bluuebunny/crossref_metadata_2025 huggingface dataset:
DEVELOPMENT AND YIELD OF CANADIAN WESTERN RED SPRING AND CANADA PRAIRIE SPRING WHEATS AS AFFECTED BY DELAYED SEEDING IN THE BROWN AND DARK BROWN SOIL ZONES OF SASKATCHEWAN
Authors: CUTFORTH H. W. , CAMPBELL C. A. , JUDIESCH D. , DePAUW R. M. , CLARKE J. M. , BRANDT S. A. , HUNTER J.
Published: March 2010

Historically, research has identified the optimum period of seeding Canadian Western Red Spring (CWRS) wheat in the Brown soil zone to be between late April and mid-May, and approximately mid-May in the Dark Brown soil zone. The recent development and release of new spring wheat cultivars with significantly different genetic makeup (Canada Prairie Spring (CPS) wheats) prompted this study to determine if the established criteria were valid for them. Seeding date experiments involving one CWRS wheat (Neepawa) and three CPS wheats (HY320, HY355, HY912) were carried out at Swift Current (1984–1988) and at Regina and Scott (1985–1988). Although significant seeding date × cultivar interactions occurred for several of the characteristics measured (e.g., yield, protein concentration), no cultivar consistently responded differently than the others. However, the difference in days to reach maturity between the later maturing CPS cultivars and the CWRS cultivar, Neepawa, generally increased with delayed seeding making the CPS cultivars more susceptible to early fall frost damage which could decrease their yields and grain quality. Our results showed no reason to change recommendations for seeding dates in either soil zone, and both types of wheat can be treated similarly except that late seeding for CPS wheats should be avoided.Key words: Seeding date, grain yield, GDD, protein, wheat
RUSSIAN WHEAT APHID (Diuraphis noxia) RESISTANCE IN WHEAT AND RELATED SPECIES
Authors: NKONGOLO K. K. , QUICK J. S. , LIMIN A. E. , FOWLER D. B. , PEAIRS F. B. , MEYER W. L.
Published: March 2010

The Russian wheat aphid (RWA) has become a crop pest of significant economic importance in wheat-producing areas of North America. Resistant cultivars offer the opportunity for both economic and effective control of this pest. The present study was initiated to identify genes for RWA resistance in wheat and wheat relatives and to assess the expression of the genes in a wide range of genetic backgrounds. Fifty-two lines, including wheat-related species from various geographic regions, synthetic hexaploid wheats, amphiploids derived from Triticum tauschii × T. timopheevii, T. ventricosum × T. turgidum, and hexaploid and octaploid triticales, were evaluated in the greenhouse for resistance to the RWA. There was a close association between leaf chlorosis and leaf rolling, two components of the RWA damage rating system, but the association varied with species. Close relationships were also observed among levels of damage recorded at six rating times for these two indices of RWA resistance. Eighteen entries were resistant to some degree. A high degree of gene expression for RWA resistance was observed in interspecific hybrids indicating that genes conferring resistance in wheat relatives are accessible for use in wheat improvement by established cytogenetic and plant breeding techniques.Key words: Russian wheat aphid, Diuraphis noxia, Triticeae, Agropyron, interspecific hybrids, gene expression
EFFECT OF LATE-SEASON FUNGICIDE APPLICATION ON GRAIN YIELD AND SEED SIZE DISTRIBUTION IN WHEAT AND BARLEY
Authors: ENTZ M. H. , BERG C. G. J. VAN DEN , STOBBE E. H. , ROSSNAGEL B. G. , LAFOND G. P. , AUSTENSON H. M.
Published: March 2010

Field trials were conducted to determine the effect of foliar fungicides on grain yield, kernel size and seed size distribution in wheat and barley. Tilt (propiconazole) was applied at 125 g a.i. ha−1 between Zadoks growth stages 49 and 59. Following harvest, seed samples from treated and untreated plots were stratified into different size classes. In barley trials, net blotch was the most prevalent leaf disease while in wheat trials, tan spot, leaf rust and Septoria leaf spot were most prevalent. Under high levels of disease, Tilt reduced the level of disease and significantly increased grain yield and the amount of large kernels in both wheat and barley. Under low levels of disease, Tilt rarely increased grain yield, but frequently increased the amount of large kernels. In barley, the increase in amount of seed in the larger size classes across all sites was correlated (P < 0.05) with reduction in net blotch severity. No significant effect of Tilt on germination at 5 °C was observed for any of the wheat cultivars considered in this study. Increases in the yield of large kernels indicate that late season applications of fungicide may be useful in pedigreed seed production, where large kernels are desired.Key words: Seed crops, kernel weight, seed vigor, tan spot, Septoria, net blotch
EFFECT OF MEFLUIDIDE APPLICATION DATE ON YIELD AND FORAGE QUALITY OF Bromus SPECIES
Authors: ESBROECK G. A. VAN , BARON V. S.
Published: March 2010

