bluuebunny/crossref_metadata_2025 huggingface dataset:
AC Excel summer rape
Authors: Rakow G.
Published: April 2011

AC Excel summer rape (Brassica napus L.), registered in 1990, is a canola-quality cultivar that combines high seed yield with high oil content and early to medium maturity. AC Excel is moderately susceptible to blackleg. It is well adapted to the B. napus growing areas of western Canada. Key words: Rape (summer), cultivar description
Postharvest physiological disorders, diseases and mineral concentrations of organically and conventionally grown McIntosh and Cortland apples
Authors: DeEll Jennifer R. , Prange Robert K.
Published: April 2011

Environmental effects and human health risks associated with synthetic chemicals has prompted several apple growers to convert to organic production. Postharvest physiological disorders, diseases and mineral concentrations of organically and conventionally grown McIntosh and Cortland apples stored in refrigerated (3 °C) ambient air and controlled atmospheres were evaluated for 2 consecutive years. More of the conventionally grown apples were marketable after storage. Organically grown apples had higher incidence of storage rots, apple scab and russetting. Production method did not influence core browning. Organically grown McIntosh stored in ambient air for 8 mo had the highest incidence of senescent breakdown. Conventionally grown McIntosh stored in CA for 8 mo had the highest incidence of internal browning. Conventionally grown McIntosh stored in air had a higher incidence of scald than organically grown McIntosh. After 4 mo of storage in air, organically grown McIntosh had a higher incidence of splitting. Production method did not influence calcium or magnesium concentrations. Organically grown apples had higher phosphorus and potassium concentrations and lower nitrogen concentrations. Key words: Malus domestica, organic apple production, controlled atmosphere, storage disorders, storage rots, whole fruit mineral concentrations
Orchard training systems influence early canopy development and light microclimate within apple tree canopies
Authors: Kappel Frank , Quamme Harvey A.
Published: April 2011

Delicious and McIntosh apple trees were trained to five orchard systems: central leader (two spacings), slender spindle, van Roechoudt trellis, and vertical axe. Radiation measurements were taken at the bottom of the canopy throughout the season or at various heights within the canopy after the growth of the canopy was completed. Early in the life of the plantings slender spindle and vertical axe trees of each cultivar had the highest yields expressed on a per hectare basis. By the fifth year of the planting, McIntosh trees trained to the slender spindle and the narrow central leader spacing were producing similar amounts of fruit. Light levels at the bottom of the canopy for some orchard systems were at or below 30% of full sun as early as 25 d after petal fall. Orchard system affected total leaf area and the number of spurs per tree in both 1989 and 1990. The low light levels at the bottom of the canopy reported in this study suggest that attention to pruning and training in the early stages of the orchard development is critical. Key words: Malus domestica, central leader, slender spindle, van Roechoudt trellis, vertical axe, light distribution, leaf area index
Influence of planting date and row covers on yield and economic value of muskmelons
Authors: Waterer D. R.
Published: April 2011

In 1990 and 1991, earliness, yield and economic value of three sequential plantings of muskmelons were compared using black plastic soil mulch alone (NC) and in combination with clear polyethylene (PT) or spunbonded polyester (RT) row covers. Both row covers increased daytime temperatures and heat unit accumulation relative to NC treatments, with PT producing the warmest microclimate. Early growth and fruit yield were highest in PT plots followed by RT. The NC crop was slow to develop and most fruit failed to mature before first frost. Early planting increased fruit yield when row covers were used, while late planting was best in NC treatments. The increase in economic value obtained with the tunnels more than offset their cost. Key words: Muskmelon, Cucumis melo, planting date, row covers
St. Williams, Scotland and Selkirk strawberries
Authors: Dale A. , Vandenberg A. A. , Wang S. L. , Ricketson C. L.
Published: April 2011

St. Williams strawberry (Fragaria × ananassa Duch.) has average size fruits with a high yield. The fruits have high quality and are outstanding for freezing. It is recommended as suitable for processing. Scotland strawberry has large extremely firm fruits, is very late maturing and can be decapped by machine. It is recommended for machine harvesting for processing. Selkirk has large, firm, high quality fruits with good yields. It is suitable for both the fresh and processing markets. Key words: Cultivar description, processing, machine harvesting
Temperature effects on seed color in black- and yellow-seeded rapeseed
Authors: Deynze A. E. Van , Beversdorf W. D. , Pauls K. P.
Published: April 2011

The effects of growth temperature on seed color of two black- and four yellow-seeded doubled-haploid genotypes of Brassica napus were examined with plants grown at 16/12, 18/14, 20/16, 22/18 and 24/20 °C (day/night). High temperatures significantly reduced seed color that developed on yellow-seeded genotypes but did not alter seed color produced on black-seeded genotypes. The decrease in pigmentation measured with a modified near-infrared reflectance analyzer was linearly related to temperature for the yellow-seeded genotypes. Significant differences in the magnitudes of the response were observed among the yellow-seeded genotypes. This is the first systematic study of temperature effects on seed color in rapeseed. The results confirm previous preliminary reports of environmental modifications of this trait. The study also illustrates a method for determining temperature effects on seed-color expressivity that may be useful for plant breeding programs. Key words: Temperature, Brassica napus, seed color
Survival, height and genotype by environment interaction in winter wheat
Authors: Thomas J. B. , Schaalje G. B. , Grant M. N.
Published: April 2011

