bluuebunny/crossref_metadata_2025 huggingface dataset:
Regrowth of smooth bromegrass (Bromus inermis Leyss.) following defoliation
Authors: Harrison T. , Romo J. T.
Published: April 2011

Regrowth and production of tillers in smooth bromegrass (Bromus inermis Leyss.) following defoliation to a 5-cm stubble height were monitored throughout the summer and in early spring the following year in central Saskatchewan. After defoliation, while smooth bromegrass was vegetative, forage began accumulating in 45–75 growingdegree-days (GDD) when moisture was favorable. Regrowth ranged from 34 to 84 g m−2. Plants also produced ≤ 51 g m−2 of regrowth when defoliated at or before culm elongation in a year with above-average precipitation. In two dry years, regrowth was minimal and plants did not regrow after defoliation in the later vegetative growth stages; however, new leaves were produced within 110–140 GDD. Following defoliation at early vegetative growth stages, 1030–1180 GDD were needed to reach maximum regrowth. Total annual production was either unaffected or reduced by defoliation. Total annual production ranged from 35 to 139 g m−2, with yields lowest when defoliated in early May or early June and highest when herbage was removed in mid-May or near flowering and seed production. When plants were defoliated during vegetative growth most tillers were produced the following spring, whereas when plants were defoliated during reproductive phases the majority of tillers emerged in the fall. The year after defoliation, the density of tillers (871–951 m−2) was not significantly different among treatments. Regrowth following defoliation cannot be related to a particular growth stage, but rather it depends on growing conditions. If smooth bromegrass is defoliated once and rested until the next year, it should be recovered by early spring and its productivity should be unaffected. Key words: Etiolated growth, forage production, grazing management, regrowth, rest requirement, tillering
Growth stress induces glucosinolate changes in pakchoy (Brassica campestris ssp. chinensis)
Authors: Shattuck V. I. , Wang W.
Published: April 2011

Glucosinolates (GS) are sulphur-containing compounds that yield breakdown products that contribute to the characteristic flavor and aroma of Cruciferae crops. No studies have been conducted on the influence of the environment on the GS levels in the leafy vegetable pakchoy (Brassica campestris ssp. chinensis). Because of the importance of GS, we studied in two separate experiments, the effect of nitrogen (N) nutrition and turnip mosaic virus (TuMV) infection on the GS content of this vegetable. As part of our study in a separate experiment, we also determined the GS profile of developing plants from 5 to 35 d. Nitrogen was applied at 14, 84, and 224 mg L−1 and plants were manually inoculated with TuMV during early (15 d) and late (30 d) development. Plants were grown hydroponically and harvested 35 or 36 d after seeding. Developing plants accumulated GS in leaf tissues. Nine GS were detected in pakchoy tissues. Plants supplied with 14 mg L−1 N and those infected with TuMV during early development had lower fresh and dry weights and had higher total GS content than control plants. Alterations in the concentrations and relative percentages of several GS were also evident in these plants. A decline in the 1-methoxy-3-indolylmethyl-GS percentage in the mature leaf tissues of stressed plants commonly occurred. Data from these experiments indicated that certain GS changes in pakchoy were tissue and stress specific. Key words:Brassica, glucosinolates, nitrogen, turnip mosaic virus
Effect of nitrogen fertilization on head size, vitamin C content and storage life of broccoli (Brassica oleracea var. Italica)
Authors: Toivonen Peter M. A. , Zebarth B. J. , Bowen P. A.
Published: April 2011

Broccoli quality in British Columbia can vary with season and with the farm site on which it is grown. One major management difference between farms is nitrogen fertilization rate. This work was conducted to determine the effect of nitrogen fertilization (0, 125, 250, 375, 500 and 625 kg N ha−1) and growing season (three plantings in 2 consecutive years) on vitamin C content, head size and storability of broccoli (Brassica oleracea var. Italica, 'Emperor'). The climatic conditions during crop growth and development had a greater overall effect on vitamin C content, head diameter and head weight than nitrogen fertilization. Weight and vitamin C losses during storage in the first year were not affected by nitrogen fertilization rates. Moderate nitrogen application rates of 125 and 250 kg N ha−1 in all three plantings produced a head size considered optimal for marketing. Key words: Postharvest, vegetable quality, climatic conditions
Influence of variety and cultural practices on garlic yields in Saskatchewan
Authors: Waterer D. , Schmitz D.
Published: April 2011

Relative growth and yield of eight garlic lines were evaluated in 2 yr of fall- and spring-planted trials in Saskatchewan. The best adapted lines produced commercially acceptable yields of high-quality garlic, while other lines proved poorly adapted to Saskatchewan growing conditions. Fall planting enhanced yields over spring planting by an average of 59 and 25% in the two test years. Some lines were only suited to spring planting. Planting date had little effect on overwinter survival or yields of fall plantings. Mulching with straw in the fall did not improve overwinter survival or yields. Key words:Allium sativum, planting date, winter survival
Rajeunissement de clones matures d'Hevea brasiliensis (Müll. Arg.) par microgreffage in vitro
Authors: Perrin Y. , Lardet L. , Enjalric F. , Carron M. P.
Published: April 2011