The plant growth regulator mefluidide (N- [2,4-dimethyl 5 [[(trifluoromethyl)sulfonyl] amino] phenyl] acetamide) has been used to enhance forage quality in several temperate grass species, but results have been inconsistent. This study was carried out to determine if stage of apical development at time of mefluidide application influenced subsequent forage yield and quality. Mefluidide was applied at 0.3 kg ha−1 to smooth bromegrass (Bromus inermis Leyss.) and meadow bromegrass (Bromus biebersteinii Roem and Schult.) at six weekly intervals beginning 27 April during 1984 and 1985 at Lacombe, Alberta. Stage of apical development at mefluidide application time was monitored closely in smooth bromegrass. Dry matter (DM) yield and quality parameters were measured at the hard dough stage. Maximum yield reductions and quality enhancement occurred consistently following an application during the first week in May. This application time (2–4 May) corresponded to a developmental stage just prior to jointing and after double ridge formation in smooth bromegrass. The 2–4 May application resulted in a 26 and 43% reduction in DM yield, a 7.8 and 6.2% increase in in vitro digestible organic matter (IVDOM) and a 41 and 50% increase in crude protein for smooth and meadow bromegrass, respectively. Fiber fractions, except hemicellulose, both on a DM and cell-wall basis, were also lowest at this application date for both species. IVDOM was negatively correlated to plant height and lignin content both on a cell-wall and DM basis. This indicated that improved quality was associated with a reduction in stem material. A negative correlation between plant height and yield was also observed. It is recommended that, for quality enhancement in smooth and meadow bromegrass, mefluidide be applied after growth has resumed in spring, but prior to jointing.Key words: Bromus species, mefluidide, application date, forage yield and quality
EFFECT OF GROWING YEAR AND APPLICATION OF A MULTI-YEAR CALIBRATION FOR PREDICTING QUALITY PARAMETERS BY NEAR INFRARED REFLECTANCE SPECTROSCOPY IN WHOLE-PLANT CORN FORAGE
Authors: VALDES E. V. , JONES G. E. , HOEKSTRA G. J.
Published: March 2010

Near infrared reflectance spectroscopy analysis (NIRA) to predict quality parameters in whole-plant corn forage was investigated. Quality parameters studied included acid detergent fiber (ADF), in vitro dry matter digestibility (IVDMD) and crude protein (CP). Samples of whole-plant corn forage were collected during three growing years (1984, 1985, 1986) across six geographical locations in Ontario, Canada and were harvested at an average 35% dry matter content. Samples were randomly divided into two sets: a calibration (CAL) set to develop NIRA equations and a testing (TEST) set to validate these equations. NIRA calibrations for ADF, IVDMD and CP percent were performed for each growing season across locations. A multi-year calibration was also developed with samples drawn from the three growing years. The accuracy of the NIRA predictions was assessed by the standard error of the estimate (SEE), bias or the mean difference between laboratory and NIRA data, the coefficient of determination (r2) and the slope (b) of the regressions between laboratory and NIRA data. The single year calibrations showed good predictions for all quality parameters in samples drawn within the year. The SEE values in the TEST sets for single year calibrations varied from 1.6 to 1.9% for ADF, 1.5 to 2.3% for IVDMD and 0.3 to 0.5% for CP, respectively. However, recalibration was necessary every year because calibrations based on a single year failed to account for variances introduced by samples drawn from other years. The multi-year calibration predicted ADF, IVDMD and CP percent accurately regardless of year. The SEE and bias for ADF, IVDMD and CP percent for the TEST set were 1.6 and 0.1, 2.2 and 0.3, and 0.5 and 0.1, respectively. The success of the multi-year calibration encourage the possibility to develop a standard calibration for whole-plant corn.Key words: Near infrared reflectance analysis, calibrations, whole-plant corn forage, year, multi-year quality parameters
EFFECT OF COMPANION CROPS ON FORAGE ESTABLISHMENT IN SOUTH COASTAL BRITISH COLUMBIA
Authors: FREYMAN S. , BITTMAN S.
Published: March 2010

Field trials were conducted at the Agriculture Canada Research Station, Agassiz, B.C. from 1986 to 1988 to study, under south coastal British Columbia conditions, the use of companion crops in grass establishment. Orchardgrass (Dactylis glomerata L.), perennial ryegrass (Lolium perenne L.), or a mixture of the two was seeded with either oats (Avena sativa L.) or barley (Hordeum vulgare L.) as a companion crop, or as sole crops with weeds either allowed to grow or controlled by herbicide. First cut yields were highest and second cut yields lowest in the establishment year whenever a companion crop was used. Companion crops had no effect on third cut yield in the establishment year, nor on yield the following year. Total yield in the establishment year was highest whenever a companion crop was used due to the higher forage yield of annual cereals than perennial grass at first cut. Proportion of weeds in the first cut was lowest with a companion crop and highest where grass was seeded alone without herbicide. Crude protein content of the first cut was lowest with a companion crop while establishment method had no effect on crude protein content of subsequent cuts. In the second year crude protein content of the forage was highest with ryegrass and lowest with orchardgrass particularly if sprayed with herbicide. A companion cereal crop can be used when seeding forage grasses in south coastal British Columbia, and there is no advantage to using a herbicide for weed control on forage seedlings grown without a companion crop.Key words: Companion crop, establishment, forages, British Columbia
CANOLA SEED SURVIVAL OVER WINTER IN THE FIELD IN ALASKA
Authors: SPARROW S. D. , KNIGHT C. W. , CONN J. S.
Published: March 2010

Factors affecting seed survival of spring canola (Brassica campestris L. ’Tobin’), over two winters in the field at Delta Junction, Alaska were studied. In October, seeds were placed in polypropylene mesh envelopes and buried. The packets were exhumed the next spring and seed viability was determined. Factors studied included seed age, seed treatment, protection by snow-fence enclosures, burial depth, and spring retrieval date. During the first winter, survival of seeds near the soil surface until March was 65%, but many died during spring. During the second winter, seed viability in March was much lower than it had been in the previous March, but no significant mortality occurred during spring. Freshly harvested seeds generally survived better than seeds which had been stored for 1 yr. Seeds buried well below the soil surface and seeds placed inside snow-fence enclosures survived better than seeds placed near the soil surface outside enclosures. Results indicate that factors such as seed storage and protection from extreme temperatures and temperature fluctuations during late winter and early spring are important determinants of canola seed survival over winter. These factors could help explain why large populations of volunteer canola arise from seeds which have fallen from mature pods, whereas harvested, stored seeds planted during fall or early spring often produce poor stands in Alaska.Key words: Seed survival, seed mortality, seed germination, seed dormancy, seed overwintering, volunteer canola
CONTROL OF STINKWEED (Thlaspi arvense) AND FLIXWEED (Descurainia sophia) IN WINTER WHEAT (Triticum aestivum)
Authors: BLACKSHAW R. E.
Published: March 2010

