bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of mass, F2-derived family, and single-seed-descent selection methods in an interracial population of common bean
Authors: Urrea Carlos A. , Singh Shree P.
Published: April 2011

Knowledge of comparative effectiveness of different selection methods is necessary for identification of superior genotypes, efficient management of populations, and use of available resources. Mass, F2-derived-family, and single-seed-descent (SSD) selection methods were compared in an interracial population (ICA Pijao × Pinto UI 114) of common bean (Phaseolus vulgaris L.). The F2-derived-family method involved elimination of low-yielding F2-derived families in replicated yield trials in F4, F5 and F6. Thirty-two random lines derived from each method and the two parents were evaluated in a replicates-in-set design in two contrasting environments in Colombia in 1992. Mean seed yield of lines derived from the SSD method was significantly lower than yields obtained from the other two methods. Mean yield of lines derived from the pedigree method was the highest, indicating that even a low intensity of selection for yield among F2-derived families was effective. The F2-derived-family method also retained a comparatively higher proportion of lines with lighter-colored medium-sized seeds and indeterminate prostrate type III growth habit. Lines with darker and smaller seeds predominated in the mass and SSD methods. These two groups also had more erect type II lines than did the F2-derived family method. On average, the SSD gave early maturing and the mass method late maturing lines. No line from any method outyielded ICA Pijao, the high-yielding parent. Two lines from the F2-derived-family method, four lines from the mass method, and no lines from the SSD method significantly outyielded Pinto UI 114. Key words: Common bean, Phaseolus vulgaris, selection methods, F2-derived family, seed yield
Effect of an oat companion crop on irrigated alfalfa yield and economic returns in southwestern Saskatchewan
Authors: Jefferson P. G. , Zentner R. P.
Published: April 2011

Companion crops are not recommended for use in the establishment of alfalfa (Medicago sativa L.) stands on dryland areas in southwestern Saskatchewan because of competition for soil water. However, their use has been common with irrigated alfalfa to control weeds and produce economic yields in the establishment year. The objective of this study was to determine the effect of an oat companion crop on forage yield and economic returns for irrigated alfalfa. In four irrigated trials at Swift Current, Saskatchewan, alfalfa was planted with and without a companion oat (Avena sativa L.) crop. The direct-seeded alfalfa produced harvestable yields in three of four trials, with forage yields ranging from 2584 to 6248 kg DM ha−1. Stands of alfalfa established with the oat companion crop exhibited 33% lower forage yields at first harvest in the first year after seeding in three of the four trials. The persistence of this treatment effect over time varied among the three trials. Economic returns for the establishment treatments differed considerably among trials and depended on the prices for oat grain and forage hay. In three of four trials, net margins for the establishment year were highest for alfalfa grown with an oat companion crop which was harvested for hay when the ratio of oat hay to alfalfa hay price was greater than 0.5. Further, it was generally more profitable to harvest the oats for grain than for hay when the ratio of oat grain to oat hay price was greater than 1.3. In the remaining trial, direct-seeded alfalfa provided the highest net margin during the establishment year. When evaluated over the 3-yr study periods, however, there was generally little consistent difference in economic rankings among the alfalfa establishment methods. Economic returns were generally higher for direct-seeded alfalfa or for alfalfa seeded with an oat companion crop that was harvested for hay when the ratios of alfalfa hay and oat hay to oat grain price were greater than 1.2 and 0.9, respectively. The study concluded that the use of an oat companion crop has both agronomic and economic merit for producers establishing alfalfa on irrigation areas in this semi-arid region of Saskatchewan. Key words: Establishment, direct seeding, forage yield, plant density, net present value, net margin
Greenhouse and field evaluation of pod dehiscence in soybean
Authors: Helms Theodore C.
Published: April 2011

A greenhouse procedure to evaluate differences among soybean [Glycine max (L.) Merr.] genotypes for pod dehiscence (shattering) susceptibility permits evaluation under controlled environments. Suitable environmental conditions do not always exist in the field. The objectives of this study were to develop a greenhouse method to screen for shattering susceptibility and to compare genotypes for shattering resistance under both greenhouse and field conditions. Eight genotypes were evaluated in both the field and the greenhouse. A split-plot treatment design in the greenhouse included watering plants after physiological maturity versus no watering after maturity as a whole-plot factor, with genotypes assigned to split plots. In the greenhouse, shattering susceptibility was not reduced by watering after physiological maturity. The genotypes most susceptible to shattering were identified on the basis of the greenhouse and field evaluation. Among the specific genotypes evaluated, the earliest maturing genotypes were not the most suscpetible to shattering. Key words: Soybean, shattering, greenhouse
AC Sterling Barley
Authors: Choo T. M. , Martin R. A. , Ho K. M. , Bubar J. S. , Walton R. , Blatt R. , Rodd V.
Published: April 2011

AC Sterling is a two-row, spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Canada Barley Breeding Group, Agriculture and Agri-Food Canada. It has high yield, high protein content, low acid detergent fibre content, high 1000–kernel weight, and resistance to powdery mildew. AC Sterling is well adapted to Eastern Canada. Key words: Barley, Hordeum vulgare L., cultivar description, high yield, high feed quality
Winter freezes of fruit trees in the Okanagan Valley, British Columbia: Relationship with the Pacific North America teleconnection and the El Nino/Southern Oscillation
Authors: Hall J. W. , Quamme H. A.
Published: April 2011