This study examines the relationship between plant height, winterhardiness and genotype-by-environment interaction in the grain yield of winter wheat in western Canada. Positive correlations between plant height and winter survival ability (WSA) and between plant height and lodging score have persisted among entries in Western Hard Red Winter Wheat Cooperative Trials (WWC) for 33 yr. Progress has been made in developing winterhardy semidwarfs; however, no short cultivars have yet been isolated in the most hardy group. For Saskatchewan and Manitoba trials, correlations between WSA and yield (WSA:Y) were mostly positive, indicating widespread and intense cold stress. In southwest Alberta trials, WSA:Y ranged from significantly positive to significantly negative, indicating the wide range and unpredictability of cold stress in this area; in North and Central Alberta the distribution of WSA: Y was intermediate between southwest Alberta and Manitoba and Saskatchewan. In high stress trials (WSA:Y > 0.4), cultivar grain yield increased with increased cultivar height (on average, +0.024 tonnes ha−1 for each centimetre increase in height) but as stress levels declined, this relationship was reversed. In trials with WSA: Y < −0.4, cultivar yield was negatively related to cultivar height (average slope of −0.026 tonnes ha−1 per centimetre increase in height). Similar results were found in a trial of six winter wheat cultivars over three sites and 6 years within southern Alberta. In high stress trials, tall and hardy cultivars stabilized grain yield through high rates of survival while non-hardy cultivars performed poorly. Without damaging cold stress, short and non-hardy cultivars showed the highest yields and the greatest response to environmental productivity. Key words: Yield, winterhardiness, coldstress
Residual effects of faba bean and soybean for a second or third succeeding forage-corn production
Authors: Paré Théophile , Chalifour François P. , Bourassa Josée , Antoun Hani
Published: April 2011

Many studies have been conducted on the effects of annual legumes on subsequent corn production but they rarely extended beyond a second succeeding crop. We have therefore conducted field experiments on a sandy gravelly loam at St-Anselme and on a silty loam at Deschambault in eastern Quebec to determine the residual effects of (i) faba bean (Vicia faba L.) and soybean (Glycine max [L.] Merr.) on a third succeeding corn (Zea mays L.) crop and (ii) 2 consecutive years of these legumes on a second subsequent corn crop. In monoculture or following legumes, corn was fertilized with 0, 50, 100 or 150 kg N ha−1 as NH4NO3. The corn stover and whole-plant dry matter yields (DMY), and the ear and whole-plant N uptake were higher following faba bean grown 3 years earlier than in monoculture at both locations. At Deschambault, the stover DMY of second subsequent corn following 2 consecutive years of faba bean did not vary with the N application. At both locations, the DMY, N concentrations and N uptake of second subsequent corn were higher after 2 consecutive years of faba bean than after other previous crop sequences. Two consecutive years of soybean had significant effects on the DMY and N uptake of a second subsequent corn crop with N application at Deschambault. At both locations, the N-fertilizer replacement values (NFRV) of soybean were lower or equal to 0 kg N ha−1. The NFRV (DMY and N uptake bases) of faba bean grown three years earlier and of 2 consecutive years of this pulse varied widely between locations. Key words: Corn, faba bean, soybean, residual N, crop sequence, rotation effects
Postharvest color development of strawberries: Influence of maturity, temperature and light
Authors: Kalt W. , Prange R.K. , Lidster P.D.
Published: April 2011

Strawberries (cv. Blomidon) that were either completely white or red at harvest were stored up to 8 d under various temperature and light conditions to examine the effects of storage conditions on postharvest color development. Strawberries, stored at 5, 10, 20 or 30 °C and at light levels of 0, 100 or 200 μmol m−2 s−1, were sampled for anthocyanin concentration, surface color, total soluble solids, titratable acidity, pH of the berry surface, and berry weight loss after 0, 1, 2, 5 and 8 d of storage. Anthocyanin concentration and surface color increased during storage with greater changes in the white-harvested than red-harvested fruit. Temperature, and to a lesser extent light, affected the rate of strawberry color development during storage. After 8 d, the proportions of the two major strawberry anthocyanins, pelargonidin 3-glucoside and cyanidin 3-glucoside, were different in red-harvested fruit and white fruit that became red during storage, compared to field-ripened fruit at harvest. Key words: Fragaria × ananassa, anthocyanin, storage
Effects of clipping and nitrogen fertilization on tiller development and flowering in Kentucky bluegrass
Authors: Thompson D. J. , Clark K. W.
Published: April 2011

One hundred cores (10 × 10 × 12 cm) of Kentucky bluegrass (Poa pratensis L. ’Nugget’) were removed from an established seed field, potted, and subjected to two clipping treatments after seed harvest (clipping at 2.5 cm to simulate straw and mechanical stubble removal and clipping at 7.5 cm to simulate straw removal) and two fertilizer treatments (solutions with and without the equivalent of 100 kg ha−1 of N). The plants were then subjected to a cold treatment (98 d at 2.5 °C) to induce flowering. Added N increased the number of large tillers formed before the cold treatment, and produced similar increases in the number of initiated tillers and flowering shoots. Added N resulted in larger inflorescences with more spikelets. Close clipping (2.5 cm) did not affect tillering or flowering shoot density, but reduced stem length and resulted in smaller inflorescences with fewer spikelets. Key words: Kentucky bluegrass, nitrogen, clipping height, tillering and flowering
Models and sampling for studying weed seed survival with wild mustard (Sinapis arvensis) as a case study
Authors: Donald William W.
Published: April 2011

