bluuebunny/crossref_metadata_2025 huggingface dataset:
Actual yield advance from selection for visual score and yield
Authors: Helms T. C. , Orf J. H. , Scott R. A.
Published: April 2011

The ability of soybean [Glycine max (L) Merr.] breeders to select for yield, based on visual score is unknown. Our objectives were (i) to determine whether a sample of three breeders were able to visually score soybean plots for yield and to identify lines that were higher yielding than the population mean; and (ii) to compare selection for visual score versus selection solely for weighed yield. Visual score was rated at physiological maturity in two environments. Experimental lines were evaluated for weighed yield in six environments. Lines were selected for weighed yield or visual score, based on data from two selection environments, and actual yield advance was measured in the other four testing environments. Two breeders identified BP-derived lines that averaged higher than the unselected population mean yield when selection was based solely on the visual score. Two of three breeders selected lines, based on visual score, that were as high yielding in testing environments as lines selected solely for weighed yield. Key words: Soybean, visual score
Restriction fragment analysis of hordein genes in western Canadian two-rowed barleys
Authors: Molnar S. J. , McKay A.
Published: April 2011

Restriction fragment length polymorphisms (RFLP) at the hordein loci were compared with hordein protein patterns for discrimination of barley cultivars. RFLP banding patterns documented extensive polymorphism for B and C hordein gene families in eight closely related western Canadian two-rowed barley cultivars, five parental cultivars and a U.K. cultivar. RFLP results were compared with published protein pattern data on the same cultivars. The power to discriminate cultivars by the two methods is similar. Key words: RFLP, hordein, barley, Hordeum vulgare, cultivar identification
Jackson barley
Authors: Wolfe R. I. , Faris D. G. , Davidson J. G. N. , Clarke P. J.
Published: April 2011

Jackson (Hordeum vulgare L.) is an early-maturing, hulled, six-row feed barley. It was developed at the Northern Agriculture Research Centre, Beaverlodge, Alberta from the cross BT607/Pomo. It is short in height, moderately strong strawed, and adapted to western Alberta and the Peace River region of British Columbia. Key words:Hordeum vulgare, barley, early maturity, cultivar description
Effect of drip and sprinkle irrigation on yield and quality of five tomato cultivars in southwestern Ontario
Authors: Tan C. S.
Published: April 2011

The purpose of this study was to assess yield and quality of tomato (Lycopersicon esculentum Mill.) in response to drip (DI) and sprinkle irrigation (SI) in southwestern Ontario. Three irrigation treatments, DI, SI and no irrigation (NI) and five tomato cultivars, FM6203, H2653, H722, OH7814 and PUR812, grown on a Fox sandy loam soil, were evaluated during four growing seasons between 1986 and 1989. Both DI and SI increased the marketable tomato yield in 3 of 4 yr. In general, DI resulted in higher tomato yields than SI, but this was only statistically significant in 1 yr. Sprinkle irrigation out performed drip irrigation in one hot, dry year in 1988. Throughout the 4 yr, OH7814 was consistently high yielding, H2653 was consistently low yielding and FM6203, H722 and PUR812 performed more consistently than the other cultivars. In wet years, yield differences due to cultivar treatments were greater than those due to irrigation treatments, while in dry years, yield differences due to both irrigation and cultivar treatments were highly significant. Soluble solids and total solids were decreased by DI and SI. The DI produced the most uniform soil moisture regime, followed by SI. The NI plots had the greatest degree of water stress, as indicated by the low soil water potential, low stomatal conductance and elevated crop canopy temperature. Key words:Lycopersicon esculentum, yield, soil water potential
Influence of vesicular–arbuscular mycorrhizal fungi and phosphorus on growth, carbohydrate partitioning and mineral nutrition of greenhouse cucumber (Cucumis sativus L.) plants during establishment
Authors: Trimble M. Rae , Knowles N. Richard
Published: April 2011

The growth response of greenhouse cucumber (Cucumis sativus L.) to infection by vesicular–arbuscular mycorrhizal (VAM) fungi and to 4, 12 and 20 mg L−1 of phosphorus (P) nutrition was characterized over 38 d of plant establishment. Although maximum growth rates were not reached with the P levels studied, foliar concentrations of P were consistent with those published for healthy cucumber plants. Plants were highly receptive to colonization by Glomus mosseae, G. dimorphicum and G. intraradices. Infection by all species decreased as P nutrition increased; however, growth rates of primary yield components (e.g., stem and leaf dry weights, leaf area) of VAM-infected plants were greater than those of noninfected plants at all levels of P nutrition. The VAM-enhanced growth was similar to that induced by increases in P nutrition. The VAM-infected plants had lower concentrations of soluble nitrogen (N) than noninfected plants early in development; however, N concentrations were equal by 38 d after planting. Total soluble carbohydrate concentration of leaves of noninfected plants increased 62% faster than that of leaves of VAM-infected plants, possibly due to decreased export and a higher degree of P stress in the non-infected plants. Relative to noninfected plants, higher concentration of soluble carbohydrates in roots of VAM-infected plants may indicate increased sink demand to support the symbiosis. Since VAM stimulated growth at levels of P nutrition considered nondeficient by tissue analysis, use of VAM to accelerate the early development of transplants may be advantageous to the greenhouse industry. Key words:Cucumis sativus L., phosphorus, vesicular–arbuscular mycorrhizal fungi, mineral nutrition
The Founding of the Canadian Society for Horticultural Science – La Société Canadienne de Science Horticole
Authors: Vick Roger
Published: April 2011

not available
Long-term spring wheat response to summerfallow frequency and organic amendment in southern Alberta
Authors: Johnston A. M. , Janzen H. H. , Smith E. G.
Published: April 2011

