bluuebunny/crossref_metadata_2025 huggingface dataset:
Canola and mustard response to short periods of temperature and water stress at different developmental stages
Authors: Gan Y. , Angadi S. V. , Cutforth H. , Potts D. , Angadi V. V. , McDonald C. L.
Published: April 2011

Seed yield of Brassica crops in semiarid environments can be increased by minimizing the crops’ exposure to high temperature and water stress that often occurs during the growing season. A growth chamber study was conducted to determine the effect of short periods of high temperature and water stress at different developmental stages on seed yield and yield components of Brassica crops. Two canola-quality Brassica juncea ‘PC98-44’ and ‘PC98-45’, a Brassica napus canola ‘Quantum’, and a B. juncea oriental mustard ‘Cutlass’ were grown under 20/18°C day/night temperatures with photoperiod of 16/8 h light/dark. High (35/18°C) and moderate (28/18°C) temperature stress was imposed for 10 d during bud formation, flowering, and pod development. Low (90% available water) and high (50% available water) water stress was imposed in combination with the temperature treatments. On average, the 35/18°C stress reduced main stem pods by 75%, seeds pod-1 25%, and seed weight 22% from the control. Seed yield per plant was reduced by 15% when plants were severely (35/18°C) stressed during bud formation, 58% when stressed during flowering, and 77% when stressed during pod development. Plants stressed at earlier growth stages exhibited recovery, whereas stress during pod development severely reduced most of the yield components. Effect of water stress on seed yield was minimal regardless of crop developmental stage. The four Brassica cultivars responded similarly to water stress. In response to temperature stress, B. juncea produced greater number of pods per plant but had a great rate of pod infertility than B. napus. Seed yield of B. juncea in semiarid environments can be increased by improving pod fertility, whereas the seed yield of B. napus can be increased by improving pod pro duction and retention. Key words: Oilseed, yield components, Brassica species, moisture.
Soil microbial biomass and diversity after herbicide application
Authors: Lupwayi N. Z. , Harker K. N. , Clayton G. W. , Turkington T. K. , Rice W. A. , O’Donovan J. T.
Published: April 2011

Greenhouse and field experiments were conducted to investigate the effects of herbicides on soil microbial C (microbial biomass), bacterial diversity and community structure. In the first greenhouse experiment, 12 herbicides were applied at recommended rates to a Gray Luvisolic soil contained in trays. Soil samples were collected 0, 1, 2, 3 and 4 wk after treatment and analysed for microbial C and bacterial diversity. The second greenhouse experiment was similar to the first, but only 6 of the 12 herbicides were applied to a Gray Luvisolic and Black Chernozemic soil. The same six herbicides were applied to the Gray Luvisolic soil at a field site near Fort Vermilion, Alberta, and to the Black Chernozemic soil at Lacombe, Alberta, in 2000. In the first greenhouse experiment, metribuzin, imazamox/imazethapyr, triasulfuron and metsulfuron methyl reduced microbial C compared with glufosinate ammonium and sethoxydim. In the second greenhouse experiment, microbial diversity as determined by Shannon index was lower after application of metribuzin, imazamox/imazethapyr and glufosinate ammonium than after application of glyphosate, but none of the herbicides altered microbial diversity relative to the control treatment. In the field experiments, herbicides had no effect on microbial C or diversity. In all experiments, examination of microbial community structure revealed herbicide-induced shifts in microbial composition even when diversity indices among treatments were not different. It was concluded that herbicides applied once at recommended rates did not have significant or consistent effects on microbial C or diversity. Key words: Environmental sustainability, substrate utilization, biological soil quality, community-level physiological profiles (CLPP)
Use of N-(n-butyl)thiophosphoric triamide (NBPT) to increase safety of seed-placed urea
Authors: Karamanos R. E. , Harapiak J. T. , A Flore N. , Stonehouse T. B.
Published: April 2011

Current guidelines for safe seedrow placement of urea N in the western Canadian prairies are based on texture, seedbed utilization and soil moisture conditions at the time of seeding. However, if N requirement is high, not all fertilizer N requirements can be met as excess urea N in the seedrow may result in plant stand reduction, delay in maturity and/or lead to yield loss. This study investigated the use of the urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT) as a means of increasing the safety of seedrow applied urea. Four experiments consisting of 39 trials were carried out over 3 yr to ascertain whether current guidelines could be modified through the use of NBPT. The experiments were carried out on loam to clay loam soils and barley, canola and wheat were sown with seedrow spacing and seed spread to produce seedbed utilization of approximately 10%. A safe N rate in this study was defined as the one that resulted in less than 15% reduction in the stand density of plants and no delay in maturity. There was no damage from seed-placement of N when the site received 5 to 10 mm of precipitation within 48 h of seeding. Treatment of urea with NBPT resulted in a significant improvement in stand density in two out of every three (20 of the 31) trials, where a significant reduction of stand density due to N application was observed. There were no cases where an increase in seedling damage was observed as a result of NBPT treatment of urea. Treatment of urea with NBPT resulted in an overall reduction in days to maturity with greater benefit at higher N rates of seed row placed N. However, there was a yield benefit as a result of NBPT application in only eight of the trials. Average guidelines for urea seedrow placement for barley, canola and wheat grown on medium textured soils with 10% seedbed utilization can be increased by 30, 20 and 15 kg N ha-1, respectively, when urea is treated with NBPT. Key words: Stand density, maturity, yield, barley, canola, wheat
Camptothecin accumulation in Camptotheca acuminata seedlings in response to acetylsalicylic acid treatment
Authors: Li Zhanhai , Liu Zhijun
Published: April 2011