In vitro micrografting of apices of two mature genotypes of Hevea brasiliensis (Müll. Arg.), IRCA 18 and PB 235, on 3-wk-old seedlings grown in vitro permitted successfull in vitro micro-cutting of these two genotypes. Microcutting of micrografted material was impossible from nodal explants or shoot tips of scions developed in vitro on rootstocks. Such explants were incapable of caulogenesis activity after their isolation. This problem was resolved using mixed explants, each consisting of a part of the rootstock in contact with the culture medium, and of the clonal scion from which axillary shoots are developed regularly along the subcultures. Budding and shoot elongation abilities along the subcultures have been compared between mixed explants from micrografts, nodal explants from juvenile material and nodal explants from non-micrografted mature genotypes. The results show a very positive effect of micrografting on the in vitro caulogenesis ability in both genotypes. Moreover, shoots produced by mixed explants from micrografts exhibit the same rooting ability as shoots produced by explants collected on juvenile material. Key words: Rejuvenation, Hevea brasiliensis, in vitro micrografting, micropropagation, in vitro microcutting
Influence of temperature after spraying on glyphosate control of quackgrass (Elytrigia repens(L) Nevski) previously exposed to light frost
Authors: McMullan P. M.
Published: April 2011

Research was conducted in controlled environment chambers to determine the influence of temperature after herbicide application on glyphosate control of quackgrass previously exposed to light frost (−2 °C). Quackgrass topgrowth control and rhizome bud viability reduction was greatest at 900 g ha−1 glyphosate and was enhanced by ammonium sulphate. Quackgrass topgrowth control was greatest at 15 °C/10 °C day/night temperature. In contrast, reduction in rhizome bud viability was different only between 15 °C/10 °C and 10 °C/5 °C. Topgrowth control of quackgrass by glyphosate may be much more affected by temperature than reduction in rhizome bud viability. Key words: Quackgrass, frost, temperature, glyphosate, ammonium sulphate
Effects of row spacing, seeding rate and nitrogen on yield of barley and wheat under zero-till management
Authors: Lafond G. P.
Published: April 2011

Adopting water-conserving tillage practices on the Canadian prairies will protect the soil against erosion while conserving soil water. The use of tall-standing stubble to conserve water creates a dilemma for producers because maximum yields can only be obtained with narrow rows, and tall stubble may limit the use of narrow row spacings. A 4-yr study on a thin Black clay soil investigated the effects of three row spacings (10, 20 and 30 cm), six seeding rates (34, 67, 100, 134, 168 and 202 kg ha−1 for wheat and 27, 54, 81, 108, 134 and 161 kg ha−1 for barley) and two rates of N (low and high) in hard red wheat (Triticum aestivum L.), durum (Triticum durum L.) and barley (Hordeum vulgare L.) using a continuous cropping, zero-till production system. The yields of cereals were maintained with 30-cm row spacing over a wide range of growing conditions under zero-till management. Durum had a 5.8% yield advantage and barley a 2.4% advantage for the 30-cm row spacing over the 10-cm row spacing. The number of plants established and the number of spikes produced decreased as row spacing increased for all crops. But wider row spacing resulted in more kernels produced per spike, which, in the case of barley and durum, more than compensated for the lower number of spikes. Increasing seeding rates significantly improved grain yield in all crops and years because more spikes were produced. Grain yield was related to the reciprocal of seeding rate. The few row spacing × seeding rate interactions observed in 2 of 12 cases suggest that seeding rates need not be adjusted for changes in row spacing. The results obtained have important implications for equipment design and the ability to more easily handle high-crop-residue situations. Key words: Yield components, seeding rate, row spacing, yield compensation
Growth, yield and quality of canola expressing resistance to acetolactate synthase inhibiting herbicides
Authors: Blackshaw R. E. , Kanashiro D. , Moloney M. M. , Crosby W. L.
Published: April 2011

On the Canadian prairies, weed control is a limitation to successful canola production which may be overcome by development of herbicide-resistant cultivars. The csr1-1 gene from Arabidopsis thaliana L., known to confer increased resistance to the acetolactate synthase inhibiting herbicide, chlorsulfuron, was transferred into spring canola (Brassica napus L.). Greenhouse and field experiments were conducted to determine the level of resistance and the yield and quality response of this transgenic canola to the acetolactate synthase herbicides chlorsulfuron, metsulfuron, imazethapyr, imazamethabenz, and flumetsulam. In the greenhouse, transgenic canola expressed higher levels of resistance to all herbicides except imazethapyr applied at the five-leaf than the one-leaf stage. In field studies, inserting the csr1-1 gene into canola did not alter maturity, seed yield, weight, or oil content. Transgenic canola resistance to the acetolactate synthase herbicides varied within and among chemical classes. The ranking of increased tolerance of transgenic canola to these herbicides in the field was chlorsulfuron (9- to 15-fold) > flumetsulam (6- to 10-fold) > imazamethabenz (3- to 6-fold) > metsulfuron (2- to 5-fold) > imazethapyr (1- to 2-fold). Key words:Brassica napus L., herbicide resistance, maturity, oil content, seed weight, yield
Wolf plant effects on water relations, growth and productivity in crested wheatgrass
Authors: Romo J. T.
Published: April 2011

When improperly managed in pastures, crested wheatgrass (Agropyron desertorum (Fischer ex Link) Schultes) develops wolf plants because of the long-term persistence of inflorescences. The objective of this study was to test the hypothesis that the wolf plants have no effect on the growth and water relations of grazed or subordinate plants in crested wheatgrass. Treatments applied to wolf plants included killing with glyphosate, mowing to a 10-cm stubble, killing with glyphosate + mowing to a 10-cm stubble, and a control. Rates of vegetative and reproductive development, tiller and whole plant weights, tiller replacement and xylem water potentials of leaves were determined for subordinate plants for 2–3 yr following treatment. The presence of wolf plants had no consistent effect on the water relations or on growth of subordinate plants of crested wheatgrass. Because they play no apparent beneficial role in the water status and productivity of crested wheatgrass, management techniques should be implemented to exploit the forage produced by wolf plants. Accessing this forage can substantially increase the grazing capacity of crested wheatgrass pastures. Key words:Agropyron desertorum (Fischer ex Link) Schultes, grazing management, pasture improvement, plant water relations
Effect of tillage practice and planting pattern on performance of white bean (Phaseolus vulgaris L.) in Ontario
Authors: Sandoval-Avila D. M. , Michaels T. E. , Murphy S. D. , Swanton C. J.
Published: April 2011

