bluuebunny/crossref_metadata_2025 huggingface dataset:
Foliar application of lipo-chitooligosaccharides (Nod factors) to tomato (Lycopersicon esculentum) enhances flowering and fruit production
Authors: John McIver Chunquan Chen, , Yuming Bai Yang Yang, , Schultz Birgit , McIver Alison
Published: April 2011

Lipochitooligosaccharides (LCO) or Nod factors, which are rhizobia-produced signal molecules, induce deformation of legume root hairs. In addition to triggering legume plant nodulation, Nod factors influence cell division and promote somatic embryo generation in non-legume plants. This suggested to us the potential of using LCO to stimulate the development of tomato flowers and fruit. This study indicated that the foliar application o f LCO to tomato plants during the appropriate stages increased flower numbers and early fruiting in greenhouse trials. Flower stimulation by LCO occurred 1-2 wk after application and fruit numbers increased 2-4 wk after application. The accelerated flowering and fruiting resulted in an increase in tomato fruit yield. The most effective concentration of LCO was 50 ng per plant applied twice in the greenhouse, initially during the early flowering stage and again in the late flowering stage. A field trial in 2002 indicated that the optimal LCO application concentration was 10 ng per plant applied at the early flowering stage, which increased fruit yield and number by up to 29.8 and 29.4%, respectively. When plants received a second LCO application at the early fruiting stage, the fruit yield increased, but most were unmarketable green fruits. Analyses of yield data showed that the yield increase in field-grown tomatoes was due to an increase in the fruit number per plant, but not to individual fruit weight or fruit size. The average weight per fruit due to the treatment was not different from the control. A second field trial, carried out in 2003, showed that a foliar application of LCO at 50 ng per plant produced the best tomato yield. Our studies indicate that an LCO foliar application to tomatoes in the range of 10-50 ng per plant can increase early flowering and fruiting, which results in improved fruit yield. Key words: early flowering, foliar application, fruiting, growth promotion, lipo-chitooligosccharides, tomato yield
Maturation effects on forage quality of Kentucky bluegrass
Authors: Hockensmith R. L. , Sheaffer C. C. , Marten G. C. , Halgerson J. L.
Published: April 2011

Kentucky bluegrass (Poa pratensis L.) is an important constituent of many permanent pastures in the northern United States and is an important source of livestock feed, but there is a paucity of information on its forage quality. The objective of this research was to assess changes with maturity in forage quality of whole herbage, leaves, and stems of Kentucky bluegrass compared with other important cool-season forage grasses. Kentucky bluegrass, orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinaceae L.), smooth bromegrass (Bromus inermis Leyss), timothy (Phleum pratense L.), and tall fescue (Festuca arundinacea Schreb) were sampled weekly beginning in mid-May until each species reached milk stage. Kentucky bluegrass had the highest or was among the grasses with the highest average leaf percentage, and leaf, stem, and whole herbage neutral detergent fiber (NDF) and acid detergent lignin (ADL) concentrations; and lowest average whole herbage, leaf, and stem in vitro digestible dry matter (IVDDM) concentrations compared with tall growing species. Kentucky bluegrass also had the slowest rates of change in leaf and stem concentration and in whole herbage IVDDM and NDF concentrations with maturity. Leaf concentration was negatively correlated with herbage NDF and ADL concentration, but was not correlated with herbage IVDDM and CP concentration. Relative to tall growing cool season grasses, Kentucky bluegrass is leafier, but it has poorer forage digestibility. Key words: Poa pratense L., forage quality, perennial grass, leaves, stems
Effects of slow-release fertilizers on growth and on uptake and leaching of nutrients in Kentucky bluegrass turfs established on sand-based root zones
Authors: Engelsjord M. E. , Singh B. R.
Published: April 2011

Sports fields constructed on sand-based root zones are generally permeable to water and nutrients, and potential contaminants of the groundwater. This study was conducted to determine the effect of slow-release and water-soluble fertilizers on growth, nutrient uptake and leaching from a sand-based Kentucky bluegrass (Poa pratensis L.) turf. Two root zone mixtures and two N rates were investigated in two independent lysimeter experiments. In the first experiment (1) the 80:20 sand-peat mixture gave better growth and darker-colored turf than the 60:40 sand-peat mixture. Only RC-NPK and water-soluble NPK treatments in this experiment gave acceptable turf quality for the entire growing season. Frequent application with water-soluble fertilizer or spring application with slow-release carriers gave generally <5 mg L−1 NO3-N in the leachate. In the second experiment (2) application of 300 or 450 kg N ha−1 (either as spring or spring/summer application) as urea-ammonium-nitrate (UAN) (gel) did not give desirable turf growth during the entire period of investigation. Sulfur-coated urea gave generally better turf quality than UAN, but not as good as biweekly compound NPK fertilization. Irrespective of fertilizer N rate, the leaching losses of N varied from 1.1 to 2.9%, giving average NO3-N concentrations in the leachate for all treatments <2 mg L−1. Sandy soil used for sports turf, and fertilized with SCU and RC-NPK, or frequent and small amounts of water-soluble N carriers, appears not to create any serious environmental concern in southern part of Norway where the rainfall is moderate. Key words: Kentucky bluegrass, leaching, nitrogen, nutrient uptake, sand-based rootzone, slow-release fertilizers
Influence du déficit de pression de vapeur et de la photopériode sur la croissance, la productivité et la composition minérale de la tomate de serre
Authors: Iraqi D. , Gauthier L. , Dorais M. , Gosselin A.
Published: April 2011