Camptothecin is an anti-cancer alkaloid. Acetylsalicylic acid (ASA) treatment was evaluated as a potential tool for increasing camptothecin accumulation (concentration and yield) in Camptotheca acuminata. Increasing ASA concentration increased leaf camptothecin concentration, but stunted growth and decreased total leaf camptothecin yield. Thus, ASA treatment does not enhance camptothecin yield. Key words: Hydroponic culture, plant secondary metabolite
Fall and spring seeding date effects on herbicide-tolerant canola (Brassica napus L.) cultivars
Authors: Clayton G. W. , Harker K. N. , O’Donovan J. T. , Blackshaw R. E. , Dosdall L. M. , Stevenson F. C. , Ferguson T.
Published: April 2011

More flexible and effective weed control with herbicide-tolerant B. napus canola allows for additional seeding management options, such as fall (dormant) and early spring (ES) seeding. Field experiments were conducted at Lacombe and Beaverlodge (1999–2001), Didsbury (1999–2000), and Lethbridge (2000–2001), Alberta, Canada, primarily to evaluate the effect of fall (late October-November), ES (late April-early May), and normal spring (NS) (ca. mid-May) seeding dates on glufosinate-, glyphosate-, and imidazolinone-tolerant canola development and yield. Fall seeding resulted in 46% lower plant density and nearly double the dockage than spring seeding. ES-seeded canola had 19% higher seed yield and 2.1% higher oil content than fall-seeded canola. ES seeding significantly increased yield compared to fall-seeded canola for 8 of 10 site -years or compared to NS seeding for 4 of 10 site-years; ES-seeded canola equalled the yield of NS-seeded canola for 6 of 10 site-years. Yield response to seeding date did not differ among herbicide-tolerant cultivars. Seeding date did not influence root maggot damage. Seeding canola as soon as possible in spring increases the likelihood of optimizing canola yield and quality compared to fall seeding and traditional spring seeding dates. Key words: Dormant seeding, seeding management, root maggot, herbicide-resistant crops, yield components, operational diversity
Field performance of imazamox-resistant spring wheat
Authors: Pozniak C. J. , Holm F. A. , Hucl P. J.
Published: April 2011

The imidazolinone herbicides possess high biological potency at low application rates, and are an attractive alternative for weed control in spring wheat (Triticum aestivum L.). Four mutation-derived spring wheat lines resistant to the imidazolinone class of herbicides were evaluated in field trials to investigate the levels of resistance to imazamox. Imazamox was applied post-emergence at 0 g (hand-weeded control; HWC) 20 g, 40 g, 80 g and 160 g active ingredient (a.i.) ha-1. A standard herbicide treatment (SHT; clodinafoppropargyl, bromoxynil and MC PA ester) representing a common herbicide application to spring wheat in western Canada was also included. The cultivar CDC Teal was included as a susceptible control. At 160 g ha-1, imazamox reduced yield in lines with a single resistance gene (TealIMI 10A, TealIMI 11A, and BW755) by up to 43% and delayed maturity up to 13 d. TealIMI 15A, the only line evaluated with two resistance genes, was the most resistant of all lines, with no significant increases in days to spike emergence (DSE), days to physiological maturity (DPM), and no reduction in yield at the highest rate of imazamox. The susceptible control was killed within 2 wk of imazamox application, regardless of application rate. These results indicate that two resistance genes are preferable for ensuring satisfactory levels of resistance to the formulation of imazamox used in these studies. Key words: Triticum aestivum L., imazamox, resistance, gene stacking
Zone tillage systems for onion and carrot production on muck soils
Authors: Swanton C. J. , Janse S. , Chandler K. , Booth B. D.
Published: April 2011

This study examined whether zone tillage was a viable alternative to conventional tillage for carrot [Daucus carota L. var. sativus (Hoffm.) Arcang.] and onion (Allium cepa L.) production on muck soils. Total and marketable yields under zone tillage were e qual to (carrot) or greater than (onion) yields under conventional tillage. Carrot yields did not differ between raised and flat bed treatments. Key words: Reduced tillage, conventional tillage, Daucus carota L. var. sativus (Hoffm.) Arcang.); Allium cepa L.
Climate change and winter damage to fruit trees in eastern Canada
Authors: Rochette P. , Bélanger G. , Castonguay Y. , Bootsma A. , Mongrain D.
Published: April 2011

Climatic conditions during the cold season represent a serious constraint to fruit production in eastern Canada. Meteorological models predict that temperatures of winter months will increase by 2 to 6°C by 2050. The possible impact of climate change on fruit trees in eastern Canada was assessed using agroclimatic indices expressing the risks associated with known causes of damage during fall, winter, and spring. Indices were calculated for 15 agricultural regions in eastern Canada for recent (1961–1990) and future periods (2010–2039 and 2040–2069) using temperature and precipitation data predicted by the Canadian Global General Circulation Model (CGCMI). Averaged across all agricultural regions, the first fall frost in 2040–2069 would be delayed by 16 d while the last spring frost (≤-2°C) would be advanced by 15 d. By 2040 to 2069, the risks of damage to fruit trees by early winter frosts in eastern Canada are likely to decrease because the shorter photoperiod at the time of the first fall frost would result in a longer hardening period. Milder winter temperatures will also reduce the cold stress as the accumulation of cold degree-days (<-15°C) would be reduced and the annual minimum temperature would be increased in all regions of eastern Canada. More frequent winter thaw events, however, would result in a loss of hardiness and in a thinner snow cover that would increase the plant vulnerability to subsequent extreme sub-freezing temperatures. The risk of damage to flower buds by a late frost would increase in southern Ontario, remain almost unchanged in the Maritimes and Ottawa Valley-southern Québec regions, and decrease in the Continental North. The projected climate change should allow for the introduction of new varieties and species where fruit trees are currently grown and for an extension further north of the commercial production in eastern Canada. Key words: Overwintering, fruit production, climatic indices, winter injury, spring frost
Resistance of Tangmai 4 wheat to powdery mildew, stem rust, leaf rust, and stripe rust and its chromosome composition
Authors: Li H. J. , Conner R. L. , McCallum B. D. , Chen X. M. , Su H. , Wen Z. Y. , Chen Q. , Jia X.
Published: April 2011