Field studies were conducted from 1986 through 1989 at Lethbridge, Alberta to determine suitable herbicides applied in either fall or spring for the selective control of stinkweed (Thlaspi arvense L.) and flixweed [Descurainia sophia (L.) Webb] in winter wheat (Triticum aestivum L.). Herbicides generally controlled these weeds better when applied in fall than in spring. Weeds emerging in the spring reduced the overall effectiveness of non-residual fall treatments. Superior control and greatest crop yields were attained with herbicides that controlled stinkweed and flixweed in the fall and provided residual control of spring flushes of these weeds. Fall-applied chlorsulfuron, metsulfuron methyl, metribuzin, dicamba plus 2,4-D, and picloram plus 2,4-D provided excellent initial and residual control of these weeds in all 3 yr. Winter survival of winter wheat was not affected by any treatment. Crop injury was observed only with treatments involving metribuzin and then only in 1 of 3 yr. Stinkweed and flixweed combined to reduce the yield of winter wheat by 18–32% over the 3 yr of the study.Key words: Bromoxynil, chlorsulfuron, clopyralid, dicamba, metsulfuron methyl, metribuzin, picloram, thifensulfuron, 2,4-D, MCPA
EFFECTS OF ROTATION AND FERTILIZATION ON ECONOMICS OF CROP PRODUCTION IN THE BLACK SOIL ZONE OF NORTH-CENTRAL SASKATCHEWAN
Authors: ZENTNER R. P. , STEPHENSON J. E. , CAMPBELL C. A. , BOWREN K. E. , MOULIN A. , TOWNLEY-SMITH L.
Published: March 2010

Effects of changes in product prices and input costs on the economic performance of 10 spring wheat (Triticum aestivum L.) -based rotations grown on a highly fertile orthic Black Chernozemic silty clay loam soil at Melfort, Saskatchewan, were examined over the 27-yr period from 1960–1986. The rotations differed in frequency of summerfallow, N and P fertilization, and cropping sequence involving canola (Brassica napus L.), grass-legume hay [bromegrass (Bromus inermis Leyss.), alfalfa (Medicago sativa L.)], and legume green manure [sweetclover (Melilotus officinalis (L.) Lam)]. During 1960–1971 fertilized rotations received the generally recommended rates of N and P for the region, but during 1972–1986, fertilizer was applied based on soil tests. Net income, riskiness, and costs of production were calculated over a range of product prices and input costs. At wheat prices greater than $147 t−1, fertilized fallow-wheat-wheat (F-W-W), fertilized fallow-canola-wheat (F-C-W), and a 6-yr fertilized grass-legume hay (H) rotation (F-W-W-H-H-W), generally provided the best overall economic return. At lower wheat prices, unfertilized F-W-W and F-W-W-H-H-W and fertilized fallow-wheat (F-W) often provided net income similar to the above rotations. It was profitable to substitute canola for wheat grown on conventional fallow, or on partial fallow after grass-legume hay, when the ratio of canola to wheat price was greater than about 2.0. Similarly, it was profitable to include grass-legume hay in wheat rotations when the hay price was greater than one-half that of wheat. Continuous wheat and sweetclover green manure-wheat-wheat (Gm-W-W) were not economically competitive with the best rotations at any of the price options examined. Fertilizer application was profitable in F-W-W and continuous wheat when the ratio of fertilizer cost to wheat price was less than about 5.0; it was profitable in F-W-W-H-H-W when this ratio was less than 3.5. The cost of producing wheat increased directly with rotation length. Income variability and frequency of economic losses increased with cropping intensity; however, all-risk crop insurance was effective in minimizing financial risk.Key words: Wheat (spring), canola, hay, net income, costs, riskiness
OAC TRIUMPH SUMMER RAPE
Authors: BEVERSDORF W. D. , HUME D. J. , GOSTOVIC P. , CHU G. , MONTMINY W. , MUSCAT J.
Published: March 2010

OAC Triumph is a canola quality, summer-rape (Brassica napus L.) cultivar resistant to s-triazine herbicides and tolerant to as-triazinone herbicides. In 22 trials over 3 yr in Ontario it has averaged 2% higher in yield and had higher oil content, better lodging resistance and fewer green seeds at harvest than the s-triazine-resistant cultivar OAC Triton. In 12 trials over 3 yr in Western Canada, OAC Triumph exhibited similar advantages over OAC Triton.Key words: Rape (summer), s-triazine-resistant, cultivar description
USE OF A SYSTEMATIC PLANTING DESIGN TO INVESTIGATE THE EFFECTS OF COMPANION CROP POPULATION DENSITY ON YIELD AND ON FORAGE ESTABLISHMENT AND PRODUCTIVITY
Authors: WADDINGTON J.
Published: March 2010

To assess forage response to a companion crop in the seeding year and the residual effects the following year, a one-directional logarithmic progression of companion crop populations was imposed on a uniform seeding of forage. Low-order inverse polynomial equations fit the results well, while allowing a biologically realistic interpretation. All forage-companion crop combinations produced similar results and suggested that for companion crop populations from the near-commercial 180 plants m−2 down to 20 plants m−2, maximum production of both companion crop and forage is not possible. The technique allowed a parsimonious use of materials and land but required superior experimental technique.Key words: companion crop, forage, competition, experimental design.
UTILISATION D’UN MODULE ROTATIF À DEUX NIVEAUX ET DE L’ÉCLAIRAGE ARTIFICIEL POUR LA CULTURE DE L’EXACUM ET DU GÉRANIUM
Authors: TARDIF MICHEL , DANSEREAU BLANCHE , THÉRIAULT ROGER
Published: March 2010