Most studies of seed survival over time are not repeated in different years because they are long-term efforts. Methodological research reported in this paper shows that the shape of seed survival curves can differ for the same species for seed produced in different years. Consequently, seed survival of wild mustard could not be described by a single type of seed survivorship curve. Wild mustard seed survival was a negative exponential function of time in one 4-yr-long trial [Y = a + b*exp(−X)], but decreased as a negative linear function of time in a second trial (Y = a + b*X), where Y is percent seed survival, X is time in years, and a, b, and c are coefficients. However, both data sets could be adequately described by a mixed negative exponential model [Y = a + b*X + c*exp(−X)]. The negative hyperbolic model [Y = a/(X + b)] did not describe both trials as well as did the mixed negative exponential model. Sample sizes of four groups of 100 seed each, harvested each year for four years, provided acceptable nonlinear regression models for seed survival data. It was not advantageous to increase sample size more than this because r2 was not greatly increased and the residual mean square error (RMSE) was not decreased. Key words: Model, seed persistence, seed survival, wild mustard, Sinapis arvensis
Relations entre les caractères morphologiques et la qualité chez la fléole des prés (Phleum pratense L.)
Authors: Durand J. , Surprenant J.
Published: April 2011

Selection of high feed quality timothy (Phleum pratense L.) would be facilitated by the identification of morphological traits associated with quality. The objectives of this study were: (1) to evaluate the presence of genetic variability for morphological traits; (2) to evaluate the relationship between morphological and quality traits; and (3) to measure the association between whole plant and stem and leaf quality. The phenotypic correlations obtained between morphological traits and quality appeared unstable from year to year for most associations. However, canonical analysis has indicated the possibility to select genotypes with high feed value based on yield, stem number, tillering area and height. Timothy genotype quality appeared to be limited mainly by stem quality. Some morphological traits appeared valuable to be used in an independent culling level selection scheme. Key words: Timothy, morphology, quality, Phleum
The inheritance of leaf rust resistance in the wheat cultivar Pasqua
Authors: Dyck P. L.
Published: April 2011

The Canadian wheat (Triticum aestivum L.) cultivar Pasqua has good resistance to leaf rust (Puccinia recondita Rob. ex Desm.) and some sprouting resistance. Backcross F2 families were used to study the inheritance of leaf rust resistance in Pasqua. Based on the leaf rust resistance genotypes of its parents, Pasqua could have genes Lr11, Lr13, Lr14b, Lr16, Lr22, and Lr30. Of these, it was found to have Lr11, Lr13, Lr14b, and Lr30. As well, it has Lr34, which must have come from the cultivar Terenzio during the development of a Neepawa backcross line with Lr30. Key words: Triticum aestivum, wheat, leaf rust resistance
Effect of time of swathing and desiccation on plant drying, seed color and germination of flax
Authors: Gubbels G. H. , Bonner D. M. , Kenaschuk E. O.
Published: April 2011

In field studies conducted between 1988 and 1990, flax (Linum usitatissimum L.) was swathed or desiccated with diquat, glufosinate-ammonium or glyphosate at various times between the 0 and 100% brown capsule stages to determine the effects on drying of plant components, seed discoloration and germination. Leaf and capsule browning were complete about 1 wk after application of diquat and glufosinate-ammonium and about 2 wk after application of glyphosate. Stem browning was variable from one application to another, but was usually adequate for harvesting 1–2 wk after application of diquat and glufosinate-ammonium and 3 to 4 wks after application of glyphosate. Diquat gave the most rapid stem browning and glyphosate the slowest. In most cases, swathing and application of diquat or glufosinate-ammonium resulted in capsule moisture low enough for harvest 2 wks after treatment. Drying of capsules following glyphosate application was less rapid. Early applications of glufosinate-ammonium sometimes resulted in darker brown seed. Glyphosate applied before all capsules were mature reduced seed germination. Key words: Flax, Linum usitatissimum L., swathing, desiccation, seed color, germination
Inheritance of a cream petal mutant in Ethiopian mustard
Authors: Getinet A. , Rakow G. , Downey R. K.
Published: April 2011

The inheritance of a cream petal colour mutant in Ethiopian mustard (Brassica carinata A. Braun) was studied in backcross and F2 generations of a cross between a cream-petalled mutant and a normal yellow-petalled cultivar. The cream petal characteristic was controlled by one pair of recessive alleles. Key words: Brassica carinata, petal colour, inheritance
Soybean cultivar reaction and row width effect on Sclerotinia stem rot
Authors: Buzzell R. I. , Welacky T. W. , Anderson T. R.
Published: April 2011