A long-term rotation experiment was established in 1951 to determine the influence of summerfallow frequency and organic amendment on the yield and quality of unfertilized spring wheat (Triticum aestivum L.) on a Dark Brown Chernozem (Typic Haploboroll) at Lethbridge, Alberta. Wheat was grown either continuously (W), in a 2-yr summerfallow-wheat rotation (FW), or in a 3-yr fallow-wheat-wheat rotation (FWW). No fertilizer N was applied and P, at 22 kg ha−1, was applied to all wheat crops starting in 1985. The 3-yr rotation was also amended with livestock manure (FmWW) and modified to include a hay mixture of alfalfa (Medicago sativa L.) and crested wheatgrass (Agropyron cristatum L.) (FWWHHH). Annual grain production was affected by summerfallow frequency and organic amendment, with the lowest grain production obtained in the FW rotation. Amendment with livestock manure resulted in the highest grain yields for wheat grown on summerfallow, while 3 yr of hay in the rotation produced the highest stubble wheat yields. These higher grain yields were accompanied by a 12–31% increase in grain N uptake. Decomposing hay roots increased plant-available N as reflected in the highest grain N concentration and grain N yield in the FWWHHH rotation. Evaluation of grain yields under a range of moisture deficit conditions revealed that a year of summerfallow was often insufficient to recharge soil water depleted by 3 yr of hay in the FWWHHH rotation. Both summerfallow and stubble wheat yields were positively influenced by May rainfall. Overwinter precipitation contributed significantly to the variability observed in stubble wheat and hay yields. In the absence of fertilizer N additions, organic amendments such as animal manures and hay residues are effective means of increasing crop productivity and grain quality in semiarid regions. Key words: Hay, manure, rotation, spring wheat, summerfallow, Triticum aestivum L.
Physical uniformity of graded railcar and vessel shipments of Canada Western Red Spring wheat determined by digital image analysis
Authors: Sapirstein H. D. , Kohler J. M.
Published: April 2011

The application of digital image analysis for objective measurement of grain uniformity in commercial samples of Canada Western Red Spring (CWRS) wheat was investigated. Official railcar-unloading (carlot) and vessel-loading (cargo) samples of three grades (Nos. 1, 2 and 3) of CWRS wheat were analyzed for 16 kernel-size, shape and brightness features that were automatically computed from digital images acquired in reflected light. Based on a subsample of 400 kernels for each graded sample, coefficient of variation (CV) data were used to evaluate the influence of grading and bulk handling on the uniformity of carlot and cargo shipments. A significant and progressive decrease in sample uniformity for No. 2 and No. 3 carlot samples, compared with No. 1, was observed for all computed kernel features. Averaged over all features, the decreases in uniformity in carlot samples were 13.4 and 13.7% with grade lowering from No. 1 to No. 2 and from No. 2 to No. 3, respectively. For cargo samples, an analogous effect was found as the grade dropped from No. 2 to No. 3 only. There was essentially no measurable difference in the level of uniformity, averaged over all kernel features, between No. 1 and No. 2 cargo samples, which were extremely uniform, as indicated by CV values of 1.27 and 1.25%, respectively. The effect of the bulk handling system was evidenced by a substantial improvement in uniformity of cargo samples compared with carlot samples. Averaged over all features, CV values for cargo samples were lower than CV values for corresponding carlots by 58, 63 and 64% for grade Nos. 1, 2 and 3, respectively. Key words: Wheat grading, digital image analysis, uniformity measurement
The effect of phosphorus fertilizer on establishment, yield and quality of pea, lentil and faba bean
Authors: Henry J. L. , Slinkard A. E. , Hogg T. J.
Published: April 2011

Crop production diversification in western Canada includes pulse crops, necessitating more information on fertilization of these crops. Experiments with seed placement (SP) and side banding (SB) of phosphorus (P) fertilizer were conducted at three Saskatchewan locations during a 3-yr period, using pea (Pisum sativum L.), lentil (Lens culinaris Medikus) and faba bean (Vicia faba L.) for a total of 24 location-crop combinations. Monoammonium phosphate was applied at six rates of up to 44 kg P ha−1. Stand counts were taken at 3–4 wk after seeding; seed yield, seed P and seed protein concentration were measured. Stand count of pea was inversely proportional to rate of SP-P, with the stand count being reduced by 50% at the 44 kg P ha−1 rate. Lentil stand was reduced by SP-P at only two locations, and the effects were much less severe than for pea. Faba bean stand was not affected by P placement or rate. Seed yield of pea was higher with SB-P than with SP-P at all locations, but with lentil, SB-P gave higher seed yield at only two of the three locations. Seed yield of faba bean was not affected by P placement. Seed P concentration was directly related to P rates at two locations but was not affected by P placement. Seed protein concentration of the three crops was not affected by P treatment. Key words: Placement, phosphorus fertilizer, pulse crops, pea, lentil, faba bean
Bellevue reed canarygrass (Phalaris arundinacea L.)
Authors: Coulman B. E.
Published: April 2011