The effect of tillage system on planting pattern and cultivar choice of white bean (Phaseolus vulgaris L.) was evaluated in 1990 and 1991. In one experiment, white bean cv. OAC Gryphon was sown in three different planting patterns: rows 20 cm apart and 375 000 seeds ha−1, 40 cm apart and 375 000 seeds ha−1 and 76 cm apart and 250 000 seeds ha−1. This cultivar was grown under chisel ploughing and no-till. No interaction (tillage × planting pattern) was detected in either year. There were no significant differences in seed yields, total aboveground dry matter or leaf area index (LAI) between tillage systems and no interaction of year × tillage system. In 1990, yield increased where white bean was planted in 20 cm rows versus 40 cm rows; however, there was no significant effect of planting pattern on total aboveground dry matter or LAI. In 1991, total aboveground dry matter and LAI increased with decreasing row width. In a second experiment, the interaction effects between tillage system and seven cultivars of white bean were evaluated. Regardless of the tillage system used, the performances of two cultivars (OAC Gryphon and OAC Laser) were consistent within the 2 years of our study. It appears that the choice of cultivars of white bean may depend more on yield potential, disease resistance and adaptation to a particular region than the tillage system to be used. Key words:Phaseolus vulgaris, white bean, no-till, chisel plough, planting pattern
AC Charlie red clover
Authors: Choo T. M. , Christie B. R. , Bélanger G. F. , Papadopoulos Y. A. , Kilyanek S.
Published: April 2011

The red clover (Trifolium pratense L.) cultivar, AC Charlie, is a diploid of the early or double-cut type. It was developed by two cycles of mass selection for persistence and vigour. Forage yields after severe winter conditions indicate that AC Charlie is more winterhardy than Florex in Atlantic Canada. It is similar in maturity to Florex and 3–4 d later than Marino. Key words: Cultivar description, red clover, AC Charlie
Changes in ribulose-1,5-bisphosphate carboxylase/oxygenase and phosphoenolpyruvate carboxylase activities and 14CO2 fixation during the rooting of strawberry shoots in vitro
Authors: Hdider Chafik , Desjardins Yves
Published: April 2011

The potential for carbon fixation was investigated in in vitro strawberry (Fragaria × ananassa Duch. Kent) shoots 5, 10 and 28 d after transfer to a rooting medium. The activities of ribulose-1,5-bisphosphate carboxylase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC) and the time course of 14CO2 fixation were investigated. Five days after transfer, Rubisco activity was low but was increased two-fold after 28 d. In contrast PEPC activity was highest at 5 d and declined to about 0.4-fold by day 28. The rate of 14CO2 fixation was similar at 5, 10 and 28 d after transfer. However, a more rapid incorporation of 14CO2 into amino acids was observed at 5 than at 10 or 28 d after transfer. These results suggest that strawberry shoots undergo a progressive transition from heterotrophic to autotrophic carbon fixation during their rooting and that PEPC plays an important role in sustaining carbon fixation and amino acid synthesis during the first few days after their transfer to rooting medium. Key words: In vitro culture, phosphoenolpyruvate carboxylase, ribulose-1,5-bisphosphate carboxylase
Growing season changes in the concentration and distribution of macroelements in Willamette red raspberry plant parts
Authors: Kowalenko C. G.
Published: April 2011

Nitrogen, P, K, Ca, Mg and Na concentrations and accumulations in Willamette red raspberry (Rubus idaeus L.) plant parts were measured in a field study to identify a potential plant-analysis-based method for evaluating site-specific fertilizer requirements. Dry matter and macroelements accumulated steadily in new canes over the season, increased early to a stable amount in floricane laterals and ripe berries, increased and then decreased in leaves and remained stable in stems. Macroelement accumulation patterns were generally similar to dry matter accumulations. The amounts of N and K that accumulated in ripe berries were similar and about eight times greater than P, Ca and Mg. Macroelement concentrations of floricane stems, laterals and berries were more stable than in leaves, making them potentially more suitable than leaves for developing tissue analysis for fertilizer recommendations. Key words: Nitrogen, phosphorus, potassium, calcium, magnesium, sodium, Rubus idaeus
The effect of edible coatings on storage quality of McIntosh, Delicious and Spartan apples
Authors: Lau O. L. , Meheriuk M.
Published: April 2011

McIntosh, Delicious and Spartan apples were coated with several concentrations of Prolong, a sucrose-fatty acid ester, or Nutri-Save, a polysaccharide, and stored in air at 0 °C for 120–50 d or in air at 20 °C for 14 d. Retention of flesh firmness and acidity were generally better in coated fruit than in control fruit during the 3-yr study. Non-coated fruit stored under CA for the same periods were superior in overall quality than coated fruit stored in air. Core flush and scald were lower in coated McIntosh fruit but core flush and breakdown were slightly higher in coated Delicious apples. The higher concentrations of coating materials caused significant skin discoloration (purplish hue) in McIntosh and Spartan. Discoloration was less severe in Delicious apples. Ripening of the fruit under low and high humidity at 20 °C did not affect quality parameters. Sensory quality was not affected by the coating materials. Key words:Malus domestica, firmness, titratable acidity, skin discoloration, disorders, sensory attributes
Seedling emergence after maternal bentazon application to 10 cocklebur (Xanthium strumarium) populations
Authors: Zhang Jianhua , Cavers Paul B.
Published: April 2011

