bluuebunny/crossref_metadata_2025 huggingface dataset:
Greenhouse and field assessments of resistance in soybean inoculated with sclerotia, mycelium, and ascospores of Sclerotinia sclerotiorum
Authors: Rousseau G. , Huynh Thanh T. , Dostaler D. , Rioux S.
Published: April 2011

Thirty-five soybean lines were evaluated for sclerotinia stem rot (SSR) resistance using stem inoculations with mycelium in the field and greenhouse, flower inoculations with mycelium or ascospores in the field and greenhouse, and soil infestation with sclerotia in the field, between 1997 and 2000. Symptoms were evaluated by stem lesion length (SLL, mm) and lesion extension (LE, mm) after stem inoculations; infected flowers (IF, %) and a disease severity index (DSI, %) after flower inoculations with ascospores and mycelium; and a DSI after soil infestation with sclerotia. Results show significant differences among lines for SLL and LE in the greenhouse and for IF and DSI in the field and greenhouse. Significant correlations were found between stem inoculation and sclerotia method and between all trials with flower inoculation using either ascospores or mycelium. Maple Donovan and Frisquet were the least susceptible genotypes after flower inoculations with ascospores, whereas OAC Bayfield was the most susceptible. Maple Donovan was also the least susceptible genotype after mycelium stem inoculation in the trials in 2000, while OAC Bayfield was again the most susceptible. Nattosan was the most susceptible genotype in trials conducted in the fields infested with sclerotia. In this study, flower inoculations provided better discrimination than stem inoculations in the assessment of soybean genotypes for SSR resistance, and the results suggested two phenotypes of partial or incomplete resistance, one occurring in the flower, and the other in the stem. Key words: Sclerotinia sclerotiorum, soybean, mycelium, ascospores, inoculation, resistance
Comparison of pre-treatments for inducing germination in highly dormant wheat genotypes
Authors: Matus-Cádiz M. A. , Hucl P.
Published: April 2011

An effective dormancy-breaking method may be of interest to wheat (Triticum aestivum L.) breeders selecting for increased seed dormancy prior to advancing their populations in greenhouse grow-outs. The objective of this study was to identify an effective pre-treatment for breaking dormancy in wheat that did not result in seedling etiolation. In 2000, eight dormant (W98616, line 211, EMDR-4, EMDR-9, EMDR-14, RL4137, Columbus, and AC Domain) and one nondormant line (Roblin) were grown at two locations in Saskatchewan. Seeds were: (i) stored for zero to 21 wks at 24°C before incubating at 20°C for 7 d; (ii) incubated at 5, 10, 15, 20, and 25°C for 14 d; and (iii) treated with gibberellic acid (GA3) (0.0006 and 0.0014 M), potassium nitrate (KNO3) (0.01 and 0.02 M), chilling, heating, chilling with 0.01 M KNO3, and heating with 0.01 M KNO3 before incubating at 10°C for 14 d. Seedling growth was observed in a duplicated growth chamber experiment. Seedling length, first inter-node length, and biomass yield data were collected from plants grown from seeds treated with four effective pretreatments. Data were subjected to an ANOVA. Six to 18 weeks of storage at 24°C were required to break the dormancy (≥ 95% germination) in dormant genotypes. Incubation at 10°C was the most effective temperature for promoting germination in dormant seeds after 10d of testing. Four pre-treatments including 0.0006 M GA3, 0.0014 M GA3, chilling with 0.01 M KNO3, and heating with 0.01 M KNO3 led to ≥ 95% germination within 10 d of testing. Only GA3 treatments were associated with etiolated seedling growth. Heating with 0.01 M KNO3 or chilling with 0.01 M KNO3, applied before incubating at 10°C in darkness, may be of interest to breeders selecting for increased dormancy before advancing breeding populations in greenhouse grow-outs. Key words: Triticum, dormancy, nitrate, chilling, heating, etiolated seedling
Morphology, forage and seed yield of soybean cultivars of different maturity grown as a forage crop in Turkey
Authors: Altinok Suzan , Eroğdu Ilker , Rajcan Istvan
Published: April 2011

Soybean [Glycine max (L.) Merr.] has long been used as a forage crop but its morphological development and forage potential have not been studied extensively. A study was conducted using oilseed soybean cultivars of different maturity to determine their morphological development, forage yield, seed components and seed yield at the University of Ankara, Turkey. Five soybean cultivars OAC Salem (earliest), OAC Bayfield (midearly), OAC Eclipse (mid-early but later than OAC Bayfield), OAC Glencoe (full-season soybean) and SA.88 (late), were used in the study conducted in 2000 and 2001. The full-season cultivar OAC Glencoe was the tallest cultivar, and had the highest levels of fresh and dry matter yield and crude protein yield among soybean cultivars in both years. Therefore, OAC Glencoe is considered to be the most suitable soybean cultivar for forage production when intercropped with corn in Ankara region of Turkey. However, attention should be given to the earliest maturing cultivar OAC Salem that had the highest seed yield and better relative seed composition of all the cultivars. Key words: Forage, soybean, cultivar, morphology, development
Pythium sulcatum and P. ultimum as causal agents of cavity spot disease of carrots in Egypt
Authors: El-Tarabily K. A. , Abouzeid M. A. , ST. J. Hardy G. E. , Sivasithamparam K.
Published: April 2011

