bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactive effects of N and S fertilizers on canola yield and seed quality on S-deficient Gray Luvisol soils in northeastern Saskatchewan
Authors: Malhi S. S. , Gill K. S.
Published: April 2011

On marginally S-deficient soils in the Parkland region, application of high rates of N and other fertilizers in combination with more frequent productionof canola (Brassica napus L. or B. rapa L.) causes rapid depletion of S and nutrient imbalance in soil, and S deficiency and yield reductionfor canola. Field experiments on Gray Luvisol (Boralfs) soils deficient in available N and S were conducted in northeastern Saskatchewan. Interactive effects of N (0, 50 100 and 150 kg N ha-1) and S (0, 10, 20 and 30 kg S ha-1) rates on yield, seed quality, and uptake of S and N in canola were determined. In the absence of S application, increasing N rate made the S deficiency symptoms more severe, and reduced yield, S concentration, oil concentration, S uptake and N uptake of seed, but there was a general response of no effect or some increase in protein concentration, S and N uptakein straw up to 50 or 100 kg N ha-1. When S was applied, canola yield, S concentration, S uptake and N uptake of seed as well as the yield and S uptake of straw increased with increasing N rate. Irrespective of S rate, fertilizer N reduced oil concentration and increased protein concentrationin canola seed. With S fertilization, yield, S uptake and N uptake of seed and straw, and total S concentration and oil concentration in seed were substantially increased, whereas there was no consistent change in protein concentration of seed. The response of these parameters to S application was generally greater at higher N rates. Sulphur and N uptake measured data indicated that significant N × S interaction effects were more frequent and pronounced for seed yield than for straw yield, indicating that the response to N rate was relatively more dependent on the S level for seed than for straw. In summary, the results suggest that an increased amount of S is needed on these S-deficient Gray Luvisol soils in northeastern Saskatchewan to adequately meet the S requirements at high N rates for optimum yield and quality of canola. Key words: Canola, N and S concentration and uptake, N and S fertilization, oil concentration, S-deficient soil, seed yield and quality
Effect of plant growth regulators on the tuberisation and physiological age of potato (Solanum tuberosum L.) tubers grown from true potato seed
Authors: Alexopoulos Alexios A , Akoumianakis Konstantinos A , Passam Harold C
Published: April 2011

The effects of plant growth regulators [6-benzyl amino purine (BA), indole-3-acetic acid (IAA), 2,4-dichlorophenoxyacetic acid (2,4-D), gibberellic acid (GA3), chlormequat chloride (CCC), daminozide] and their time of application on tuberisation and physiological age of cv. Chacasina F1 grown from true potato seed (TPS) were studied in four experiments conducted in spring or autumn in Greece. BA, IAA and 2,4-D did not affect plant development, tuberisation or the physiological age of the tubers produced. Daminozide and CCC reduced plant height when applied 30 but not 60 d after transplanting (DAT) in both spring and autumn. Neither substance affected tuberisation or the physiological age of the tubers formed. Application of GA3 30 DAT significantly increased plant height and the number, but not the weight, of tubers formed per plant. Tubers from GA3-treated plants tended to be elongated with a low dry matter content. When GA3 was applied at 60 DAT, plant height was increased, but tuber number, weight and dry matter content were not affected. Late application of GA3 induced a high percentage of sprouted tubers prior to harvest and significantly increased the physiological age of the tubers, as reflected by an increased rate of respiration, sprouting and weight loss after harvest. Although early application of GA3 also increased tuber sprouting prior to harvest, it had no effect on sprouting, respiration and weight loss after harvest. Application of GA3 early in the vegetative cycle may be useful for the production of mini-tubers for propagation, whereas application at a later stage may aid in early planting by accelerating the breaking of tuber dormancy. Key words: Gibberellin, chlormequat chloride, daminozide, dormancy, tuberisation
Chickpea, lentil and pea response to delayed spring seeding on the Northern Great Plains
Authors: Miller P. R. , Brandt S. A. , McDonald C. L. , Waddington J.
Published: April 2011

We compared the effects of spring seeding date on stand density, crop growth, seed yield, water-use-efficiency, and grain quality of three pulse crops [chickpea (Cicer arietinum L.), lentil (Lens culinaris Medik.) and pea (Pisum sativum L.)] grown at Scott and Swift Current, SK, during 1993 to 1997. Wheat (Triticum aestivum L. emend. Thell.) was used as a reference crop. Seeding date did not meaningfully affect plant density for chickpea, lentil or pea. Crop growth stage related to thermal time resulted in robust prediction equations for chickpea, lentil and pea (R2 = 0.87 to 0.98). When seeding was delayed 2 wk, the crop response was inconsistent. When seeding was delayed by 4 wk, consistent, mainly negative, effects on crop parameters occurred due to the exacerbation of summer drought stress. Pulse crop yields were more negatively affected by delayed seeding than were wheat yields. When seeding of chickpea, lentil, and pea was delayed 4 wk, seed yield decreased at the majority of site-years. When yield reductions occurred, the average reductions were 44, 38, and 31%, for the respective species. For chickpea and lentil, seeding delays of 2 and 4 wk decreased seed size at the majority of site-years with seed size reductions averaging 10% when they occurred. In the semiarid Northern Great Plains (NGP), chickpea, lentil, and pea should be seeded before spring wheat due to a greater risk of loss of yield and quality. Key words: Chickpea, growth stage, lentil, northern great plains, pea, seeding date
Resistance of sweet cherry cultivars to fruit surface pitting
Authors: Kappel Frank , Toivonen Peter , Stan Sabina , McKenzie Darrell-Lee
Published: April 2011