A cultivar of exacum (Exacum affine Balf. f. ’Elfin’) as well as two cultivars of geranium (Pelargonium × hortorum L. H. Bailey ’Hollywood Star’ and ’Hollywood Red’) were given three light treatments. The first treatment using standard production practices received only ambient light, the second treatment using standard production practices received ambient light combined with a photosynthetic photon flux (PPF) of 100 μmol m−2 s−1 provided by high pressure sodium (HPS) lamps, and the third treatment used a rotating two-level system where ambient light on the top level and a PPF of 100 μmol m−2 s−1 on the bottom level were used. An increased growth (height and width) effect was observed for the two geranium cultivars grown on the two-level system compared to the plants receiving the other treatments. The dry weight of exacums grown on the two-level system was 25% greater than those plants receiving only ambient light (during Winter/Spring-88). Certain processes such as thigmomorphogenesis, thermomorphogenesis, and photomorphogenesis may explain physiological modifications undergone by the plants growing on the two-level system.Key words: Rotating two-level system, photosynthetic photon flux, Exacum affine, Pelargonium × hortorum, photomorphogenesis, thermomorphogenesis
GEOGRAPHICAL DIVERSITY, PARENTAL SELECTION AND HETEROSIS IN OILSEED RAPE
Authors: BRANDLE J. E. , McVETTY P. B. E.
Published: March 2010

Heterotic patterns of geographic origin can be useful in the initial stages of a hybrid oilseed rape (Brassica napus L.) breeding program. Mid-parent values, a reflection of parental line performance per se, could be an efficient means of screening potential parents to be used as source populations for hybrid breeding. The purpose of this study was to establish heterotic patterns and to evaluate mid-parent values as a screening tool for use in hybrid oilseed rape breeding. Twenty-one cultivar-derived hybrids and their seven parents were grown in three environments and evaluated for seed yield, height and oil and protein concentration. Four of the parental cultivars were of European ancestry, two were Canadian and one was Australian. Results of the study indicate that the Canadian and European cultivars belong to the same, or partially overlapping heterotic groups and that the Austrialian cultivar belonged to another. Mid-parent was a good descriptor of hybrid performance only when general combining ability was the predominant form of variation among hybrids.Key words: Brassica napus L., hybrids, mid-parent
INTERACTION OF CULTIVAR, SEEDING DATE AND DOWNY MILDEW INFECTION ON VARIOUS AGRONOMIC CHARACTERISTICS OF BUCKWHEAT
Authors: GUBBELS G. H. , CAMPBELL C. G. , ZIMMER R. C.
Published: March 2010

Field studies were conducted over 5 yr to determine the effect of seeding date on agronomic characteristics and disease reaction of buckwheat (Fagopyrum esculentum Moench). Two large-seeded, mid-season buckwheat cultivars, Manor and a semi-dwarf line, G410 or G474, and a small-seeded early-maturing cultivar, CM 169, were grown at Morden and Portage la Prairie during the period 1983–1985 at early, mid- and late June or early July seeding dates. In 1986 and 1987, Manor was grown at three seeding dates, with and without a fungicide treatment to control downy mildew (Peronospora ducometi Siemaszko and Jankowska). In the 1983–1985 experiments, seed yield generally declined with delay in seeding. The smallest decline occurred in the early-maturing cultivar CM 169. From first to last seeding, yield decreases were 38, 44 and 18% for Manor, the semi-dwarf lines and CM 169, respectively. In 1985, downy mildew infection increased linearly to a small degree with delay in seeding and was negatively correlated with seed yield. However, it was considered a minor factor in the response of yield to seeding date. In 1986 and 1987, mildew infection was minimal. The fungicide treatment had no effect on seed yield. Seed yields decreased with delay in seeding as in the previous tests. It was concluded that seed yield declined markedly with delay in seeding from early to late June, more so in the later-maturing cultivars and the declines were independent of mildew infection.Key words: Buckwheat, Fagopyrum esculentum Moench., seeding date, downy mildew, Peronospora ducometi Siemaszko & Jankowska
EFFECTS OF COMBINED NITROGEN, Rhizobium STRAIN AND SUBSTRATE ON A SUPERNODULATING MUTANT OF Phaseolus vulgaris L.
Authors: BUTTERY B. R. , PARK S. J. , DHANVANTARI B. N.
Published: March 2010

Nodulation, plant growth and seed yield of the supernodulating mutant Rico 32M2-BS and its parent, cv. OAC Rico (Phaseolus vulgaris L.) are described in relation to supply of combined N and inoculation with Rhizobium leguminosarum bv. phaseoli and R. fredii. Combined N depressed nodule numbers more severely in the mutant than in its parent line, OAC Rico, at the first sample 14 d after seeding, but at 35 d, combined N increased nodule numbers in both the mutant and OAC Rico, and increased nodule mass in the mutant. In the absence of N, AR per plant increased between 14 and 35 d but AR per gram nodule weight declined. In the +N treatment, AR per plant and per gram nodule was greatest at 28 d, but in other samples AR of the +N treatments tended to be lower than in −N treatments. Plant growth of both the mutant and OAC Rico was stimulated by combined N. Both the mutant and OAC Rico nodulated well and effectively with three pure strains of R. leguminosarum bv. phaseoli and with indigenous soil strains. They both nodulated ineffectively with three strains of R. fredii, but the mutant plants still expressed their supernodulating characteristic. In the field test, plant growth of the mutant and OAC Rico was similar at the three levels of N fertilizer. Nodule dry weight was greater in the mutant than in OAC Rico; nitrogen depressed nodule dry weight in both lines. Seed yield of OAC Rico was 1.5 times that of the mutant.Key words: Combined N, common bean, nitrogen fixation, nodulation mutants, Phaseolus, Rhizobium, supernodulation
THE EFFECTS OF 2-CHLORO-6 (TRICHLOROMETHYL)-PYRIDINE (’N-SERVE’) AND N FERTILIZERS ON PRODUCTIVITY AND QUALITY OF CANADIAN OILSEED RAPE
Authors: BAILEY L. D.
Published: March 2010