In a survey of carrot diseases of the Nile delta region of northern Egypt, Pythium sulcatum (Pratt and Mitchell) and P. ultimum (Trow) were isolated from 74 and 26%, respectively, of carrot roots showing cavity spot disease. In laboratory and glasshouse pathogenicity tests, P. sulcatum caused significantly (P < 0.05) more severe damage than P. ultimum. The greater level of pathogenicity of P. sulcatum was associated with its ability to produce a wider array of cell-wall-degrading enzymes with significantly (P < 0.05) higher enzymatic activities compared to P. ultimum. Polygalacturonase, pectin lyase, pectate lyase and cellulase were detected in cavity spot lesions induced by both P. sulcatum and P. ultimum. Pectin methylesterase was detected in tissues invaded by P. sulcatum and not by P. ultimum. This is the first record of cavity spot disease of carrots in Egypt and indicates P. sulcatum and P. ultimum as the causal agents of this disease in the region surveyed. Key words: Carrots, cavity spot, cell-wall-degrading enzymes, Egypt, Pythium
Influence of variable rates of imazamethabenz and difenzoquat on wild oat (Avena fatua) seed production, and wheat (Triticum aestivum) yield and profitability
Authors: O’Donovan J. T. , Neil Harker K. , Blackshaw R. E. , Stougaard R. N.
Published: April 2011

Field experiments to investigate the effects of variable imazamethabenz rates on wild oat seed production and wheat yield and profitability were conducted at Lacombe, Lethbridge and Vegreville, Alberta, and Kalispell, Montana, over several years. Similar studies with difenzoquat were conducted at Lacombe and Lethbridge. In most cases, reducing the herbicide rates below those recommended resulted in increases in wild oat seed production, but the potential for returning relatively large amounts of wild oat seed to the soil seedbank depended on the extent of the rate reduction. For example, averaged over locations and years, reducing the rate of imazamethabenz to 75% of the recommended rate resulted in wild oat seed production increasing by 25% compared with an increase of over 100% when the rate was reduced to 50%. Wheat yields and economic returns as functions of rate also varied for both herbicides. It was more economical, in most cases, to apply imazamethabenz at 50 or 75% of the recommended rate compared with the full rate. However, an economic loss occurred in four and three of the 11 location-years when the imazamethabenz rate was reduced to 50 and 75%, respectively, and losses were more severe at the 50% rate. Compared with imazamethabenz, reducing the rate of difenzoquat tended to be more risky in terms of increased wild oat seed production and reduced net economic return. Key words: Reduced herbicide rates
Compositional changes over four years for binary mixtures of grass species grown with white clover
Authors: McKenzie D. B. , Papadopoulos Y. A. , McRae K. B. , Butt E.
Published: April 2011

Kentucky bluegrass, meadow fescue, orchardgrass, tall fescue, timothy, and reed canarygrass were seeded in all possible two-grass combinations with white clover in conventional and underseeded barley treatments using a split-plot design at the Western Agriculture Centre near Pynn’s Brook, NL. The objectives were: (1) to assess dry matter yield (DMY) of two binary grass species when sown with white clover in mixtures under a system with cuttings at similar crop growth stages as rotational grazing and to assess the effect of underseeding to barley on this system; (2) to identify mixtures that enhance herbage distribution throughout the grazing season; and (3) to assess the sward dynamics over successive cropping seasons. The composition of the binary grass mixtures with white clover affected seasonal DMY, seasonal herbage distribution, and sward dynamics over the production years. Orchardgrass in mixtures decreased DMY, shifted the herbage distribution toward early season, and competed with other species. Timothy composition of the stand showed the largest decline over the 3 production years, whereas white clover declined in mixtures with bluegrass, orchardgrass, or tall fescue. Meadow fescue and reed canarygrass with white clover was the most productive mixture with excellent persistence and good yield distribution over the growing season. Orchardgrass was the least compatible species in the mixtures; it dominated first growth and contributed the least to biomass production in later years. Both bluegrass and reed canarygrass performed well in mixtures over the 3 production years; bluegrass appeared to enhance the performance of the other species during summer regrowth whereas reed canarygrass was superior in the later part of the growing season. Underseeding with barley did not affect white clover yield in any production year but detrimentally affected the yield of orchardgrass and meadow fescue in mixtures, and their seasonal distribution. Key words: Bluegrass, orchardgrass, meadow fescue, tall fescue, timothy, reed canarygrass, repeated measurements, principal component analysis, herbage DM distribution, species competition
Nitrogen diagnosis of Christmas tree needle greenness
Authors: Parent L. E. , Khiari L. , Pettigrew A.
Published: April 2011

Christmas tree (Abies balsamea L.) fertilization is generally guided by needle colour or chemical analysis. Our objective was to develop critical values for the traditional critical nutrient range (CNR) and the compositional nutrient diagnosis (CND) of Christmas tree needles for the Quebec Appalachians. We collected survey specimens (n = 174) and obtained a validation dataset made up of 10 paired dark green and pale green stands. The compositional simplex for CND comprised five nutrient concentration values (N, K, P, Ca, and Mg) and a filling value R5 computed from differences between the whole tissue composition (i.e., 1000 g kg-1) and the known nutrient concentration values expressed in g kg-1. Nutrient multi-ratios were computed as the natural logarithm of the ratio of one nutrient concentration value to the geometric mean of all nutrients and the R5. Nutrient indexes (IN1, …, IR5) were computed as standard variables usin the mean and the standard variation of nutrient multi-ratios for the high-greenness sub-population. A nutrient imbalance index, CNDr2, was computed as the sum of squared CND indexes. Needle colour was assessed using a colour chart and a SPAD-502 chlorophyll meter. The critical SPAD value was set at 48–50 for a high greenness rating in the survey dataset, and the high-greenness sub-population comprised 95 specimens. Nitrogen and P concentrations were highly correlated to each other. Critical concentrations were found to be 17.8 g N kg-1, and 1.8 g P kg-1. CND diagnosis of the validation dataset was similar to CNR, but CND classified nutrients in the order of their limitation to colour rating. Using the validation dataset, critical values were 17.2 g N kg-1 and −1.015 as IN. The validated critical CNDr2 for five nutrients (N, K, P, Ca, and Mg) was 12.6, which was close to the critical CNDr2 value using the survey dataset (11.6) and to the theoretical χ2 value of 11.1 (P < 0.05). Key words: Tissue analysis, nutrient diagnosis, chlorophyll index, nutrient imbalance index
Cutlass field pea
Authors: Tom Warkentin Stanford Blade, , Vandenberg Albert
Published: April 2011