Every 5–7 years there are severe winter freezes in the Okanagan Valley which lower yields or kill apple trees. Our goal was to determine whether winter freezes (December, January and February) could be related to the Pacific North America teleconnection (PNA) and the El Nino/Southern Oscillation (ENSO). Fall and spring freezes were also discussed. A list of ENSO warm event, cold event and neutral years was available from 1947 to 1986 as well as monthly temperature and precipitation records. Months were classified as having a PNA, reverse PNA (r-PNA) or neutral pattern. There was a tendency for the r-PNA pattern to occur more and the PNA pattern less frequently in cold event winters than in warm event winters. The average temperature was lower when the r-PNA predominated but ENSO events had no additional effect. No relationship was detected with precipitation. Fall and winter freezes occurred when there was an r-PNA pattern combined with either a neutral or a cold event ENSO. These results suggest that the risk of winter freezes will be low during ENSO warm events and high when the r-PNA pattern predominates. Key words:Malus domestica, Prunus persica, freezing injury, teleconnexions, El Nino/Southern Oscillation
Growth response of four hard red spring wheat cultivars to date of seeding
Authors: Hucl P.
Published: April 2011

An increasing number of spring wheat cultivars released for production in western Canada are daylength insensitive. In contrast, until a decade ago virtually all Canada Western Red Spring (CWRS) wheat cultivars were daylength sensitive. The impact of photoperiod response on CWRS wheat growth and yield has not been studied to date. A growth analysis study was conducted in each of 3 yr at Saskatoon. Growth and yield traits of the photoperiod-sensitive cultivars Conway and Katepwa and photoperiod-insensitive cultivars Laura and Leader were compared in early versus late plantings. Laura had the highest leaf area index at anthesis and produced more spikelets and kernels per spike than the other cultivars. Laura, however, had a higher tiller mortality, producing fewer spikes per square metre. The cultivars did not respond uniformly to delayed seeding from one year to the next. Significant crossover cultivar × seeding date interaction was detected in each of the 3 yr. The cultivar × seeding-date interactions did not appear to follow a pattern that might be ascribed to differing cultivar photoperiod sensitivity. Conway was involved in one case of significant (P = 0.10) cultivar × seeding cross-over interaction for grain yield, while Katepwa and Leader were each involved in two cases and Laura in three cases. This study failed to determine whether differing photoperiod responses would translate into gross differences in cultivar growth and yield. Thus, there is a need to develop near-isogenic lines to determine whether photoperiod insensitivity is detrimental to yield stability in CWRS wheats. Key words: Canada Western Red Spring wheat, growth analysis, seeding date, genotype × environment interaction
Long-term (35 years) effects of fertilization, rotation and weather on corn yields
Authors: Drury C. F. , Tan C. S.
Published: April 2011

Long-term effects of fertilization, crop rotation and weather factors [temperature, precipitation, net radiation, maximum (potential) evapotranspiration (ET) and corn heat units (CHU)] on the sustainability of corn grain yields were investigated over 35 yr. Treatments included fertilized and unfertilized continuous com and rotation corn-oats-alfalfa-alfalfa. The fertilized rotation corn treatment produced the greatest corn grain yields (15% moisture content) with an average of 7.75 t ha−1 followed by the fertilized continuous corn treatment with 6.02 t ha−1. Fertilization increased grain yield for continuous corn treatments by 279% and increased grain yields in the rotational corn treatments by 70%. Corn grain yields increased with time with the fertilized rotation treatment, remained relatively constant with the fertilized continuous corn and decreased with the unfertilized treatments. Growing season precipitation was the only weather variable tested which was significantly related to corn grain yield. Precipitation in July was proportional to corn grain yield for all fertilized treatments. Weather variation played little role for unfertilized corn. Continuous corn production was sustained (yields did not decrease with time) when fertilizer was added. There was a considerable yield advantage with fertilized corn when grown in a rotation compared with fertilized continuous corn. Fertilization and crop rotation practices increased and buffered corn yields. Key words: Long-term, corn, yield, fertilization, rotation, weather
Influence de la date et de la dose de semis sur l'apparition de l'ergot chez l'orge
Authors: Pageau Denis , Wauthy Jean-Marie
Published: April 2011

A study was conducted from 1987 to 1991 at Saint-Eugène, Québec, to evaluate the effect of seeding dates and rates on the susceptibility of barley to ergot. The experiment was seeded on three dates (early, intermediate and late) and at three seeding rates (160, 320 and 480 seeds m−2). The effect of seeding dates on sclerotia content was variable because of weather conditions. Consequently, it should not be considered for reducing the sclerotia content in barley. However, high seeding rates could possibly be used to reduce the sclerotia content in barley. Key words: Barley, ergot, seeding date, seeding rate
The biology of Canadian weeds. 105. Linaria vulgaris Mill.
Authors: Saner Marc A. , Clements David R. , Hall Michael R. , Doohan Douglas J. , Crompton Clifford W.
Published: April 2011