The objective of this study was to determine the effect of four vapour pressure defecits (VPD) and three photoperiods on growth, yield and mineral composition of tomato plants. A factorial experiment was conducted from 28 July 1993 to 30 May 1994 in a greenhouse at Laval University Envirotron in Québec, Canada. Four day/night VPD treatments were compared: 1) 0,4/0,4 kPa, 2) 0,97/0,4 kPa, 3) VPD adjusted to a transpiration rate of 800 mL d−1 plant−1 and 4) 0,97/0,97 kPa. For each VPD treatment, three photoperiods were used: 1) 12 h, 2) 14 h and 3) seasonal progressive photoperiod of 12 to 16 h. The highest VPD significantly increased total and marketable yield, biomass and Ca, Mg, K, N and P contents of the leaves. Results obtained with adjusting the VPD to transpiration needs showed no significant differences with those obtained with the highest VPD. Photoperiod effects were not significant. Key words: Vapour pressure defecit, tomato, Lycopersicon esculentum, biomass, mineral analysis
The influence of tillage and crop rotation on nitrogen fixation in lentil and pea
Authors: Matus A. , Derksen D. A. , Walley F. L. , Loeppky H. A. , Kessel C. van
Published: April 2011

Direct seeding into standing stubble and crop diversification are two practices that are becoming widely adopted in western Canada. This study was conducted to determine: i) the influence of zero and conventional tillage on N-fixation in lentil (Lens culinaris Medikus) and pea (Pisum sativum L.), and ii) the effect of cropping history on N-fixation in lentil. Data were obtained from a crop rotation experiment being conducted on a silty clay soil in east-central Saskatchewan, which included six cereal-oilseed-cereal-pulse rotations, each managed using zero and conventional tillage practices. The finding showed that N-fixation was 10% higher by lentil and 31% higher by pea when grown using zero tillage as compared to conventional tillage practices. On average, lentil grown in highly diversified crop rotations fixed 12% more nitrogen than when grown in less diversified crop rotations. Key words: Nitrogen fixation, lentil (Lens culinaris Medikus), pea (Pisum sativum L.), zero tillage, conventional tillage
Heritability in the early nodulation of F3 and F4 soybean lines
Authors: Pazdernik D. L. , Graham P. H. , Orf J. H.
Published: April 2011

We have previously identified differences among soybean [Glycine max (L.) Merr.] lines in early nodulation and N2 fixation, and related early nodule development and overall plant performance under N-limited field conditions. The objectives of the present study were: 1) to estimate heritabilities for nodule fresh weight (NFW), shoot dry weight (SDW), and root dry weight (RDW) determined 17 d after inoculation (DAI); 2) to examine genetic variation for total nodule soluble protein (TSOLP) at 17 DAI, and SDW and shoot N derived from fixation (SNdfa) at the R5 growth stage; and 3) to assess relationships between early nodulation and subsequent R5 shoot mass and SNdfa. The two populations used were derived from the Minnesota-adapted cultivars Kasota and Parker, and two plant introductions PI 437966 and PI 384469B. Genetic variances within populations were significant for most traits measured at 17 DAI, and at the R5 growth stage. Heritability estimates ranged from 0.79–0.82 for NFW, 0.51–0.56 for SDW, and 0.38–0.40 for RDW, with SDW also correlated with seed size at 17 DAI (r = 0.88**). Additional correlation analyses showed SNdfa correlated with NFW (r = 0.33**) and TSOLP (r = 0.46**). The results of this study suggest that gains from selection are possible for NFW and SDW at early stages of plant development. Key words: Glycine max (L.) Merr., nodulation, nitrogen fixation, heritabilitynot available
Mapping dry matter and sugars in potato tubers for prediction of whole tuber process quality
Authors: Pritchard M. K. , Scanlon M. G.
Published: April 2011

Processing quality parameters within different sections of potato (Solanum tuberosum L.) tubers grown in Manitoba were measured to determine variability within tubers and to determine if whole tuber quality could be predicted from a specific section. The section that provided the best prediction of overall tuber quality parameters was determined. Changes in specific gravity (SG) and sugars in the outside and the inside of tubers during several months of storage were also measured. Dry matter (DM) of potato cvs. Russet Burbank and Shepody was generally higher at the apical and stem ends than in the middle section and was significantly higher in the outside than in the inside of the tuber. Sucrose concentration generally decreased from the stem end to the apical end of the tuber in Russet Burbank but increased from the stem end to the apical end in Shepody. Sucrose, glucose, and fructose were generally greater, though not always significantly, in the inside of the tuber compared with the outside with the exception of sucrose in Shepody where it was somewhat higher in the outside section. Glucose and fructose generally decreased from stem end to apical end although the difference between the two ends was significant only in Shepody. There was more variability in DM and the three sugars within Shepody tubers than those of Russet Burbank. The outer section of the tuber at the centre of the longitudinal axis (CO) was, overall, most highly correlated to the DM (r2 > 0.91) of the entire tuber for both cultivars and would be the most appropriate single location for estimating the DM of the entire tuber. Sugar concentrations of whole tubers could not consistently be estimated from that of any particular tuber location although the CO section had the highest correlations overall. During 6 mo storage SG did not change while sucrose decreased and glucose and fructose generally increased in both the outside (CO) and inside (CI) of the tuber. Linear regressions relating DM, SG, and sugars of the CO section to the whole tuber, and relating DM to SG were developed. Key words: Solanum tuberosum L., specific gravity, storage, processing, product quality
Inheritance of stomatal conductance in a durum wheat cross
Authors: Clarke J. M.
Published: April 2011