A recently developed technique was used to determine the susceptibility to fruit surface pitting of new sweet cherry (Prunus avium L.) cultivars and compare them to an industry standard. The cultivars tested included Bing (industry standard), Cristalina, Lapins, Sandra Rose, Santina, Skeena, Sonata, Staccato, and Sweetheart. Fruit were harvested at commercial maturity, injured, held at 1°C for 2 wk and then rated for fruit surface pitting. The cultivars Lapins, Skeena, Staccato, and Sweetheart had less pitting than Bing. Cristalina and Sonata tended to have similar levels of injury to Bing and Sandra Rose and Santina tended to have more severe pitting than Bing. Key words: Sweet cherries, cultivars, simulated pitting injury
Factors influencing pollen germination in three Explorer™ roses
Authors: Richer C. , Poulin M. , Rioux J. -A.
Published: April 2011

Pollen germination is useful for the estimation of pollen viability. For three cultivars from the Explorer™ series, Champlain, Nicolas and Frontenac, a liquid medium with a pH of 5.6 and a saccharose concentration of 15% provides optimal germination conditions. Four flower stages were determined and evaluated according to the following scale: flower bud at stage 0 (closed bud), stage 1 (closed petals but open sepals), stage 2 (bud with petals three-quarters open) and stage 3 (fully open flower). Pollen germination was higher when the pollen was collected at stages 0 and 1 for Champlain, at stages 1 and 2 for Frontenac and at stage 2 for Nicolas. Based on the results of the evaluation of pollen drying techniques, it is recommended that pollen be dried for 24 h in darkness before use in crossing. Key words: Rosa, rose, rose breeding, pollen harvesting, pollen drying, pollen germination test
In vitro ruminal digestion of anthocyanidin-containing alfalfa transformed with the maize Lc regulatory gene
Authors: Wang Y. , Frutos P. , Gruber M. Y. , Ray H. , McAllister T. A.
Published: April 2011

In vitro ruminal digestion was conducted on novel “purple-green” alfalfa forage that accumulated anthocyanidin and proanthocyanidins through the expression of a maize bHLH anthocyanidin regulatory gene (Lc). The Lc-transgenic genotypes were compared with parental (non-transformed, NT) alfalfa in their in vitro ruminal fermentation, dry matter (DM) and N disappearances, and DM degradability. The transgenic genotypes expressed the Lc gene at different levels when grown under high light conditions, resulting in anthocyanidin contents as high as 136 g g-1 DM. Lc genotypes had lower true DM disappearance than NT alfalfa at 0, 4 and 12 h of incubation, but not at 24 or 48 h. Compared with NT, Lc-transgenic genotypes had a lower content of rapidly soluble DM, but a similar content and rate of degradation of the slowly degradable DM fraction, and a similar lag time for digestion. True disappearance of N was lower for Lc- transgenic than NT alfalfa at the initiation of the incubation. The solubility of both DM and N were negatively correlated with the concentration of anthocyanidins measured in the forage. The results indicate that Lc-transformation reduced the initial rate, but not the extent of DM and N digestion of alfalfa in the rumen. These properties could improve the utilization of protein and possibly reduce the risk of bloat in ruminants consuming fresh alfalfa. However, further increasing the amount of anthocyanidins (or proanthocyanidins) produced in the forage may be required to make this a viable strategy for improved protein utilization and bloat prevention. Key words: Alfalfa, anthocyanidins, Lc-transformation, nitrogen, ruminal digestion
A genetic examination of early flowering and maturity in Canadian spring wheat
Authors: Iqbal M. , Navabi A. , Salmon D. F. , Yang Rong-Cai , Spaner D.
Published: April 2011

Under short-season western Canadian growing conditions, vernalization non-responsiveness is generally considered a preferable spring wheat (Triticum aestivum L.) phenotype, to avoid inconsistent maturity and yield patterns. The objectives of this study were to investigate the genetic factors affecting early flowering and maturity, and related agronomic traits, in a set of five Canadian spring wheat cultivars. The cultivars were first studied under 10- and 16-h photoperiods and 0- and 42-d vernalization treatments. Thereafter, the parents and F1 hybrids from a one-way diallel mating design were grown with and without a 42-d vernalization treatment. Shorter photoperiod delayed flowering time in all cultivars, and increased final leaf number in AC Barrie. Vernalization hastened flowering and decreased final leaf number in AC Foremost and AC Taber. AC Foremost and AC Taber carry at least one different allele, from the rest of the cultivars studied, at the major loci governing vernalization response. Leaf and spikelet number on the main culm, days to anthesis and maturity, tiller number and yield plant-1 were mainly controlled by additive gene action. Narrow-sense heritability was medium to high (0.53–0.93) for final leaf number, days to anthesis, spikelet number and grain yield, but low to medium (0.20–0.71) for days to maturity and tiller number. Selection for early flowering under non-vernalizing conditions may aid in the breeding of (vernalization non-responsive) early-maturing spring wheat cultivars in western Canada. Key words: Diallel cross, earliness, photoperiod, vernalization, Triticum aestivum L.
Control of herbicide-resistant common waterhemp (Amaranthus tuberculatus var. rudis) with pre- and post-emergence herbicides in soybean
Authors: Vyn J. D. , Swanton C. J. , Weaver S. E. , Sikkema P. H.
Published: April 2011