Cutlass, a yellow cotyledon field pea (Pisum sativum L.) cultivar, was released in 2003 by Alberta Agriculture Food and Rural Development and the Crop Development Centre, University of Saskatchewan, for distribution to Select seed growers in Saskatchewan and Alberta through the Variety Release Committee of the Saskatchewan Pulse Growers. Cutlass has semileafless leaf type, powdery mildew resistance, medium-sized, round seeds, and good yielding ability. Cutlass is adapted to the field pea growing regions of western Canada. Key words: Field pea, Pisum sativum L., cultivar description
Accumulation and distribution of micronutrients in Willamette red raspberry plants
Authors: Kowalenko C. G.
Published: April 2011

Willamette red raspberry (Rubus idaeus L.) plants were sampled monthly to determine the accumulation and distribution of copper (Cu), boron (B), zinc (Zn), manganese (Mn) and iron (Fe) over the growing seasons of four different years. The soil (Marble Hill series) was typical of that commonly used for commercial raspberry production in the area. No micronutrients were applied. The micronutrients generally accumulated as the season progressed in a manner similar to the accumulation of dry matter. Maximum accumulation of micronutrients in the aboveground portion of the plants did not necessarily occur at the end of the growing season because of different growth patterns of the floricanes and primocanes. The ripe berries, which would be removed by harvesting, contained a significant proportion of the total accumulation of micronutrients: Cu (18–26%), Zn (15–25%), B (3–16%), Fe (5–8%) and Mn (4–7%). However, concentrations of the micronutrients in the various parts of the plant varied considerably from month to month and year to year. There was no obvious relationship between weather conditions and the variations in micronutrient concentrations. Extreme variations within and between growing seasons suggest concentrations of micronutrients in leaves cannot readily be used to develop tissue-analysis-based fertility recommendations. Floricane stem micronutrient concentrations were more stable but the relationship between these concentrations and the overall nutrient status of the plants needs to be determined before they can be used for diagnostic purposes. Before accumulation and distribution patterns of micronutrients in raspberry can be used as a basis for development of fertilizer management strategies, additional measurements from other locations are needed. The results from this study should serve as guidelines for developing sampling procedures and their practical applications. Key words: Copper, boron, zinc, manganese, iron, Rubus idaeus L.
Turia pepino
Authors: Rodríguez-Burruezo A. , Prohens J. , Leiva-Brondo M. , Nuez F.
Published: April 2011

Turia is a new salad pepino cultivar adapted to greenhouse cultivation in a wide range of environments with high yield and improved fruit quality. Its fruit is ovate in shape and has golden yellow skin covered with purple stripes, mild flavour and intense aroma. Turia is the first pepino cultivar tolerant to tomato mosaic virus. Key words: Solanum muricatum, cultivar description, tomato mosaic virus
Effects of initial N reserve status and residual leaf area after cutting on leaf area and organ establishment during regrowth of alfalfa
Authors: Simon J. C. , Decau M. L. , Avice J. C. , Jacquet A. , Meuriot F. , Allirand J. M.
Published: April 2011

Nitrogen reserves in remaining organs and residual leaf area after cutting have long been recognized as key factors during alfalfa (Medicago sativa L.) regrowth. The present work examined which morphological components were influenced by contrasting initial N status and residual leaf area during 29 d of regrowth after cutting at 15 cm height. Two levels of initial N reserves (high and low) and of residual leaf areas (not or completely defoliated) were combined in four treatments. Both factors affected shoot dry matter (DM) production at the end of regrowth. The increase in DM of new organs observed with high N reserves resulted from a combination of short- and long-term effects on plant morphology; i.e., (1) an increase in the rate of axis appearance from the crown in the early regrowth stage (day 0–9) and (2) an increase in individual leaf area (ILA) all along the regrowth. Compared with completely defoliated plants, plants with a residual leaf area at cutting exhibited an increased rate of axillary stems appearance all along the regrowth. Then the architecture of plants with a residual leaf area was more branched than the one of defoliated plants. This increase in branching was always associated with smaller ILA. Hence, differences in plant leaf area were only significant in the early growth stage. This suggested that differences observed in new stems DM at the end of the regrowth were established by day 9 and remained unchanged in late regrowth. Our results clearly showed that initial N reserve status and residual leaf area both significantly modify the dynamic of leaf area establishment and new organ growth of alfalfa. Key words: Medicago sativa L., defoliation, morphology, N storage, stems regrowth
Bioassay for assessing resistance of Arabidopsis thaliana L. (Heynh.) to the adult crucifer flea beetle, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae)
Authors: Hallett Rebecca H. , Ray Heather , Holowachuk Jennifer , Soroka Juliana J. , Gruber Margaret Y.
Published: April 2011