Stomatal conductance tends to be positively correlated with grain yield of wheat (Triticum spp.) in irrigated environments and negatively correlated in dry environments, but little is known of its inheritance. High stomatal conductance appeared to be controlled by a single dominant gene in a durum wheat (T. turgidum L. var. durum) cross. Realized heritability, calculated from divergent F3-derived F5 families, was 0.40 ± 0.07. Key words: Triticum turgidum L. var durum, realized heritability
Early corn seedling growth response to phenolic acids
Authors: Janovicek K. J. , Vyn T. J. , Voroney R. P. , Allen O. B.
Published: April 2011

Phenolic (vanillic, p-coumaric, ferulic and p-hydroxybenzoic) acids inhibited corn seedling radicle elongation in bioassay studies, especially at solution concentrations exceeding 1.0 × 10−4M. Radicle growth inhibition among hybrids was different when p-coumaric or ferulic acids were assayed, suggesting that corn sensitivity to phenolic acid phytotoxicity may be hybrid dependent. Key words: Allelopathy, phenolic acids, radicle growth inhibition, corn, Zea mays L., hybrid response
Relationships between planting date, winter survival and stress tolerances of soft white winter wheat in eastern Ontario
Authors: Andrews C. J. , Pomeroy M. K. , Seaman W. L. , Butler G. , Bonn P. C. , Hoekstra G.
Published: April 2011

Reduction of populations of fall planted crops in the course of winter can result in substantial losses in economic yield. Variations in planting date of soft white winter wheat (Triticum aestivum L.) in eastern Ontario are known to influence both survival and grain yield. This study was conducted to determine relationships between fall-accumulated growing degree days (GDD), cold hardiness, ice tolerance and a number of plant characteristics with survival recorded the next spring. Locations were at Ottawa (45°23′N) and Douglas (45°33′N) with four planting dates, 27 August, 10 September, 24 September and 8 October in 4 yr, 1983–1986. Delayed planting was associated with reduced survival at Ottawa in 1987 and in all years at Douglas. Consequently, survival at Ottawa showed little association with cold hardiness and ice tolerance, but there were significant correlations at Douglas. Measurements in 3 yr showed that late planted wheats were single tillered, up to 10 times lower fresh weight than the 3–5 tillered August-planted wheat, and their cold hardiness and ice tolerance were decreased. Moisture content of the crown tissue (CrW) increased with delayed planting despite the growth of the plants in acclimating conditions. Highest CrW developed in late-planted wheat at Douglas and showed a high negative correlation with survival. Cold hardiness and ice tolerance correlated with survival at Douglas and there were significant relationships between the stress tolerances. However, no consistent associations across location-years could be defined to explain winter survival in terms of fall-measured stress tolerances and plant parameters. Key words: Cold acclimation, cold hardiness, crown moisture, winter injury, ice encasement, delayed planting
Wheat residue management options for no-till corn
Authors: Opoku G. , Vyn T. J.
Published: April 2011

Corn (Zea mays L.) yield reduction following winter wheat (Triticum aestivum L.) in no-till systems prompted a study on the effects of tillage and residue management systems on corn growth and seedbed conditions. Four methods for managing wheat residue (all residue removed, straw baled after harvest, straw left on the soil surface, straw left on the soil surface plus application of 50 kg ha−1N in the fall) were evaluated at two tillage levels: fall moldboard plow (MP) and no-till (NT). No-till treatments required at least 2 more days to achieve 50% corn emergence and 50% silking, and had the lowest corn biomass at 5 and 7 wk after planting. Grain yield was similar among MP treatments and averaged 1.1 t ha−1 higher than NT treatments (P < 0.05). Completely removing all wheat residue from NT plots reduced the number of days required to achieve 50% corn emergence and increased grain yields by 0.43 and 0.61 t ha–1 over baling and not baling straw, respectively, but still resulted in 8% lower grain yields than MP treatments. Grain yield differences among MP treatments were insignificant regardless of the amount of wheat residue left on the surface or N application in the fall. Early in the growing season, the NT treatments where residue was not removed had lower soil growing degree days (soil GDD) compared with MP (baled) treatment, and higher soil moisture levels in the top 15 cm compared with all other treatments. The application of 50 kg N ha−1 in the fall to NT (not baled) plots influenced neither the amount of wheat residue on the soil surface, nor the soil NO3-N levels at planting. Our results suggest that corn response in NT systems after wheat mostly depends on residue level. Key words: Winter wheat, straw management, no-till, corn, soil temperature, soil moisture
The biology of Canadian weeds. 106. Linaria dalmatica (L.) Mill.
Authors: Vujnovic Ksenija , Wein Ross W.
Published: April 2011