Common waterhemp was first identified in Ontario in 2002. Eight trials were conducted ove r a 3-yr period (2003-2005) at Cottam and Petrolia, Ontario to determine the efficacy of various preemergence and postemergence herbicides for the control of herbicideresistant waterhemp in soybean [ Glycine max (L.) Merr.]. Waterhemp was resistant to the a cetolactate synthase-inhibiting herbicides at both locations and to the photosystem II-inhibiting herbicides at Petrolia; therefore, results varied by location. Results at Petrolia also varied across years. Waterhemp interference resulted in soybean yield losses of up to 73% in weedy versus weed-free checks. Preemergence-applied metolachlor, dimethenamid, and linuron provided greater than 80% control and metolachlor plus metribuzin 94% or greater control of waterhemp 70 d after emergence at both locations. Acifluorfen, fomesafen, imazamox plus fomesafen, and glyphosate applied postemergence resulted in 87% or greater waterhemp control 70 d after application at Cottam in 2003 and 2004 and at Petrolia in 2004; however, waterhemp control with these herbicides was only 60 to 66% at Petrolia in 2005 due to prolonged weed emergence. Multiple herbicide applications per season may be required for effective waterhemp control in soybean. Key words:
Sapote mamey [Pouteria sapota (Jacquin) H.E. Moore & Stearn]: A potential fruit crop for subtropical regions of Michoacan, Mexico
Authors: Bayuelo-Jiménez Jeannette Sofía , Alcantar Norma Rivera , Ochoa Iván
Published: April 2011

Genotypes of sapote mamey, Pouteria sapota [(Jacquin) H.E. Moore & Stearn] from central-western Michoacán in Mexico were characterized based on physical and chemical fruit characteristics. Cluster analysis of data indicated seven distinct genotype clusters. The greatest variability among clusters was attributed to physical and chemical fruit characteristics. Those were fruit weight, length, width, shape and texture; the ratio of fruit weight to seed weight; seed weight and length; mesocarp thickness and weight; epicarp weight; and the compositional components titratable acidity (TA), protein, total soluble solids (TSS), TSS to TA ratio and TSS to pH ratio. Canonical discriminant analysis was a used to identify the most desirable sapote mamey fruits based on physical (fruit and mesocarp weight) and compositional parameters. Two canonical discriminant functions explained >90% of the accumulated variation a mong the seven clusters of genotypes. Fruit weight, mesocarp thickness, and the ratio of total soluble solids to titratable acidity were dominant in the first function; and fruit weight and mesocarp thickness were dominant in the second. These morphological variables could be used for selecting sapote mamey trees with uniform fruit quality for either direct consumption or processing. Key words: Sapotaceae, sapote mamey, Pouteria sapota, cluster analysis, canonical discriminant analysis, fruit, morphological characterization
The Biology of Invasive Alien Plants in Canada. 6. Berteroa incana (L.) DC
Authors: Warwick S. I. , Francis A.
Published: April 2011

The cruciferous weed Berteroa incana, hoary alyssum, has been known in temperate North America since the late 19th century, but has recently begun to spread aggressively in upland and dry areas in the Great Lakes and western foothills regions of both Canada and the United States. It is an annual, winter annual to short-lived perennial and is considered an invasive weed in turf, rangelands, pastures and forage crops, with harmful effects on horses an added concern. The species is most common on sandy gravel and poorer soils. It has recently i nvaded Christmas tree plantations in Michigan. Its prolific seed production, woody stems and deep taproot enable it to persist under dry conditions and to resist mechanical control; and it has virtually no natural enemies in North America. It can be partially controlled by herbicides in crops it has invaded, but herbicides are not generally used on rangelands, pastures, turf and natural and semi-natural areas, where it is now prevalent. Key words: Berteroa incana, hoary alyssum, bertéroa blanc, BEFIN, weed biology, invasive alien
Row spacing and irrigation effects on water consumption of winter wheat in Taian, China
Authors: Zhou Xun-Bo , Li Quan-Qi , Yu Shun-Zhang , Wu Wei , Chen Yu-Hai
Published: April 2011

Management practices can have a major impact on the successful production of winter cereals. A field experiment was conducted with winter wheat (Triticum aestivum) to compare the effects of two row spacing planting patterns (row width set at 30 cm, 30; or row widths set at a narrow row of 20 cm and a wide row of 40 cm, 20 + 40) and four irrigation schedules (no irrigation, T0; irrigation given at stem elongation stage, T1; at stem elongation and heading stage, T2; at stem elongation, heading and milk stage, T3) on yield, water use efficiency (WUE), evapotranspiration (ET) and soil water content (SWC) for the 2003/2004 and 2004/2005 seasons at Taian, Shandong Province, China. Mean soil daily evaporation (Es) was greater in the wide row than the narrow row, and resulted in decreased SWC in the wide row. For the same irrigation treatment, no significant differences in changes of SWC and yield were found between the row-spacing planting patterns in either season. Differences in ET were found in 2005 with ET from the T0 treatment being much lower than the irrigated treatments for both planting patterns. During the cropping season in 2005, WUE of the T3 treatment was lower than from the T1 and T0 treatments at the same planting patterns. The WUE of the 20 + 40 planting pattern was lower than that of the 30 planting pattern with the same irrigation schedule, perhaps due to elevated levels of evaporation from the soil beneath the canopy and decreased yields for the 20 + 40 planting pattern. Therefore, based on WUE, the effect of the 30 planting pattern was better than that of the 20 + 40. Key words: Planting pattern, soil water content, evapotranspiration, water use efficiency, grain yield, Triticum aestivum
The effects of Cd on lipid peroxidation, hydrogen peroxide content and antioxidant enzyme activities in Cd-sensitive mutant rice seedlings
Authors: Chen J. , Zhu C. , Lin D. , Sun Z. -X
Published: April 2011