’N-Serve’ has been shown to reduce losses of applied N-fertilizer and thereby increase fertilizer N-utilization by plants. This study was undertaken to test the effects of ’N-Serve’ on fertilizer N efficiency in oilseed rape production and quality. Field experiments were conducted on two chernozemic soils over 4 yr in Manitoba. The oilseed rape cultivars Tower (Brassica napus L.) and Torch (B. campestris) were used in the study. Spring and fall applied ammonium nitrate, urea and fluid-N, with and without ’N-Serve’ delayed flowering and increased the herbage yield of both oilseed rape cultivars. The number of days from full pod to maturity was increased with application of N fertilizers, but the number of days from flowering to full pod was constant. Increased herbage yield and total plant N at flowering was reflected in increased seed yield and meal protein content, but decreased oil content. ’N-Serve’ applied with and without N fertilizer reduced oil content and oil yield. However, when ’N-Serve’ was applied in the fall with urea and fluid-N it improved their efficiency, resulting in higher seed yields and meal protein content equivalent to that of spring applications. ’N-Serve’ used with fall applied ammonium nitrate or with all three sources of spring applied N had no similar effect. It is concluded that ’N-Serve’ should not be applied to oilseed rape, mainly because of its negative effect on seed oil content.Key words: Oilseed rape, ammonium nitrate, urea, fluid-N, chernozemic soil, protein, oil
FIELD EVALUATION OF TISSUE CULTURE DERIVED SORGHUM FOR INCREASED TOLERANCE TO ACID SOILS AND DROUGHT STRESS
Authors: WASKOM R. M. , MILLER D. R. , HANNING G. E. , DUNCAN R. R. , VOIGT R. L. , NABORS M. W.
Published: March 2010

Plant tissue culture is being recognized as an important tool for generating useful variants for crop improvement. The objective of this research was to determine if improved tolerance to acid soil and drought stress can be generated in sorghum [Sorghum bicolor (L.) Moench] through tissue culture. Two environments were used to screen for enhanced field tolerance: (1) a low pH field in Griffin, Georgia for testing acid soil stress tolerance, and (2) an arid environment in Yuma, Arizona for testing drought stress tolerance. A population of 212 R1 sorghum lines from tissue cultures of Hegari and Tx430 were increased in 1986. Screening was then conducted in both environments during 1987. Selected entries which showed improved tolerance were advanced and re-tested during 1988. From this original population, four lines were identified as having improved acid soil tolerance and five lines were identified as having improved drought tolerance as compared to the non-regenerated checks. Three of these lines performed better than the non-regenerated checks under both acid soil and drought stress conditions. These results indicate that somaclonal variants for increased tolerance to environmental stresses can be generated in tissue culture and be selected under proper field conditions.Key words: Sorghum bicolor, somaclonal variation, drought tolerance, acid soil tolerance, tissue culture
NITROGENASE ACTIVITY, PHOTOSYNTHESIS AND TOTAL NONSTRUCTURAL CARBOHYDRATES IN COWPEA DURING AND AFTER DROUGHT STRESS
Authors: PARARAJASINGHAM S. , KNIEVEL D. P.
Published: March 2010

Greenhouse experiments were conducted to determine whether depressed nitrogenase activity (NA) of cowpea (Vigna unguiculata (L.) Walp.) nodules during drought stress is associated with altered carbohydrate supply to the nodules. Nitrogenase activity of the nodules, midday abaxial stomatal conductance, leaf net photosynthesis and mg total nonstructural carbohydrate (TNC) g−1 dry weight of several plant parts were measured in cowpea subjected to and recovering from drought stress periods of 0, 4 and 8 days. In addition, cowpea plants were shaded or partially defoliated (75% leaf removal) to limit carbohydrate supply to the nodules of well-watered plants. Stomatal conductance, leaf net photosynthesis and nodule NA declined 60, 62 and 90%, respectively, within 4 d of withholding water. After 8 d of drought stress, leaf net photosynthesis and nodule NA were near zero. Stomatal conductance and leaf net photosynthesis returned to the level of unstressed plants within 24 h following rewatering while recovery of NA was delayed. Shading and defoliation of cowpea plants under well watered conditions decreased NA 62 and 44%, respectively. TNC concentrations of leaves, petioles, stems, roots and nodules did not differ appreciably between drought stressed and control plants. In contrast, TNC concentrations of shoot plant parts from shaded or defoliated plants declined significantly compared to controls and nodule TNC concentrations declined in shaded plants. The decline in NA by cowpea nodules during drought stress did not appear to be directly associated with carbohydrate supply to the nodules, but rather the result of a new equilibrium attained with overall limited plant growth under the stress.Key words: Vigna unguiculata (L.) Walp., nitrogenase activity, drought stress recovery, assimilate stress, shading, defoliation, total nonstructural carbohydrate
QUALITY EFFECTS OF PULSES ON SUBSEQUENT CEREAL CROPS IN THE NORTHERN PRAIRIES
Authors: WRIGHT A. T.
Published: March 2010