The hard red winter wheat Tangmai 4 did not develop symptoms of infection following inoculation with powdery mildew (Erysiphe graminis DC. f. sp. tritici E. Marchal) isolates from regions of western Canada and northern China. Tangmai 4 exhibited resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & Henn.) and leaf rust (P. triticina Eriks.) races from western Canada. This wheat line was resistant to individual stripe rust (P. striiformis Westend. f. sp. tritici Eriks.) races from the U.S. and Canada. Sequential C-banding and genomic in situ hybridization (GISH), and electrophoretic analyses of high molecular weight glutenins and gliadins demonstrated that Tangmai 4 carried a pair of T1BL·1RS wheat-rye (Secale cereale L.) translocated chromosomes. Since the genes located on T1BL·1RS are no longer effective in controlling powdery mildew and the rust diseases, Tangmai 4 must carry additional genes for resistance to these diseases, which makes it a valuable resource for the improvement of resistance in wheat against these diseases. Key words: T1BL·1RS translocation, disease resistance, sequential C-banding and GISH, glutenin, gliadin
The biology of Canadian weeds. 130. Solidago nemoralis Ait.
Authors: Chmielewski Jerry G. , Semple John C.
Published: April 2011

Solidago nemoralis, the gray goldenrod, is a polycarpic hemicryptophyte that reproduces vegetatively from branched caudices. This native North American species is morphologically variable throughout its range, and includes an eastern (ssp. nemoralis) and western (ssp. decemflora) race. The eastern subspecies occurs throughout the eastern deciduous forest region of North America and is commonly diploid, though tetraploids do occur throughout. The western race typically occurs on the prairies and is strictly tetraploid. The species occupies riparian habitats, rock outcrops and open fields and roadsides and grows best in well-drained sandy soils in full sunlight. Although the species is weedy in both Canada and the United States it is not noxious. Key words: Solidago nemoralis, gray goldenrod, verge d'or des bois, Asteraceae, Compositae
Intra-specific and inter-sub-specific crossing in lentil (Lens culinaris Medik.)
Authors: Fratini Richard , Ruiz Ma Luisa , de la Vega Marcelino Pérez
Published: April 2011

Lentil crosses (Lens culinaris ssp. culinaris and L. c. ssp. orientalis) were carried out in the greenhouse and in the field, and the effects of genotype and some environmental conditions on crossing success were assessed. In the greenhouse in the fall, the independent variables “Male” and “Hour” influenced pod and seed set per pollinated flower and “Temperature” affected seed number per pod. Some genotypes and different cross combinations were better under greenhouse conditions. Seed set per pollinated flower of the best inter-sub-specific cross combination in the greenhouse (Lupa × orientalis) averaged 55.2%, while for other intra and inter-sub-specific crosses the average ranged between 3.6 to 23.5%, with an average seed set of 24.4%. Selfed progeny, as determined by morphological and molecular markers, was 5%. Fall crossing success in the greenhouse was favored by temperatures of 20–25°C and sunny mornings. In the field, none of the dependent variables significantly influenced pod or seed set per cross. The intra-specific field seed set per pollinated flower ranged from 0 to 31.1%, with a mean seed set of 13.3%. Spring crossing success in the field was favored by cloudy and rainy days with mild temperatures. Under field conditions, intra-specific crossing success was considerably lower in the spring compared to the inter-sub-specific (L. c. ssp. culinaris × L. c. ssp. orientalis) success obtained in the greenhouse in the fall. Key words: Lentil, Lens culinaris ssp. culinaris, Lens culinaris ssp. orientalis, crossing success, hybrids, environmental conditions
Effect of harvesting time on incidence of seed-borne Fusarium spp. in spring wheat in eastern Ontario
Authors: Xue A. G. , Frégeau-Reid J. , Rowsell J. , Babcock C. , Hoekstra G. J. , Sparry E.
Published: April 2011