Yellow toadflax, Linaria vulgaris Mill. (Scrophulariaceae), is a weed of rangelands and agricultural crops. Introduced from Eurasia into North America more than 300 yr ago, it is now naturalized in all provinces and territories up to 60° northern latitude and beyond 2000 m altitude. It became a concern in the middle of this century when it invaded the prairies. Its seriousness as a weed declined in the late 1950s, possibly as a result of biological control. Concern has been renewed recently because the adoption of minimum tillage techniques could lead to greater abundance. Reproduction is vigourous by means of adventitious root buds and by high seed production. Growth forms, vegetative reproduction, flower phenology, and germination are variable. The capability for regrowth from root parts makes L. vulgaris a difficult weed to eradicate and limits the efficacy of cultural control methods. The possibilities for chemical control are limited due to resistance to common herbicides. Biological control projects conducted during the past 50 yr have been partly successful and are on-going. Key words:Linaria vulgaris, toadflax, Scrophulariaceae, weed biology, control, review
Alternating strips of grass and legume, and nitrogen fertilization strategy, for long-term herbage production from a brome-alfalfa stand
Authors: Fairey N. A. , Lefkovitch L. P.
Published: April 2011

The distribution of grass and legume plants in a conventional herbage mixture precludes the possibility of providing optimal N nutrition for the grass while retaining the N-fixing capability of the legume. For 8 production years, the productivity of a conventional GLM was compared to that of three SC stands comprised of alternating, broadcast-seeded strips (40, 60, or 80 cm width) of pure grass [smooth bromegrass (Bromus inermis Leyss.)] and pure legume [alfalfa (Medicago sativa L.)]. There were three N fertilizer treatments: N0 = no N; NGL = 150 kg N ha−1 applied uniformly to grass and legume; and NG = 150 kg N ha−1 distributed only over the plot areas seeded originally to grass (actual N rate on grass strips of 300 kg ha−1). The 8-yr mean herbage yield decreased progressively as the width of the alternating grass and legume strips increased for both N0 (5.68–4.73 t ha−1) and NGL (6.75–5.70 t ha−1). For NG, however, the 8-yr mean yields were equal for the three SC treatments (6.30–6.38 t ha−1) although they were 0.37–0.45 t ha−1 (P < 0.05) lower than the 6.75 t ha−1 of the GLM-NGL treatment combination that received the same amount of N fertilizer. Herbage yield was influenced more by management and environmental factors than by stand age over the 8 yr of the study. The long-term benefit of growing grass-legume herbage stands in alternating strips, and applying the N fertilizer just to the grass component, is associated more with improved use of inputs, especially of N fertilizer, than with increased herbage yield. Key words: Grass-legume mixtures, nitrogen response, stand arrangement, herbage production, long-term yield
Nitrogen fixation and growth of one-year stands of non-dormant alfalfa in Manitoba
Authors: Kelner David J. , Vessey J. Kevin
Published: April 2011

Nitro is a non-dormant, special purpose alfalfa (Medicago sativa L.) developed in Minnesota for use as a 1-yr hay source and fall plow-down green-manure crop. Field experiments were established at two Manitoba sites to examine growth and N2 fixation characteristics of Nitro. Nitro was compared with two dormant alfalfa cultivars in 1991, and with three dormant cultivars and another non-dormant cultivar in 1992. Dinitrogen fixation was measured using the 15N isotope dilution technique. Nitro yielded similarly to the other cultivars at the summer hay harvests, but produced significantly more herbage for soil incorporation in the fall relative to the dormant alfalfa cultivars (25% average increase in 1991, 39% increase in 1992). The quantities of N2 fixed were also similar among cultivars at the hay harvests, but were greater in Nitro in the fall relative to the dormant cultivars. Nitro and the dormant cultivars added an average 121.4 and 39.7 kg ha−1 of fixed N to the soil in the fall of 1992, respectively. Nitro was not significantly different from CUF 101, the other non-dormant cultivar tested in 1992, in any of the measured parameters. Over-winter survivability of the non-dormant cultivars ranged from 2 to 62% over the 2 yr. Nitro seems to have an advantage over the traditionally used dormant alfalfa cultivars as a 1-yr hay and fall N source, although further testing is required to determine it's superiority over other non-dormant alfalfa cultivars. Key words: Alfalfa, dormant, Nitro, nitrogen fixation, non-dormant, crop rotations, yield
Four interspecific germplasm lines (302–1, 302–3, 302–5, 302–20) of spring wheat with resistance to common root rot (Cochliobolus sativus) derived from Aegilops ovata
Authors: Bailey K. L. , Harding H. , Hucl P.
Published: April 2011