The response of soybean (Glycine max (L.) Merr.) cultivars to Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, was assessed in replicated field trials in 1985–1987 and 1990 to obtain information relating to control of the disease. In 1986 and 1987, there were differences (P = 0.01) in disease incidence among 19 indeterminate cultivars. Cultivar differences in disease incidence were partially related to maturity (R2 = 0.67 in 1986; R2 = 0.37 in 1987) with earlier-maturing cultivars having less disease. Cultivars differed (P = 0.01) in the number of sclerotia produced per diseased plant and per square meter in 1986 and 1987. In a test conducted in 1990 there were differences (P = 0.05) in disease incidence among 14 determinate lines. In three tests in 1985–1986, row spacings of 23, 45 and 69 cm had no significant effect on the incidence of white mold in the cultivars Maple Arrow, Evans, S1346 and Corsoy 79. Yield loss from stem rot may be reduced by planting cultivars that are more resistant, earlier maturing and more tolerant to lodging. This practice would also result in fewer sclerotia to serve as primary inoculum in future years. Key words: Glycine max, soybean, Sclerotinia stem rot, cultivar and row width effects
Comparison of inoculation methods for selection of plants resistant to Leptosphaeria maculans in Brassica napus
Authors: McNabb W. M. , Berg C. G. J. van den , Rimmer S. R.
Published: April 2011

The relationship between ratings following four inoculation techniques and field ratings and the usefulness of these techniques for screening large populations was determined. Plants of Brassica napus ’Westar,’ ’Wesroona’, ’Topas’, ’Hanna’ and ’R8314’ were inoculated with L. maculans using four techniques: cotyledon inoculation with cotyledon rating, leaf inoculation with leaf and stem rating, stem inoculation with stem rating and inoculation using infested oat kernels with stem rating. Plants from each combination of cultivar and technique were self-pollinated for evaluation of disease rating in the field. The highest precision was obtained with cotyledon rating following cotyledon inoculation. The correlation coefficient between the rating of inoculated plants and the field rating of their progeny ranged from 0.50** for oat kernel inoculation to 0.72** for cotyledon inoculation. Considerable variation for field rating was associated with each rating following artificial inoculation. Selection of resistant plants using low cotyledon reaction was a more efficient technique than leaf or stem inoculation; it was rapid, required less labour and space and correlated well with the field ratings. Key words: Leptosphaeria maculans, Brassica napus, blackleg, oilseed rape, inoculation methods, canola
Importance of tolerance and growth rate in the resistance of oilseed rapes and mustards to flea beetles, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae)
Authors: Brandt R. N. , Lamb R. J.
Published: April 2011

The resistance of oilseed rapes and mustards to crucifer flea beetles, Phyllotreta cruciferae (Goeze), is known to vary, and tolerance to feeding damage may be a factor in the resistance shown by two of the species. The tolerance of Brassica juncea L., Brassica napus L., Brassica rapa L. and Sinapis alba L. was compared in field and laboratory studies. The growth rates of damaged and undamaged plants were measured at four early growth stages, and the level of antixenosis was determined to ascertain the relative importance of tolerance and antixenosis and the relationship between tolerance and growth rate. Antixenosis was confirmed to be a factor in the resistance of S. alba, but this species also proved to be most tolerant of feeding damage and showed rapid compensatory growth at three early growth stages. Brassica juncea showed no antixenosis, but it was tolerant of damage particularly at germination, the cotyledon stage, and the first true leaf stages, which probably accounts for its resistance to moderate flea beetle damage. Brassica rapa showed only a very low level of tolerance, and B. napus was intolerant of damage at all four growth stages. The level of tolerance was species specific and growth-stage specific and was not related to the rates of growth of the species. Key words: Insecta, antixenosis, canola, crucifer flea beetles
Residues of 2,4-D in wheat following application after heading
Authors: Cessna Allan J. , Holm F. A.
Published: April 2011

When drought conditions persist throughout the early part of the cereal growing season, vigorous weed growth may not occur until the crop is maturing and thus may cause seed harvesting and storage problems. Weed desiccation by application of 2,4-D could alleviate such problems but would also raise concerns regarding the magnitude of 2,4-D residues in the seed. This concern has been addressed in a 2-yr study in which residues of 2,4-D were determined in wheat following application of 526 and 1052 g acid equivalent ha−1 after the crop had headed and was in the soft-dough stage. In both years, residues in the crop (whole plants) immediately after spraying were of the order of 20 and 30 mg kg−1 for the 526 and 1052 g ha−1 application rates, respectively. At maturity, the corresponding maximum residues detected in the straw were 4.63 ± 0.77 and 8.76 ± 0.70 mg kg−1, whereas those in the seed were at or exceeded the maximum residue level of 0.1 mg kg−1 permissible in Canada, being 0.10 ± 0.04 and 0.26 ± 0.03 mg kg−1, respectively. Key words: 2,4-D, wheat, residues, preharvest application
Effect of timing of propiconazole application on foliar disease and yield of irrigated spring wheat in Saskatchewan from 1990 to 1992
Authors: Duczek L. J. , Jones-Flory L. L.
Published: April 2011

Applications of propiconazole on spring wheat at various growth stages at Outlook, Saskatchewan showed that the optimal time to spray was between the extension of the flag leaf growth stage to the medium milk growth stage (G.S. 41–75). The maximum yield increase was about 10% on the soft white spring wheat, Fielder, compared to a 3% yield increase on the hard red spring wheat, Katepwa. The disease levels on penultimate leaves was reduced by spray applications between stem elongation and medium milk growth stages (G.S. 31–75). Most of the foliar disease was caused by Septoria spp. with S. nodorum being the most prevalent pathogen; Pyrenophora tritici-repentis was also present. Key words: Propiconazole, septoria leaf blotch, tan spot
Effect of preharvest applications of glyphosate on the drying, yield and quality of wheat
Authors: Darwent A. L. , Kirkland K. J. , Townley-Smith L. , Harker K. N. , Cessna A. J. , Lukow O. M. , Lefkovitch L P.
Published: April 2011