Dalmatian Toadflax, Linaria dalmatica (L.) Mill. (Scrophulariaceae), is an important weed of rangelands, agricultural crops and waste areas in North America. The literature is less extensive than for the closely related yellow toadflax (Linaria vulgaris Mill.). Introduced from Eurasia as an ornamental plant into North America by 1894, it became naturalized in seven Canadian provinces and all of the United States of America west of the 100th meridian except for New Mexico. In North America it ranges from ca. 35° to 56°N latitude and it grows from near sea level to altitudes up to ca. 2800 m. Production of up to one-half million seeds per plant and its long-lived perennial nature make the species highly competitive and able to invade cropland and even stands of native ungrazed vegetation. Linaria dalmatica is a hemicryptophyte with strong vegetative reproduction and dormant seeds. Growth of creeping roots after removal of aboveground plant parts limits the effectiveness of control treatments such as grazing, clipping, mowing or burning. Several herbicides control the species for the short term; the smooth and waxy leaf surfaces may hinder herbicide uptake. Experimental biological control with insects since the 1960s shows promise. Key words: Linaria dalmatica, Dalmatian toadflax, Scrophulariaceae, weed biology, control, review
Effects of simulated and flea beetle injury to cotyledons on growth of drought-stressed oilseed rape, Brassica napus L.
Authors: Nowatzki Timothy M. , Weiss Michael J.
Published: April 2011

Simulated injury was compared with flea beetle injury on cotyledons of oilseed rape grown at various soil moistures to determine the effects of injury on seedling growth in the greenhouse. The cotyledons of 7-d-old seedlings were injured at 0, 25, 50, and 75% of the total area with a 0.5-mm mechanical pencil or by flea beetles. The soil moisture was maintained at the field capacity, half field capacity, and the permanent wilting point. The growth response of the seedlings was compared for simulated flea beetle injury and soil moisture 7, 14, and 21 d post-injury, and for simulated and flea beetle injury, and soil moisture 7 d post-injury. Simulated injury had the greatest effect on seedlings grown at the field capacity, at 7 d post-injury. At the reduced soil moistures, increased levels of simulated injury were necessary to cause a significant loss in growth. By 14 and 21 d post-injury, compensation to the simulated injury occurred. Simulated injury caused significantly less growth reduction across all injury levels compared with flea beetle injury. However, at injury levels above 25%, both simulated and flea beetle injury had similar trends in growth reduction. The simulated injury tested in these experiments cannot be used in place of flea beetles for resistance screening studies, but may be useful if incorporated as a preliminary tool. Key words: Phyllotreta cruciferae, canola, oilseed rape, injury, damage response
The inheritance of β-glucan concentration in three oat (Avena sativa L.) crosses
Authors: Kibite Solomon , Edney M. J.
Published: April 2011

Several reports have indicated that oat β-glucans may play an important role in reducing the incidence of degenerative diseases in humans. However, little information has been published on the inheritance of β-glucan concentration in oat. The development of new cultivars with improved β-glucan concentration would be simplified if the mode of inheritance is understood. Three experiments, each using two parental lines and their F1, F2, F3, BC1F2 and BC2F2 generations, were carried out to determine the inheritance of β-glucan concentration. The results indicate that β-glucan concentration is controlled by a minimum of two or three factor pairs with a predominantly additive type of gene action. In the majority of the generations, β-glucan concentration was found to be positively correlated with protein content and negatively correlated with oil content. It was not correlated with grain yield, number of panicles/plant, or number of kernels per panicle. The broad-sense heritability of β-glucan concentration ranged from 0.45 to 0.58 in the F2, and from 0.48 to 0.56 in the F3 generations, suggesting that it may be relatively easy to develop new oat cultivars with high- or low-β-glucan concentration. Key words: Avena sativa, oat, β-glucan concentration, inheritance
Stubble height effects on microclimate, yield and water use efficiency of spring wheat grown in a semiarid climate on the Canadian prairies
Authors: Cutforth H. W. , McConkey B. G.
Published: April 2011

In the semiarid region of the western Canadian prairies, seeding directly into standing cereal stubble is gaining popularity. This four year study was conducted at Swift Current, SK, to determine how seeding into tall (>30 cm high), short (about 15 cm high) and cultivated cereal stubble altered the microclimate thereby affecting the growth and yield of hard red spring wheat (Triticum aestivum L.). The treatments were deployed immediately before seeding on plots that had overwintered with tall stubble. Seeding wheat into tall stubble increased grain yield and water use efficiency by about 12% compared to wheat seeded into cultivated stubble. Yield and water use efficiency for wheat seeded into short stubble were intermediate to the other stubble treatments. As well, wheat seeded into tall stubble grew taller than wheat seeded into the cultivated stubble. Further, there was a tendency for spring wheat grown in tall stubble to produce more dry matter and more leaf area, to have a lower proportion of dry matter as leaves and a higher proportion as stems, and to have a lower harvest index than the other treatments.Growing season evapotranspiration (ET) was not affected by stubble height. When the seedlings were small, compared to cultivated stubble, tall stubble altered the microclimate near the soil surface by reducing the daily average windspeed, soil temperature, and incoming solar radiation, and increasing the reflected solar radiation. Throughout much of the growing season, potential ET at the soil surface, measured with minilysimeters, was significantly lower in the tall stubble. Tall stubble, compared to cultivated stubble, increased the proportion of ET that was transpired by the wheat. As well, reduced windspeeds and increased photosynthetic area may have increased the efficiency of net carbon assimilation. To increase grain yields, producers in the semiarid prairies who direct-seed spring wheat are advised to seed into stubble left standing as tall as practical (at least 30 cm). Key words: Standing stubble, wheat, microclimate, water use, yield
Performance of isolated microspore-derived doubled haploids of wheat (Triticum aestivum L.)
Authors: Hu Tianci , Kasha Ken J.
Published: April 2011