Bellevue is a cultivar of reed canarygrass (Phalaris arundinacea L.) developed by the Plant Science Department at the Macdonald Campus of McGill University, Ste. Anne de Bellevue, Québec. It was developed by phenotypic selection from introduced lines for vigour, seed retention and low alkaloid concentrations, followed by half-sib progeny testing for forage yield. In forage dry matter, it yielded 101% of the check cultivar Vantage over 18 station years in the trials of the Québec forage testing network. Bellevue is free of the tryptamine and carboline alkaloids, and has moderate concentrations of gramine. Key words: Reed canarygrass, Phalaris arundinacea, cultivar description
Relationship between surface color and other maturity indices in wild lowbush blueberries
Authors: Kalt W. , McRae K. B. , Hamilton L. C.
Published: April 2011

The surface color, size, and sugar, titratable acid and anthocyanin contents were measured on samples of various maturities from 72 individual lowbush blueberry clones to determine the relationships between surface color and other ripeness indicators. Among the total 504 berries, the maximum sugar content was approximately 5 times that of the minimum, while the maximum titratable acid and anthocyanin contents were 20 and 11 times those of the minimum contents, respectively. Correlations among variates were generally strongest for samples within clones, and they were weakest among the variate means for the 72 clones. For the total 504 berries, sugar content correlated more strongly with surface color than with berry size, while acid content correlated similarly with surface color and size. Correlations (positive or negative) among berry size and sugar and titratable acid contents did not exceed 0.60. Principal component analysis, which was used to identify groupings of correlated variates, indicated coordinated changes in berry characteristics during ripening, lower sugar and anthocyanin concentrations in large berries, and substantial interclonal variation in wild blueberries. Clonal selections obtained from an experimental trial differed significantly in all the variates measured, while wild clones without a surface bloom were not different from those clones with bloom. Key words: Lowbush blueberry, Vaccinium angustifolium, color, sugar, titratable acid, anthocyanin
Impact of irrigation management of greenhouse tomato: Yield, nutrition, and salinity of peat substrate
Authors: Norrie J. , Charbonneau J. , Gosselin A. , Graham M. E. D.
Published: April 2011

Irrigation dynamics and the response of greenhouse tomato (Lycopersicon esculentum Mill. 'Caruso') to different irrigation management treatments (nutrient solution EC and irrigation matric potential setpoints) were examined in plants grown in peat-based substrate during either the spring or fall of 1989. Two nutrient solutions with differing electrical conductivity (EC of 1.5 and 3.0 dS m−1) were automatically applied to plants until saturation at one of two substrate matric potential (SMP) setpoints (−6.5 or −4.5 kPa). Yield measurements indicated no significant effects due to different SMP setpoints but spring total yield and average marketable fruit weight were higher for low-EC solution treatments. Blossom-end rot was slightly higher in the fall under the highest EC treatment. Foliar mineral concentration analysis of spring-grown plants indicated increases in nitrogen, potassium, zinc, and manganese, and a decrease in calcium in plants receiving high-EC solution. The EC of peat substrates was also found to be higher than applied solutions indicating an overall accumulation of salts within the peat under different irrigation regimes, even with periodic overwatering. This study indicates that increasing nutrient solution EC from 1.5 to 3.0 dS m−1 can negatively affect the production and nutritional status of tomato plants more than changing irrigation setpoints from −4.5 to −6.5 kPa. Key words: Electrical conductivity, fruit quality, peat, tensiometers, matric potential
Ear moisture during kernel development as influenced by field and laboratory selection
Authors: Cross H. Z.
Published: April 2011

Grain quality, timeliness of harvest, and profitability can be increased by improving field drying characteristics of maize (Zea mays L.) hybrids. To better understand hows genes control ear drying, I compared maize strains developed by divergently selecting three cycles for (1) high HM or low LM moisture content at 45 d post pollination in the field or (2) fast FD vs. slow ear drying SD In laboratory. A field study across five locations compared HM, LM, FD, and SD strains from each of five synthetics for grain yield, ear moisture at harvest, test weight, lodging, and other agronomic traits. I studied ear moisture during grain filling for two subsets of divergently selected strains from one and three synthetics for 2 yr. In a third 2-yr field study, I measured mature kernel weight, lag period duration (LPD), effective grain-filling period (EFPD), and rate of dry matter accumulation (RDMA) for LM and HM strains developed from each of four synthetics. When averaged across the five synthetics, both SD and LM selections produced equivalent yields but lower ear moisture at harvest than the corresponding divergent strains. The LM strains had higher test weights than HM strains. When averaged across three synthetics and 2 yr, the HM strains produced higher moisture than LM strains at 15, 30, 45, and 60 d after silking. However, environments also influenced moisture content of the kernels during grain filling. In three of the four synthetics studied, HM strains had heavier kernels than corresponding LM strains. The heavier kernels seem to be due to increased RDMA. When averaged across four synthetics, LM strains had shorter LPD than HM strains. These correlated selection responses suggest that a genetic association exists among moisture content during grain filling, moisture content at physiological maturity, moisture content at harvest, LPD, and test weight. Breeding for LM or SD should improve field-drying characteristics of maize without increasing stalk breakage or decreasing yields. Key words:Zea mays L., grain filling, dry-down rates, mass selection, breeding methods
Effect of variations in seed size and planting depth on emergence, infertile plants, and grain yield of spring wheat
Authors: Gan Y. , Stobbe E. H.
Published: April 2011