The effect of five harvesting times on the incidence of seed-borne Fusarium spp. was examined using three spring wheat cultivars grown at two locations in eastern Ontario in 1999 and 2000. Twelve Fusarium spp. were isolated from 3831 of the 24 000 seeds, which were surface disinfected and plated onto modified potato dextrose agar. Fusarium sporotrichioides Sherb., F. graminearum Schwabe, F. poae (Peck) Wollenw., F. equiseti (Corda) Sacc., and F. avenaceum (Fr.) Sacc. were the most frequently isolated species and were isolated from 6.8, 3.7, 2.8, 1.8, and 0.6% of total seeds, respectively. The remaining species, F. acuminatum Ellis & Everh., F. crookwellense Burgess, Nelson & Toussoun, F. culmorum (W.G. Sm.) Sacc., F. oxysporum Schlecht., F. sambucinum Fuckel, F. solani (Mart.) Sacc., and F. tricinctum (Corda) Sacc., collectively infected only 0.3% of total seeds. The incidence of F. graminearum, F. sporotrichioides, and total Fusarium spp. increased about twofold, from 1.7, 3.9, and 9.5% in seed harvested very early to 5.5, 8.7 , and 19.8%, respectively, after delayed harvest. Also, F. poae had a significantly lower incidence at very early and early harvest times compared to normal or later harvest dates. Incidence of total other Fusarium spp., percentage of fusarium damaged kernels (FDK), and deoxynivalenol (DON) concentration were relatively low in the harvested grain and not affected by harvesting time. Of the three cultivars used, AC Barrie had the lowest incidence of Fusarium spp., FDK, and DON concentration in the grain; Quantum was intermediate; and Celtic had the highest. Variations in the incidence of Fusarium spp. for location and year were observed and likely related to levels of inoculum and weather conditions before and during harvesting times. Key words: Wheat, grain quality, farinograph, protein concentration, N management, cultivar selection and marketing
The use of reflective tarps at harvest to improve postharvest quality of blueberries
Authors: Toivonen Peter M. A. , Delaquis Pascal J. , Stan Sabina , Stanich Kareen
Published: April 2011

Effects of covering blueberries with reflective tarps to protect the fruit from exposure to the sun after picking were assessed. Quality was evaluated after 7 d storage at 1%C as well as after two additional days holding at 13%C. Covering fruit with reflective tarps resulted in significant improvement in quality. Improved quality of the blueberries was attributed to the lower fruit pulp temperatures and higher humidity in the airspace surrounding the tarp-covered fruit. Key words: Postharvest handling, temperature, humidity, reflective (laminated Mylar) film, microbial populations
Effect of N fertilizer on the productivity and nutritive values of perennial grass mixtures in the alpine region of Qinghai-Tibetan Plateau, China
Authors: Dong S. K. , Yang Z. F. , Long R. J. , Hu Z. Z. , Kang M. Y.
Published: April 2011

A study was conducted on grass mixtures that included smooth bromegrass (SB) + drooping wild ryegrass (DW), smooth bromegrass + Siberian wild ryegrass (SW) + crested wheatgrass (CW) and smooth bromegrass + Siberian wild ryegrass + drooping wild ryegrass + crested wheatgrass in the alpine region of Qinghai-Tibetan Plateau. The study was conducted from 1998 to 2000 to investigate the effects of N application rates and growing year on herbage dry matter (DM) yield and nutritive values. Herbage DM production increased linearly with N application rates. The effect of N application on DM yields was greater (P < 0.05) in the 2nd and 3rd production years than in the establishment year. Dry matter yields of SB + SW + CW and SB + SW + DW + CW can reach as high as 15 000 kg ha-1 at 345 kg ha-1 N rate in the 3rd growing year. With increased N application rates, crude protein (CP) contents and 48 h in sacco DM degradability of grasses increased (P < 0.05). No effect (P > 0.05) of N application was detected on organic matter (OM) and acid detergent fibre (ADF) concentration. It can be concluded that for increased biomass production in the alpine region of the Qinghai-Tibetan Plateau, a minimum of 345 kg N ha-1 should be applied to grass stands in three split application of 115 kg N ha-1, in early June, early July and late July. Key words: Nitrogen levels, herbage dry matter yield, leaf shoot ratio, crude protein contents, dry matter degradability
Evaluation of components of resistance to powdery mildew in field pea
Authors: Xue A. G. , Dyck B. S. , Warkentin T. D.
Published: April 2011

Field trials were conducted to evaluate 12 field pea (Pisum sativum L.) cultivars and lines (AC Melfort, AC Tamor, Highlight, Tara, 267-PS210713, 89-2910, JI100, JI1543, JI95, JI96, PI273605, PI311112) for resistance to disease progression and components of resistance to powdery mildew (Erysiphe pisi DC.), in comparison to the susceptible check cultivar Radley in 1998 and 1999. The disease progression was measured as area under the disease progress curve (AUDPC) and the components of resistance were leaf area with symptoms (LAS), lesion diameter (LD), lesion numbers (LN), and sporulation (SP). All 12 lines had significantly lower AUDPC, LAS, LN, and SP than the susceptible check, but only five (AC Tamor, Tara, 267-PS210713, 89-2910, JI1543) showed a smaller LD. A greater range of variability was observed for AUDPC, LAS, and LN than for SP among the 12 lines, suggesting that AUDPC, LAS, and LN are more useful for measuring varietal resistance. Since AUDPC, LAS, and LN were highly correlated (P < 0.01), only one component would be required in screening pea lines for powdery mildew resistance. Key words: Powdery mildew, Erysiphe pisi, field pea, Pisum sativum, resistance
Effect of nitrogen, seeding date and cultivar on oat quality and yield in the eastern Canadian prairies
Authors: May William E. , Mohr Ramona M. , Lafond Guy P. , Johnston Adrian M. , Craig Stevenson F.
Published: April 2011