In experiments conducted from 1988 to 1990 at four locations in the Parkland zone of western Canada, the drydown of seed and foliage, seed yield, seed quality and baking quality of wheat (Triticum aestivum L.) following preharvest applications of glyphosate were compared with those following windrowing prior to harvest or direct cutting of the standing crop. Glyphosate was applied in late July to early September at rates of 0.45, 0.9 and 1.7 kg acid equivalent ha−1 to wheat with seed moisture contents ranging from 80 to 11%. When compared with a standing crop, all glyphosate treatments applied at seed moisture contents above 25% slightly enhanced the drydown of wheat seed and foliage. Treatments applied at seed moisture contents below 25% had no effect on either seed or foliage drydown. Seed yields were generally greater from plots to which glyphosate was applied than from windrowed control plots, although in one of five experiments the reverse trend occurred. Increasing the rate from 0.45 to 1.7 kg ha−1 had no effect on yield. Windrowing or applying glyphosate to wheat with a seed moisture content of 61% or more reduced yields more than windrowing or applying glyphosate at seed moisture contents below this level. In experiments where the wheat in both control and sprayed plots was direct cut at maturity, average yields decreased as the rate of glyphosate increased from 0 to 1.7 kg ha−1. However, applications at seed moisture of 40% or less, caused little or no yield loss. There was little or no difference in 1000-seed weight, sample density, seed germination and protein content from plots sprayed with glyphosate at seed moisture contents below 40% than from control plots windrowed at the same moisture content or direct cut at maturity. Baking quality was not affected by any of the glyphosate treatments in experiments where the wheat was harvested by direct cutting. Key words: Glyphosate, wheat, desiccation, wheat quality, Triticum aestivum
Field pea cultivar and weed response to crop seed rate in western Canada
Authors: Townley-Smith L. , Wright A. T.
Published: April 2011

Weed competition is a serious limitation to field pea (Pisum sativum L.) production. Trials were conducted in northeastern Saskatchewan to determine the effects of field pea growth habit, stand density and herbicide treatments on weed growth and on field pea stand and yield. Century, a long-stem leafy type, Tipu, a long-stem semi-leafless type, and Express, a short-stem leafy type, were seeded at 6, 12, 25, 50 and 100 seeds m−2. Some of each cultivar was unsprayed sprayed with a sethoxydim-metribuzin tank-mix for control of grass and broadleaf weeds. Field pea growth habit (cultivar) did not affect number of weeds, but increasing stand density (seed rate) reduced weed numbers in all 3 yr. Express reduced above-ground dry matter production of broadleaf weeds in 1988 and 1991. Increasing seed rate reduced above-ground dry matter production of weeds in all 3 yr. Field pea yield increased with increasing seed rate to a rate between 50 and 100 seeds m−2. Herbicide application reduced weed dry matter production, with the largest effect at low field pea populations. Despite differences in growth habit, the three cultivars competed similarly with weeds. High populations of field peas competed well with weeds and may not require herbicide application, but if producers retain thin stands, good weed control will be critical to attaining high crop yield. Key words: Field pea, Pisum sativum L., seed rate, weed competition, growth habit
Performance of inter-cultivar summer turnip rape hybrids in Saskatchewan
Authors: Falk K. C. , Rakow G. , Downey R. K. , Spurr D. T.
Published: April 2011

The agronomic performance of inter-cultivar hybrids of Brassica rapa L. was studied in crosses between four B. rapa cultivars. Six reciprocal hybrid combinations were produced by hand pollination in the greenhouse. Hybrids and their parents were tested in replicated yield tests for 3 yr. An average, over all hybrid combinations, of 13% heterosis for seed yield was observed. Heterosis for seed yield was greatest in crosses between genetically diverse cultivars, which agrees with classical theories on heterosis. There were also significant differences in yield of reciprocal F1 combinations. Seed oil content was not heterotic. The results of this study indicated that the level of heterosis of seed yield in crosses between B. rapa cultivars adapted for production in western Canada is sufficient to warrant the development of a suitable pollination control system for hybrid B. rapa production. Key words:Brassica rapa, Brassica campestris, inter-cultivar hybrids, seed yield, heterosis
Quackgrass control in established alfalfa with sethoxydim
Authors: Twidwell E. K. , Kephart K. D. , Clay S. A.
Published: April 2011

Field studies were conducted during 1990 and 1991 in northeast South Dakota to determine the effect of sethoxydim application timing on quackgrass [Elytrigia repens (L.) Nevski] control in established alfalfa (Medicago sativa L.). Sethoxydim was applied as single applications in the fall, spring, after the second cut of alfalfa or as various repeated applications in the fall, spring, and after the first and second cuts of alfalfa. The alfalfa-quackgrass mixture was harvested three times per year, and dry matter yields of alfalfa, quackgrass, and total herbage were determined. Total herbage samples were analyzed for crude protein (CP) concentration. Usually, single application of sethoxydim in either the fall or spring did not control quackgrass as well as multiple applications. However, three and four applications of sethoxydim per year did not consistently control quackgrass any better than two applications per year. Sethoxydim reduced quackgrass yields in most instances, but yields and CP concentrations of total herbage were seldom affected. Use of sethoxydim for quackgrass control in established alfalfa may be warranted only in situations where relatively weed-free forage is desired. Key words: Application timing, forage yield, competition, stand density
Residues of glyphosate and its metabolite AMPA in wheat seed and foliage following preharvest applications
Authors: Cessna A. J. , Darwent A. L. , Kirkland K. J. , Townley-Smith L. , Harker K. N. , Lefkovitch L. P.
Published: April 2011