Maternal environments have been reported to affect various seed and seedling characteristics in many plants. In this study, we examined the effect of bentazon application to the mother plants on seed germination and seedling emergence of 10 cocklebur populations from wetlands or cultivated land. The mortality or longevity of fully developed seeds was affected significantly by bentazon application. Rate of seedling emergence showed little response, whereas percentage seedling emergence and percentage viable seeds in the soil were reduced by bentazon treatment to the mother plants. Populations from wetlands produced seedlings earlier than those from cultivated land. Key words: Seedling emergence, seed bank, herbicide, bentazon, cocklebur, Xanthium strumarium
The biology of Canadian weeds. 103. Vallisneria americana Michx.
Authors: Catling P. M. , Spicer K. W. , Biernacki M. , Doust J. Lovett
Published: April 2011

American wild celery (Vallisneria americana Michx.) is a native submerged aquatic plant that differs from other ribbon-leaved aquatics in having leaves with a well-defined midvein and paler zones on either side of a central dark band. In southern Ontario and Québec the dense leaf growth, and in particular the floating plants dislodged from the sediment, impede water traffic and restrict water-based recreation. Mechanical harvesting may be the best method of control in most situations. American wild celery is beneficial as an important food source for waterfowl and other wildlife, as cover and spawning area for fish, and may also be used as fertilizer and to feed livestock. There is also potential for increased use in biomonitoring. Widespread in eastern North America, it reaches its northern limit in southeastern Canada. It is introduced in British Columbia and the northwestern United States, and has also recently been reported from the southwestern United States, Mexico, the Carribean islands, northern Central America, southeast Asia and Australia. American wild celery occurs in alkaline to slightly saline waters with pH > 6, at depths of 0.3–7 m, and in a variety of sediment types. Clonal growth is extensive. Parent rosettes can each produce 20 or more new shoots within a season. These develop from buds at the tip of stolons, some of which overwinter as turions. Pollination takes place on the surface of the water with free-floating male flowers tipping into the surface depression created by the larger, attached female flowers. Fruits mature under the water. Key words:Vallisneria americana, American wild celery, weed biology, aquatic macrophyte, Canada, distribution
Determination of the water use of two pairs of soybean isolines differing in stomatal frequency using a heat balance stem flow gauge
Authors: Tan C. S. , Buttery B. R.
Published: April 2011

Using heat-balance stem flow gauges, we were able to measure directly and continuously the sap flow rates in two pairs of soybean [Glycine max (L.) Merr.] isolines differing in stomatal frequency. Plants with high stomatal frequency transpired significantly more water than the low stomatal frequency plants at high soil moisture levels. Under low soil moisture levels, the water use rate decreased greatly for the high stomatal frequency plants. Plants with low stomatal frequency were able to maintain greater sap flow rates than those with high stomatal frequency. Higher leaf temperatures associated with the low stomatal frequency plants were likely due to lower transpiration rates which reduced evaporative cooling especially under well-watered conditions. Key words:Glycine max (L.) Merr., transpiration, water deficits
Growth and chemical composition of flax cultivars on artificially salinized soil
Authors: Beke G. J. , Graham D. P.
Published: April 2011

Seven flax cultivars, grown in a greenhouse in nonsaline, moderately saline, and strongly saline (1, 6, and 12 dS m−1) soils had greater dry weights of plant tops on moderately saline treatment. Tops had higher K+ and Na+ concentrations on the saline treatments, but K:Na ratios decreased with increasing salinity. Tops were less salt tolerant than roots. Cultivars responded differently to the treatments, but appeared, overall, similar in salt tolerance. Key words: Flax cultivars, ion concentrations, ion ratios, soil salinity, semi-arid region
Authentification des 13 cultivars de fraisier du programme de certification du Québec par l'analyse d'ADN polymorphe amplifié au hasard (RAPD)
Authors: Parent Jean-Guy , Pagé Danièle
Published: April 2011

Random amplified polymorphic DNA analysis was used to identify and differentiate the 13 strawberry cultivars of Quebec's certification program. DNA extracts from leaves of field plants were analyzed. Young and apparently healthy leaves were chosen to ensure a good quality of DNA. A selection of only two primers, in a test combination, was sufficient to attain the anticipated result. Key words: Strawberry (Fragaria spp.), random amplified polymorphic DNA, RAPD, cultivar identification
Quackgrass control with glyphosate and SC-0224 in corn and soybean
Authors: Hamill Allan S. , Zhang Jianhua
Published: April 2011

Studies on quackgrass control were conducted using a factorial combination of glyphosate or SC-0224, each at 0.28, 0.56 and 0.84 kg ha−1, and ammonium sulphate at 0 and 2.5 kg ha−1 in corn and soybean plots on a severe infestation in southwestern Ontario during 5 yr. The two herbicides at a given rate provided similar degrees of quackgrass control. With the addition of ammonium sulphate, the effective rate of both herbicides was reduced from the recommended rate of 0.9 kg ha−1 to 0.56 kg ha−1, which results in a higher economic return. Although a lower rate, 0.28 kg ha−1, also provided satisfactory initial control of quackgrass, there was a tendency to increasing quackgrass coverage with time despite the repeated application of herbicides over years. After 5 yr of treatment at a consistently low rate (0.28 kg ha−1), quackgrass coverage approached the original level in the soybean field. The increase in quackgrass coverage caused a corresponding reduction in soybean yield. The results suggest that glyphosate or SC-0224 at about 0.56 kg ha−1 is effective when applied in conjunction with ammonium sulphate. Lower rates may be acceptable if used with a high rate at properly chosen intervals. Key words: Quackgrass control, glyphosate, SC-0224, ammonium sulphate, soybean, corn
Productivity and composition of bromegrass alfalfa mixtures for hay in the Aspen Parklands of western Canada
Authors: Pearen J. R. , Baron V. S. , Cowan I. W.
Published: April 2011