A bioassay arena and a laboratory screening protocol were developed for assessing lines of Arabidopsis thaliana L. (Heynh.) for feeding damage by the adult crucifer flea beetle, Phyllotreta cruciferae (Goeze). The arena consists of a 96-well microtitre plate with a modified top to contain flea beetles and allow ventilation. Eight lines of A. thaliana, arranged in an 8 × 8 Latin square design, were screened simultaneously in each arena using 50 starved flea beetles. Two cotyledons and the first pair of true leaves per plant were rated visually under a dissecting microscope using a visual damage rating scale. The protocol was used to screen 29 wild ecotypes, eight mutant lines and a single transgenic line of A. thaliana. Discrimination between both cotyledon and leaf tissue was apparent for young beetles that were both non-reproductive or reproductive, but not for old reproductive beetles. Differences were observed between Asian and European ecotypes of A. thaliana, suggesting that geographic origin may play a role in susceptibility of Arabidopsis ecotypes to flea beetle feeding. The transparent testa regulatory gene mutants (lines 82, 111, 164) were most susceptible to flea beetle feeding, possibly indicating a role for anthocyanins and/or flavonoids in governing flea beetle susceptibility. Significant variation in damage levels indicates that expression of flea beetle resistance in the A rabidopsis genome is plastic, and that potential exists to use the wide array of publicly available Arabidopsis germplasm as tools in the transfer of resistance to agronomically important host plants. Key words: Seedling bioassay, Arabidopsis thaliana, wild ecotypes and mutants, crucifer flea beetle, Phyllotreta cruciferae, host plant resistance
Early seeding improves the sustainability of canola and mustard production on the Canadian semiarid prairie
Authors: Angadi S. V. , Cutforth H. W. , McConkey B. G. , Gan Y.
Published: April 2011

Canola and mustard production is increasing in the semiarid prairie and seeding date affects the heat and water stress experienced by those crops. We conduced a 4-yr field study on the effect of fall (November with expected spring germination), early spring (late April) and late spring (late May) seeding on the growth of two cultivars representing two different canola species (B. napus L. ‘Arrow’ and B. rapa L. ‘Sunbeam’) and of two cultivars representing two different mustard species (B. juncea L. Coss. ‘Cultass’ and Sinapis alba L. ‘Pennant’). Generally, all cultivars from the four different species responded similarly to seeding dates. Flowering during a period of less water stress increased grain yields so years with good moisture availability in spring (1999 and 2000) favored earlier seeding (fall and early spring) while a drier spring with moister summers (2001 and 2002) favored spring seeding. Fall seeding resulted in lower plant populations than spring seeding. Early spring seeding was most frequently the highest yielding and, when another seeding date was higher yielding, the yield difference from early spring seeding was relatively small (191 kg ha-1). These results, plus the typical Prairie weather pattern of increasing moisture stress from spring into summer, indicate that canola and mustard should be seeded as early in spring as practical. Cutlass was generally the highest yielding cultivar while Sunbeam was the lowest yielding. Key words: Dormant seeding, seeding date, Brassica oilseeds, yield, semiarid prairie
Interspecific hybridization between diploid Fagopyrum esculentum and tetraploid F. homotropicum
Authors: Wang Yingjie , Scarth Rachael , Campbell Clayton
Published: April 2011

The wild diploid species Fagopyrum homotropicum (2n = 2x = 16) has been used for buckwheat improvement, but, prior to this study, the tetraploid form (2n = 4x = 32) had not been hybridized with the cultivated species F. esculentum. The objective of this study was to hybridize F. esculentum with tetraploid F. homotropicum to increase the genetic variability. Forty-one interspecific F1 hybrids were obtained through ovule rescue in vitro, with hybridity confirmed using morphological characters, chromosome numbers (2n = 3x = 24) and DNA analysis. The F1 plants were mainly sterile. However, seven seeds were set spontaneously on two hybrid plants, and a large number of seeds were obtained after colchicine treatment. The F2 plants were divided into two groups based on chromosome numbers and morphology. The first group was hexaploid plants (2n = 6x = 48) or hypohexaploid plants (2n = 44–46), partially fertile with “gigas” features including increased height, dark green leaves, and large seeds with thick seed hulls. The second group of plants was diploid (2n = 2x = 16) (one plant had 17 chromosomes), with normal growth and fertility, and a combination of characters from both parents, indicating that genetic recombination had occurred during chromosome elimination. The diploid group was superior to the hexaploid group for use in buckwheat breeding programs due to the desirable characters and the ease of crossing. This is the first report of interspecific hybridization using different ploidy levels in the Fagopyrum genus. Key words: Buckwheat (F. esculentum; F. homotropicum), interspecific hybridization, breeding, tetraploid, diploid, hexaploid, fertility
Aggregation of potato leafhoppers, Empoasca fabae (Harris) (Homoptera: Cicadellidae), on a trap crop in an edible bean, Phaseolus vulgaris L., intercropping system
Authors: S Bullas-Appleton E. S. , Gillard C. , Schaafsma A. W.
Published: April 2011