Crop yield can be improved by minimizing plant-to-plant variability in seedling emergence. A study was conducted to determine the effect of variations in seed size and planting depth within a plot on emergence, proportion of infertile plants and grain yield in hard red spring wheat (Triticum aestivum L.). Large seed (40.8 mg kernel−1) was hand planted at 25-, 50- and 75-mm depths, creating three uniform seed size - planting depth treatments. Three other treatments consisted of repeating patterns within the same row: three large seeds and one small seed (23.4 mg kernel−1) at each of 25-, 50- and 75-mm depths. Two additional treatments consisted of 1) three seeds planted 25 mm deep and one seed planted 50 mm deep and 2) three seeds planted 25 mm deep and one seed planted 75 mm deep within the same row. Variation in seed size or planting depth within a row had no impact on percentage emergence, but nonuniform planting depth increased the proportion of infertile plants, mainly as a result of late-emerging plants. On a single-plant basis, mainstem grain yields were relatively uniform, but tiller grain yields were highly variable. When small and large seeds were planted 75 mm deep within a plot, the small-seeded plants produced 34% lower tiller grain yield than neighbouring large-seeded plants, while the large-seeded plants produced 10% higher tiller grain yield than plants from a treatment in which only large seeds were planted. Thus, the variation in seed size within a plot had no impact on total grain yield per plot. When seed was planted at variable depths within a plot, grain yield per plant produced by deep-seeded (75 mm) plants was only 20% of that produced by neighbouring shallow-seeded (25 mm) plants and was only 26% of that produced by plants where all seeds were planted deep (75 mm). Within-plot variation in planting depth increased the proportion of infertile plants (up to 158%) and decreased the grain yield. To maximize grain yield in hard red spring wheat, seed should be planted at uniform, shallow planting depth. Key words: Seed size, planting depth, emergence, fertile plants, interplant variation
Genotype × environment interactions for two-row barley grain yield and implications for selection of test locations
Authors: May K. W. , Kozub G. C.
Published: April 2011

The response of barley grain yield to Canadian prairie environments was studied to evaluate genotype × environment interactions, and to group locations according to genotype response, which identifies locations whose removal would not significantly affect the validity of conclusions. The data were also used to illustrate a method for handling a large genotype × location × year data base with few common entries. Information from 20 test locations with 11–19 annual entries over 7 yr was used. Analyses of variance of data sets with three to seven common entries in adjacent years indicated significant genotype × location × year interactions for grain yield. The structure of the genotype × location interaction was studied using cluster analysis within each year and summarized over years. Cluster analysis using individual years allowed more test entries and should increase the reliability of the conclusions compared to that using average over years with few entries. Clustering identified six locations with dissimilar genotype yield responses. In the 7 yr, 19 pairs of locations usually clustered together. The 19 pairs involved eight of the 20 locations and most were in the same geographical region. Some of the eight locations could be eliminated without significant loss of reliability. Rankings of test entries for grain yield at locations within a cluster were generally similar when genotype effects were larger. Key words:Barley, Hordeum vulgare L, genotype-environment interaction, grain yield
Free fatty acid levels in Ontario-grown summer rape cultivars
Authors: May W. E. , Hume D. J.
Published: April 2011

High levels of FFA have been a recurring problem in the seed oil of Ontario-grown, canola-quality summer rape (Brassica napus L.). Examination of seed samples from the Eastern Canadian Co-operative Cultivar Trials conducted at several locations in 1988–1993 showed significant, consistent differences in FFA levels among cultivars. In each year from 1988 to 1991 the cultivars Kristina, Delta and Westar had FFA levels that were about 40% of those of Global and the triazine-tolerant cultivars Stallion, OAC Triton and OAC Triumph. Pearson's correlations and Spearman's rank correlation between years for FFA levels of genotypes were all significant, with the exception of the Spearman's rank correlation between 1992 and 1993. Significant differences in FFA occurred among locations in southern Ontario, but location differences were not consistent across years. Cultivars grown in western Canada, however, had FFA levels between 2 and 41% of their FFA levels at the southern Ontario locations. The FFA levels of cultivars at one Ontario location were significantly correlated with the mean FFA levels of the same cultivars from all the other Ontario locations in the same year, 28 out of 34 times. Correlations were higher before the high-FFA cultivars were removed from the trials in 1991. Screening of lines in a breeding program for susceptibility to high FFA at one southern Ontario location appeared to be predictive of FFA levels at other southern Ontario locations. Selection of cultivars that have low FFA levels should reduce the FFA problem in Ontario-grown spring canola. Key words:Brassica napus, canola, free fatty acids, cultivars, stress, environment
CROPSIM — WHEAT: A model describing the growth and development of wheat
Authors: Hunt L. A. , Pararajasingham S.
Published: April 2011