Dry matter yield of smooth bromegrass (Bromus inermis Leyss.) - alfalfa (Medicago sativa L.) mixtures is restricted by short growing seasons and poor legume persistence in the Aspen Parklands of western Canada. Meadow bromegrass (Bromus riparius Rehm.) has recently gained acceptance, but comparative information on smooth and meadow bromegrass in grass-alfalfa mixtures is unavailable. We examined DM yield of binary grass-legume mixtures containing either Carlton or Manchar smooth bromegrass or Regar meadow bromegrass with Peace or Beaver alfalfa under a two-cut hay-management system at four sites in central Alberta for 3 yr. Annual DM yield was 40% greater (P ≤ 0.0001) at sites near Lacombe (7570 kg ha−1) than at Bluffton and Vegreville (5420 kg ha−1). Dry matter yield of smooth bromegrass mixtures (8020 kg ha−1) was 20% higher (P ≤ 0.01) than that of meadow bromegrass mixtures (6690 kg ha−1) near Lacombe. Alfalfa DM yield was 2.1 times higher at Bluffton and Vegreville (2770 kg ha−1) than near Lacombe (1300 kg ha−1). Near Lacombe, alfalfa regrowth was suppressed (P ≤ 0.0001) by smooth bromegrass, which had 2.3 times larger (P < 0.001) tillers than meadow bromegrass at first cut. At Bluffton and Vegreville, DM yield of meadow bromegrass mixtures equalled or exceeded (P ≤ 0.05) that of smooth bromegrass mixtures. Although first-cut tiller weight of smooth bromegrass was 73% more (P ≤ 0.0001) than that of meadow bromegrass at Bluffton and Vegreville, tiller density of meadow bromegrass was 1.7 times greater (P ≤ 0.0001) than that of smooth bromegrass. Results indicate that smooth bromegrass mixtures were superior to meadow bromegrass mixtures for hay production at moist fertile locations, despite reduced alfalfa persistence. At drier or less fertile sites, however, DM yield of meadow bromegrass mixtures was higher than that of smooth bromegrass mixtures when weather conditions for regrowth were favourable. Key words: Bromegrass-alfalfa mixtures, hay, parklands
Development of an agronomically superior blackleg resistant canola cultivar in Brassica napus L. using doubled haploidy
Authors: Stringam G. R. , Bansal V. K. , Thiagarajah M. R. , Degenhardt D. F. , Tewari J. P.
Published: April 2011

The doubled haploid breeding method and greenhouse screening using cotyledon bio-assay were successfully applied to transfer blackleg resistance from the Australian cultivar Maluka (Brassicas napus), into susceptible advanced B. napus lines from the University of Alberta. This approach for blackleg resistance breeding was effective and efficient as several superior blackleg resistant breeding lines were identified within 4 yr from the initial cross. One of these lines (91–21864NA) was entered in the 1993 trials of the Western Canada Canola/Rapeseed Recommending Committee. Key words: Blackleg resistance, Leptosphaeria maculans, doubled haploid, Brassica napus
AYR soybean
Authors: Ablett G. R. , Stirling B. T. , Fischer J. D.
Published: April 2011

AYR is an early maturity group II soybean [Glycine max (L.) Merr.] cultivar with excellent yield potential, agronomic and quality characteristics. Key words: Soybean, cultivar description
Effect of soil moisture and temperature on seedling emergence and incidence of Pythium damping-off in safflower (Carthamus tinctorius L.)
Authors: Mündel H.-H. , Huang H. C. , Kozub G. C. , Barr D. J. S.
Published: April 2011

The effects of soil moisture, soil temperature and Pythium ultimum Trow var. ultimum, on the emergence of safflower seedlings were investigated. The effect on emergence of safflower cultivar, Saffire, in Pythium-infested and in sterile soil was tested at three moisture stress levels (1500 kPa, 30 kPa, or 0 kPa), and five temperatures (5, 10, 15, 20, and 25 °C). Both factors affected emergence. At 0 kPa, emergence of safflower seedlings in both the Pythium-infested and sterile soil treatments averaged 4%. In sterile soil, at both 30 kPa and 1500 kPa, seedling emergence exceeded 85% at all temperatures. In Pythium-infested soil at 30 kPa, emergence was greater than 85% at 5 and 10 °C, but only 67, 49, and 27% at 15, 20 and 25 °C, respectively. Within the temperature range, 10–25 °C, seedling emergence in Pythium-infested soil was significantly less at 30 kPa than at 1500 kPa. In fields in the southern Canadian prairies infested with Pythium ultimum, safflower seeded into warm soil is likely to have poor stand establishment due to damping-off, especially if soil is wet. Thus it is advisable to plant safflower early, when soil is cool. Key words:Carthamus tinctorius, Pythium ultimum var. ultimum, Pythium sp. "group G", damping-off, seedling blight, soil moisture, temperature
Nectar sugar production in alfalfa fields treated with several herbicides
Authors: Curry P. S. , Waddington J. , Malik N. , Bowes G. G.
Published: April 2011

