be minimal in this study. It is concluded that in cases where the effect of pol A-line contamination on the oil content and (or) protein content of contaminated hybrids is significant, these effects can be predicted from a comparison of the relative oil and protein contents of the pure pol A-line and the pure hybrid. It is also concluded that the current 75% hybridity standard, set by the Canadian Seed Growers Association for the CMS hybrid summer rape seed lots is a reasonable initial minimum standard. Key words: Polima cytoplasmic male sterility, hybrid seed production
Date and rate of seeding of winter cereals in central Alberta
Authors: Jedel P. E. , Salmon D. F.
Published: April 2011

Winter survival is often the most limiting factor for the use of winter cereals for grain production in the Black soil zones of the Canadian prairies. Production practices that optimize winter survival are an important part of extending the winter cereal acreage in this area. In this study, three dates of fall seeding (late August, early September, and late September) at two rates of seeding (258 and 328 seeds m−2) were investigated in 1988–1989, 1989–1990, and 1991–1992, at Lacombe, AB, using Musketeer fall rye (Secale cereale L.), Norstar and Norwin winter wheats (Triticum aestivum L. EM Thell), and Decade and Wintri winter triticales (× Triticosecale Rimpani Wit.). Survival was found to be best in all years when planting was conducted in late August and early September (78–99% survival). In both 1989 and 1990 the early planting resulted in the lowest yields (3.09 and 3.91 t ha−1), while in 1992 the latest planting resulted in the lowest yields (0.92 t ha−1). The early seeding resulted in earlier maturity in 1989 and 1992 (1–13 d). Test weight and kernel weight decreased with later planting (10–116 kg m−3 and 1–3.4 mg, respectively). Kernel protein was generally not affected by the treatments but was higher in some later planted material (0.2–1.0 g 100 g−1). Seeding rates were without effect on most traits, except grain yield in 1992 and kernel weight in 1990 and 1992 when rate effects varied among seeding dates. Date of seeding did not affect plant height except in 1992 when the later planted material was shorter. For all cultivars, survival was decreased with the late planting thereby increasing the risk of crop production. The window for seeding winter cereals in central Alberta is wider for the hardier cultivars and if forced to seed late, these cultivars should be selected. Key words: winter triticale, winter wheat, fall rye, yield, winter survival
Influence of post-harvest residue management and cultivar on tiller dynamics and seed yield in timothy
Authors: Entz M. H. , Smith Jr. S. R. , Cattani D. J. , Storgaard A. K.
Published: April 2011

Timothy (Phleum pratense L.) is a bunch-type cool season perennial grass species grown in Manitoba primarily for seed production. The objectives of this study were to determine the effect of post-harvest residue management (straw removal-SR, straw and stubble removal-SSR and fall burning-Burn) on tiller production, yield components and seed yield of five timothy cultivars (Basho, Climax, Goliath, Hokuo and Salvo), and to better understand the association between yield components and final seed yield in timothy crops grown in the dry subhumid region of the Canadian prairies. Two experiments were conducted over four production seasons at Arborg, MB and one production season at St. Claude, MB. Tiller number per m2 in spring (TS) and at harvest (THV) were measured in 1990 at St. Claude and in 1990 and 1991 at Arborg. Residue management (RM) treatment ranking for TS was Burn < SR < SSR, but tiller senescence and compensatory mechanisms resulted in equivalent THV values across all RM treatments. The number of seed-bearing tillers m−2 at harvest was also unaffected by RM. Seed yield was unaffected by RM in all instances, except at Arborg in 1989 where a significant RM × cultivar interaction was observed. The basis of the interaction was the greater sensitivity of Hokuo to the Burn treatment. Cultivar differences for seed yield were relatively consistent over years and between the two experiments, with Climax always ranking in the high yielding group and Salvo with the low yielding group. Based on analysis of yield components, it appeared that RM most affected early season growth (i.e. TS), while cultivar most affected later season growth (fertile tillers per unit area, seed yield per fertile tiller (SYFT)). Seed yield differences were most closely associated with SYFT (r2 = 0.97**) across cultivar treatments. Key words: Burning, straw removal, harvest index, yield components, forages