In a 2-yr study at four locations in western Canada, residues of glyphosate and its major metabolite aminomethyl-phosphonic acid (AMPA) were measured in the seed and foliage of wheat (Triticum aestivum L.) following preharvest applications at rates of 0.45, 0.9 or 1.7 kg acid equivalent ha−1. Herbicide treatments were applied in early August to mid-September at seed moisture contents ranging from 52 to 12%. Glyphosate and AMPA residues in the seed increased as the rate of application increased, and decreased as the seed moisture content at the time of application decreased. However, when the maximum application rate of 1.7 kg ha−1 was sprayed at seed moisture contents of 40% or less, glyphosate residues in the seed were < 5 mg kg−1, the Maximum Residue Level recently established by Health Canada. Glyphosate and AMPA residues in the straw also increased with increasing application rate, but there was no consistent pattern in residues of either chemical with seed moisture content at the time of application. Physiological maturity of the crop, rainfall washoff, and application rate appeared to play important roles in determining the magnitude of glyphosate and AMPA residues in the seed and straw of wheat. Key words: Glyphosate, AMPA, residues, wheat, seed, preharvest application
Grain and straw yields of barley under four tillage systems in northeastern Alberta
Authors: McAndrew D. W. , Fuller L G. , Wetter L G.
Published: April 2011

The agronomic feasibility of reduced tillage management for barley (Hordeum vulgare) production in northeastern Alberta was evaluated with respect to grain and straw yield. Five sites were established in 1988 and continued until 1992 within the Dark Brown, Black, and Gray soil zones. Four tillage management systems were studied including zero (ZT), minimum (MT), and two conventional systems (C1 and C2). Fungicide (propiconazole) was applied to one-half of the plots to evaluate the need for fungicide in a continuous barley rotation using reduced tillage systems. Fungicide had no effect on grain and straw yields and no interaction between fungicide and tillage system occurred thus indicating that fungal diseases controllable by propiconazole did not limit yields during this study. Tillage system significantly affected grain and straw yields in approximately one-third of the site-years studied. Grain yields averaged over 5 yr ranged from 2.55 to 4.27, 2.61 to 3.93, 2.51 to 4.08, and 2.63 to 3.99 Mg ha−1 for ZT, MT, C2 and C1, respectively. Straw yields averaged over 5 yr ranged from 2.56 to 4.32, 2.61 to 3.90, 2.48 to 4.08, and 2.59 to 4.07 Mg ha−1 for ZT, MT, C2 and C1, respectively. In general, grain and straw yields of barley under ZT were equal or superior to yields obtained under C1, C2 and MT systems. Straw yields followed closely the trends observed for grain yields. Zero tillage grain yields significantly exceeded those of C1, C2 and MT in 30–50% of the site-years when growing season precipitation was below normal. This is believed to be related to better soil water conservation and greater water use efficiency under ZT compared with other tillage systems in years with below normal precipitation and particularly when June and July precipitation was low. Key words: Zero tillage, minimum tillage, fungicide
Growth of transgenic and standard canola (Brassica napus L.) varieties in response to soil salinity
Authors: Redmann R. E. , Qi M. Q. , Belyk M.
Published: April 2011

Seedling emergence and plant growth of two canola varieties (Brassica napus L.) were investigated in response to soil salinity under growth chamber conditions. HCN92, a genetically transformed variety tolerant to the broad spectrum herbicide glufosinate-ammonium, and variety Legend were grown in five field-collected soils with salinities between 0.8 and 11.5 dS m−1. Salinity treatments significantly reduced total seedling emergence and emergence rate, and also caused decreased leaf area, shoot and root biomass, and evapotranspiration in both canola varieties. Vegetative growth of the genetically transformed variety, HCN92 was essentially equivalent to that of variety Legend at all salinity levels. Key words: Emergence, HCN92 canola, Legend canola, plant growth, salt tolerance
AC Eatonia hard red spring wheat
Authors: DePauw R. M. , McLeod J. G. , Clarke J. M. , McCaig T. N. , Fernandez M. R. , Knox R. E.
Published: April 2011

AC Eatonia hard red spring wheat (Triticum aestivum L.) has several improved traits relative to Leader: increased stem solidness and resistance to cutting by the wheat stem sawfly, resistance to common bunt, common root rot and seed shattering, and higher grain yield potential. It is adapted to the Brown and Dark Brown soil zones. Key words:Triticum aestivum L., cultivar description, solid stem, disease resistance
Response of flax and lentil to seeding rates, depths and spring application of dinitroanaline herbicides
Authors: Wall D. A.
Published: April 2011