Cadmium-sensitive rice (Oryza sativa L. subsp. Japonica ‘Zhonghua11’) mutants were obtained using an Agrobacterium tumefaciens-based gene delivery system. Significant phenotypic differences were observed between a Cd-sensitive mutant (ST) and wild type (WT) rice seedlings. Results indicated that Cd accumulation in the leaves of the mutant was twice that of the wild type after 10 d of 0.5 mM Cd2+ treatment. Furthermore, a rapid Cd-induced H2O2 increase was observed in the mutant leaves, which induced abnormally early activity in antioxidant enzymes such as superoxide dismutase (SOD). However, the mutant leaves showed lower catalase (CAT) activity. By contrast, guaiacol peroxidase (G-POD) activities were higher in the mutant than in the wild type roots. Together with the Cd toxicity-induced decline of early responsive enzymatic activities in vivo, especially CAT, the inability of mutants to scavenge accumulated H2O2 resulted in higher lipid peroxide levels. H2O2 might also strengthen the expression of G-POD as a signaling molecule. Results suggest that G-POD activity can be a potential biomarker reflecting Cd sensitivity in rice seedlings. Key words: Antioxidant enzyme, Cd toxicity, Cd-sensitive mutant, lipid peroxidation, rice (Oryza sativa L.)
Growth and yield of barley in relation to grasshopper feeding damage
Authors: Begna Sultan H. , Fielding Dennis J.
Published: April 2011

Grasshoppers are common pests of barley (Hordeum vulgare L.) in subarctic Alaska and cause substantial crop loss during outbreaks, but there is little information about the growth response of barley to grasshopper feeding damage. In two growth chamber experiments, we studied the effect of four densities (0, 1, 2, and 3 pot-1, equivalent to 0, 25, 50 and 75 grasshoppers m-2) of grasshoppers (Melanoplus sanguinipes F.) on the above-and below-ground growth of barley (eight plants per pot). Plants were exposed to grasshoppers beginning in the 3rd to 4th leaf stage (exp. 1) and in 1st to 2nd leaf stage (exp. 2). Plants were harvested and growth variables were measured shortly after anthesis and at maturity. Generally, the reduction in above-ground dry matter, at the highest density was 29 and 47% for exp. 1 and exp. 2, respectively. Effects of grasshoppers on below-ground growth (dry matter and surface area of roots) was less consistent than on above-ground variables; however, at the highest grasshopper density in exp. 2, dry matter and surface area of roots were reduced by about 40–53%.Grain yield (pooled over experiments) decreased by 19 and 36% for grasshopper densities of 2 and 3 pot-1, respectively. Most of the yield loss was accounted for by reduced seed weights, while protein content per seed remained nearly constant. The proportion of total above-ground dry matter represented in harvested grain and root:shoot ratios were not affected by grasshopper feeding. These results provide greater understanding of plant responses to insect feeding damage and will lead to more accurate estimates of economic injury levels. Key words: Cropyield loss, economic injury level, harvest index, Insecta
Inter simple sequence repeat (ISSR) to assess genetic diversity within a collection of wild lingonberry (Vaccinium vitis-idaea L.) clones
Authors: Debnath Samir C.
Published: April 2011

Forty-three wild lingonberry [Vaccinium vitis-idaea ssp. minus (Lodd) Hult.] clones collected from four Canadian provinces were assessed for genetic variability by using inter simple sequence repeat (ISSR). Fifteen primers generated 356 polymorphic ISSR-PCR bands. A substantial degree of genetic diversity was found am ong the wild collections. Cluster analysis by the unweighted pair-group method with arithmetic averages (UPGMA) separated the wild clones into four main clusters, and identified the two remaining clones as outliers. Furthermore, within four clusters, the genotypes tended to form sub-clusters that were in agreement with the principal coordinate (PCO) analysis. Geographical distribution explained 10% of total variation as revealed by analysis of molecular variance (AMOVA). The ISSR markers detected a sufficient degree of polymorphism to differentiate among lingonberry clones, making this technology valuable for germplasm management and the more efficient choice of parents in current lingonberry breeding programs. Key words: Vaccinium vitis-idaea, DNA fingerprinting, molecular marker
The biology of Canadian weeds. 134. Bromus inermis Leyss
Authors: Otfinowski R. , Kenkel N. C. , Catling P. M.
Published: April 2011

Smooth brome (Bromus inermis Leyss.), a native of central Eurasia, was introduced to Canada as a forage and hay crop around 1888. Early reports of plants escaped from cultivation appear in 1903, however, based on the number of collections prior to 1920, smooth brome spread more rapidly in western Canada. Smooth brome is common along roadsides, forest margins, clearings, shorelines and disturbed areas, but its most detrimental impact is on the diversity of prairies and native grasslands. In Riding Mountain National Park, MB, plant diversity of fescue prairies recently invaded by smooth brome decreased by 70%. Vegetative proliferation through underground rhizomes is key to the invasiveness of smooth brome, but long-range dispersal of seeds is facilitated by animals, wind and the transport of hay. Smooth brome is effectively controlled using selective applications of glyphosate and well-timed clipping. However, restoration of infested areas depends on the composition of native seed banks. Smooth brome remains valuable as a forage and cover crop in every province and territory in Canada. Key words: Bromus inermis, weed biology, prairie, Canada distribution, alien, smooth brome, biological invasion
Red River 1852 Roundup Ready™ high erucic acid, low glucosinolate summer rape
Authors: McVetty P. B. E. , Fernando W. G. D. , Scarth R. , Li G.
Published: April 2011