The potato leafhopper is a serious pest of edible beans, causing significant yield reductions in the absence of control measures. Control recommendations in edible beans involve the application of phorate at planting or the foliar application of dimethoate when thresholds are reached. As an alternative to broadcast insecticide applications, the use of a highly susceptible bean cultivar, Berna Dutch brown, as a trap-crop was tested by interplanting one, two and four rows of Berna among rows of Stingray white bean at two locations in Ontario, Canada, in 2001 and 2002. Transect sampling of adults and nymphs indicated that potato leafhopper populations in the crop were not affected by different numbers of rows of Berna, although there were many more potato leafhoppers in rows of the Berna trap crop compared with adjacent rows of the white bean crop. An insecticide seed treatment (thiamethoxam) applied to rows of Berna in treated plots effectively lowered insect populations early in the season, but this combination did not improve the effectiveness of Berna as a trap for migrating adults. Damage inflicted by potato leafhoppers was initially highest in untreated plots and in the arrangement containing four rows of Berna. Differences among yields for treated and untreated plots of white bean were not significant. If planted as early-sown border rows, combined with better leafhopper management in the trap crop, Berna may be used as a trap cultivar to attract leafhoppers and consequently protect an edible bean main crop. Key words: Empoasca fabae, trap-crop, edible beans
Potential utilization of native prairie grasses from western Canada as ethanol feedstock
Authors: Jefferson Paul G. , McCaughey W. Paul , May Ken , Woosaree Jay , McFarlane Linden
Published: April 2011

The utilization of native grass species for potential biomass feedstocks of the emerging ethanol industry requires more information about their cellulose and hemicellulose concentration. Ten native species were grown at seven sites across the prairie region of western Canada for two to four growing seasons. Northern wheatgrass, Elymus lanceolatus, produced high concentrations of cellulose (363 g kg-1) but low concentrations of hemicellulose (266 g kg-1). Green needlegrass, Nasella viridula, produced high concentrations of both constituents (351 and 307 g kg-1). Four warm-season grasses, big bluestem, Andropogon gerardii, little bluestem, Schizachyrium scoparium, prairie sandreed, Calamovilfa longifolia, and switchgrass, Panicum virgatum, had 346, 342, 340 and 338 g kg-1, respectively, concentrations of cellulose and also exhibited a positive response to temperature that resulted in increased hemicellulose concentration. Accumulated thermal time (degree day base 10°C) was correlated to hemicellulose concentrations in the warm-season grasses but not for cool-season grasses. Holocellulose (cellulose + hemicellulose) concentration differences varied among site-years but warm-season grasses were more stable in hollocellulose concentration than cool-season grasses. Key words: Biomass, native grasses, cellulose, hemicellulose, biofuel
Knowles hybrid bromegrass
Authors: Coulman Bruce
Published: April 2011

Knowles was selected from hybrid populations resulting from crosses between meadow bromegrass (Bromus riparius Rehm.) and smooth bromegrass (Bromus inermis Leyss.). It has a unique array of plant characteristics, some similar to meadow bromegrass, and others more similar to smooth bromegrass. In regional trials, Knowles produced hay yields greater than meadow brome, but lower than smooth bromegrass. It was superior to smooth bromegrass in regrowth after cutting. For steer grazing performance, Knowles was equal or superior to its parental species, perhaps due to its lower fiber concentrations at vegetative growth stages. Key words: Hybrid bromegrass, Bromus riparius × Bromus inermis, cultivar description
Long-term changes in the frost-free season on the Canadian prairies
Authors: Cutforth Herb , O’Brien EG (Ted) , Tuchelt Jason , Rickwood Rick
Published: April 2011

The climate of the prairies has warmed over the past century, especially during late winter and early spring. Some regions of the prairies have warmed faster than others. Climate change has been documented to affect living systems in North America, such as promoting earlier phenological development and longer growing seasons. We examined weather records gathered at several long-term weather-recording sites across the agricultural regions of the Canadian prairies for evidence of trends in last spring frosts, first fall frosts, and frost-free durations. During the latter half of the 20th century, the trends were towards earlier last spring frost dates and towards longer frost-free seasons in the agricultural regions of the Canadian prairies. Across most of the prairies the trends towards later first fall frost dates were smaller and generally not significant. The largest changes have occurred in the central and northern agricultural regions of Alberta, whereas the least change occurred over much of southern Alberta and in southern Manitoba. Key words: Last spring and first fall frost dates, frost-free season, agroclimatic indices, climate change, Canadian prairies
Polymer seed coating of early- and late-fall-seeded herbicide-tolerant canola (Brassica napus L.) cultivars
Authors: Clayton G. W. , Harker K. N. , O’Donovan J. T. , Blackshaw R. E. , Dosdall L. , Stevenson F. C. , Johnson E. N. , Ferguson T.
Published: April 2011

Polymer seed coatings offer an opportunity to fall seed Brassica napus earlier in October, thus avoiding difficult seeding conditions (wet/frozen soils) common in late October or early November. A multi-year field experiment was conducted at four locations in Alberta, Canada, to investigate the effect of early (mid-October) and late fall (late October-early November) canola seeding with and without a germination-inhibiting polymer seed coat. Yield and yield components were determined in glufosinate (hybrid and open-pollinated), glyphosate (open-pollinated), and imidazolinone (open-pollinated) herbicidetolerant canola cultivars. Early-seeded canola without the polymer coat had a reduced plant density of 58% compared to late-fall-seeded canola. Application of the polymer coat on early-seeded canola increased plant density by 80% compared to uncoated seed. Seed yield and dockage were not affected by seeding date when a polymer seed coating was used. Without the polymer seed coat, canola yield was reduced 42% and dockage increased 6% when seeding occurred in early vs. late fall. Increased pod production from early-fall-seeded uncoated canola compared to other seeding dates could only partially compensate for canola yield. Cultivar interactions generally were not agronomically important. The use of polymer seed coatings with all these herbicide-tolerant cultivars will allow producers to seed earlier in fall, rather than waiting for cooler soil conditions in late fall. Key words: Canola (Brassica napus L.), dormant seeding, polymer seed coating
HT-2 and T-2 toxins in barley inoculated with Fusarium sporotrichioides
Authors: Abramson D. , McCallum B. , Tekauz A. , Smith D. M.
Published: April 2011