Field studies were conducted at three sites in northeastern Saskatchewan to determine the effects of several herbicides applied in late fall or early spring on nectar sugar production in alfalfa (Medicago sativa L.) grown for seed. In general, sugar production was not affected detrimentally by the herbicides, but at one site alfalfa treated annually with metribuzin for 4 yr at the break of winter dormancy produced flowers in early July containing significantly less nectar sugar than flowers of plants not treated with herbicide. Increases in nectar sugar production sometimes occurred. At one site, chlorsulfuron at 0.11 kg ha−1 or more, hexazinone at 1.0 kg ha−1 and dichlobenil at 2.4 kg ha−1 increased nectar sugar production in early August. Herbicide effects were not consistent among sites, and it seems unlikely that leafcutter bee (Megachile rotundata Fabr.) cocoon production will be affected significantly by these weed control practices. Key words: Metribuzin, hexazinone, chlorsulfuron, terbacil, dichlobenil, imazethapyr
Quality and germination of rapeseed and canola seed damaged by adult cabbage seedpod weevil, Ceutorhynchus assimilis (Paykull) [Coleoptera: Curculionidae]
Authors: Buntin G. D. , McCaffrey J. P. , Raymer P. L. , Romero J.
Published: April 2011

Adult feeding injury by the cabbage seedpod weevil (Ceutorhynchus assimilis Paykull) on pods and seeds of winter rapeseed and canola (Brassica napus L.) in Georgia and Idaho reduced seed weight and oil content an average of 16.2 and 2.2%, respectively. Injury also reduced seed germination by 40.5%, increased me proportion of germinated seed with abnormal growth and reduced seedling emergence from soil. Key words: Insecta, Ceutorhynchus assimilis, canola, rapeseed, Brassica napus, seed injury
Dry matter accumulation and seed yield of dwarf autumn-sown white lupin (Lupinus albus L.)
Authors: Harzic N. , Huyghe C. , Papineau J.
Published: April 2011

DM accumulation and seed yield formation of the dwarf autumn-sown white lupin XA100 were compared with those of the tall cultivar Lunoble for 3 yr and at two plant densities to analyse to what extent the DM allocation to seed could be altered by dwarfism. At maturity, XA100 produced an average of 10.5 t ha−1 of above-ground DM, whereas Lunoble produced 12.3 t ha−1. Seed yield of XA100 (3.59 t ha−1) and Lunoble (3.36 t ha−1) were not significantly different, but the harvest index was 0.38 for XA100 and 0.32 for Lunoble. The reduction of the proportion of DM in XA100 stems was associated with an increase in the proportion of DM allocated to pods. The contribution of each pod order to total seed yield was different for XA100 and Lunoble, with XA100 producing more on the third and fourth branch orders. The low mainstem seed yield of XA100 was associated with late pod and seed abortion. XA100 mean seed weight was 0.287 g, and its seed protein concentration was 382 g kg−1, both of which were higher than for Lunoble. XA100 was not selected for its yield potential. However, no agronomic problem associated with dwarfism was detected in this experiment. Consequently, the characteristics of the dward lupin have to be considered for the breeding of autumn-sown white lupin. Key words: White lupin, dwarfism, growth, dry matter partitioning, seed yield, harvest index
Influence of hydrophilic gel polymers on water relations and growth and yield of barley and canola
Authors: Volkmar K. M. , Chang C.
Published: April 2011

Hydrophilic super-absorbent polymers retain large amounts of plant-available moisture and have been promoted for use as soil amendments in drought-prone regions. This controlled-environment study evaluated the capacity of two commercial polymer gels, Grogel and Transorb, to mitigate the effects of recurring moderate water-deficit stress (dry-down to 50% field capacity before rewatering) on growth and yield of barley and canola. Rates of 0.03, 0.12, 0.47 and 1.87 g polymer kg−1 sandy loam soil (1, 4, 16 and 64 times the recommended commercial application rate) were tested. Plants were grown at a soil moisture content of approximately 50% of field capacity. Neither polymer was effective at the commercially recommended rate. Barley and canola grain yields were unaffected at any Grogel rate, and Transorb had no effect on barley grain yield. Grogel at the highest rate enhanced early shoot mass, mature biomass production and grain yield of barley and increased leaf RWC. Canola had greater early and late vegetative biomass, but pod yield was not increased by Grogel at any rate. Transorb was most effective at four times the recommended rate, significantly increasing tiller and fertile spike number and mature biomass production at that rate. Leaf RWC were unaffected by Transorb treatment. Grogel stimulated root growth of barley but had no effect on roots of canola. Both polymers tended to increase consumptive water use. Spatial restriction was found to drastically reduce the water retention of both polymers and limit the absorbency of both polymers in this study. The high rates of polymer required to elicit a crop yield response under relatively mild water-deficit conditions limit the value of these polymers for agricultural field use of the crop species tested. Key words: Barley, canola, drought, hydrophilic polymer, soil conditioner, water stress
Delay of harvest effects on forage yield and regrowth in spring and winter cereal mixtures
Authors: Baron V. S. , St Remy E. A. de , Dick A. C. , Salmon D. F.
Published: April 2011