Red River 1852 summer rape (Brassica napus L.) is the world’s second Roundup Ready™ high erucic acid, low glucosinolate cultivar. It has a 3% yield advantage over Reston high erucic acid, low glucosinolate summer rape in the mid-season zone, is 26 g kg-1 higher in seed oil content than Reston, is equal to Reston in meal protein content and is adapted to all B. napus growing regions of western Canada. Key words: Rape, Roundup Ready™, high erucic acid, low glucosinolate, cultivar description
Fresh market sweet corn production with clear and wavelength selective soil mulch films
Authors: Zhang T. Q. , Tan C. S. , Warner J.
Published: April 2011

Earliness of fresh market sweet corn (Zea mays L.) is important to increasing profitability and maintaining market occupancy. Maturity of fresh market sweet corn may be advanced by the use of plastic soil mulch films. In 2000 and 2001, the effects of clear (CMF) and wavelength selective (WLSMF) mulch films on soil temperature and moisture and the performance of fresh market sweet corn with and without N fertilization were evaluated in a Granby loamy sand soil in southwest Ontario. Both mulch films increased soil temperature and moisture compared with bare soil. Soil temperatures were 1.8°C higher at 5 cm and 1.6°C higher at 15 cm soil depth under CMF than WLSMF averaged over the growing season in two years. Both mulches increased soil moisture levels relative to bare soil, but less increase occurred under CMF than WLSMF. Both CMF and WLSMF advanced sweet corn maturity by 6-7 d relative to the bare soil. Compared with bare soil, marketable yields increased by 25 to 63% without added N and by 72 to 114% with added N under CMF. Under WLSMF, the corresponding increases in marketable yields were 97 to 98% without added N and 120 to 200% with added N. While WLSMF was superior to CMF for increasing fresh market sweet corn yields in southwestern Ontario, the relative economic advantage of each mulch type needs to be studied. Key words: Marketable yield, nitrogen, soil cover, soil moisture, soil temperature
Mineral concentration and distribution in tubers of fertilized and unfertilized potato cultivars Shepody and Russet Burbank as determined by VP-SEM/EDS
Authors: LeRiche E. L. , Wang-Pruski G. , Zheljazkov V. D.
Published: April 2011

Plant nutrients are difficult to measure in situ using traditional chemical methods. In this study, a variable pressure scanning electron microscope (VP-SEM) equipped with energy dispersive X-ray spectrometry (EDS) was used to map elemental nutrients in potato tissue. Samples were taken from tubers of the cultivars Shepody and Russet Burbank from fertilized and non-fertilized plots. Each sample was divided into eight segments from stem to bud. X-ray mapping showed a higher overall concentration of P, M g, and Ca in tubers from fertilized plots compared with those from unfertilized plots for Shepody and Russet Burbank. P content was correlated with Mg content in Shepody (r = 0.851) and in Russet Burbank (r = 0.748). An increasing gradient of P and Mg from stem end to center of tubers and decrease again towards the bud end was observed in Russet Burbank, but was not as noticeable in Shepody. Ca showed a steady decline from stem end to bud end of tubers and little or no correlation to P or Mg for both cultivars. Results obtained using VP-SEM/EDS showed good correlation to those found using traditional chemical methods. We demonstrated that VP-SEM/EDS can be successfully used for mapping of nutrients in potato tubers. This study gives support to this technique as an alternative to traditional chemical methods of measuring minerals and nutrients. Key words: Potato, scanning electron microscopy, energy dispersive X-ray spectrometry, distribution (mineral), P, Mg, Ca
Prince Edward Island growers can reduce soil phosphorus buildup while maintaining carrot crop yield
Authors: Sanderson Kevin R , Sanderson J. Brian
Published: April 2011

Producers seek to manage the application of nutrients in a manner that maximizes economic crop returns; however, emphasis must now include sensitivity to environmental issues such as increasing soil phosphorus. To address this issue in carrot (Daucus carota L.) production, we studied the effect of soil-applied P fertilizers on yield and soil P content in Prince Edward Island. Six field studies over a 3-yr period evaluated the yield response of carrot on sandy to loamy sand Orthic Podzol soils. Treatments consisted of pre-plant broadcast applied P at 0, 33, 66, 99 or 132 kg ha-1 on sites where residual P levels ranged from 81 to 162 µg P g-1. When the total yield response of carrots to increasing P levels was fitted to a quadratic response curve, 110 kg P ha-1 was required to achieve maximum yield, but an application of as little as 22 kg P ha-1 resulted in 95% of maximum marketable yield. This reduced application rate resulted in a saving of 88 kg P ha-1 and slowed the buildup of soil P levels. Therefore, by applying more conservative amounts of P fertilizer carrot growers can maintain excellent crop yield while reducing the potential for environmental damage caused by the buildup of soil P. Key words: Orthic Podzol soil P, tissue P, fertilizer P, maximum yield, Daucus carota L.
Biochemical components of advanced selections and raspberry cultivars
Authors: Ehsani-Moghaddam B. , Khanizadeh S. , Sullivan J. A.
Published: April 2011