Ploidy level, genetic stability and field performance of isolated microspore-derived wheat plants were evaluated. The ploidy levels of isolated microspore-derived wheat plants from cv. Chris and reciprocal crosses of Chris × Sinton were determined by two methods, namely chromosome counts of root tip cells and flow cytometric measurement of nuclear DNA content from leaves. Both methods gave similar results with the frequencies of spontaneous chromosome doubling and completely fertile plants among microspore-derived H0 plants of wheat being about 80% and 75%, respectively, based on two H0 populations. Only 1.7% were aneuploid and 16% were haploid. Spontaneous mutation frequencies were low with 1 of 124 Chris DH plants having a recessive mutant for lemma awns while three were grass-like plants in the H0 generation. The field-measured traits of microspore-derived DH lines were similar to the check by the third generation. Ninety-two percent and 70% of Chris DH lines had 1000-kernel weights and yields similar to the check, respectively. These results indicate that microspore-derived DH lines should have good potential for applications in plant breeding, in vitro selection, plant transformation and genetic studies. Key words: Wheat, microspore, culture, haploidy, performance, stability
Inheritance of powdery mildew resistance in pea
Authors: Tiwari K. R. , Penner G. A. , Warkentin T. D.
Published: April 2011

Pea, an important grain legume crop, suffers significant yield and quality losses because of infections by the parasitic fungus Erysiphe pisi Syd., the causal agent of powdery mildew. Most pea cultivars in western Canada are susceptible to this fungus. The genetic basis of resistance found in certain Canadian cultivars is unclear. Resistant cultivars and lines were intercrossed with each other and crossed with susceptible lines to determine the genetic basis of resistance. Resistance in the cultivars Highlight, AC Tamor, Tara, Mexique 4, Stratagem and lines JI 210, JI 1951, JI 1210 was found to be conferred by a single recessive gene, er-1. The resistance in line JI 2480 is conferred by a different recessive gene, er-2. Resistance provided by er-1 was durable under both field and growth cabinet conditions, however, resistance of er-2 was broken under controlled growth conditions. Combining er-1 and er-2 in a cultivar could increase the durability of resistance. Key words: pea, Pisum sativum, powdery mildew, Erysiphe pisi, inheritance, resistance
Field and producer survey of ACCase resistant wild oat in Manitoba
Authors: Bourgeois Luc , Morrison Ian N. , Kelner David
Published: April 2011

In a previous study, 729 townships in Manitoba were differentiated as being at low, medium, or high risk of evolving wild oat resistant to Group 1 herbicides based on herbicide use histories from 1981 to 1993. In the present study, 16 townships representing the three risk categories were surveyed in 1994 in order to determine the percentage of resistant wild oat patches. As well, a questionnaire was mailed to farmers in these townships requesting information on practices and attitudes relating to herbicide resistance. The wild oat survey consisted of sampling seed from conspicuous wild oat patches visible from north-south roads in each township. A total of 533 samples were collected and screened with fenoxaprop-P and sethoxydim using a bioassay. An average of eight resistant wild oat patches was found in the high risk townships. This was significantly higher than in low and medium risk townships where an average of less than one resistant wild oat patch per township was detected. The attitude of producers towards herbicide resistance was similar in all risk categories. However, the number of respondents suspecting Group 1 resistance on their farms was related to risk categories with producers in high risk areas suspecting the most cases of resistance. Key words: Weed survey, resistance assessment, wild oat, ACCase inhibitors
CDC Triffid transgenic flax
Authors: McHughen A. , Rowland G. G. , Holm F. A. , Bhatty R. S. , Kenaschuk E. O.
Published: April 2011

CDC Triffid is a transgenic sulfonylurea herbicide resistant cultivar with agronomic features similar to NorLin. It is intended to provide a sustainable, broadleaf cropping option to summerfallowing or continuous cropping to cereals in soils previously treated with residual sulfonylurea herbicides. CDC Triffid flax was developed at the Crop Development Centre, University of Saskatchewan. Key words: Flax, linseed, Linum usitatissimum L., cultivar description, transgenic, biotechnology, sulfonylurea, herbicide resistance, herbicide residue, germplasm
CDC Osprey winter wheat
Authors: Fowler D. B.
Published: April 2011

CDC Osprey is a high-yielding, lodging-resistant, semidwarf winter wheat (Triticum aestivum L.) with good winterhardiness. CDC Osprey has excellent grain quality. It has a grain protein concentration that is similar to Norstar combined with the superior agronomic performance of CDC Kestrel in Alberta and Saskatchewan. However, more susceptible rust reactions and lower grain yields than CDC Kestrel may limit the production of CDC Osprey in southeastern Manitoba. CDC Osprey is eligible for grades of the Canada Western Red Winter Wheat class. Key words: Triticum aestivum L., cultivar description, wheat (winter)
Yield and grain quality of plump-kernelled spring triticale windrowed at different kernel water concentrations
Authors: Jedel P. E. , Salmon D. F.
Published: April 2011