Spring-planted mixtures of spring and winter cereals extend the grazing season and maximize dry matter yield if the initial defoliation is delayed until the milk stage of kernel development of the spring cereal component. However, fall regrowth may be less than spring-planted winter cereal monocrops. Research was conducted at Lacombe, Alberta to determine the effect of time of initial cut and winter cereal species on initial yield, regrowth yield and factors affecting regrowth (tiller density, water-soluble carbohydrate (WSC) and etiolated regrowth immediately post-cutting) of the winter cereal component of spring-seeded monocrops of fall rye (Secale cereale L.), winter triticale (× Triticosecale Wittmack) and winter wheat (Triticum aestivum L.) and in binary mixtures with spring barley (Hordeum vulgare L.). Treatments were planted in early May and harvested initially when the barley reached the boot (B), heads emerged (H), H + 2 wk, H + 4 wk and H + 6 wk stages. Three weeks after the initial cut a regrowth harvest was conducted. Initial yields of both mixtures and monocrops increased until approximately H + 4 wk and H + 6 wk respectively, with no differences due to species in the mixture. The effect of crop stage at initial harvest on regrowth was much larger than the species effect. Monocrop regrowth decreased almost linearly with delay of defoliation, while that of the mixture (winter and spring components combined) declined at a faster rate. Tiller density, WSC and etiolated regrowth also followed decreasing trends with time of initial cut in the monocrops and mixtures. These trends were due directly or indirectly to very low light intensities in the lower levels of the canopies of both cropping systems after H + 2 wk. Both initial and regrowth yields of the winter cereal component of mixtures involving rye and triticale were generally superior to those involving wheat. The ability of the winter cereal component to regrow in mixtures may be related to plant size and therefore ability to compete during initial growth. In general, the initial harvest of the mixture should occur no later than H + 2 wk of the spring cereal component in order to allow sufficient time for recovery of the winter cereal component after harvest. Otherwise, a spring-seeded winter cereal would be a better alternative for fall pasture. Key words: Delayed harvest, spring and winter cereals, forage yield, regrowth
Cytogenetic behaviour of the interspecific hybrid of Manihot neusana Nassar and cassava, M. esculenta Crantz, and its backcross progeny
Authors: Nassar Hala Nagib , Nassar Nagib M. A. , Vieira Clibas , Saraiva Luiz S.
Published: April 2011

An interspecific hybrid between cassava, Manihot esculenta Crantz, and M. neusana Nassar and the backcrossed progenies was examined meiotically and mitotically. The F1 hybrid showed irregular meiosis due to unpaired chromosomes. The backcrossed progeny ranged in fertility from 17.7 to 35.8%. Meiotic restitution was also observed in all of the hybrids. Diploid pollen formation also occurred and ranged from 0.6 to 1.6%. Irregular meiosis among the F1 hybrid produced aneuploidy in backcrossed progeny. When the F1 hybrid was used as the maternal plant in backcrosses with cassava, this improved seed setting in the BC1 progenies, whereas the reciprocal backcross produced sterile progenies. Key words: Wild species, meiotic restitution, aneuploidy, diploid gamete
EPIC model parameters for cereal, oilseed, and forage crops in the northern Great Plains region
Authors: Kiniry J. R. , Williams J. R. , Major D. J. , Izaurralde R. C. , Gassman P. W. , Morrison M. , Bergentine R. , Zentner R. P.
Published: April 2011

The EPIC computer simulation model has potential for assessing agricultural management scenarios in the northern Great Plains region of the United States and western Canada. The objectives of this study were to develop parameters for economically important crop and forage species grown in these regions and to determine whether EPIC could use these parameters to reasonably simulate yields. Parameters for leaf-area development, temperature responses, biomass growth and partitioning, and nutrient concentrations were derived from data in the literature for spring canola, wheat, barley, maize and six forage species. Because of the growing importance of canola in Canada and the United States, much emphasis was placed on deriving its parameters. With these inputs, EPIC reasonably simulated forage and crop yields in six locations and canola yields in four locations. The model should provide reasonable simulations for a wide range of applications throughout these regions. Key words: simulation modeling, canola, agricultural management
AEC Highlander slender wheatgrass
Authors: Darroch B. A. , Acharya S. N.
Published: April 2011

AEC Highlander slender wheatgrass, Elymus trachycaulus (Link) Gould in Stunners subsp. trachycaulus, was developed for use in reclaiming and revegetating disturbed sites in the mountains and foothills of Alberta. Its primary advantage over other varieties is its ability to grow rapidly and produce mature seed in the short growing seasons found at higher elevations. Key words: Slender wheatgrass, Elymus trachycaulus, cultivar description, reclamation
Response of four annual broadleaf crops to simulated imazamethabenz spray drift
Authors: Wall David A.
Published: April 2011

Field experiments were conducted from 1992 to 1994 in southern Manitoba to investigate the tolerance of buckwheat, canola, field pea and lentil to simulated imazamethabenz spray drift. Imazamethabenz was applied at 0, 7.5, 15, 30, 60 and 120 g a.i. ha−1 2 wk after crop emergence when buckwheat and canola were in the two- to three-leaf stage and lentil and field pea vine length was 10 cm. Application rates corresponded to 0, 1.6, 3.1, 6.3, 12.5 and 25% of the recommended field rate for control of wild oat (482 g a.i. ha−1). At the dosages examined, buckwheat and canola leaf area index 2 and 4 wk after treatment, seed yield and thousand seed weight were unaffected. Lentil and field pea were severely injured by 60–120 g a.i. ha−1 of imazamethabenz. Injury consisted of foliar chlorosis, stunting, increased basal branching and delayed maturity. Field pea and lentil yields were reduced only at 60–120 a.i. ha−1 of imazamethabenz. At these rates, yield losses were 27–59% and 25–76% for lentil and field pea, respectively. Yield losses differed among years, with the highest percentage yield losses occurring under cold, wet growing conditions. Key words: Buckwheat (tame), canola, pea (field), lentil, spray drift, sublethal rates
History of the Canadian Society of Agronomy
Authors: Coulman B. E.
Published: April 2011

not available
Effect of heat stress during seed development and maturation on wheat (Triticum durum) seed quality. II. Mitochondrial respiration and nucleotide pools during early germination
Authors: Grass L. , Burris J. S.
Published: April 2011