To assess field production of the Fusarium trichothecenes HT-2 toxin, T-2 toxin, and neosolaniol, inoculation trials with four barley cultivars and local isolates of Fusarium sporotrichioides were performed over 2 yr at an experimental farm in southern Manitoba. In the 1998 study, HT-2 toxin was detected in 14 of 16 barley rows at levels between 0.14 and 0.52 µg g-1, with positive samples averaging 0.26 µg g-1. T-2 toxin was not detected. Fusarium sporotrichioides infection ranged between 15 and 49% with an average value of 29%. In the 1999 study, HT-2 toxin was detected in 16 of 16 barley rows at levels between 0.67 and 3.72 µg g-1, averaging 1.92 µg g-1, and T-2 toxin in 15 of 16 rows between 0.35 and 1.27 µg g-1, with positive samples averaging 0.70 µg g-1. Fusarium sporotrichioides infection ranged between 52 and 93% with an average value of 7 5%. No neosolaniol was detected in any of the samples. The data suggest that in years of moderate F. sporotrichioides infection, HT-2 toxin might to be found in Manitoba barley, and in summers of higher rainfall and fungal infection, T-2 toxin might also be present. Key words: HT-2 toxin, T-2 toxin, Canada, barley, Fusarium sporotrichioides
Seed and herbage production of Westerwolds ryegrass as influenced by applied nitrogen
Authors: Kunelius H. T. , McRae K. B. , Dürr G. H. , Fillmore S. A. E.
Published: April 2011

Seed production, plant characteristics and herbage regrowth of three cultivars of Westerwolds ryegrass (Lolium multiflorum Lam.) were determined during 3 production years. Ryegrass was fertilized with nitrogen at 60, 90 and 120 kg ha-1 applied either all at the two- to three-leaf stage or split (3:2) between the two- to three-leaf stage and stem elongation. Seed yield of three cultivars ranged from 742 to 1440 kg ha-1. Nitrogen fertilizer at 90 kg ha-1 resulted in near maximum seed yields. Single and split applications of nitrogen resulted in similar seed yields. Density of fertile tillers ranged from 541 to 911 m-2 among the cultivars and responded linearly to applied N. A positive relationship was detected between the density of fertile tillers and seed yield. Herbage in aftermath averaged 2280 kg ha-1 dry matter, 125 g kg-1 crude protein, 597 g kg-1 neutral detergent fibre and 344 g kg-1 acid detergent fibre. Key words: Lolium multiflorum, Westerwolds ryegrass, nitrogen fertilizer, seed, tiller, spikelet, herbage, herbage composition
Seeding date and polymer seed coating effects on plant establishment and yield of fall-seeded canola in the Northern Great Plains
Authors: Johnson E. N. , Miller P. R. , Blackshaw R. E. , Gan Y. , Harker K. N. , Clayton G. W. , Kephart K. D. , Wichman D. M. , Topinka K. , Kirkland K. J.
Published: April 2011

The time interval for planting fall-seeded Brassica napus L. canola in the Northern Great Plains is narrow, since seeding must occur as close to soil freeze-up as possible to minimize the risk of winter kill. The Prairie ecoregion tends to have more stable fall and winter temperatures than the Rocky Mountain foothill region, where fall and winter chinooks may initiate germination and increase the risk of winter mortality. Our objectives were to determine an optimum seeding date interval for fall-seeded canola and whether a water-impervious polymer seed coating could advance the seeding date and reduce the risk of stand loss and corresponding yield reduction in two distinct agroecoregions. A range of fall seeding dates and a water-impervious polymer seed coating vs. a control treatment (water-soluble film) were assessed at 14 sites (five locations) from 1998 to 2001 in Alberta and Saskatchewan (Prairie sites) and at six sites (four locations 1999–2001) in Montana, USA (Foothill sites). Highest seedling densities and canola yield responses for the control treatment were attained in the first 2 wk of November in the Prairie sites, while responses to seed date were much more variable in the Foothill region. In the Prairie sites, the water-impervious polymer seed coating improved seedling density and seed yield as seeding date was progressively moved forward from the first week of November to the first week of October. The benefit of the water-impervious polymer seed coating became notable when soil temperatures were above 5°C. The water-impervious polymer coating provided only marginal improvement in plant stand and canola yield in the Foothill region. In the Foothill region and at Lethbridge, fall-seeded canola densities were on average 60% lower than spring-seeded canola densities and fall seeding increased canola yield in only one site-year when compared with spring-seeded canola. In the Prairie region, a water-impervious polymer coating can broaden the time interval for fall seeding; however, it does not ensure that recommended densities of spring seedlings will be attained. The optimum seeding date for fall seeding in the Foothill region could not be adequately defined for either the control or the water-impervious polymer coated seed due to the variable nature of the late fall and winter weather. Key words: Canola (Brassica napus L.), alternative seeding date, germination
Emergence, height, and yield of tall, NewHy, and green wheatgrass forage crops grown in saline root zones
Authors: Steppuhn H. , Asay K.
Published: April 2011