Little information is available on the response of plump-kernelled spring triticales (X Triticosecale Wittmack) to windrowing at different kernel water concentrations (KWC). The objective of this research was to determine the effects of windrowing at KWCs of 1600 g kg−1 or less on the yield and grain quality of spring triticales compared with a Canadian prairie spring (CPS) wheat (Triticum aestivum L. 'Oslo'). Field experiments were conducted from 1989 to 1993 at Lacombe, AB, using the spring triticale cv. Wapiti in all years, and the cvs. Banjo and Frank in 1992 and 1993. Rate of dry-down varied between the cultivars and years. Oslo dried at a rate of 1.67 to 3.23 g kg−1 per growing degree day (GDD 0 °C basis). The rate of dry-down for the triticales ranged from 2.80 to 10.80 g kg−1 per GDD. Although the triticales reached physiological maturity much later than Oslo in any given year, they dried at a faster rate (with fewer GDDs) than Oslo. Windrowing at KWC of up to 1600 g kg−1 (62% moisture) had no effect on test weight, grain protein or germination of harvested grain. Effects of windrowing on grain yield varied but, when yield differences were significant, windrowing at 430 to 530 g kg−1 (30 to 35% moisture) optimized grain yield. When effects of windrowing on kernel weight were significant, kernel weight increased as KWC at windrowing decreased. When windrowing to curtail secondary growth of spring triticale is necessary in central Alberta, windrowing at 430 to 530 g kg−1 (30 to 35% moisture) is recommended to optimize yield without loss of test weight, protein content or germination. Key words: Spring triticale, Canadian prairie spring wheat, windrowing, kernel water concentration
Effects of modifying the phytosterol profile of canola, Brassica napus L., on growth, development, and survival of the bertha armyworm, Mamestra configurata Walker (Lepidoptera: Noctuidae), the flea beetle, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae) and the aphids, Lipaphis erysimi (Kaltenbach) and Myzus persicae (Sulzer) (Homoptera: Aphididae)
Authors: Bodnaryk Robert P. , Luo Ma , Kudryk Lubomir
Published: April 2011

The sterol profile of canola, Brassica napus, was altered by treatment with 5 ppm of the systemic fungicides fenpropimorph and tridemorph. The usual Δ5-phytosterols sistosterol, campesterol, and stigmasterol were depleted in leaves and roots and replaced by unusual 4-alpha-methyl and 4-desmethyl sterols that were never observed in untreated plants. Growth, development, and survival of the bertha armyworm, Mamestra configurata, fed leaves of treated canola in the laboratory were affected adversely at specific stages in the life cycle. Larval survival was high and not significantly different in treated and control groups. Most of the mortality in the treated group occurred at pupation and during pupal-adult development. At ecolosion a high proportion of adults were deformed (crumpled wings, failure to exit the pupal case). The adverse effects of feeding on fenpropimorph-treated canola were not attributable to the fungicide itself because larvae fed an artificial diet containing a 10-fold higher concentration of fenpropimorph had normal growth, development, and survival.Although larvae of M. configurata fed canola with a modified sterol profile showed no obvious physiological symptoms, the larvae were more susceptible to the insecticide methomyl (Lannate). Phytosterol modification of the plant in combination with insecticide application may lead to a synergistic interaction in the pest insect.Fewer larvae, prepupae and pupae of the flea beetle, Phyllotreta cruciferae, were recovered from soil samples in field plots with canola treated with fenpropimorph or tridemorph in the laboratory. Adult beetles began to emerge from the soil later, emergence progressed more slowly and fewer were trapped in plots with treated canola.Fewer larvae and adults (up to 50% reduction) of the aphids M. persicae and Lipaphis erysimi, were produced on canola treated with tridemorph. Since aphids harbour sterol-synthesizing mycetocyte-symbionts and are not dependent on a dietary source of sterols, factors other than a deficiency of Δ5-phytosterols must be responsible for the reduction in aphid numbers on treated plants. Key words: Brassica, sterol, fungicide, insecta, development, survival
Alfalfa seed germination tests and stand establishment: The role of hard (water impermeable) seed
Authors: Hall John W. , Stout Darryl G. , Brooke Barbara M.
Published: April 2011

Freeze thaw scarification has been observed to increase the germination rate of alfalfa (Medicago sativa L.) seed containing a large proportion of hard (water impermeable) seed in a 7-d laboratory germination test; however, a comparable increase in plant density is not always seen in the field. To investigate this discrepancy, a field experiment with untreated and scarified seed was carried out using cultivars with high (Apica, 35%; Barrier, 32%) and low (Apollo II, 1%; WL316, 0.3%) percentages of hard seed. Plants were counted at the three-trifoliate-leaf and 10% bloom stages in 1992, the planting year, and at 10% bloom in 1993. In the field, effects of scarification were seen only at the 10% bloom stage in 1992, increasing the plant densities of high hard seed cultivars by 17% while decreasing those of low hard seed cultivars by 10%. Two laboratory experiments were also done to determine the effect of temperature, lighting (light, shade, dark) and media (on blotter, in soil) on the germination of hard seed. Germination was highest at alternating 35/5 °C and higher at 28/14 °C than at constant 20 °C. At 20/–10 °C most germinated seed died. Differences among germination media and lighting treatments were small. Scarification may possibly have some negative effect on the quick-germinating fraction of the seed in the field but the net effect for cultivars with a high hard seed content appears positive. Some seed identified as hard in a 7-d test at constant 20 °C likely germinate and contribute to an alfalfa stand in the field when soil temperatures are higher. Thus the discrepancy previously observed between the laboratory and field results may possibly be accounted for in part by a negative effect of scarification and also by differences in temperature. Key words: Medicago, germination, seed coat, temperature
An ecoregional analysis of morphological variation in British Columbia coastal strawberries (Fragaria) for germplasm protection
Authors: Catling Paul M. , Porebski Sue
Published: April 2011