Marzak and Oum-rabia wheat seeds were produced under three temperature regimes (20:15, 28:21, 36:29 °C) starting 10 d after anthesis through harvest. Nucleotide levels and respiratory activity of mitochondria isolated from imbibing embryos were determined. Mitochondrial structure from the radicle meristem region of imbibed embryos was examined under electron microscopy. Embryos from low-temperature treatments showed rapid accumulation of adenosine triphosphate (ATP) and higher energy levels and rates of oxygen uptake than embryos from high-temperature treatments. Embryos from medium-temperature treatments exhibited intermediate values. Parallel to these metabolic changes during early seed germination, results from electron microscopy revealed visible differences in mitochondrial structure. Mitochondria from the low-temperature regime were well developed with visible membranes and cristae; those from the high-temperature regime were degenerating. These results provide clear evidence of the influence of parent temperature conditions on the seed metabolism during early stages of germination. Key words: Embryo, mitochondria, nucleotide, oxygen uptake, vigor, wheat
Variation in starch, protein, and fibre of Canadian barley cultivars
Authors: Kong D. , Choo T. M. , Narasimhalu P. , Jui P. , Ferguson T. , Therrien M. C. , Ho K. M. , May K. W.
Published: April 2011

Barley (Hordeum vulgare L.) is a major feed in the Maritime region of Canada, but information on the chemical composition of barley cultivars grown in the Maritimes is lacking. Therefore, a study was undertaken to determine if starch, protein, neutral-detergent fibre (NDF), and acid-detergent fibre (ADF) of barley vary from region to region in Canada and to determine if barley cultivars that originated from Eastern Canada exhibit different chemical composition than those that originated from Western Canada. The chemical composition of two-row and six-row, covered and hulless, and feed and malting cultivars were also compared. Seventy-five cultivars were tested in eight environments (i.e. Charlottetown, Ottawa, Brandon, and Bentley in 1991 and 1992). These cultivars were classified into eight classes in four comparisons: eastern vs. western, two-row vs. six-row, hulless vs. covered, and feed vs. malting. Charlottetown grains were relatively low in protein, high in starch, and intermediate in NDF and ADF in comparison with grains produced at the other three locations. This suggests that more research in cultivar development and crop management is needed to increase the protein concentration of barley in the Maritimes. On average, two-row cultivars contained more starch and less fibre than six-row cultivars. Eastern two-row cultivars contained more protein than western two-row cultivars. As expected, hulless barleys contained more starch and protein, but less fibre than covered barleys. Canadian barley cultivars exhibited considerable variation in chemical composition. The cultivar x environment interaction was much smaller than the cultivar effect. Therefore, it is important to identify barley cultivars with high nutritional quality for use in commercial production. Key words: Barley, Hordeum vulgare L., cultivars, starch, protein, fibre
Effects of tall wheatgrass windbreaks on hay production of three alfalfa varieties at a semiarid location in Saskatchewan
Authors: Waddington J. , Steppuhn H.
Published: April 2011

Soil water limits alfalfa (Medicago sativa L.) growth in semi-arid southwest Saskatchewan. The dry matter yields of three alfalfa varieties with contrasting growth habits were compared when grown between tall wheatgrass [Thinopyrum ponticum (Podp.) Barkworth & D.H. Dewey] windbreaks spaced on 15-m centres, and when grown without windbreaks. Over a 7-yr period, and including the area occupied by the windbreaks, alfalfa yields were 2110 kg ha−1 dry matter on average. This was 40% more dry matter than from alfalfa grown outside the windbreaks. There were no consistent yield differences between the three varieties, but Beaver, a branch-rooted variety, produced more dry matter than Angus, a tap-rooted variety with fast regrowth potential, and Rangelander, a creeping-rooted variety, in the years when differences reached significance, and on average over the 7-yr period. Alfalfa regrowth was sufficient for a second cut in 3 of 7 yr. Cultivating to a depth of 35 cm with a Paraplow subsoiler prior to seeding had no effect on hay yields. Key words:Medicago sativa, dry matter yield, snow management
Effects of an insect vacuum device on strawberry pollination
Authors: Chiasson H. , Oliveira D. de , Vincent C.
Published: April 2011

The Biovac®, a tractor-propelled insect vacuum device, was evaluated for its effect on strawberry pollination. The device had little effect on the dispersal pattern of pollen ejected by its exhaust pipe. However, viability of ejected pollen was half that of pollen collected directly from flowers. Fruit weight and degree of pollination of fruit from flowers pollinated only by pollen dispersed by the Biovac were inferior (significantly 12 times out of 16) to those of flowers exposed to all pollinating agents. Key words: Biovac®, insect vacuum device, strawberry, pollination, Fragaria × ananassa
Residual effects of ethametsulfuron on succeeding broadleaf crops
Authors: Wall D. A.
Published: April 2011

The response of dry bean (Phoseolus vulgaris L.), buckwheat (Fagopyrum esculentum Moench.), potato (Solanum tuberosum L.) and sunflower (Helianthus annuus L.) to soil residues of ethametsulfuron was determined. Buckwheat and sunflower exhibited moderate to severe injury 4 wk after planting; navy bean, buckwheat, sunflower and potato yields were unaffected in the cropping year after ethametsulfuron application. Key words: Sulfonylurea, crop tolerance, yield