Germplasm resistant to common root rot was developed from crossing Aegilops ovata with Triticum aestivum, using Chinese Spring ph 1b genetic stock and the cultivar Leader. The germplasm lines had yellow flour pigment and a longer mixing time and lower SDS sedimentation volume, falling number, and mixograph peak height than Leader. Yet, for most agronomic and quality traits, the germplasm was similar to that of Leader and Neepawa. Seed was classed as CWRS. This germplasm represents a different source of genes for resistance to common root rot than currently available in red spring wheat cultivars or breeding lines. Key words: Common root rot, resistance, Aegilops ovata, Triticum aestivum, germplasm
Dissipation of glyphosate and its metabolite AMPA in established crested wheatgrass following spring application
Authors: Cessna Allan J. , Waddington John
Published: April 2011

Using glyphosate to suppress resident vegetation while establishing sod-seeded alfalfa in pastures may result in unacceptably high residues within the treated foliage. In a 2-yr study, the dissipation of glyphosate and its major metabolite, AMPA, was measured in the foliage of established crested wheatgrass [Agropyron desertorum (Fisch.) Schult.] following spring application at 2.2 kg a.i. ha−1. Within 2 wk, glyphosate residues had decreased to < 50 mg kg−1, the international MRL for fodder of grasses. Washoff by rainfall appeared to be the major route of dissipation. Residues of AMPA were generally about one order of magnitude less than the corresponding glyphosate residues. Key words: Glyphosate, residues, dissipation, crested wheatgrass, Agropyron desertorum
Selection of locations for safflower cultivar trials on the Canadian prairies by using the AMMI procedure
Authors: Mündel H.-H. , Entz T. , Braun J. P. , Kiehn F. A.
Published: April 2011

Additive main effects and multiplicative interaction (AMMI) analysis of Safflower Cooperative Registration Test (SCRT) data gathered from 1984 to 1991 across the Canadian prairies was used to assess the possibility of reducing the number of locations for cultivar evaluation. The cultivars Saffire, Hartman, S-208, and S-541 were included in the 1984–1986 data set; and Saffire, AC Stirling, S-208, and S-541 in the 1988–1991 set. Seed yield, percent oil, days to maturity, and test weight were measured at 12 locations, although due to weather conditions, data were sometimes not available for all locations in any given year. The AMMI model fit the data well for all four traits, and indicated that among-year variability at a given location was usually higher than inter-location variability in a given year. Cultivar interaction effects for all four characteristics assessed were usually large for both data sets, indicating that differences among cultivars at a given location can vary considerably over years. Intra-location variability was not consistent for the four traits and no clear grouping of locations or locations with cultivars over years was evident. These results suggest that local environmental factors significantly influence safflower traits, and potential cultivars need to be evaluated at as many locations as resources permit. Key words:Carthamus tinctorius, cultivar × environment interactions, yield, oil, maturity, test weight
Genetic studies on the resistance of winter wheat to speckled snow mould
Authors: Rioux S. , St-Pierre C. A. , Couture L.
Published: April 2011

Speckled snow mould (caused by Typhula ishikariensis) is a potential threat to winter wheat (Triticum aestivum L.) production in eastern Canada. Information on the inheritance of snow mould resistance is needed to develop an effective breeding strategy. In this study, the inheritance of resistance to the speckled snow mould was examined using crosses of a resistant genotype, PI 173438, and four susceptible cultivars, Lennox, Kitami-2, Norin-8 and Ena. The parental lines, and the F1 and F2 populations from each of the four crosses were grown in the field and in an unheated plastic greenhouse and scored for snow mould resistance. Biomass yield, survival, plant height and number of tillers/plant, all expressed as percentage of check plants, were used as indices of snow mould resistance. Generation means analysis, combining data from the field and greenhouse experiments, indicated that snow mould resistance was largely influenced by environmental conditions, and that additive genetic effects were more important than epistatic effects in controlling the expression of the disease. Dominance effects oriented towards susceptibility were detected in only one of the four crosses. Estimates of broad sense heritability in the four F2 populations ranged from 0.62 to 0.96 and from 0.34 to 0.79, respectively, when biomass yield and number of tillers/plant were used as indices of snow mould resistance. When plant height was used as an index of snow mould resistance, the heritability estimates ranged from 0.10 to 0.53. Key words: Wheat (winter), Triticum aestivum, speckled snow mould, Typhula ishikariensis, heritability
AC Mustang oat
Authors: Kibite Solomon , Pearen J. R. , Nadja H. , Fairey N. A. , Clayton G. , Ferguson T. , Westerlund D.
Published: April 2011

AC Mustang is a dual purpose (grain/silage) oat with high grain yield, good lodging resistance, plump kernels, high test weight, and desirable agronomic features. Its maturity rating is intermediate to Cascade and Dumont, and its forage/silage yield potential is higher man other registered cultivars with the exception of Foothill. Its hull content is higher than is desirable for milling. AC Mustang is well adapted to Alberta and the rust-free areas of western Saskatchewan. Key words:Avena sativa, oat (spring), cultivar description
Computerised decision support systems: Aids to rational and sustainable weed management
Authors: O'Donovan John T.
Published: April 2011