Crop simulation models consolidate mathematical representations of the various physiological processes underlying crop growth and development into an entity that can be used to predict the outcome of various crop, soil and weather scenarios. For wheat, a number of simulation models are already available, but most of these do not appear to be set-up to facilitate easy comparison of model outputs with experimental data, to allow easy modification for new cultivars, and to facilitate the addition of disease routines, an aspect necessary for models to be useful in the general field situation. Cropsim-wheat was developed to help overcome some of these deficiencies.The model assumes that a crop consists of a collection of uniform plants, and performs calculations on a daily basis. It is driven by daily weather data dealing with solar radiation receipt, maximum and minimum temperatures, and precipitation. Water and nitrogen balance subroutines are included, and the rate of various crop processes is modulated through the use of multipliers that reflect the water and nitrogen states of the crop. Developmental processes are simulated using the concept of "biological days", a time measure that equates to chronological days under optimum conditions. The phases into which the life-cycle is broken relate closely to those in the widely used "Zadoks" scale. Dry matter accumulation is calculated from intercepted radiation, and distributed largely on the basis of demand. A minimum fraction of daily assimilate, however, is reserved for root growth. Leaf area is computed on the basis of potential leaf size and available dry matter, whereas stem and spike areas are calculated from the stem and spike weights. Both leaf and stem area are used in calculating radiation interception. Critical stresses, water saturation during early seedling growth and low temperature during the winter period, can result in plant death. Low temperatures, when they occur around heading, can also result in sterility and reduced grain number.The model performance has been compared with datasets from North America and Europe, and results of these comparisons will be conveyed in companion publications. The model has been set-up, however, on the premise that model development should be a continuing process as new datasets become available and new applications are contemplated. With this in mind, it has been built to use file structures that facilitate the handling and storage of field data, and the easy comparison of field and simulated data. It should thus be useable by experimenters as a tool to help in the analysis of field studies. Key words: Wheat, simulation, nitrogen, water, development, growth
Growth analysis of timothy cultivars differing in maturity
Authors: Bélanger G. , Richards J. E.
Published: April 2011

The delay in ear emergence or heading between early and late-maturing timothy (Phleum pratense L.) cultivars can be up to 3 wk. The objective of this study was to determine the relative importance of radiation interception and radiation-use efficiency in the differences in shoot growth between early and late-maturing timothy cultivars. During the primary growth in 1991 and 1992, four timothy cultivars differing in maturity were compared for shoot growth, leaf area development, radiation interception and radiation-use efficiency using weekly samplings. Stem elongation of early-maturing cultivars progressed faster than that of late-maturing cultivars. Early-maturing cultivars had greater shoot growth and RUE than late-maturing cultivars. Differences in cumulative intercepted PAR among cultivars were relatively small compared with cultivar differences in RUE. Hence, the greater shoot growth of early-maturing cultivars compared with that of late-maturing cultivars was attributed to a greater RUE of the early-maturing cultivars. Consequently, different values of RUE should be used for early and late-maturing timothy cultivars in crop models based on efficiencies of radiation interception and utilization. Key words:Phleum pratense L., cultivars, growth, radiation, photosynthesis
Three spring wheat germplasm lines (839–984, 841–2, and 839–1076) with resistance to common root rot
Authors: Bailey K. L. , Harding H. , Hucl P.
Published: April 2011

Three spring wheat germplasm lines were developed with higher levels of resistance to common root rot than is currently available in CWRS and CPS wheats. Grain yield, plant height, flour yield, flour protein, sedimentation volume, and other quality traits of the lines were similar to those of Biggar. Key words: Common root rot, resistance, Triticum aestivum, germplasm
AC Hamilton barley
Authors: Ho K. M. , Seaman W. L. , Choo T. M. , Martin R. A.
Published: April 2011

AC Hamilton is a six-rowed spring feed barley (Hordeum vulgare L.) cultivar bred at the Plant Research Centre, Agriculture and Agri-Food Canada, and evaluated by the Eastern Canada Barley Breeding Group. It was selected from a Leger/OAC Kippen cross and is suitable for growing in Ontario, where it outyielded the check cultivars AC Stephen and Chapais. AC Hamilton is moderately resistant to powdery mildew (Erysiphe graminis f. sp. hordei) and is resistant to septoria leaf blotch (Septoria passerinii). Key words:Hordeum vulgare L., six-rowed barley, feed barley, high yield, powdery mildew
Influence of temperature on interaction of resistance genes in spring wheat differentials with races of common bunt (Tilletia tritici and T. laevis)
Authors: Gaudet D. A. , Puchalski B. J.
Published: April 2011