Two field studies were conducted at Morden, Manitoba in 1992 and 1993 to investigate the effect of seeding depth and seeding rate on flax and lentil recovery following spring application of dinitroanaline herbicides. In the first study, the effect of seeding depth on flax and lentil tolerance to ethalfluralin, pendimethalin and trifluralin, applied preplant soil incorporated at 1.1 kg a.i. ha−1 in the spring, was investigated. Deep seeding (6 cm) reduced flax population density by 59%, averaged over 2 yr, when compared with shallow seeding (3 cm). Ethalfluralin, pendimethalin and trifluralin, reduced flax population density, but the effect of herbicide was less when flax was seeded shallow. Trifluralin and ethalfluralin reduced flax yield more when the crop was seeded deep than when seeded shallow. Herbicide treatments had no effect on flax yield when the crop was seeded shallow. Ethalfluralin and trifluralin reduced lentil population density and seed yield in one year only. Pendimethalin did not reduce lentil population density or seed yield. Deep seeding did not affect lentil population density, seed yield or phytotoxicity of dinitroanalines in this crop. In a second study, flax and lentil were seeded at 15, 30, 45, 60 and 90 kg ha−1 at 3 and 6 cm planting depths to assess the effect of seeding depth and seeding rate on crop recovery following spring application of ethalfluralin. In ethalfluralin treated plots, seeding rate had to be increased from 60 to > 90 kg ha−1 to achieve similar population densities as 45 kg ha−1 in untreated plots. Flax yields were unaffected by ethalfluralin when the crop was seeded shallow, but yields were reduced significantly when the crop was seeded deep. Lentil population density increased linearly with seeding rate. Lentil population density was unaffected by seeding depth or herbicide treatment. Ethalfluralin did not reduce lentil yield in either year. Lentil yields increased with seeding rate up to 30 kg ha−1, with little further increase in yield for seeding rates between 30 and 90 kg ha−1. Key words:Lens culinaris, Linum usitatissimum, population density, seeding depth, seeding rate, yield, seed test weight, ethalfluralin, pendimethalin, trifluralin
Comparison of five wheat simulation models In southern Alberta
Authors: Touré A. , Major D. J. , Lindwall C. W.
Published: April 2011

Increasing concentrations of greenhouse gases are expected to result in global warming which will affect crop production. Crop modelling is a useful tool for assessing the impact of climate change on crop production. The objective of this study was to select an appropriate model for climate change studies. Five simulation models, EPIC, CERES, Century, Sinclair and Stewart, were assessed using data from a long-term experiment begun in 1911 on a clay loam (Dark Brown Chernozem) soil at Lethbridge, AB. Yields predicted by the five models were compared with actual spring wheat yields in continuous wheat, fallow-wheat and fallow-wheat-wheat rotations. The EPIC model gave the best simulation results over all rotations and the most accurate predictions of mean yields during droughts. It was concluded that the EPIC model had the greatest potential for assessing the impact of climate change on wheat yield. The Stewart model was the most accurate for unfertilized continuous wheat and fallow-wheat. The Sinclair model was most accurate for fertilized fallow-wheat and CERES was the most accurate model for fertilized continuous wheat. The Century model simulated average yield accurately but did not account for year-to-year variability. Key words: Global warming, crop simulation, spring wheat yields
Sensitivity of four wheat simulation models to climate change
Authors: Touré A. , Major D. J. , Lindwall C. W.
Published: April 2011

Crop simulation models may be valuable in anticipating crop production under a changed climate. We compared four computer simulation models of wheat, crop estimation through resources and environment synthesis (CERES), erosion productivity impact calculator (EPIC), Stewart and Sinclair, for evaluating the impact of climate change on dryland spring wheat yield for continuous rotation in southern Alberta. To a varying extent, the four models showed decreases in dryland spring wheat yields due to high temperature and low precipitation. All the models except Stewart had similar sensitivity to low precipitation; however, they showed differences to high-moisture conditions. Within the range considered, the Sinclair model was the most sensitive to temperature, followed by CERES and Stewart. Only EPIC indicated optimum temperature and precipitation levels, while CERES had the most pronounced precipitation optimum. Although the CERES, Stewart and Sinclair models have different phenology submodels, they predicted similar phenological response to a doubled CO2 climate scenario generated from the Canadian Climate Center General Circulation Model for Lethbridge, AB. Growing seasons shortened by 19 d were predicted using CERES and 18 d by using the Sinclair and Stewart models. The CERES, Stewart and Sinclair models were modified to include the effect of CO2 on radiation-use-efficiency. With current atmospheric CO2 concentration in the future climate scenario, the EPIC and Stewart models predicted significant (25%) and non-significant (3%) yield increases for dryland wheat and Sinclair and CERES predicted yield losses. Higher CO2 levels may compensate for the effect of global warming; doubling CO2 from present levels in a warmer climate scenario resulted in yield increase predictions at different amplitudes using EPIC, Stewart and CERES and a slight yield decrease with Sinclair. Key words: Sensitivity, climate change, dryland spring wheat
Development and preliminary field testing of a glufosinate-ammonium tolerant transgenic flax
Authors: McHughen Alan , Holm F. A.
Published: April 2011