Computerised decision support systems offer an ideal means of achieving economical, environmentally safe, and sustainable weed management. Systems based on weed economic threshold concepts have been developed in the United States and Europe. In several of these, weed density is the sole variable used for estimating crop yield losses due to weeds. In Canada, there have been few attempts to develop computerised decision support systems to facilitate rational weed management. A notable exception is a microcomputer program developed by the Manitoba Department of Agriculture for assessing the economics of wild oat (Avena fatua L.) control in cereal and oilseed crops. A relative time of emergence variable is a crucial component of the program There is a need to develop a more comprehensive system for managing multiple weed species in a range of crops grown in Canada. For reliable recommendations to be made, input requirements for the system should include information on the relative time of emergence of the crop and weed, crop density, environmental factors and method of fertilizer application, as well as weed density. In terms of output, the system should indicate realistic weed monitoring procedures, and the long-term bioeconomic implications of seed production by uncontrolled weeds. Key words: Bioeconomic models, weed economic thresholds, decision support systems, rational weed management
Crop growth models for decision support systems
Authors: Jame Y. W. , Cutforth H. W.
Published: April 2011

Studies on crop production are traditionally carried out by using conventional experience-based agronomic research, in which crop production functions were derived from statistical analysis without referring to the underlying biological or physical principles involved. The weaknesses and disadvantages of this approach and the need for greater in-depth analysis have long been recognized. Recently, application of the knowledge-based systems approach to agricultural management has been gaining popularity because of our expanding knowledge of processes that are involved in the growth of plants, coupled with the availability of inexpensive and powerful computers. The systems approach makes use of dynamic simulation models of crop growth and of cropping systems. In the most satisfactory crop growth models, current knowledge of plant growth and development from various disciplines, such as crop physiology, agrometeorology, soil science and agronomy, is integrated in a consistent, quantitative and process-oriented manner. After proper validation, the models are used to predict crop responses to different environments that are either the result of global change or induced by agricultural management and to test alternative crop management options.Computerized decision support systems for field-level crop management are now available. The decision support systems for agrotechnology transfer (DSSAT) allows users to combine the technical knowledge contained in crop growth models with economic considerations and environmental impact evaluations to facilitate economic analysis and risk assessment of farming enterprises. Thus, DSSAT is a valuable tool to aid the development of a viable and sustainable agricultural industry. The development and validation of crop models can improve our understanding of the underlying processes, pinpoint where our understanding is inadequate, and, hence, support strategic agricultural research. The knowledge-based systems approach offers great potential to expand our ability to make good agricultural management decisions, not only for the current climatic variability, but for the anticipated climatic changes of the future. Key words: Simulation, crop growth, development, management strategy
Integration of cover crops into no-till and ridge-till wheat (Triticum aestivum L.) – corn (Zea mays L.) cropping sequence
Authors: Swanton C. J. , Chandler K. , Janovicek K. J.
Published: April 2011

The use of underseeded red clover (Trifolium pratense L.) as a cover crop in winter wheat has been declining because of poor clover establishment during dry growing seasons, the lack of selective herbicides for weed control in clover, and the difficulty in using burn-down herbicides to remove the clover before planting no-till corn. During 1990–1992, we conducted on-farm trials on silt loam no-till and sandy ridge-till fields in southern Ontario to evaluate the establishment and growth of alternative stubble-seeded cover crops following wheat and their effects on subsequent weed and volunteer wheat growth. In general, oats (Avena sativa L.), oilseed radish (Raphanus sativus L.), and barley (Hordeum vulgare L.) produced more biomass than the other stubble-seeded cover crops, hairy vetch (Vicia villosa Roth.), red clover, and buckwheat (Fagopyrum esculentum L.). In comparison, winter-hardy underseeded hairy vetch and red clover produced the most biomass and provided better weed control; however, any reduction in herbicide use is offset by the need to burn down these cover crops. An evaluation of cover-crop effects on post-wheat-harvest weed growth was not possible because of sparse and variable weed growth, which occurred even in the absence of a cover crop. However, volunteer wheat biomass was inversely correlated with cover-crop biomass. At the no-till site, cover-crop response to straw baling and the subsequent effects on weed and volunteer wheat growth and corn performance also were evaluated. Straw baling had minimal effects on cover-crop growth; however, volunteer wheat growth doubled. No-till corn was not adversely affected by the amounts of residue present where cover crops were established the previous year. Importantly, reducing the amount of wheat straw by baling increased early-season growth rates and corn grain yield by 0.91 Mg ha−1. We conclude that alternative stubble-seeded cover crops, such as oats, barley and oilseed radish, are suitable for no-till corn. At present, cover crops augment weed management but are not a substitute for herbicides, as burn-down herbicides are required to remove existing weeds or winter-hardy cover crops. Key words: Underseeded, stubble seeded, baling, volunteer wheat
AC Darkid common bean
Authors: Park S. J. , Tu J. C.
Published: April 2011

AC Darkid is a high-yielding dark red kidney bean (Phaseolus vulgaris L.) cultivar maturing in mid-season in Ontario. Its main advantages are high yield potential and earlier maturity than presently recommended dark red kidney beans in Ontario. Seed has acceptable cooking/canning quality. AC Darkid is resistant to alpha and alpha Brazilian races of anthracnose and to races 1 and 15 of BCMV. Key words: Dark red kidney, Phaseolus vulgaris, dry edible bean, cultivar description, anthracnose, Colletotrichum lindemuthianum, bean common mosaic virus
Sunrise apple
Authors: Lane W. D. , MacDonald R. A. , Lapins K. O. , Lau O. L.
Published: April 2011