Temperature affects the expression of resistance to common bunt and can influence the efficacy of tests to screen for resistance to this disease. A study was undertaken to determine the response of spring wheat differentials possessing bunt resistance genes to temperature and races of Tilletia tritici and T. laevis. Differential wheat lines carrying resistance genes Bt-2, Bt-7, Bt-8, Bt-9, and Bt-10, were individually inoculated with bunt races L3, T1, T15, and T27, and incubated at 8, 10 or 15 °C for 0–10 wk. Responses to bunt infection following low temperature incubation at 8, 10, and 15 °C differed among differentials carrying the Bt genes. The resistance of the Bt-10 differential was effective at all three temperatures for all incubation periods whereas the resistance in differentials carrying the Bt-2 or Bt-8 gene was effective at 15 °C but not at 8 °C and 10 °C. Resistance in the Bt-9 differential was ineffective at all three temperatures. The four races of common bunt were similar in their level of infection in the differentials carrying individual Bt genes at the different temperatures although some differences in infection levels were observed. A screening test consisting of 2–4 wk growth at 15 °C followed by growth to maturity in the greenhouse can identify wheat lines containing Bt-8 and Bt-10. Key words:Triticum aestivum, smut, race specific resistance
Variation for stem solidness and its association with agronomic traits in spring wheat
Authors: Hayat M. A. , Martin J. M. , Lanning S. P. , McGuire C. F. , Talbert L. E.
Published: April 2011

The wheat stem sawfly (Cephus cinctus Norton) is a major insect pest of spring wheat (Triticum aestivum L.) in the Northern Great Plains of the US and Canadian Prairie provinces. The development of solid-stemmed wheat cultivars has been the main strategy to minimize losses from this insect. Solid-stemmed cultivars generally yield less than hollow-stemmed cultivars of the same era, and there are reports that degree of stem solidness is inversely related to grain yield. Our purpose was to examine the association between stem solidness and other agronomic traits and measure changes in progeny performance from three solid-stemmed parents representing different eras of cultivar development. Random, F4-derived F6 lines were obtained from crosses between solid-stemmed Rescue, Fortuna, and Lew and hollow-stemmed Newana and Thatcher. The random lines plus parents were evaluated in three environments. Changes during time from Rescue to Lew were in the desired direction for days to heading, plant height, and test weight, while stem-solidness score decreased for the parents themselves and in cross combination. Grain yield showed significant gains in two of three environments. A significant solid-stemmed × hollow-stemmed parent interaction was observed for stem solidness score suggesting epistatic gene action in the inheritance of this trait. The only significant associations of stem solidness score with agronomic traits were with plant height in one cross and grain protein concentration in two crosses. Results show the development of high yielding, solid-stemmed cultivars is not limited by undesirable associations between degree of stem solidness and other agronomic traits. Key words: Wheat stem sawfly, solid-stemmed wheat, trait associations
Quantum summer rape
Authors: Stringam G. R. , Degenhardt D. F. , Thiagarajah M. R. , Bansal V. K.
Published: April 2011

Quantum is a canola quality cultivar adapted to the B. napus growing regions of western Canada. It combines high yield, good lodging resistance, excellent resistance to blackleg disease, and is superior in all of these traits to Legend, Delta, and Profit. Key words: Rape (summer), cultivar description, high yield, blackleg resistant, lodging resistant
Relative sensitivity of leaf elongation and stomatal conductance of cucumber plants to changes in leaf and soil water potentials
Authors: Melkonian Jeffrey , Wolfe David W.
Published: April 2011

Identification of drought-resistant cucumber genotypes and optimization of irrigation scheduling require an improved understanding of cucumber plant water relations. Stomatal conductance (ks), relative leaf elongation rate (RLER), and leaf water relations were examined on greenhouse-grown cucumber (Cucumis sativus L. 'Marketmore 80') over two drought cycles. Water was withheld from the entire root system of cucumber plants and ks, leaf length, leaf water (ΨL) and osmotic potential, and soil matric potential were measured periodically. In both drought cycles, ks decreased before, and RLER decreased after predawn ΨL began to decline. No osmotic adjustment was found after one drought cycle and slight osmotic adjustment (−0.14 MPa) was observed in expanding leaves after a second drought cycle. Evidence for a nonhydraulic root signal in cucumber was examined in split-root experiments. ΨL was similar in plants which received water to one (stress treatment) or to both halves (control treatment) of the root system. Stomatal conductance and RLER remained at control levels as soil water potential (Ψ soil) around half the root system declined to −0.25 to −0.30 MPa. No convincing evidence for effects of root signals on ks and RLER at lower Ψ soil was observed. Key words:Cucumis sativus L., leaf elongation, osmotic adjustment, split root, stomatal conductance, water stress
Yield and protein content of cereals and oilseed as influenced by long-term use of urea and anhydrous ammonia
Authors: Ukrainetz H. , Campbell C. A. , Biederbeck V. O. , Curtin D. , Bouman O. T.
Published: April 2011