A study comparing the crop sequences pulse-barley-wheat and barley-barley-wheat was conducted from 1982 to 1987 on black and gray soils in northeastern Saskatchewan. Faba bean, field pea, and lentil had a similar effect on the subsequent barley crop increasing kernel mass by 1.9 mg, plumpness by 5 percentage units, and protein content by 0.6 percentage units. This indicates that barley produced on pulse residues would likely have higher nutritive value and higher malting quality than that grown on barley residues, unless conditions were such that the increase in protein were enough to cause the sample to be discriminated against for malting purposes. Incorporation of pulse residues was unnecessary to attain high barley quality. In general, linear response of kernel mass and plumpness to N fertilizer was greater on barley than pulse residues, but the response of protein content to N fertilizer was unaffected by preceding crop. Fertilizer N was unable to increase barley quality produced on barley residues to the level of that produced on pulse residues. Protein content of wheat grown in year 3 of each cycle was unaffected by whether or not a pulse crop had been included in the crop sequence.Key words: Barley, faba bean, field pea, lentil, wheat, tillage
YIELD EFFECT OF PULSES ON SUBSEQUENT CEREAL CROPS IN THE NORTHERN PRAIRIES
Authors: WRIGHT A. T.
Published: March 2010

A study comparing the crop sequences pulse-barley-wheat and barley-barley-wheat, was conducted from 1982 to 1987 on Black and Gray-wooded soils in northeastern Saskatchewan. Faba bean (Vicia faba L.), field pea (Pisum sativum L.), and lentil (Lens culinaris Medic.) had similar effects, increasing subsequent cereal yield, on average, by 21% in the first and 12% in the second year. Incorporation of pulse residue was not necessary in order to attain high yields. The yield response of barley (Hordeum vulgare L.) to N fertilizer was slightly greater on barley than on pulse residue, but N fertilizer alone was unable to bring the yield on barley residue up to the yield on pulse residue. However, there were great differences in the effect of year, soil type, preceding crop, residue incorporation, and fertilizer response, and there were many significant interactions of these treatments. These treatment effects could not be consistently accounted for by differences in N cycling, soil moisture, or disease.Key words: Barley, faba bean, field pea, lentil, wheat, crop sequence
EFFECT OF HERBICIDE TREATMENTS ON DANDELION, ALFALFA AND SAINFOIN YIELDS AND QUALITY
Authors: MOYER J. R. , HIRONAKA R. , KOZUB G. C. , BERGEN P.
Published: March 2010

Sainfoin (Onobrychis viciaefolia Scop.) and alfalfa (Medicago sativa L.) were seeded in 1978 and 1979, respectively. Weed control treatments initiated in sainfoin in 1979 and in alfalfa in 1980 included annual applications of terbacil, metribuzin, simazine, hexazinone and chlorsulfuron until 1985 plus an untreated check. Dandelion (Taraxacum officinale Weber) was the main weed infesting check plots in the sainfoin and alfalfa stands. Quackgrass (Agropyron repens L. Beauv.) and nonpalatable weeds such as foxtail barley (Hordeum jubatum L.) produced 4.5 and 4.0% of the total yield, respectively, where chlorsulfuron selectively controlled broadleaf weeds. In hexazinone, metribuzin and chlorsulfuron treatments, alfalfa and sainfoin stands were almost free of dandelions. In sainfoin plots, dandelion control produced large increases in sainfoin and total herbage yield. In alfalfa plots, dandelion control had no effect on alfalfa yield or total yield. In sacco dry matter digestibility in a 72-h experiment was higher for dandelions than for alfalfa, whereas protein digestibilities were similar for these herbages. The protein content was less in dandelions than in alfalfa at the first harvest. Thus, dandelion control in sainfoin may increase yield, whereas dandelion control in alfalfa does not seem to increase yield but may increase protein content and marketability.Key words: Control, protein, digestibility, hexazinone, terbacil, metribuzin
DOWNY BROME (Bromus tectorum) INVASION INTO SOUTHWESTERN SASKATCHEWAN
Authors: DOUGLAS B. J. , THOMAS A. G. , DERKSEN D. A.
Published: March 2010

Downy brome (Bromus tectorum L.) has rapidly invaded crop and pasture land in southwestern Saskatchewan since 1960. By 1989, 116 townships in 31 rural municipalities were infested. The spread of downy brome is associated with the increased area of winter wheat and fall rye grown using minimum and zero tillage practices, a lack of effective herbicides for selective in crop control and weather conditions which favor autumn germination and early spring competition. Although downy brome has been found on seven soil associations in the Brown soil zone and one association in the Dark Brown soil zone, the occurrence of the weed is related to cropping practices rather than soil texture or association.Key words: Downy brome distribution, downy brome invasion, Bromus tectorum, winter wheat
FRANK SPRING TRITICALE
Authors: McLEOD J. G. , DePAUW R. M. , LENDRUM C. W. B. , McCRYSTAL G. E. , PAYNE J. F. , TOWNLEY-SMITH T. F.
Published: March 2010

Frank triticale (× triticosecale Wittmack) was developed at the Agriculture Canada Research Station, Swift Current, Saskatchewan. It was produced by intercrossing genotypes developed by the International Center for the Improvement of Maize and Wheat (CIMMYT), the University of Manitoba and the South Saskatchewan Wheat Program prior to subjecting the segregants to early generation yield-testing procedures. Frank demonstrates major improvements in yield, test weight, and earliness relative to other Canadian triticale cultivars.Key words: Cultivar description, Triticale (spring), × triticosecale Wittmack
REACTION OF Brassica SPECIES TO INFECTION BY Alternaria brassicae
Authors: BANSAL V. K. , SÉGUIN-SWARTZ G. , RAKOW G. F. W. , PETRIE G. A.
Published: March 2010