Sunrise apple (Malus domestica Borkh.) has firm, crisp fruit with bright attractive colour. It matures in mid-August. The tree is easily managed, but its fruit has a short shelf life. Key words: Apple, cultivar description
The transfer of stem rust resistance from the Ethiopian durum wheat St. 464 to common wheat
Authors: Knott D. R.
Published: April 2011

Two genes for stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & Henn.) resistance were transferred from the Ethiopian durum wheat (Triticum turgidum L) accession St. 464 to Thatcher and Prelude/8* Marquis common wheat. One gene was shown by monosomic analysis to be on chromosome 4B and proved to be Sr7a. Monosomic analysis failed to locate the second gene. It is only partially dominant and conditions resistance to a range of races. Key words: Rust resistance, stem rust, wheat, Puccinia graminis tritici, Triticum aestivum, Triticum turgidum
Relative cost to soil fertility of long-term crop production without fertilization
Authors: Campbell C. A. , Selles F. , Harapiak J. T. , Lafond G. P.
Published: April 2011

An earlier analysis of yield trends of stubble-wheat in six cropping systems, over 35 yr, in a thin Black Chernozemic soil at Indian Head, Saskatchewan, showed that fertilizer improved soil quality, while absence of fertilizer, combined with frequent fallowing, led to soil degradation. The inclusion of a legume green manure crop in the rotation failed to maintain soil fertility, apparently because legumes do not supply P. Because the fertility and stored moisture effects were confounded, we conducted a growth chamber experiment to quantify soil responses to N and P in these six cropping systems. Soil from the top 15-cm of the rotation phase that had just grown two successive wheat (Triticum aestivum L.) crops was used. Various factorial combinations of ammonium nitrate-N and triple superphosphate-P were applied at N/P2O5 rates up to 200/200 kg ha−1. Soil moisture was maintained in the available range. Regression analysis showed that the fallow-wheat-wheat (F-W-W) and continuous wheat (Cont W) systems that had not been fertilized in 35 yr, and which had moderate amounts of NaHCO3-P, only responded to N. In contrast, the green manure (GM)- and hay (H)- containing systems, which had also not been fertilized before had low levels of NaHCO3-P and responded to both N and P. In the field, the yields of wheat grown on stubble in 1991 rated: Cont W (N + P) > F-W-W (N + P) > F-W-W-H-H-H > Cont W > GM-W-W > F-W-W. However, in the growth chamber the rating was: Cont W (N + P) > F-W-W-H-H-H > GM-W-W > Cont W > F-W-W (N + P) > F-W-W. We suggest that the growth chamber results more accurately reflect the present fertility status of these soils, because fertility is no longer confounded with soil moisture. Grain yields in the growth chamber were directly proportional to the previously measured initial potential rate of N mineralization, indicating the value of the latter parameter as a useful index of soil N fertility. Key words: Nitrogen, phosphorus, soil degradation, legumes, fertilizers
Disposition of nitrogen in the soil-plant system for flax and spring wheat-containing rotations in the Brown soil zone
Authors: Campbell C. A. , Zentner R. P.
Published: April 2011

Recently, there has been a marked increase in the production of oilseed crops instead of hard red spring wheat (Triticum aestivum L.) in the semiarid Brown soil zone of Saskatchewan. In this study we compare the disposition of N and soil water in two 3-yr fallow-containing crop rotations, one with flax (Linum usitatissimum L.) and wheat, and the other with only wheat. These rotations were initiated at Swift Current, Saskatchewan, in 1967 on a silt loam soil, but this assessment applied to the 1985 to 1995 period when complete soil water, NO3-N, and plant N measurements were collected. Flax grown on fallow produced less plant biomass and N uptake was lower than for wheat grown on fallow; thus, it left more NO3-N and water in the soil (especially in the 60–120 cm depth) at harvest. This residual NO3-N and water following flax rarely resulted in higher grain yields or higher grain N concentrations in the succeeding stubble-wheat crop. We hypothesized that this excess NO3-N and water may leach and thereby increase contamination of groundwater. Key words: NO3-N, soil water, N uptake, grain yield, straw yield, grain protein
Seasonal changes in yield and nutritional quality of cicer milkvetch and alfalfa in northeastern Saskatchewan
Authors: Loeppky H. A. , Hiltz M. R. , Bittman S. , Frick B.
Published: April 2011