Commercially grown raspberry cultivars (Rubus idaeus L.) (Festival, Boyne, Nova and Killarney) and advanced selections (88–18, 88–117, 88–134, SJR942-7) from the University of Guelph and Agriculture and Agri-Food Canada (AAFC) were evaluated for total antioxidant capacity, soluble solids content and acidity. The crude, hydrophilic and lipophilic antioxidant content of berries were measured using the Trolox equivalent antioxidant capacity (TEAC) method. Significant variations were observed among crude, hydrophilic and lipophilic antioxidant content of the different advanced selections. Selection 88–18, had the highest crude, hydrophilic and lipophilic antioxidant capacity, while SJR942-7 had the highest soluble solids. The study shows the importance of genetic background in determining the antioxidant potential in raspberry and the possibility of developing new lines rich in phytochemicals. Key words: Hydrophilic, lipophilic, total antioxidants, TEAC, Trolox, soluble solids
Strategies to propagate Vaccinium nuclear stocks for the Canadian berry industry
Authors: Debnath Samir C
Published: April 2011

Vacinium fruits are genetically heterozygous species characterized as “not coming true from seed”. Conventional methods for vegetative propagation of these species, although successful, are slow and labour-intensive, and few propagules can be produced from one plant of a selected clone or hybrid. Micropropagation techniques are important for clonal multiplication, germplasm im provement and gene conservation of Vaccinium fruits cultivated in Canada including blueberries, cranberries and lingonberries. In vitro propagation of these species using axillary bud proliferation and adventitious shoot regeneration has been investigated in a number of studies. Morphogenesis seems to be highly dependent on plant growth regulators and media used for culture, and this dependence is genotype specific. The paper presents the progress in-depth of various aspects of the in vitro culture of Canadian Vaccinium species for their commercial production. Also discussed are techniques for clone rejuvenation and plant tissue culture for mass propagation of Canadian Vaccinium nuclear stocks. Key words: Blueberry, cranberry, lingonberry, micropropagation, regeneration, morphology
Nitrogen and sulphur fertilizer management for growing canola on sulphur sufficient soils
Authors: Karamanos R. E. , Goh T. B. , Flaten D. N.
Published: April 2011

Canola is a crop that demands high nitrogen (N) and sulphur (S) inputs to achieve maximum seed yield. The practice of balancing these two nutrients by applying them in a fixed ratio has shown yield benefits on soils deficient in both these nutrients. A 9 site-year study was conducted between 2002 and 2004 to determine whether this practice is necessary for soils containing sufficient S levels. The practice was tested for both hybrid (HC) and open pollinated (OPC) canola cultivars by applying six rates of N (0, 40, 80, 120, 160 and 200 kg N ha-1) and supplementing N rates with S, so that three N:S ratios (1.5, 6 and 12 to 1) were achieved. Seed yield, protein and oil content responses of both HC and OPC cultivars were obtained primarily with N, with no evidence for a need of balancing this nutrient with S additions to achieve a ratio within those applied at this study. Hybrid canola cultivars overall yielded 23.7% more than OPC cultivars when they received the N application rate at which maximum yield of the OPC cultivars was obtained (120 kg N ha-1). Application of an additional 30 kg ha-1 to obtain maximum HC seed yield only resulted in an additional 1.5% yield advantage for the OPC. As N application rate was increased, small increases in seed protein levels (≈2.5%) were accompanied by a small reduction (≈2%) in seed oil content. Increased yield by HC compared with OPC canola reduces N residual fertility, hence, assessment of soil fertility status by soil testing after growing HC canola is a highly beneficial management practice. Our results indicate that the practice of balancing N and S to a fixed ratio is unnecessary and wasteful on canola grown on soils containing sufficient S. Key words: Hybrid canola, N:S ratio, open pollinated, residual soil fertility
A review of agricultural land use by shorebirds with special reference to habitat conservation in the Fraser River Delta, British Columbia
Authors: Evans-Ogden Lesley J , Bittman Shabtai , Lank David B
Published: April 2011

Many estuaries worldwide are important habitats for shorebirds. Agricultural fields adjacent to food-rich intertidal areas can provide roosting and feeding habitat, particularly at high tide. The Fraser River Delta (FRD) contains rich agricultural land and is Canada’s most important non-breeding site for shorebirds. We review and synthesize recent studies that have investigated agricultural land as non-breeding habitat for shorebirds in the FRD using radio-tracking, day-time and night-time surveys, stable isotope analysis of blood samples, examination of prey in stomach and faecal samples, and farmer surveys regarding field management. The three primary shorebirds studied in the FRD were dunlin (Calidris alpina pacifica), black-bellied plover (Pluvialis squatarola), and killdeer (Charadrius vociferus). Field use is mainly nocturnal for dunlin, but diurnal for black-bellied plovers and killdeer. Dunlin and black-bellied plovers mainly use bare or winter cover crop fields, preferring short cover. Killdeer mainly use berry and winter vegetable fields. All species prefer fields recently manured, fertilized, or laser levelled. Day length and precipitation influenced field use. Stable isotope analysis (δ13C, δ 15N) of dunlin blood indicates that approximately 38% of dunlin diet is obtained from agricultural habitat. Younger birds have a higher terrestrial contribution to diet (~43%) than adults (~35%). Dunlin prey includes agricultural pest species such as leatherjacket (Tipulidae) larvae and wireworm (Agriotes spp.). Coastal agricultural land with diverse crop types benefits shorebirds, and its loss may negatively impact fitness, especially for juveniles. Research conducted in the FRD shows the importance of farmland for wintering shorebirds and suggests conservation and management strategies to preserve and enhance the wildlife value of this agricultural habitat. Key words: Farmland, agricultural land, shorebirds, Fraser River Delta, management, wildlife conservation
CTH2 flue-cured tobacco F1 hybrid
Authors: Haji H. M. , Mishra S. , DeVos M.
Published: April 2011