Thirty-five cultivars/strains belonging to six Brassica species were evaluated for their reaction to Alternaria brassicae under laboratory conditions. Detached leaves were wounded and inoculated with a spore suspension, and incubated at room temperature for 4 d. Lesion diameter was used as an indicator of resistance. The smallest lesions were observed in B. carinata, followed by, in order of increasing lesion size, B. oleracea, B. napus, B. campestris, B. juncea, and B. nigra. Intraspecific differences for lesion size occurred in B. napus, B. campestris, B. juncea, and B. oleracea.Key words: Brassica, Alternaria brassicae, summer rape, summer turnip rape, mustard
RESPONSE OF EARLY-MATURING SUNFLOWER HYBRIDS TO ROW SPACING AND PLANT DENSITY
Authors: GUBBELS G. H. , DEDIO W.
Published: March 2010

Two early-maturing sunflower hybrids, Sunwheat 101 and MRS 34, with shorter than normal height and a narrower growth habit were grown at 30- and 60-cm row spacings and three plant densities at each row spacing in the 1986 and 1987 seasons at Morden, Manitoba. There were no differences in achene yield or oil content between row spacings. Plant height and oil content of achenes increased with increase in plant density, while achene weight decreased. Achene yield of both hybrids increased as plant density increased from 55 000 to the 74 000 plants ha−1 density, then remained relatively constant to 148 000 plants ha−1.Key words: Oilseed sunflower, Helianthus annuus L., plant row spacing, plant density
RADISSON SMOOTH BROMEGRASS
Authors: SURPRKNANT J. , KNOWLES R. P.
Published: March 2010

Radisson is a southern-type smooth bromegrass (Bromus inermis Leyss.) developed at Agriculture Canada, Saskatoon that has produced high yield of forage dry matter in Eastern Canada. Registration Number 3154 was issued for Radisson on 15 Sept. 1989, by the Food Production and Inspection Branch, Agriculture Canada.Key words: Bromus inermis Leyss., Radisson, cultivar development, smooth bromegrass
WILD MUSTARD CONTROL IN SUNFLOWER WITH FLURTAMONE
Authors: FRIESEN G. H. , WALL D. A.
Published: March 2010

Flurtamone applied preplant soil incorporated at 0.6 and 0.8 kg a.i. ha−1 selectively controlled wild mustard, Brassica kaber (DC) Wheeler var. pinnatifida (Stokes) Wheeler, in sunflower (Helianthus annuus L. ’Hybrid Sun M20’) in field experiments at Morden, Manitoba from 1987 to 1989. Mixtures of flurtamone and trifluralin or ethalfluralin did not reduce the efficacy of flurtamone and controlled a broad range of annual weeds. Flurtamone had no significant effect on sunflower seedling emergence, achene yields, achene weight, achene density, or oil content.Key words: Wild mustard, Sinapis arvensis, Brassica kaber, sunflower, Helianthus annuus, flurtamone, RE-40885
LAMB’S-QUARTERS INTERFERENCE WITH DIRECT SEEDED BROCCOLI
Authors: BITTERLICH IRIS , UPADHYAYA MAHESH K.
Published: March 2010

Field experiments were conducted in 1987 and 1988 to study the effect of lamb’s-quarters (Chenopodium album L.) interference on broccoli (Brassica oleracea L. var. botrytis ’Emperor’) growth and yield. Broccoli growth was initially affected by weed interference at 28–36 d after seeding. Generally, the negative effect of weed interference on broccoli growth increased with increasing weed density and time after seeding. Interference by 15 lamb’s-quarters plants m−2 reduced the biomass of broccoli plants by 71–73% compared to the weed-free control at 57–58 d after seeding. Weed density-crop yield relationship curves showed that one lamb’s-quarters plant m−2 decreased total yield by 18–20% and marketable yield by 22–37%. Lamb’s-quarters reduced the total yield per plot by decreasing the average head weight of broccoli. The number of heads per plot was not affected. Weed interference also reduced the weight of heads classified as marketable (> 10 cm across). However, in 1987 more heads failed to reach a marketable size which resulted in a much smaller marketable yield than in 1988.Key words: Brassica oleracea var. botrytis, broccoli, Chenopodium album L., weed density, weed interference, cole crop
DYNAMICS OF SOIL MICROBIAL BIOMASS AND WATER-SOLUBLE ORGANIC C IN BRETON L AFTER 50 YEARS OF CROPPING TO TWO ROTATIONS
Authors: McGILL W. B. , CANNON K. R. , ROBERTSON J. A. , COOK F. D.
Published: March 2010

Amounts and turnover rates of biomass and water-soluble organic C (WSOC) were measured at the Breton plots where records of long-term management of a Gray Luvisolic soil are available. Plots (control, manure, and NPKS) which had been cropped to either a wheat-fallow or a wheat-oats-barley-forage-forage rotation for 50 yr were sampled 13 times during 1981 and 1982. Biomass C and flush of microbial N were measured using the chloroform fumigation technique. Long-term crop yields were used to derive C supply to the plots. Regression analyses were used to relate seasonal fluctuations in environmental conditions to biomass and WSOC dynamics. Reinoculation with soil was unnecessary but Lysobacter sp. formed a greater proportion of isolates following incubation of fumigated soil than of unfumigated samples. Reinoculation with Lysobacter sp. is suggested to provide a more standardized biological assay. The 5-yr rotation contained 38% more N but 117% more microbial N than did the 2-yr rotation, and manured treatments contained twice as much microbial N as did NPKS or control plots. A management effect on soil organic matter quality is indicated. Averge turnover rates of biomass were 0.2–3.9 yr−1; being 1.5–2 times faster in the 2-yr rotation than in the 5-yr rotation. Replenishment of the WSOC component would have to occur 26–39 times yr−1 to supply microbial turnover. Most of the biomass must be dormant because annual C inputs are two orders of magnitude less than maintenance energy requirements. Seasonal variations in biomass were most consistently related to losses during desiccation and regrowth upon moistening. Regrowth appears to be at the expense of native soil organic matter. Management practices and environmental conditions therefore affect amount of organic matter by controlling both input of C and biomass turnover. Key words: Crop rotations, Luvisol, organic matter, biomass, soluble C, Breton plots
LATE-FALL APPLICATION OF POTASH TO WINTER RYE TO IMPROVE GROUND COVER EFFECTIVENESS
Authors: EDWARDS LINNELL M.
Published: March 2010