Nitrogen use on the Canadian Prairies has gradually increased in recent years, and producers have switched from ammonium nitrate to urea and anhydrous ammonia. Ammoniacal N is known to acidify soil, and some segments of society question the efficacy of using anhydrous ammonia, suggesting it might adversely affect soil productivity. A 10-yr experiment conducted on a moderately acid, medium-textured, Orthic Dark Brown Chernozem at Scott, Saskatchewan, enabled us to assess the impact of annual rates of N (0–180 kg ha−1), applied as urea or anhydrous ammonia, on yields of hard red spring wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and canola (Brassica campestris L.). The soil was gradually acidified by the fertilizers, with the effect being greatest for anhydrous ammonia. Yields of cereals reflected the positive influence of added nutrients in the case of urea, but because of soil acidification, response to anhydrous ammonia decreased in the later years. Yield of canola (only grown in two later years, when the soil was severely acidified) was negatively related to N rate and was lower for anhydrous ammonia than for urea. Acidification increased soil solution Mn, and this probably contributed to the suppressed yield responses. Grain protein was positively related to rate of N, except when yield increases caused a dilution effect. Different responses to the two N sources may have been due to loss of N from the urea via volatilization, and, thus, urea acidified the soil to a lesser extent than anhydrous ammonia. We concluded that if producers use recommended rates of N, there should be little deleterious influence of acid-forming N fertilizers on cereal production; however, more care will be necessary when growing canola. Key words: Nitrogen rate, canola, wheat, soil acidity, Mn toxicity
Effects of photoperiod on leaf appearance rate and leaf dimensions in winter and spring wheats
Authors: Pararajasingham S. , Hunt L. A.
Published: April 2011

Research on genotypic variation in the response of leaf-area production and expansion to photoperiod in wheat is limited. Growth-cabinet experiments using four spring and four winter wheat (Triticum aestivum L.) cultivars and four photoperiod (8, 12, 16 and 20 h) treatments were thus conducted with the objective of investigating the effect of photoperiod on leaf appearance rate and leaf dimensions. Winter wheats were grown without vernalization. In the spring wheats, flag leaves and spikes were formed under the longer photoperiod (16 and 20 h) treatments, and leaf number increased linearly with time. At the shorter photoperiods, flag leaves and spikes appeared in some cultivars only, and the rate of increase in leaf number decreased in the later stages. Final leaf number was greater at shorter photoperiods. In the winter cultivars, more leaves appeared than in the spring types under the longer photoperiods. For leaves 3–7, leaf number was a linear function of time, with photoperiod and cultivar effects. For one of four spring cultivars, the rate of leaf appearance was greater at 8 h than at 20 h, whereas for three of the winter cultivars the reverse was true. Leaf length increased with leaf number up to at least nodes 5–6 for both spring and winter types but decreased for the later-formed leaves for the spring but not for the winter types. Leaves of plants grown under photoperiods longer than 8 h were longer and broader than those grown under the short photoperiod, and the effect was more pronounced in winter than in spring cultivars. Such genotypic differences in the direct effects of photoperiod on leaf dimensions, which could influence the rates of leaf-area production and dry-matter accumulation under field conditions, emphasize that future studies should incorporate genotypes from different eco-physiological regions and that simulation models of wheat growth and development may need to account for variability in the control of vegetative growth. Key words: Wheat, photoperiod, leaf appearance rate, leaf length, leaf width
Prediction of seeding date in southern Alberta
Authors: Major D. J. , Hill B. D. , Touré A.
Published: April 2011

Predicting seeding date is an important component of modeling the impact of climate change on agricultural production. The objective of this study was to develop and evaluate models for predicting seeding dates based on weather variables. Data from 60 yr of a long-term experiment conducted on a silty clay loam (Dark Brown Chernozem) at Lethbridge, Alberta, were used for modeling seeding dates. Four approaches were used: an empirical model, a stepwise regression analysis, an iterative regression analysis, and a neural network (NN). An accuracy analysis was utilized to compare the results produced by the four methods. The best method was the NN model. It required 17 inputs, derived from date, air temperature and precipitation. The empirical model — which required that maximum temperature be at least 13 °C, that precipitation be less than 1 mm, and that the surface 15 cm of soil moisture be no greater than 90% of field capacity for four consecutive days — was the next best model. Stepwise regression identified air temperature and precipitation as the two most important weather variables. The predictive capability of this method was not satisfactory. Iterative regression analysis, also using maximum air temperature and precipitation, did not produce a satisfactory model. The stepwise and iterative regression methods predicted average seeding dates accurately but did not account for the variability in seeding dates. Key words: Neural network, climate change, model comparisons
Sampling forage corn for quality
Authors: Cherney J. H. , Cherney D. J. R. , Casler M. D.
Published: April 2011

Plant-to-plant variation for corn (Zea mays L.) forage-quality traits has not been adequately described. A field study was conducted for 2 yr, using hybrids with a range in maturation, each grown at two sites. Precipitation and temperature deviated considerably from normal in both growing seasons. Ten consecutive plants were harvested from each plot and separately analyzed for forage-quality traits. Differences among the forage-quality variables were consistent for the hybrid maturity groups, and data were pooled for analysis. When the product of variance × total cost was minimized, sample size was not greatly different for any of the measured variables when the cost ratio was low. If the cost per plot is 10 times that of the cost per plant, the product of variance × total cost is minimized at 9 plants plot−1 for whole-plant digestibility. When detection limits were considered but not costs, whole-plant digestibility was the least variable trait and grain proportion was the most variable trait among the traits measured. If a detectable difference of 20 g kg−1 in whole-plant digestibility between hybrids is desired, it would require sampling 4 plants plot−1, while a difference of 20 g kg−1 in stover digestibility could not be detected with an infinite number of plants per plot. Grain proportion explained a relatively small portion of the variation in whole-plant digestibility and was better related to stover-quality traits. Key words: Corn, maize, forage quality, variation, stover, grain
AC Rifle winter rye
Authors: McLeod J. G. , Payne J. F.
Published: April 2011