In order to enhance the utilization and protection of wild Fragaria germplasm from coastal British Columbia, patterns of morphological variation were assessed in plants from the Pacific coastal region of Canada. Twenty-five characters were evaluated in 87 plants grown in the uniform garden at the Canadian clonal genebank. Seven characters including the number of veins, length of the terminal tooth, roundness of tooth, tooth distribution, leaf thickness, leaf color and leaf surface were significant at the 5% level in distinguishing ecoregional groupings, and a discriminant analysis was also significant. The major pattern of variation involved plants from southern Vancouver Island to the upper Strait of Georgia, ecoregions 192 and 194, which have thinner, paler, more glaucous leaves with less broadly rounded teeth, suggesting hybridization of F. chiloensis with F. virginiana. A clustering of ecoregional group centroids using the unweighted pair group method with arithmetic averages indicated that, in order to optimally protect genetic variation, 28.35% of the protected accessions should be selected from each of ecoregions 192 and 194, with ecoregion 191 accounting for 15.98%, and the remaining ecoregions contributing 13.66% of accessions. Key words: Fragaria chiloensis, Fragaria virginiana, Pacific coast, genetic variation, ecoregions, germplasm protection
Nectar quality in open-pollinated, pol CMS hybrid, and dominant SI hybrid oilseed summer rape
Authors: Pernal S. F. , Currie R. W.
Published: April 2011

Nectar sugar composition and temporal patterns of nectar sugar production were examined in oilseed summer rape (Brassica napus L. ssp. oleifera (Metzg.)) from six open-pollinated, eight pol cytoplasmic male-sterile (CMS) hybrid and seven dominant self-incompatible (SI) hybrid cultivars at three field plot sites in Manitoba. The total sugar content of nectar samples was measured by the Dreywood anthrone reaction for total carbohydrate, and simple sugar composition was determined using an enzymatic bioanalysis for D-glucose, D-fructose and sucrose. Hybrid and open-pollinated cultivar flowers had similar sugar content. Mean total sugar content per flower also did not vary among hybrid breeding systems when compared within individual weeks of the bloom period or within daily sampling periods. However, for all cultivars, total nectar sugar content per flower was lower during the 08:00 and 11:00 h sampling periods and increased to maximum levels during the 14:00 and 16:00 h sampling periods. Significant differences in nectar sugar content were also found in relation to the bloom phenology of the cultivars. Cultivars produced the greatest amount of sugar per flower during the first 2 wk of the bloom period, then sugar production decreased in the third and fourth weeks. Nectar sugar ratios from all cultivars averaged approximately 1:1 glucose:fructose. Nectar glucose content among cultivars was similar but, among breeding systems, CMS cultivars tended to have lower amounts of glucose than SI or open-pollinated cultivars. Selecting for higher total sugar content may produce nectars more attractive to foraging honeybees (Apis mellifera L.), thereby ensuring adequate pollination of hybrid parental lines and F1 hybrid plants. Selecting for lower nectar glucose will produce honeys with more desirable granulation characteristics. Overall, the production and quality of nectar sugar in oilseed rape hybrids are similar to those of open-pollinated cultivars, and are not likely to adversely affect the pollinating activities of honeybees or their potential for honey production. Key words: oilseed summer rape, Brassica napus, honeybees, Apis mellifera, nectar, simple sugars
AC Cadillac hard red spring wheat
Authors: DePauw R. M. , Thomas J. B. , Knox R. E. , Clarke J. M. , Fernandez M. R. , McCaig T. N. , McLeod J. G.
Published: April 2011

AC Cadillac, a hard red spring wheat (Triticum aestivum L.), is adapted to the Canadian Prairies. It combines high grain yield with high grain protein concentration, heavy kernel and volume weights. It has improved resistance to leaf spots compared with the check cultivars, and resistance to prevalent races of leaf rust, stem rust, loose smut, and common bunt. AC Cadillac is eligible for grades of Canada Western Red Spring wheat. Key words: Triticum aestivum L., red spring wheat, yield, protein, disease resistance, volume weight
Long-term evaluation of cover crop and strip-tillage on tomato yield, foliar diseases and nematode populations
Authors: McKeown Alan W. , Cerkauskas R. F. , Potter John W. , Driel L. van
Published: April 2011