Cicer milkvetch (Astragalus cicer L.) is a winter hardy, non-bloating forage legume. In southern Alberta and Montana, cicer milkvetch retains its leaves longer and maintains forage quality later in the season than alfalfa (Medicago sativa L.). Consequently, it has the potential to provide nutritious forage in the fall, at a time when pasture productivity and quality is limited, particularly in northern areas. The objectives of this study were (i) to compare the yield and quality of monocultures of cicer milkvetch and alfalfa over the growing season and (ii) to evaluate the long-term productivity of cicer milkvetch under Parkland conditions. Studies were initiated in Melfort, Saskatchewan in 1986 and 1987, and subplots were harvested monthly during the growing season in the 2nd to 6th years. Cicer milkvetch peak yields were similar to or higher than alfalfa in 7 out of 10 harvest years. Forage yield of alfalfa was generally higher than that of cicer milkvetch in early season harvests, but cicer milkvetch had similar or higher yields later in the season. As the growing season progressed alfalfa declined in leafiness and in in vitro dry matter digestibility whereas corresponding values for cicer milkvetch were higher than those for alfalfa in all harvests. The protein content of both legumes was similar for all harvests, declining with plant maturity. Cicer milkvetch maintained its production similar to alfalfa over the 6-yr period studied. Key words: Cicer milkvetch, Astragalus cicer L., Medicago sativa L., leaf retention, protein, digestibility
Seed pod shattering in the genus Lotus (Fabaceae): A synthesis of diverse evidence
Authors: Grant William F.
Published: April 2011

Birdsfoot trefoil (Lotus corniculatus L.) is a perennial dehiscent species with an indeterminate growth habit. Pod shattering has been a major problem as seed loss is high due to the continuous flowering and time of pod maturity. The anatomy of the pod plays a role in pod shattering. A change in the orientation of the cells in the pericarp in which unequal swelling and shrinkage occur and a lower lignification of the mesocarp have been considered as major causes. The relative humidity (RH) at the time of harvest is also a major factor. The critical RH for dehiscence varies with genotypes between 35 and 49%. Pod dehiscence is uncorrelated with plants grown to maturity under green house conditions and the same plants grown in the field. Management practices (timing of the harvest, clipping early in the season, misting, mowing and turning the windrow during drying, desiccants) have not been successful to control pod shattering. Shattering resistance is a character of high heritability and in Lotus is considered to be controlled by more than one gene. Breeding to reduce shattering through recurrent selection has been unsuccessful. Attempts to transfer the indehiscent seed pod trait from distantly related indehiscent species via interspecific hybridization, diploid bridge species, amphidiploidy, and backcrossing to birdsfoot trefoil, or similarly by interspecific somatic hybridization, have shown promise. The molecular approach has so far not been attempted but since genetic transformation can be carried out in Lotus, this avenue should be investigated. Key words: Birdsfoot trefoil, Lotus corniculatus, indehiscence, dehiscence, pod shattering, interspecific and somatic hybridization
Caractérisation du potentiel de rusticité de sept arbustes ornementaux en fonction de l'intensité des dommages hivernaux
Authors: Richer-Leclerc C. , Côté J. , Rioux J. A. , Drapeau R.
Published: April 2011

The winter-hardiness of seven ornamental shrub species was characterized based on their ability to regenerate and to maintain their ornamental characteristics following winter damage. Lonicera involucrata and Weigela hybrida 'Brystol Ruby' reached full ornamental expression in zone 5b of the Canadian Climatic Classification System, while Cotoneaster dammeri 'Skogholm', Hydrangea arborescens 'Annabelle, Kerria japonica, Rosa multiflora and Weigela florida 'Variegata' required warmer conditions. Rosa multiflora and Lonicera involucrata survived in zone 2a, Weigela hybrida 'Brystol Ruby' in zone 2b and the other species m zones 3 or 4. The partial expression of ornamental characteristics restricted the utilization of Lonicera involucrata to zone 2a, of Hydrangea arborescens 'Annabelle' to zone 2b and of Cotoneaster dammeri 'Skogholm' and Weigela hybrida 'Brystol Ruby' to zone 4. Rosa multiflora Weigela florida 'Variegata' and Kerria japonica both received two classifications based on the expression of different ornamental characteristics. Key words: Winter damage, survival, ornamental shrubs, growth
Expert systems in agriculture and long-term research
Authors: Robinson Brian
Published: April 2011

Expert systems (ES) technology has many existing and potential uses as input into the agricultural production process. ES are simply computer programs that attempt to emulate human expertise for problem solving purposes. This technology is well suited to agricultural problem solving because of its ability to encode existing knowledge within specific application areas and then apply this knowledge within the problem solving process. ES effectively leverage management's input into agricultural production systems by allowing for the assimilation of all available knowledge pertinent to the task at hand. There are many types of agricultural ES and these can generally be categorized into: Crop Management Advisors, Livestock Management Advisors, Planning Systems, Pest Management Sytems, Diagnostic Systems, Conser-vation/Engineering Systems, Process Control Systems and Marketing Advisory Systems. The cost of ES development can be high. Potential projects, therefore, should be subjected to a benefit/cost analysis to ensure that development efforts are well targeted. ES development and agricultural research are complementary processes and should become more coordinated within an integrated knowledge production and implementation cycle. Key words: Expert systems, knowledge, management, agriculture, research
Codac barley
Authors: Falk D. E. , Meatherall G. , Rossnagel B. G.
Published: April 2011