The salinity tolerance of a crop relates to its inherent ability to yield economic product while subjected to root-zone salinity. Tall wheatgrass [Thinopyrum ponticum (Podp.) Liu & Wang, previously Agropyron elongatum (Horst.) Beauv.] ranks as one of the most salt-tolerant forage crops, but producers feeding or grazing livestock with it often report of its poor palatability. NewHy [Elytrigia repens (L.) Nevski × Pseudoroegneria spicata (Pursh.) A. Love] and green wheatgrasses (Elymus hoffmannii Jensen and Asay) are new forages with potentially better palatability. In order to determine the responses of these forages to saline rooting media, two tests were conducted in Canada’s Salinity Tolerance Testing Facility. The plants were grown in sand tanks flushed four times daily with hydroponic solutions consisting of nutrients and salts dominated either by chloride ions measuring from 1.5 to 48 dS m-1 or by sulphate ions from 1.5 to 50 dS m-1. In the chloride test, maximum emergence-survival, emergence rate, and emergence at the time of maximum rate for Orbit tall wheatgrass differed significantly from green wheatgrass (Breeding Strain A6) and NewHy. The maximum percent emergence and survival within the range of test salinity levels averaged 93, 88, 86% for tall, NewHy, and Strain A6 wheat grasses, respectively. In the sulphate test, maximum percent emergence-survival averaged 94, 91, and 87% for Orbit tall wheatgrass and green wheatgrass breeding strains A6 and S2 across the eight salinity levels of the test. Relative crop heights at harvest did not differ significantly among the test forages in either test. In the chloride test, shoot biomass yields relative to the salt-free production analysed by the modified-discount equation resulted in salinity-tolerance-indices of 11.2, 5.7, and 12.9 for tall, NewHy, and green wheatgrasses, respectively. In the sulphate test, salinity-tolerance indices for the tall wheatgrass, A6 and S2 green wheatgrass strains registered 11.7, 12.8, and 12.5, respectively. This and the covariance yield analyses based on paired t-tests lead to the inference that the salinity tolerance for both strains of green wheatgrass equalled that of the Orbit tall wheatgrass and exceeded that of the NewHy. Producers will soon have the option of growing AC Saltlander, a variety of green wheatgrass (Strain S2), which has just been released for commercialization and seed increase. Key words: Salt tolerance, salt resistance, salinity, tall wheatgrass, green wheatgrass, NewHy, crop response to salinity
Identification of RAPD markers linked to pod length in Brassica napus L. canola
Authors: Hawkins Glen P. , Zhang Xiugang , Thiagarjah Mohan R. , Corrigan Lisa M. , Stringam Gary R.
Published: April 2011

The purpose of this study was to develop molecular markers as a tool to make important agronomic selections in the absence of a scorable phenotype. This project focused on the trait of pod length in Brassica napus L. canola. Pod length is an important parameter involved in total yield in this crop. In this study, the inheritance of long pods was found to be controlled by two independent genes in a dominant relationship with additive effects. Using bulk segregant analysis (BSA) and linkage analysis using RAPD markers, two corresponding linkage groups that segregate with the long pod trait were identified. The application of this trait for possible benefit in a canola breeding program is discussed. Key words: Spring canola, RAPD, pod length, plant breeding, Brassica napus
Effect of formulation and placement of Mesorhizobium inoculants for chickpea in the semiarid Canadian prairies
Authors: Gan Y. , Selles F. , Hanson K. G. , Zentner R. P. , McConkey B. G. , McDonald C. L.
Published: April 2011

The use of bacterial inoculants can increase root nodulation and the seed yield of annual legumes. A six site-year study was conducted to determine the effect of formulations (peat-based powder vs. granules) and placement in the soil (seed-row vs. side-band) of Mesorhizobium inoculants on plant establishment and seed yield of chickpea (Cicer arietinum L.) in the semiarid Canadian prairies. Two market classes of chickpea, namely desi and kabuli, were grown on silt loam and heavy clay soils in southwestern Saskatchewan from 1999 to 2002. Inoculation reduced plant population by 10% for desi chickpea, but had no effect on kabuli chickpea. However, the use of inoculant increased seed yield by an average of 35% for desi chickpea and 7% for kabuli chickpea. On the heavy clay, soil inoculation increased seed yield by 16% for desi and 9% for kabuli compared with seed inoculation, whereas the yield increase due to soil inoculation, over seed inoculation, was 3% when the crops were grown on the silt loam. Granular inoculant applied in the seed row produced similar seed yields to side-banded inoculant. Inoculation delivery systems had a marginal impact on plant height, with no effect on the lowest pod height from the soil surface or days to maturity. Regardless of placement, soil inoculation with a granular form of Mesorhizobium was preferred over seed inoculation because of its greater positive impacts on plant establishment and seed yield for both desi and kabuli chickpea in this semiarid region. Key words: Cicer arietinum, seed weight, heavy clay, silt loam, harvestability
Inclusion of plant growth regulators into priming solution improves low-temperature germination and emergence of watermelon seeds
Authors: Korkmaz Ahmet , Tiryaki Iskender , Nas Mehmet Nuri , Ozbay Nusret
Published: April 2011