A 6-yr (1987–1992) experiment, continuous on the same site, evaluated potential problems for yield, nematodes and diseases with tomatoes (Lycopersicon esculentum Mill.) grown in a strip-till system. Treatments consisted of conventional tillage (CT) and strip tillage (ST), rye (Secale cereale L.), wheat (Triticum aestivum L.) and perennial ryegrass (Lolium perenne L.) cover crops and a 2-yr rye-tomato rotation. Results of the first 5 yr indicated a decrease in tomato yield over time for both tillage treatments and cover crops. However, yield rebounded overall for treatments in 1992 with the highest yield in the rye-tomato rotation. We suspect this was a result of high populations of root-knot nematodes which collapsed over the winter of 1991/1992. Tomato yields were lower following wheat and perennial ryegrass than rye. In only 1 yr out of 6, strip-tillage reduced yield compared with conventional tillage. Bacterial speck/spot symptoms on foliage, although minor, were significantly greater in ST than in CT plots during the last 3 yr. No major trends in incidence and severity of bacterial and fungal diseases and of disorders of fruit were evident during the 5-yr period and neither fruit yield nor quality were significantly affected by these factors. Root-knot nematodes (Meloidogyne hapla Chitwood) were numerically less in the rye-tomato rotation than in other treatments; both root-knot and root lesion nematodes (Pratylenchus penetrans [Cobb]) tended to be less numerous under CT than under ST. Strip-tillage is feasible for machine harvest processing tomatoes. However, we are concerned about the tendency of tomatoes grown under reduced tillage to have lower yields than those grown under conventional tillage. More work is required on the interactions of cultivars, cover crops and nematodes in soil conservation systems. Key words: Tomato, bacterial speck/spot, foliar diseases, root-knot nematodes, root lesion nematodes, tillage
Reviewing/editing a manuscript for scientific publication
Authors: Chong Calvin
Published: April 2011

The peer review process is the basis of evaluation or "quality control" in modern science. Peer review ensures publication of valid scientific results that are appropriately presented and interpreted. As scientists, we benefit from and are expected to review the work of our colleagues. A request to review a manuscript recognizes the reviewer's expertise as an authority or leader in a field of research. The capacity to conduct a good review enhances one's reputation and career advancement, and is well worth the effort expended. Manuscripts submitted to the Agricultural Institute of Canada (AIC) scientific journals are logged and monitored through a centralized processing system. A primary goal of the journals is to review manuscripts within 90 d of submission. Good reviews provide a constructive and well-reasoned appraisal of a manuscript phrased in the spirit of professional courtesy and confidentiality. Both anonymity of the reviewer and confidentiality of manuscript contents must be maintained in the peer review process. Any question of conflict of interest or ethical standing of a reviewer or duplication of publication should be directed to the editor immediately. Editors, authors, and reviewers are important partners in the peer review process. Key words: Peer review, manuscript processing, scientific journals
Effects of deicing salt on lowbush blueberry flowering and yield
Authors: Eaton Leonard J. , Hoyle Jeff , King Andrew
Published: April 2011

The effects of deicing salt (NaCl) on buds, blossoms and yields of lowbush blueberry (Vaccinium angustifolium Ait.) were assessed over 3 yr in two commercial fields adjacent to a major Nova Scotia highway. Concentrations of road salt on exposed stems were highest next to the highway, and decreased with distance from the road. Numbers of blossoms, and subsequent fruit yields were low nearest the road, and increased with distance from the highway. Numbers of live blueberry buds and blossoms, and subsequent yields, were inversely related to concentrations of road salt on the stems. Plants under plastic shelters placed near the highway had more live buds and blossoms, as well as higher yields relative to plants exposed to deicing salt. Key words: Vaccinium, sodium chloride, salt damage, desiccation
Effect of imazethapyr and imazamox soil residues on several vegetable crops grown in Ontario
Authors: O'Sullivan J. , Thomas R. J. , Bouw W. J.
Published: April 2011

Use of imidazolinone herbicides has often resulted in carryover effects on sensitive rotational crops. The effect of soil residues of imazethapyr and imazamox on several vegetable crops grown in rotation with soybean (Glycine max [L.] Merr.) was investigated over a 5-yr period in southern Ontario. Imazethapyr at 0, 100 and 200 g a.i. ha–1 was applied preemergence to soybean from 1991 to 1993. Imazethapyr at 0 and 100 g a.i. ha−1 and imazamox at 35 g a.i. ha−1 was applied postemergence to soybean in 1994 and 1995. Cabbage (Brassica oleracea L.), potato (Solanum tuberosum L.), tomato (Lycopersicon esculentum L.), sweet corn (Zea mays L.) and cucumber (Cucumis sativus L.) were planted each spring, 1 and 2 yr following preemergence imazethapyr application and 1 yr following postemergence imazethapyr and imazamox application. Potato and sweet corn showed visual injury symptoms 1 yr after preemergence imazethapyr application in 2 of 3 yr while cabbage, tomato and cucumber showed visual injury symptoms all 3 yr. Minor visual injury symptoms did not reduce yields. Cabbage was the most sensitive to imazethapyr soil residues. Cabbage yields were reduced in 2 of 3 yr, due to carryover residues from 100 and 200 g ha−1 of imazethapyr applied the previous year. Tomato and potato also showed yield reductions in 2 of 3 yr due to imazethapyr soil residues. The degree of injury and yield reduction was influenced by soil pH and soil moisture. There were no yield reductions for any crop 2 yr after imazethapyr application. Imazamox soil residues were less injurious than imazethapyr soil residues to vegetable crops grown in rotation and resulted in only minor visual injury symptoms and no yield reductions on tomato, potato or cabbage. Key words: Crop tolerance, yield, rotation, herbicide carryover