The proportion of oat (Avena sativa L.) being used for race horses and human consumption has increased over the past 15 yr. The objective of this study was to evaluate the effects of N, seeding date and cultivar on grain yield components, grain yield and grain quality of oat under a direct seeding system. Four N rates, three seeding dates and two cultivars were tested at Indian Head, Melfort, and Canora, SK, and Brandon, MB. Yield was more responsive to increasing N rates from 15 and 80 kg ha-1 when oat was seeded in early May versus early June. Panicles plant-1 was the yield component that accounted for most of the yield increase achieved from increasing rates of N, while kernel weight was the yield component that decreased as the rate of N increased. Physical seed quality decreased (plump seed decreased and thin seed increased) with delayed seeding and greater N fertilizer rates. Nitrogen fertilizer and seeding date had a much larger effect on the quality of CDC Pacer than AC Assiniboia. Combining early seeding, appropriate N fertility and well-adapted cultivars should increase the likelihood of optimizing oat yield and quality necessary for high-value markets. Key words: Avena sativa L., yield components, test weight, lodging, plump seed, thin seed
Mycorrhizal colonization of flax under long-term organic and conventional management
Authors: Entz M. H. , Penner K. R. , Vessey J. K. , Zelmer C. D. , Thiessen Martens J. R.
Published: April 2011

Arbuscular mycorrhizal fungi are of particular interest in organic agricultural systems. We studied the effects of crop rotation and crop management system (conventional vs. organic) on mycorrhizal colonization of flax roots, in the 12th year of a long-term crop rotation trial. Colonization was higher in organic treatments than conventional, possibly due to decreased P availability. There was a highly significant rotation × management system interaction, which may be explained by differences in the abundance of mycorrhizal and non-mycorrhizal weed species between the two management systems. Further research is required before stronger conclusions can be made. Key words: Crop rotation, arbuscular mycorrhizal fungi, flax, wild mustard, host-plant dynamics, organic agriculture
Physicochemical properties of fruit of 16 saskatoon (Amelanchier alnifolia Nutt.) cultivars
Authors: Zatylny A. M. , Ziehl W. D. , St-Pierre R. G.
Published: April 2011

Physicochemical properties were assessed for the fruit of 16 saskatoon (Amelanchier alnifolia Nutt.) cultivars harvested in 1998–2000 from replicated trials at two sites (Saskatoon and Moonlake, SK). The cultivars included Bluff, Buffalo, Elizabeth (at Saskatoon only), Forestburg, Honeywood, JB30, Martin, Nelson, Northline, PAR 90, Parkhill, Pearson II, Pembina, Smoky, Success, and Thiessen. Fruit weight and total solids, soluble solids, pH, titratable acidity, anthocyanin content, and colour characteristics of the fruit juice extracts were measured. Fruit of Martin, Thiessen and PAR 90 had the highest fruit weights (mean = 1.63 g), and Success and Bluff the lowest (mean = 0.79 g). Total and soluble solids contents ranged among cultivars from 19.9% and 14.0 °Brix, respectively, for JB30, to 27.9% and 20.1 °Brix, respectively, for Pembina. Fruit pH ranged from 3.65 for Nelson to 4.18 for Parkhill and Smoky. Fruit of Nelson had a titratable acidity (0.63%) that was approximately twice that of Success, Pearson II, Forestburg, Honeywood, Smoky and Parkhill. The soluble solids to titratable acidity ratio (SS/TA) differed greatly among cultivars ranging from 27 for JB30 to 55 for Parkhill. The colour characteristics of the fruit juice extracts differed among cultivars in chroma and L values, but not in hue angle. Anthocyanin analysis by HPLC identified four peaks: cyanidin-3-galactoside, cyanidin-3- glucoside and two unknowns. Total fruit anthocyanin content ranged from 414 µg g-1 for Forestburg to 852 µg g-1 for Nelson. Correlations were found between anthocyanin content and fruit pH, titratable acidity, hue angle and L value. Key words: Amelanchier alnifolia, saskatoon, fruit composition, acidity, anthocyanin content
Evaluation of growth and fruit production characteristics of 15 saskatoon (Amelanchier alnifolia Nutt.) cultivars at maturity
Authors: St-Pierre R. G. , Zatylny A. M. , Tulloch H. P.
Published: April 2011

The objective of this study was to quantitatively evaluate the growth, yield, fruit size and ripening characteristics of mature plants of 15 saskatoon (Amelanchier alnifolia Nutt.) cultivars. Data were collected from two sites in Saskatchewan over 5 yr (1999–2003). The cultivars included Bluff, Buffalo, Forestburg, Honeywood, JB30, Martin, Nelson, Northline, PAR 90, Parkhill, Pearson II, Pembina, Smoky, Success, and Thiessen. Mean annual growth of shoots ranged from 10.5 cm yr-1 for Parkhill to 21.4 cm yr-1 for JB30. The number of days for fruit to change from 10 to 90% ripe did not differ among the cultivars and averaged 13.8 d. The Julian date to attain 50% ripe fruit ranged from 196 to 209. Fruit of PAR 90, Honeywood, JB30, Martin, Success and Thiessen matured 4–13 d earlier than fruit of Bluff, Northline, Parkhill, Buffalo, Nelson, and Pembina. Marketable yields, which averaged 93.4% of the total harvested yields, ranged from 0.72 to 4.16 kg plant-1. Pearson II, Honeywood, and Smoky had greater marketable yields (4.1–4.16 kg plant-1) than did PAR 90, Parkhill, Nelson, Success, and Pembina (0.72–2.49 kg plant-1). Thiessen, Martin, PAR 90 and JB30 had the largest fruit (13.3–13.9 mm), and Success and Bluff had the smallest (10.8–10.9 mm). Data from this study provide a basis on which to evaluate currently available cultivars and new cultivars or future selections that may be developed. Key words: Amelanchier alnifolia, fruit size, shoot growth, cultivar evaluation, ripening
A field method for screening maize cold to lerance
Authors: Dwyer L. M. , Ma B. L. , Ying J. , Topp G. C.
Published: April 2011