Flax (Linum usitatissimum L.) is a poor biological competitor and so requires chemical weed control for optimal productivity. An alternative to current, relatively expensive combinations of herbicides might be to introduce into a commercial flax genotype, using Agrobacterium mediated transformation, a gene conferring tolerance to a non-selective herbicide. Here, we describe the transformation of Norlin flax with a PAT (phosphinothricin acetyl transferase) gene conferring tolerance to glufosinate, a non-selective herbicide (Harvest™, Ignite™, Agrevo). We also present results from a preliminary field trial, showing the efficacy of the PAT gene in conferring tolerance while not dramatically altering the normal agronomic traits of the parent cultivar. Key words:Linum usitatissimum, flax, transgenic, glufosinate, phosphinothricin, field trial, herbicide tolerance
Effects of nitrogen fertilizer on dry matter and nitrogen yields of herbaceous legumes in interior Alaska
Authors: Panciera M. T. , Sparrow S. D.
Published: April 2011

Birdsfoot trefoil (Lotus corniculatus L.), arrowleaf clover (Trifolium vesiculosum Savi.), berseem clover (Trifolium alexandrinum L.), crimson clover (Trifolium incarnatum L.), barrel medic (Medicago truncatula Gaertn.), winter vetch (Vicia villosa subsp. varia L.), flatpea (Lathyrus tingitanus L.), red clover (Trifolium pratense L.), alfalfa (Medicago sativa L.), sweetclover (Melilotus officinalis Lam.), fababean (Vicia faba L.), field pea (Pisum sativum subsp. arvense L.) and white lupin (Lupinus alba L.) were grown for 2 yr in interior Alaska to assess their potential as forage and green manure crops and to evaluate the effects of N fertilizer on legume performance. Herbage yield, crude protein, and total N yield were the criteria used. In addition to previously identified promising species, berseem clover, arrowleaf clover, winter vetch and flatpea consistently produced over 3 t ha−1 of herbage and accumulated over 67 kg N ha−1. Nitrogen fertilizer (90 kg N ha−1) improved yields of arrowleaf clover and winter vetch at Fairbanks (5344 vs. 3685 kg ha−1), but N fertilization depressed yields at Delta Junction. Forage crude protein for the promising species ranged from 120 to 220 g kg−1. Several species exhibited adequate tolerance of low soil pH to be grown on acid soils without liming. Key words: Forage legume crops, Alaska, N fertilization, subarctic
Differences among orchardgrass cultivars in response to hay and rotational grazing management
Authors: Papadopoulos Y. A. , Price M. A. , Laflamme L. F. , Fulton N. R. , Hunter G. M. , Caldwell C. D. , McRae K. B.
Published: April 2011

This study was conducted to compare orchardgrass (Dactylis glomerata L.) cultivar performance under contrasting management systems (hay vs. rotational grazing) during the first two production years. The trial consisted of eight orchardgrass cultivars broadcast seeded in a randomized complete-block design, with three replications. The perimeter of each replication was fenced, and the area was divided into two sections. The first section was managed as a simulated hay production system. The second section was managed by simulating a rotational grazing system using crossbred ewes. Dry matter (DM) yield was determined before harvesting or grazing. Tiller density (TD) and leaf area index (LAI) were measured on four cultivars prior to harvesting and grazing. Excellent DM yield and persistence were obtained from all cultivars in both years under hay management but varied considerably under grazing management. Cultivar ranking according to DM yield under hay management was different from ranking based on performance under pasture management. One group of four cultivars had a decrease in yield of 19.9% in the second year of grazing, over the first year, but yield of the remaining group increased by 5.7% (SED = 9.83). Production of hay was similar for both groups. Early-maturing cultivars yielded 7% more DM and had higher crop growth rates (CGR), LAI and TD than late-maturing cultivars. Growth characteristics of orchardgrass cultivars as measured by DM yield, CGR, LAI and TD were modified by management practice. As a result, evaluating orchardgrass varieties under a hay management system was not effective in determining their performance under grazing. Key words:Dactylis glomerata, cultivar evaluation, cultivar development, grazing, yield, yield components
Frequency of post-emergence harrowing effects wild oat control and spring wheat yield
Authors: Kirkland Kenneth J.
Published: April 2011

Crops grown by organic producers or others choosing not to use herbicides require alternative weed control methods. In a 3-yr study at Scott, Saskatchewan, several harrowing frequencies were applied to emerged wild oats infesting spring wheat. Two passes with diamond tooth harrows at the one- to two-leaf stage of wild oats reduced panicle density and fresh weight in 2 of 3 yr. Multiple harrowings reduced wheat culms, fresh weight, and yield in 2 of the 3 yr. In 1992, four harrowings reduced wheat culms and yield, but had no effect on wild oat. In 1993, two harrowings reduced wild oat panicles and fresh weight, but had no effect on wheat culms and fresh weight, suggesting that moisture conditions at and immediately following harrowing have a differential effect on the ability of the two species to recover. Key words:Avena fatua L., Triticum aestivum L., cultural control, organic production
Mercury high erucic low glucosinolate summer rape
Authors: Scarth R. , McVetty P. B. E. , Rimmer S. R.
Published: April 2011

Mercury summer rape (Brassica napus L.) is a high-erucic acid rapeseed cultivar with canola-quality meal. The oil provides a good source of erucic acid for industrial applications and the canola-quality meal can be used in the feed industry. Mercury has an average 10% yield advantage over Hero rapeseed with seed oil and protein contents comparable with Hero rapeseed. Mercury is adapted to the southern B. napus growing regions of western Canada. Key words: Rape (summer), high erucic acid-low glucosinolate, cultivar description