The effects of incorporating plant growth regulators into the priming solution on low temperature germination and emergence performance of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai. cv. Crimson Sweet] seeds were investigated. Seeds were primed in 2.5% (0.25 M) KNO3 solution for 6 d at 25°C in darkness containing one of the following: 1, 3 or 5 µM methyl jasmonate (MeJA), or 1, 3 or 5 mM spermine. Following priming, seeds were subjected to germination and emergence tests at 15°C. Priming watermelon seeds in the presence or absence of plant growth regulators significantly improved germination percentage and rate at 15°C compared to untreated seeds, which failed to germinate. Seeds primed in KNO3 solution containing 1 or 3 µM of MeJA had significantly higher germination percentages, 96 and 85%, respectively, compared to seeds primed in KNO3 only (69%). Germination rate and synchrony were improved by 1 and 3 µM of MeJA added to the priming solution. Emergence was enhanced by priming seeds in the presence of 1 µM (75%) and 3 µM (63%) MeJA compared to seeds primed in KNO3 solution, (35%) while non-primed seeds were unable to emerge at 15°C. Inclusion of spermine at all three concentrations into the priming solution did not significantly improve germination and emergence characteristics of watermelon seeds compared to seeds that were primed in KNO3 solution only. Therefore, priming watermelon seeds in 1 or 3 µM of MeJA incorporated into the KNO3 solution can be used as an effective method to improve low temperature performance of watermelon seeds. Key words: Watermelon, methyl jasmonate, polyamines, germination, emergence.
Rotational yield and apparent N benefits of grain legumes in southern Manitoba
Authors: Przednowek D. W. A. , Entz M. H. , Irvine B. , Flaten D. N. , Thiessen Martens J. R.
Published: April 2011

Knowledge of rotational N benefits of grain legumes can assist in crop rotation planning and N fertilizer management. Four annual grain legumes were tested in Manitoba field trials over 3 yr. Field pea provided the largest and most consistent apparent N benefit to a succeeding wheat crop; soybean provided relatively little N benefit. The apparent N benefits of chickpea and dry bean were inconsistent, although chickpea shows greater potential in dry conditions. Key words: Wheat rotations, N credit, crop rotation
Residue management and crop sequence effects on the yield and brown girdling root rot of canola
Authors: Soon Y. K. , Klein-Gebbinck H. W. , Arshad M. A.
Published: April 2011

Brown girdling root rot (BGRR) is a serious and widespread disease of canola (Brassica rapa L.) in the Peace River region of northwestern Canada. There is no chemical control treatment for the pathogen, and farmers have observed that the disease is more severe when canola follows red fescue (Festuca rubra L.) or clover (Trifolium spp.) compared to summer fallow. A field study was conducted to determine how crop sequences following red fescue termination can be combined with residue and tillage management to reduce BGRR infection and increase canola yield. The five treatments consisted of rotations of: continuous canola (CCC) and oat (Avena sativa L.)-oat-canola (OOC), both managed using reduced tillage (RT), and wheat (Triticum aestivum L.)-wheat-canola (WWC), managed using RT, conventional tillage (CT) or no-till (NT). Canola yield followed the trend: OOC (RT) = WWC(RT) > WWC(CT) > CCC(RT) = WWC(NT). BGRR infection increased with tillage intensity: WWC(CT) > CCC(RT) = WWC(RT) = OOC(RT) > WWC(NT), and was reduced when canola followed two cereal break crops. Yield was highest when canola was preceded by a cereal crop and lowest without a break crop. The low yield with NT was attributed to poor crop emergence from a hard seed bed with unbroken turf and to competition from re-emerged fescue in the third year after fescue breaking. This study demonstrated that the cropping sequence and tillage system used influenced canola yield to a greater extent than did BGRR infection. Key words: Brown girdling root rot, canola, crop sequence, red fescue termination, tillage
Physicochemical properties of fruit of chokecherry (Prunus virginiana L.), highbush cranberry (Viburnum trilobum Marsh.), and black currant (Ribes nigrum L.) cultivars grown in Saskatchewan
Authors: Zatylny A. M. , Ziehl W. D. , St-Pierre R. G.
Published: April 2011

Physicochemical properties of the fruit of chokecherry (Prunus virginiana L.), highbush cranberry (Viburnum trilobum Marsh.), and black currant (Ribes nigrum L.) were assessed from fruit harvested from replicated cultivar trials at Saskatoon, SK, and at Yorkton, SK, in 1999 and 2000. Fruit weight, total solids, soluble solids, pH, titratable acidity, percent pit, estimated percent flesh, and Hunterlab colour characteristics were measured. Fruit of the chokecherry cultivars ranged in their 10-fruit weights from 6.6 to 9.2 g, percent pit from 9.4 to 16.0%, estimated percent flesh from 17.2 to 23.7%, and pH from 3.86 to 4.25. Mean total solids and soluble solids contents were 35.2% and 18.3°Brix, respectively, and did not differ among the cultivars. Hue angle, chroma and L values of chokecherry fruit juice extracts ranged from 34.6 to 88.2°, 15.3 to 23.9, and 23.3 to 51.1, respectively. Fruit of the highbush cranberry cultivars ranged in their 10-fruit weights from 4.1 to 7.3 g, percent pit from 4.6 to 9.0%, estimated percent flesh from 10.9 to 14.0%, soluble solids content from 10.2 to 13.3°Brix, and pH from 2.89 to 3.13. The hue angle and L values of the fruit juice extracts of the highbush cranberry cultivars ranged from 16.0 to 18.2°, and from 15.5 to 21.3, respectively. Mean total solids content and L values were 18.9% and 18.0, respectively; both measurements did not differ significantly among the cultivars. Fruit of the black currant cultivars differed only in their 10-fruit weight, pH and titratable acidity which ranged from 7.5 to 12.8 g, 2.85 to 3.04, and 3.04 to 4.03%, respectively. Mean total solids and soluble solids contents of black currant fruit were 22.3% and 15.8°Brix, respectively. Black currant fruit juice extracts had a mean hue angle, chroma and L values of 13.2°, 12.6 and 9.8, respectively. Key words: Chokecherry, Prunus virginiana, highbush cranberry, Viburnum trilobum, black currant, Ribes nigrum, native fruit