Screening of cold-tolerant genotypes is hampered by the lack of a reliable field-evaluation method. A study was conducted to develop a field screening method for cold tolerance by recreating seedbed conditions limiting seed growth and quantifying the effect of those limiting parameters on the germination and emergence of two maize hybrids. By comparing maize germination and emergence in uncovered control plots with those covered with reflective insulation, differences were monitored in soil temperature, soil water content, oxygen and air content. Maize germination and emergence were monitored, and rate of radicle and coleoptile growth was measured. Soil temperature was significantly reduced by covering with reflective insulation. The average soil temperature at 5 cm depth was 5.5 and 7.4°C in late April, 11.0 and 16.0°C in May and 14.0 and 16.6°C in early June for the covered and uncovered treatments, respectively. In addition, day-to-day fluctuation in maximum and minimum temperatures was much smaller under covered than uncovered conditions. Although air content was maintained (about 34% on average), seedbed oxygen content dropped tremendously three times during the growing period. Reflective insulation cover caused a 5-d delay in germination and emergence for both hybrids. On average, across hybrids, the daily growth rate of radicle and coleoptile was 50% and 22% higher in uncovered than in covered treatments. Reflective insulation cover created adverse growth conditions and reduced seed germination, which suggests that it could be used to create uniform cold seedbed conditions for screening maize cold tolerant lines under field conditions. Key words: Soil temperature, soil water content, germination, emergence, Zea mays L.
RCAT Dover soybean
Authors: Stirling B. T. , Fischer J. D. , Zhao G. , Ablett G. R.
Published: April 2011

RCAT Dover is a 3150 crop heat unit (CHU) soybean [Glycine max (L.) Merrill] cultivar with excellent yield potential and good lodging resistance. It was developed by the Ridgetown College, University of Guelph, and is adapted to the 3100–3400 CHU areas of Ontario. RCAT Dover was issued registration number 5342 on 2001 Feb. 04 by the Variety Registration Office, Plant Production Division of the Canadian Food Inspection Agency. Key words: Soybean, cultivar description
PRO 28-53 soybean
Authors: Stirling B. T. , Fischer J. D. , Zhao G. , Ablett G. R.
Published: April 2011

PRO 28-53 soybean [Glycine max (L.) Merrill] was developed by the Ridgetown College, University of Guelph, and was issued registration number 5569 on 2002 Dec. 12 by the Variety Registration Office, Plant Production Division of the Canadian Food Inspection Agency. PRO 28-53 has excellent yield potential and moderate lodging resistance, and is adapted to the 2800–3000 crop heat unit (CHU) areas of Ontario. Key words: Soybean, cultivar description
Impact of crop sequence decisions in the Saskatchewan Parkland
Authors: Johnston A. M. , Kutcher H. R. , Bailey K. L.
Published: April 2011

Rotations are constantly being adapted to current economic and management realities. As a result, the crop sequence used tends to depend more on the economic value of particular crop types, principally cereals, oilseeds and pulse crops in the Saskatchewan Parkland, than on the best management practices for optimizing crop productivity. A study was conducted from 1999 to 2001 at Melfort, SK, to assess the effects of growing barley, wheat, canola, flax, and field pea on their own and the other crop stubbles. When a crop was seeded on its own stubble, the poorest grain yield and quality were recorded, a difference that often was related to major pathogens affecting crop productivity. In the first 2 yr of this study, when near normal temperature and precipitation were recorded, little difference was observed in the average crop yield response when any of the crops were seeded on the other broadleaf and cereal stubbles considered in the study. The exception was flax, which performed poorer when seeded on canola than flax stubble, a reflection of the negative impact canola has on arbuscular mycorrhizae populations on subsequent flax in rotation. In 2001, a year with below-normal precipitation and above-average temperature, crops seeded into pea and flax stubble had yields that were 15–40% of the best stubble treatments. Under these drought conditions, field pea was the best crop choice for flax stubble, while wheat was the best choice for pea stubble. The results of this study indicate that for the Saskatchewan Parkland, the lowest risk crop sequence decision is to avoid seeding a crop in its own stubble. Key words: Malt barley (Hordeum vulgare L.), spring wheat (Triticum aestivum L.), canola (Brassica napus L.), flax (Linum usitatissimum L.), pea, (Pisum sativum L.), crop rotation, disease management
Down-regulated gene expression of cold acclimated Poncirus trifoliata
Authors: Zhang Can-Kui , Lang Ping , Ebel Robert C. , Dane Fenny , Singh Narendra K , Locy Robert D. , Dozier William A.
Published: April 2011

Citrus sp. are important commercial fruit crops throughout the world that are occasionally devastated by subfreezing temperatures. Poncirus trifoliata (maximum freeze tolerance of -26°C) is a close relative of commercial Citrus sp. (maximum freeze tolerance of -10°C) that has been used in breeding programs to develop more cold-hardy genotypes and as a rootstock to enhance freeze tolerance of the scion. Species with greater freeze tolerance vary in gene expression during cold acclimating temperatures. mRNA differential display (DDRT-PCR) and quantitative relative RT-PCR were used to study down regulation of gene expression in intact P. trifoliata exposed to a gradual cold acclimation regime to enhance our understanding of the mechanism that makes this specie so freeze tolerant. Six down-regulated genes were isolated and sequenced. These down-regulated genes showed high homology to the following known genes: chlorophyll a/b binding protein, photosystem II OEC 23, carbonic anhydrase, tumor related protein, pyrrolidone-carboxylate peptid ase and β-galactosidase. Photoprotection and the global control of gene expression related to photosynthesis appear to be important mechanisms for cold acclimation of P. trifoliata. Key words: Differential display, down-regulated genes, Poncirus trifoliata, cold acclimation and quantitative relative RT-PCR
Relationships among growing degree-days, tenderness, other harvest attributes and market value of processing pea (Pisum sativum L.) cultivars grown in Quebec
Authors: Nicolas Tremblay Edith Fallon, , Desjardins Yves
Published: April 2011