In view of the difficulty of establishing a winter cover crop after potato harvesting in the late fall in Prince Edward Island, a study was done to test the effect of three levels of banded K on the cool-season establishment and survival of two cultivars of winter rye (Secale cereale L.). There was no significant effect of K level on shoot or root dry weight in either late fall or early spring, or on shoot or root K content. There were significant cultivar differences in shoot and root dry wt in late fall and early spring, but no interaction between K level and rye cultivar. Key words: Cold stress, winter ground cover, critical K concentration
AN EVALUATION OF SCREENING TESTS FOR SOIL CONDITIONERS
Authors: TOPP G. C. , ZEBCHUK W. D.
Published: March 2010

Two laboratory tests, sorptivity of air-dry soil and satiated hydraulic conductivity, were evaluated for preliminary screening of soil conditioners to which are attributed improved water intake or increased hydraulic conductivity. Based on the variability found in these tests, five replicates or fewer would be required to demonstrate a 20% effect of soil conditioners on sorptivity. For a 40% effect on ln Ksat, four replicates would be advisable. These levels of response were suggested as the minimum response which might be discernible in practice. Key words: Soil conditioners, hydraulic conductivity, sorptivity
TRANSIENT GROUNDWATER FLOW SURROUNDING A RECHARGE SLOUGH IN A TILL PLAIN
Authors: MILLS J. G. , ZWARICH M. A.
Published: March 2010

Knowledge of the groundwater flow system around a slough aids in the resolution of conflicting opinions on slough drainage. This study reports on the flow system around a typical temporary slough in a low relief till plain landscape. The site is located in a regional groundwater recharge area, with till of low hydraulic conductivity overlying a shale aquifer. The distribution of soil profile types in the landscape reflects a wide range of soil water regimes. Instrumentation at the site revealed an annual cycle of water levels and transient flow that was related to spring ponding of water in the slough. Numerical simulation of the flow system, under conditions of ponding, surface saturation, and evapotranspiration, helped to clarify and extend the field observations. Each depression in the landscape has a local flow system that is superimposed on the regional system. Hydraulic conductivity, water supply to the slough, and the amount and timing of infiltration and exfiltration all affect the local flow system. Temporary sloughs, such as the one studied, do not benefit agriculture, but drainage of these sloughs raises other concerns. Key words: Groundwater, transient flow, recharge, slough, pothole, simulation
FIELD CALIBRATION OF A NEUTRON PROBE
Authors: CHANASYK D. S. , McKENZIE R. H.
Published: March 2010

A study near Lethbridge, Alberta examined the effect of soil texture and bulk density on the calibration of a neutron probe and explored the feasibility of using only one calibration curve for measuring soil moisture. The effect of soil texture was found to be negligible. Bulk density did affect calibration, but not enough to warrant calibration based on bulk density. A calibration curve derived using all data was adequate for estimating soil moisture content and moisture changes, but the manufacturer’s curve was highly inappropriate for determination of either. Key words: Neutron probe, calibration, texture, bulk density
THE SULPHUR STATUS OF EASTERN CANADIAN PRAIRIE SOILS: SULPHUR RESPONSE AND REQUIREMENTS OF ALFALFA (Medicago sativa L.), RAPE (Brassica napus L.) AND BARLEY (Hordeum vulgare L.)
Authors: BAILEY L. D.
Published: March 2010

Alfalfa (Medicago sativa), rape (Brassica napus) and barley (Hordeum vulgare) were grown in a growth chamber with and without sulphur (S) on surface samples (0–15 cm) of 17 eastern Canadian prairie soils. The soil varied in pedological origin and were divided into three groups based on their total nitrogen:total sulphur (N:S) ratios. Herbage yield of alfalfa (full bud) and rape (flowering) were highly correlated (P < 0.01) with soil (N:S)s ratios and soil SO4-S, while for barley (shot blade) the relationships were significant [Formula: see text]. Herbage yields of the three crops were also significantly correlated [Formula: see text] with plant (N:S)p ratios. Soil (N:S) ratio was considered the best predictor of herbage yield because it is more stable over time than soil SO4-S and because plant (N:S)p ratio only indicates a need for future fertilization. The highest yields and S and N composition of plant tissues were obtained on soils with SO4-S concentrations greater than 12 mg kg−1 and an (N:S)s ratio of approximately 6. These soils had sufficient S to meet the requirements of all three crops. Addition of S had no effect on herbage yield but did increase S uptake. Results indicated that soils with (N:S)s ratio of 9 and SO4-S concentration of 7 mg kg−1, may have sufficient S to meet the requirement of barley but not alfalfa and rape. However, soils with higher (N:S)s ratios and lower SO4-S content were deficient in S for all crops. Barley was the most responsive to applied S of the three crops, although it had the lowest concentration of S (0.15 mg S g−1 dry herbage) and highest plant (N:S)p ratio (16) at its highest yield. Rape was more responsive to applied S than alfalfa but the concentration of S in the herbage of both crops at their highest yields were similar, 0.27 and 0.26 mg S g−1 dry herbage, respectively. Both crops also had lower (N:S)p ratios than barley at the highest yield (14 (alfalfa) and 12 (rape)), reflecting their greater S uptake. Key words: Plant-available S, soil (N:S)s ratio, plant (N:S)p ratio, plant uptake of S, plant uptake of N