AC Rifle, a cultivar of winter rye (Secale cereale L.), was developed at the Semiarid Prairie Agricultural Research Centre, Research Branch, Agriculture and Agri-Food Canada, Swift Current, Saskatchewan. It is the first semi-dwarf cultivar registered for production in the Prairie Provinces of Western Canada. AC Rifle represents a 30% reduction in plant height compared to conventional height cultivars. Gram yield potential and winter hardiness of AC Rifle is equal to the check cultivars It has improved lodging resistance over all other adapted cultivars of winter rye. Key words: Cultivar description, semi-dwarf, rye (winter), Secale cereale L.
Plant water relations and mineral nutrition of containerized nursery plants in relation to irrigation method
Authors: Hicklenton Peter R. , Cairns Kenneth G.
Published: April 2011

Cotoneaster dammeri C. K. Schneid. 'Coral Beauty' and (Forsythia ovata × Forsythia europaea Deg. and Bald.) Forsythia 'Northern Gold' were grown in 3.8-L containers in a softwood bark–peat–sand medium, using overhead, pulse, drip or subirrigation methods. N, P and K were supplied from Nutricote 16N-4.4P-8.1K (type 140) controlled-release fertilizer. Overhead sprinklers irrigated containers during two 45-min periods each day. Daily pulse irrigation was from sprinklers for four 7-min periods, and drip irrigation to individual containers occurred during two 5-min periods. For subirrigation, plants were placed on permanently saturated sand beds. Subirrigation resulted m significantly higher plant dry weights at the end of the growing season than all other treatments. Measured daily leaching volumes were greatest from overhead-irrigated containers, followed by drip- and then pulse-irrigated containers. Leaching from the subirrigated treatment was small and sporadic, occurring only after moderate rainfall. Shoot water potential (ψT) was measured at weekly intervals through the middle of the growing season. There were no differences in predawn or dusk ψT values between treatments, but midday ψT was generally lower in subirrigated plants. At the end of the growing season, electric conductivity of the medium was highest for subirrigation, intermediate for drip and pulse irrigation, and lowest for overhead irrigation. This pattern was repeated for foliar K levels. It appears that superior growth of subirrigated plants is due more to better nutrient retention in the medium than to any effect on plant water status. Key words: Capillary irrigation, nutrient leaching
Effect of water-table management and nitrogen supply on yield, plant growth and water use of corn in undisturbed soil columns
Authors: Tan C. S. , Drury C. F. , Gaynor J. D. , Wesenbeeck I. van , Soultani M.
Published: April 2011

The effect of three water-table depths (30, 60 and 80 cm below the soil surface) and four N rates (0, 45, 90 and 135 kg ha−1) on plant growth, yield and water use were evaluated for corn (Zea mays L.). Research was conducted in a greenhouse, using 36 undisturbed foil columns (20 cm i.d. and 90 cm length) collected with a Meta-Drill vibrating core sampler from a Fox sandy loam soil at Harrow Research Centre. Corn grown in the 80-cm water-table depth had the greatest degree of water stress, as indicated by low volumetric soil water content, low stomatal conductance and transpiration rates, and elevated soil-surface and leaf-surface temperatures. There was a substantial increase in plant dry weight and grain yields as the N rates increased from 0 to 135 kg ha−1 with the 30- and 60-cm water-table depths. Under our experimental conditions, maximum grain yields were obtained with a 60-cm water-table depth. Grain yields were significantly reduced with the 80-cm water-table depth. With this water-table depth, grain yield was also reduced by N addition. Key words: Water-table management, Zea mays, yield, stomatal conductance, leaf temperature
Persistence of a field heterogeneity index
Authors: Lin C. S. , Morrison M. J. , Binn M. R.
Published: April 2011

Yield data from four fields at the Central Experimental Farm, Ottawa, from 1986 to 1991, were used to investigate the persistence of a field heterogeneity index (b-value). The index was derived from the intraclass correlation in 274 experiments of either barley (Hordeum vulgare L.), oat (Avena sativa L.) or soybean (Glycine max L. Merr.) For each field, in each year, the field map of the index was drawn based on the actual position of experiments in the field. A grid template was placed over the map and the b-value at each grid point was obtained. The persistence of the index across different years was measured by two statistics: (1) a simple correlation of b-values between two corresponding sets of coordinates and (2) a percentage of the total number of grid points, in each paired set, where the b-value categories matched(b = 0.0–0.3, 0.3–0.7, and 0.7–1.0). The former statistic measured the persistence of b-values across years, and the latter measured the pattern persistence. Positive correlations were observed in two of the four fields, while the percentage of pattern persistence was 50% or greater in five out of the 10 cases compared. Key words: Field heterogeneity index, plot size