In Quebec, grower income from processing peas is a function of yield and tenderometer reading. If peas are harvested early, the yield is poor, but the overall quality is superior, as indicated by lower tenderometer readings. Later harvests result in g reater yields but reduced quality (higher tenderometer readings). A better understanding of the relationship between harvest time, yield and quality is needed. In this study, the relationships between yield, tenderometer readings, size distribution and grain moisture content were examined as a function of growing degree-days (GDD) and production year for pea cultivars of different seed size categories. Yield and harvest attributes (tenderometer readings, seed size distribution and moisture content) were highly season dependent and their rates of change over the course of the harvest period also varied with the cultivar and year. Quality declined rapidly once the crop reached optimal maturity, while yield increased in a less predictable manner. Consequently, it was difficult to identify a harvest time that would consistently maximize grower returns. The highest income was generally not obtained at the optimal tenderometer readings presently used by the industry. Key words: Maturity, harvest date, climate, fresh matter yield, tenderometer, pea size
CDC Bronco field pea
Authors: Warkentin Tom , Vandenberg Albert , Banniza Sabine , Slinkard Al
Published: April 2011

CDC Bronco, a yellow cotyledon field pea (Pisum sativum L.) cultivar, was released in 2004 by 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. CDC Bronco has a semileafless leaf type, good lodging resistance, powdery mildew resistance, medium-sized, round seeds, and good yielding ability. CDC Bronco is adapted to the field pea growing regions of western Canada. Key words: Feld pea, Pisum sativum L., cultivar description
A comparison of seed-propagated and micropropagated Amelanchier alnifolia (saskatoon): Yield and yield components in relation to crown architecture characteristics
Authors: Remphrey William R. , Pearn Linda P.
Published: April 2011

A study of the architecture and yield components of young micropropagated and seed-propagated Smoky saskatoons over a 4-yr period revealed no differences in height, but the diameters and branchiness ratings of the seedling plants were greater. In the 3 yr of fruit harvest there were no differences in mean fruit weight or fruit number between propagation types, but there was a difference among years. The yield was considerably greater in the third year of harvest (1996), possibly reflecting the natural tendency for yield to increase as the plants develop. In all 3 yr, fruit ripening peaked in July, with most fruit harvested within about a week on either side of the peak. Although there were strong correlations between the number of infructescences and both fruit weight and fruit number, there was little difference between propagation types. There were no relationships between main-stem diameter and the weight or number of fruit that the plant bore. However, there was a positive linear relationship between yield parameters and the diameter of the shoots bearing that portion of the crop in 1994 and 1995. Although not different between propagation types, terminal shoots were longer and greater in diameter and in 1995 bore three times more fruit yield than did lateral shoots. There were no differences between propagation types in the weight of fruit per infructescence or in the mean weight (0.71 ± 0.02 g) or diameter (10.81 ± 0.11 mm) per fruit. Key words: Fruit size, fruit number, Smoky, ripening period
Glenavon hard red extra strong spring wheat
Authors: Humphreys D. G. , Townley-Smith T. F. , Czarnecki E. , Fox S. L. , Brown P. D.
Published: April 2011

Glenavon hard red extra strong spring wheat (Triticum aestivum L.) is adapted to the Canadian prairies. It combines 2 to 6% higher grain yield with improved test weight compared to AC Corinne, Glenlea and Wildcat. It is resistant to moderately resistant to prevalent races of leaf and stem rust, resistant to loose smut, and of intermediate resistance to common bunt. Glenavon is eligible for all grades of the Canada Western Extra Strong wheat class. Key words: Triticum aestivum L., Canada Western Extra Strong, hard red extra strong spring wheat, cultivar description, yield, disease resistance
Winter damage to perennial forage crops in eastern Canada: Causes, mitigation, and prediction
Authors: Bélanger G. , Castonguay Y. , Bertrand A. , Dhont C. , Rochette P. , Couture L. , Drapeau R. , Mongrain D. , Chalifour F.-P. , Michaud R.
Published: April 2011

Harsh winter climate results in frequent losses of stands and yield reduction in many forage-growing areas of Canada and other parts of the world. Climatic conditions and crop management both affect the winter survival of perennial forage crops. In this review, we present the main causes of winter damage in eastern Canada and we discuss crop management practices that help mitigate the risks of losses. Predictive tools available to assess the risks of winter damage both spatially and temporally are also presented. Our understanding of the causes of winter damage and of the plant adaptation mechanisms to winter stresses, particularly the role of N and C organic reserves, has improved. Forage species commonly grown in eastern Canada differ in their tolerance to subfreezing temperatures and to anoxia caused by the presence of ice on fields. Some improvement in winter hardiness of forage legume species has been achieved through breeding in eastern Canada but new technologies based on laboratory freezing tests and the identification of molecular markers may facilitate the future development of winter-hardy cultivars. Crop management practices required for good winter survival are now better defined, particularly those involving cutting management and the interval between harvests. Simulation models and climatic indices derived from our current knowledge of the causes of winter damage provide general indications on the risk of winter damage but their degree of precision and accuracy is still not satisfactory. Further improvements in winter survival require a more thorough understanding of the different causes of winter damage and, primarily, of their complex interactions with genetic, climatic, and management factors. Key words: Alfalfa, organic reserves, culitvars, species, management, climate
CDC ChiChi kabuli chickpea
Authors: Warkentin Tom , Banniza Sabine , Vandenberg Albert
Published: April 2011