Codac is a six-rowed spring feed barley (Hordeum vulgare L.) bred at the Crop Development Centre, University of Saskatchewan and registered by the Crop Science Department, University of Guelph for Eastern Canada. It was produced from a cross of Diamond/Duke and has shown adaptation to Eastern Canada. It has been high yielding, early maturing and has medium height straw. It has good resistance to scald, leaf rust, stem rust and the smuts, but is susceptible to powdery mildew. Key words: Six-rowed barley (spring), Hordeum vulgare L., feed barley, high yield, early maturity, smut resistance, scald resistance, cultivar description
AC Pinson soybean
Authors: Voldeng H. D. , Frégeau-Reid J. A. , Guillemette R. J. D. , Leonard D. A. , Cober E. R.
Published: April 2011

AC Pinson is a 2550 heat unit soybean (Glycine max [L.] Merr.) cultivar developed for natto soyfood production. Key words: Soybean, cultivar description, natto
The effect of nitrogen on growth and architecture of Fraxinus pennsylvanica 'Patmore' (green ash) in Field-grow containers at two sites in Manitoba, Canada
Authors: Remphrey W. R. , Davidson C. G.
Published: April 2011

Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern. 'Patmore' green ash was established at two sites in southern Manitoba. Four levels of N fertilizer (4.5–400 ppm) were applied during two growing seasons. Growth and development of the trees was dependent on the site and local environmental conditions. At Morden, the annual height growth increment was greater with lower levels of N applications and declined at higher levels, while at Winnipeg higher levels resulted in greater growth. Stem diameter changes followed a similar pattern. The numbers of lateral shoots per parent shoot were only weakly affected by N treatment and any differences appeared to be an indirect effect of parental shoot length. The Field-grow containers at the Winnipeg site were installed in crass-sod which penetrated the containers and appeared to result in competition for N resources. The Morden site was kept cultivated and thus there was no such competition. At Morden, it is possible that wicking from the surrounding soil may have moved excessive salts into the containers resulting in high conductivity values and toxicity. Key words: Field-grow, biomass, roots, architecture, fertilization, Fraxinus pennsylvanica
Supplemental soil sulphur increases cabbage yield
Authors: Sanderson K. R. , Sanderson J. B. , Ivany J. A.
Published: April 2011

Marketable yield of cabbage (Brossica oleracea L. var. capitata) was significantly increased from 11 to 14% by a soil application of sulphur-containing materials, potassium sulphate and gypsum, on sandy loam to loamy sand soils in Prince Edward Island. Calcite had no effect on yield. Gypsum resulted in the highest yield on five sites. Potassium sulphate and gypsum increased leaf S concentration 0.70 and 1.45% respectively. Gypsum decreased while calcite increased soil pH. Key words: Cabbage, calcite, calcium, gypsum, potassium sulphate, sulphur
Control of aspen poplar, balsam poplar, prickly rose and western snowberry with metsulfuron-methyl and 2,4-D
Authors: Bowes G. G. , Spurr D. T.
Published: April 2011

Aspen poplar, balsam poplar, prickly rose and western snowberry species grow together in pastures of the aspen parkland and reduce the grass and forb production available for grazing. Two 7-yr studies were conducted in east central Saskatchewan to evaluate metsulfuron-methyl (metsulfuron), 2,4-D and a mixture of metsulfuron + 2,4-D for the long-term control of these woody species. Metsulfuron applied at 60 g a.i. ha−1 effectively controlled the four woody species for 7 yr. Control was not improved when 2,4-D at 2 kg a.i. ha−1 was added to the 60 g ha−1 rate of metsulfuron. Aspen poplar control was improved when sucker regrowth was 2-yr old rather than 3-yr old. Grass and forb production was increased 50% from 1023 kg ha−1 in the untreated areas to 1619 kg ha−1 following application of 60 g ha−1 metsulfuron in two experiments averaged over 5 yr. Forbs production decreased from 44% on the untreated area to 8% on areas treated with metsulfuron. Key word: Aspen poplar, balsam poplar, prickly rose, western snowberry, metsulfuron-methyl, 2,4-D
Sunflower (Helianthus annuus L) tolerance to sublethal doses of imazethapyr
Authors: Wall David A.
Published: April 2011

Field experiments were conducted from 1992 to 1995 at Morden, Manitoba to investigate the tolerance of sunflower to sublethal doses of imazethapyr {2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid). Imazethapyr was applied at 0, 0.375, 0.75, 1.5, 3, and 6 g a.i. ha−1 plus a nonionic surfactant at 0.25% vol/vol when sunflowers were in the six-leaf stage. Dosages higher than 1.5 g ha−1 severely injured sunflowers in some years. Injury symptoms consisted of chlorosis, stunting and seed head deformities. At the dosages tested, imazethapyr reduced sunflower yields in only 1 of 4 yr. In 1994, dosages greater than 1.5 g ha−1 reduced achene yields by 19–38%. Seed oil content was reduced in 2 of 4 yr. At 6 g ha−1 of imazethapyr seed oil content was reduced by as much as 3.2 percentage points compared with the untreated check. While low dosages of imazethapyr may not reduce yields in most years, the potential for severe yield losses and reduced oil contents exist and caution should be used when applying imazethapyr in fields next to sunflowers. Key words: Crop injury, herbicide drift, yield, oil content