CTH2 is the first flue-cured tobacco (Nicotiana tabacum L.) hybrid recommended for commercial release in Canada. Yields and economic returns of CTH2 are significantly higher than the check varieties, Delgold and CT157. It has uniform growth both in the greenhouse and in the field, and is resistant to black root rot disease (Chalara elegans Nag Raj and Kendrick, causal agent). Leaf quality traits of CTH2 are far superior to Delgold, as well as commercial varieties that are also immune to black root rot disease. Key words: Nicotiana tabacum L., tobacco, hybrid, male sterility, black root rot, cultivar description
Genotypic and environmental variation in grain, flour, dough and bread-making characteristics of Western Canadian Spring Wheat
Authors: Finlay G. J. , Bullock P. R. , Sapirstein H. D. , Naeem H. A. , Hussain A. , Angadi S. V. , DePauw R. M.
Published: April 2011

Wheat (Triticum aestivum L.) grain, flour, dough and bread quality characteristics are strongly influencedby growing-season weather conditions. Understanding the impact of genotype, environment, and their interactions on Canadian wheat quality is important for Canada to maintain its high standard for delivery of consistent quality wheat to domestic and international customers. The effects of genotype, environment and genotype by environment (G × E) interaction on numerous grain, flour, dough and bread-making characteristics were assessed. The Canadian Western Red Spring (CWRS) cultivars were AC Barrie, Superb, AC Elsa, and Neepawa; the Canadian Prairie Spring (CPS-white) cultivar was AC Vista; and the Canadian Western Hard White Spring (CWHWS) cultivar was Snowbird. These genotypes were grown at five locations across the Canadian prairies in 2 yr to provide a total of 7 site-years of milling quality wheat for analysis. Genotype, environment and their interactions had significant effects on most parameters tested. The relative magnitude of the environmental contribution to wheat quality variance, depending on the trait, was considerably larger (14 to 89%) than the variance contribution of either genotype (0 to 33%) or G × E interaction (0 to 17%). The greatest environmental contribution to total variance (83%) was, on average, for grain traits including yield. Genotypic contribution to variation was greatest (~15%) for flour characteristics. The G × E interaction contributed relatively little to total variance and was comparable for flour, dough and bread properties (~6.5% on average). This large difference in variance between environmental and genotypic influences clearly demonstrates the importance of growing-season weather impacts on yield and quality for adapted bread wheat genotypes and strategies to mitigate these effects are discussed. Key words: Wheat, bread-making quality, Canadian prairies, environment, genotype, genotype by environment
Probability of a recombinant inbred diploid plant for two linked genes
Authors: Helms Theodore C
Published: April 2011

For some discreet traits, breeders may need to break genetic linkage between a desirable trait and an undesirable trait. Breeders need to be able to determine the minimum number of plants to grow to have a specified probability of identifying at least one plant that is recombinant between two linked loci. Since 1931, recurrence equations have been available to determine the genotypic frequencies of each genotype when two loci are linked as the level of inbreeding changes. However, these genotypic frequencies have not been published in a tabular form that would be helpful to the applied plant breeder. The objectives are to: (1) provide genotypic proportions as the intensity of linkage and the level of inbreeding increases; (2) determine the most efficient method of identifying a homozygous recombinant genotype as the level of inbreeding and linkage intensity are varied. Numerical examples and formula are provided to determine the number of plants that must be grown to have a given probability of success of identifying a specified number of recombinant types. For close linkage, the number of plants that must be genotyped is greatly decreased by waiting until the population is highly inbred. Key words: Genetic recombination, inbreeding
Effects of seed size and seed weight on seedling establishment, seedling vigour and tolerance of summer turnip rape (Brassica rapa) to flea beetles, Phyllotreta spp.
Authors: Elliott R. H. , Mann L. W. , Olfert O. O.
Published: April 2011

A 3-yr study was conducted on three synthetic Brassica rapa L. cultivars to determine the effects of seed size and seed weight on seedling establishment, seedling growth and susceptibility to feeding damage by flea beetles, Phyllotreta spp. (Coleoptera: Chrysomelidae). Seed lots of AC Boreal, Fairview and Hysyn 110 were sieved to obtain small, medium and large seeds (1.4–1.6, 1.6–1.8 and 1.8–2.0 mm, respectively). In the laboratory, seedlings grown from large seeds had the largest cotyledons, highest shoot dry weight and highest biomass. Shoot weights increased as seed size increased. Sized seeds of the three cultivars were grown in the field without insecticides in 1998–2000. Seedlings of small seeds had the highest flea beetle damage and poorest seedling establishment. Shoot dry weight and biomass 14–35 d after planting increased as seed size and seed weight increased. Compared with small seeds, large seeds improved shoot dry weight, biomass and seed yield by 13–43, 25–57 and 12%, respectively. Results indicated that seedlings of medium and large seeds are more vigorous and tolerant to flea beetle damage than seedlings of small seeds. Tolerance was due to a higher initial seedling weight rather than higher relative growth rate. Shoot dry weights, biomass and yield of the three cultivars were more strongly correlated with 1000-seed weight than with seed diameter. Key words: Canola, flea beetles, seed size, seedling vigour, tolerance, seed weight
Harohawk common bean
Authors: Park S. J. , Rupert T. , Yu K.
Published: April 2011