CDC ChiChi, a kabuli chickpea (Cicer arietinum L.) cultivar, was released in 2002 by the Crop Development Centre, University of Saskatchewan for distribution to Select seed growers in western Canada through the Variety Release Program of the Saskatchewan Pulse Growers. CDC ChiChi has a pinnate leaf type, poor ascochyta blight [Ascochyta rabiei (Pass.) Labr.] resistance, medium maturity, large seed size and good yielding ability in the Brown and Dark Brown soil zones of the Canadian prairies. Key words: Chickpea, Cicer arietinum L., cultivar description, ascochyta blight
Variable crop plant establishment contributes to differences in competitiveness with wild oat among cereal varieties
Authors: O’Donovan John T. , Blackshaw Robert E. , Neil Harker K. , Clayton George W. , McKenzie Ross
Published: April 2011

Field experiments were conducted at three locations in Alberta to determine the relative competitiveness with wild oat (Avena fatua L.) of three hard red spring (HRS) and three Canada prairie spring (CPS) wheat (Triticum aestivum L.) varieties and a semidwarf hull-less barley (Hordeum vulgare L.) (Falcon), and normal height general purpose barley (AC Lacombe). Crop variety significantly affected crop yield loss, wild oat shoot dry weight and wild oat seed yield (competitive indicators). AC Lacombe barley was consistently more competitive than Falcon barley or any of the wheat varieties, while the HRS wheat varieties were mainly more competitive than the CPS varieties. Falcon barley was generally similar in competitiveness to the CPS wheat varieties. Differences among varieties in crop plant density at establishment correlated significantly with the competitive indicators suggesting that this factor contributed to the differences in competitiveness among the varieties. Crop density tended to be higher with the more competitive AC Lacombe barley and HRS wheat varieties than with the less competitive Falcon barley and CPS wheat varieties. Variety and seeding rate did not interact significantly but intentionally increasing the seeding rate improved the competitiveness of all varieties. Key words: Hard red spring wheat, Canada prairie spring wheat, crop seeding rate, hull-less barley, semi-dwarf wheat and barley
Regulation of low-temperature tolerance in barley under field conditions in northwest Iran
Authors: Mahfoozi S. , Limin A. E. , Ahakpaz F. , Roustaii M. , Ketata H. , Fowler D. B.
Published: April 2011

Low-temperature (LT) stress is a major factor limiting the over-winter survival of barley (Hordeum vulgare L.). The objective of this study was to determine the relationship between vegetative/reproductive transition and expression of LT tolerance in barley cultivars acclimated under field conditions. Three cultivars with different vernalization response and photoperiod sensitivity were planted in the field at the Maragheh Dryland Agricultural Research Station (37°15′N, 46°15′E; 1720m) in Iran in the autumns of 2002 and 2003. LT tolerance, as measured by LT50, and stage of phenological development, as estimated from final leaf number (FLN) and shoot apex developmental morphology, were determined during the autumn and winter seasons. The short-day insensitive spring-habit cultivar Rihane-03 had a limited ability to acclimate to LT and it reached its maximum level of LT tolerance very quickly. The winter-habit cultivar Dobrinya reached its maximum LT tolerance at the point of vernalization saturation. The very short-day (SD) sensitive spring-habit cultivar Dicktoo entered the double ridge (DR) stage at about the same time as the winter-habit Dobrinya. The delay in the phenological development of both Dobrinya and Dicktoo was accompanied by increased expression of LT tolerance confirming that the length of the vegetative phase determines a plant’s ability to maintain a high level of cold-tolerance gene expression when temperatures are in the acclimation range. These observations suggest that more detailed studies should be initiated to establish the importance of interactions between photoperiod sensitivity and vernalization requirement with the objective of identifying genetic combinations and management systems that extend the vegetative stage and provide longer-term protection from LT stress in regions with long mild winters like those normally experienced in north-west Iran. Key words: Vernalization, photoperiod, phenological development, freezing resistance, barley
Oat quality and yield as affected by kernel moisture at swathing
Authors: May William E. , Mohr Ramona M. , Lafond Guy P. , Craig Stevenson F.
Published: April 2011

Increased demand for high-quality oat has rekindled interest in improving oat (Avena sativa L.) yield and quality by managing the timing of oat swathing. The objective of this study was to determine the effect of swathing at five levels of kernel moisture on yield and seed quality at Indian Head, SK, and Brandon, MB, from 1997 (Indian Head only) to 2000. The largest benefit to yield and quality was achieved when swathing was delayed from 50 to 41% kernel moisture. Kernel weight, plump seed and groat yield were optimized when kernel moisture was between 36 and 30% moisture content. Dockage, protein content and oil content also improved with later swathing dates. Swathing should not begin until a kernel moisture content of 41% has been reached. After 30% kernel moisture was reached, no improvement in oat yield and quality occurred when swathing was delayed any further. Key words: Avena sativa L., test weight, thin seed, groat yield, protein, germination