Harohawk black bean bean (Phaseolus vulgaris L) has high yield potential with dull seed coat luster and semi-determinate growth habit with erect plant type and lodging resistance, medium season maturity and is moderately resistant to common bacterial blight. Key words: Phaseolus vulgaris, black bean, cultivar description, plant type, common bacterial blight
Association of salt tolerance at seedling emergence with adult plant performance in slender wheatgrass
Authors: Pearen J. R. , Pahl M. D. , Wolynetz M. S. , Hermesh R.
Published: April 2011

Regrowth of 15 slender wheatgrass (SWG, Elymus trachycalus sp. Trachycalus (= Agropyron trachycaulum Link Malte) lines was evaluated after 3 (harvest-one) and 11 wk (harvest-two) after clipping at four salinity levels. Lines were previously categorized into salt-tolerant (TOL) and non salt-tolerant (NT) accessions based on percent emergence at 15 mS cm−1 relative to a salt-tolerant control, tall wheatgrass (TWG, Agropyron elongatum (Host) Beauv. [= Thinopyron ponticum (Podpera) Lu & Wong]. Regrowth of five TOL, five NT, five untested (UT) SWG lines and TWG were compared in a greenhouse with nutrient solutions salinized to ECe values of 2, 7, 15, and 23 mS cm−1. Regrowth of all SWG lines decreased from 68 to 98% as salinity increased. Orbit tall wheatgrass shoots were about threefold larger than SWG shoots at 15 and 23 mS cm−1. Phenological development of NT lines was slower (P ≤ 0.05) than that of TOL and UT lines at all ECe levels. However, shoot growth of NT lines exceeded (P ≤ 0.05) that of TOL lines at 23 mS cm−1. Regrowth after 3 and 11 wk were correlated within ECe levels, (r = 0.22 to r = 0.34, P ≤ 0.01). Lack of a positive relationship between lines selected for emergence in saline media and their subsequent growth under saline conditions indicates that improvements in adult plant growth under saline conditions will require additional selection for appropriate traits in SWG. Key words: Slender wheatgrass, Elymus trachycalus sp. trachycalus (= Agropyron trachycaulum Link Malte), tall wheatgrass, Agropyron elongatum (Host) Beauv. (= Thinopyron ponticum (Podpera) Lu & Wong), salt tolerance, genetic screening, emergence
The selection of superior winter-hardy genotypes using a prolonged freeze test
Authors: Gusta L. V. , O'Connor B. J. , MacHutcheon M. G.
Published: April 2011

Methods of assessing the freezing tolerance of winter cereals must be improved in order to distinguish small differences due to genotype or environment. Seed of eight winter wheat (Triticum aestivum L. em Thell) cultivars, ranging in winter hardiness, were sown either in mid-August, the first week of September or mid-September. Individual plants of each were collected in late October and stored at either −4° or −8 °C. In December controlled freeze tests, employing a cooling rate of 2 °C h−1, could not distinguish the less freezing-tolerant cultivars stored at −4 °C. However, by March the less winter-hardy cultivars from the third seeding date stored at −4 °C could be distinguished. Seedlings stored at −8 °C declined in freezing tolerance more rapidly than seedlings stored at −4 °C. In December, the less hardy winter wheat cultivars, Rose, Rita and Siouxland, were less freezing tolerant than the hardy cultivars (e.g. Norstar). Seedlings of Rita and Siouxland from the second and third seeding date died by February when stored at −8 °C. Seedlings of all winter wheat cultivars were dead by March, except Norstar and Alabaskaja, the most winter-hardy cultivars. Storage of seedlings of wheat, triticale (× Triticosecale Rimpani Wit.) and rye (Secale cereale L.) at either −12° or −15 °C readily identified the superior winter-hardy genotypes. For example, in mid-winter both Siouxland and Norstar winter wheat had a similar LT50 (temperature at which 50% of the plants are killed). However, Siouxland could not tolerate storage at either −12° or −15 °C for the same length of time as Norstar. These results support the theory that winter kill in nature is more a function of duration of exposure to sub-lethal temperatures rather than exposure to a minimum low temperature for a short duration as programmed in a conventional freeze test. A more realistic and precise freeze test would be to determine the ability of genotypes to survive lengthy exposure to sub-lethal low temperatures. Key words: Winter cereals, freezing tolerance, winter injury, duration effects, screening method
Resistance to homologous and heterologous strains of potato virus Y in transgenic tobacco carrying the PVYN coat protein gene
Authors: McDonald J. G. , Brandle J. E. , Gleddie S. , Hermans J. A. , Kermali I. R.
Published: April 2011

Pure breeding lines of transgenic Nicotiana tabacum L. 'Delgold' were generated which expressed transcripts of the coat protein gene of the tobacco veinal necrosis stain of potato virus Y (PVYN) and were highly resistant to the virus. The form of resistance appeared to be RNA-mediated as no coat protein could be detected by enzyme linked immunosorbent assay. Resistant lines had two or three copies of the transgene but segregation analysis of the R1 and R2 progeny indicated that one copy in each line was functional for virus resistance. Simultaneous screening of lines for resistance against both PVYN and the heterologous PVYO (common) strain allowed for optimal selection of heterologous strain resistance. Resistance against the PVY-mn and PVY-nn strains and an ungrouped isolate, PVY-136, was less than against the PVYO isolate. The degree of heterologous strain resistance did not appear to directly correlate with the degree of sequence homology previously reported. The lines had no resistance against the related potato virus A and pepper mottle virus. Key words: Resistance to potato virus Y, transgenic, Nicotiana tabacum, enzyme linked immunosorbent assay, monoclonal antibodies