bluuebunny/crossref_metadata_2025 huggingface dataset:
AC Earlired small red bean
Authors: Saindon Gilles , Mündel Hans-Henning , Huang Henry C. , Kiehn Ferdinand A.
Published: April 2011

AC Earlired is an early-maturing small red dry bean (Phaseolus vulgaris L.) cultivar. It was developed from a cross of Ember by line 5217 at the Lethbridge Research Centre, with cooperation from the Morden Research Centre, AC Earlired is particularly well adapted to the irrigated western Canadian prairies, maturing on average 5 d before NW63, with equal seed yield. Key words: Phaseolus vulgaris, small red bean, cultivar description, early maturity
Selection for persistence in red clover
Authors: Christie B. R. , Martin R. A.
Published: April 2011

To increase the persistence of red clover (Trifolium pratense L.), phenotypic recurrent selection was conducted under field conditions. After three cycles of selection, a strain designated as CRS-16, was developed. This strain has better persistence than the check cultivars, Florex and Marino, and has a more fibrous root system. Among 4-yr-old plants, about 10% initiated new shoots from below the crown. Key words: Red clover, Trifolium pratense L. persistence, root type
RCAT Bobcat soybean
Authors: Ablett G. R. , Stirling B. T. , Fischer J. D.
Published: April 2011

RCAT Bobcat is an early Maturity Group I soybean [Glycine max [L.] Merr.] cultivar with excellent yield potential and good lodging resistance. It was developed by Ridgetown College, University of Guelph and is widely adapted to Ontario. Key words: Soybean, cultivar description, Glycine max
Canonical variate analysis of genotype × environment interactions
Authors: Tai G. C. C.
Published: April 2011

The additive main effects and multiplicative interaction (AMMI) model is used to investigate genotype × environment interactions often encountered in variety trials. Interaction effects are accounted for by several multiplicative terms in the model, with each consisting of a genotypic and an environmental parameter. These effects are estimated using principal-component analysis. An alternative method is presented to estimate the genotypic and environmental parameters in the multiplicative terms of the AMMI model by canonical variate analysis. The number of significant interactive terms can be easily determined using the χ2 test. Each of the multiplicative terms include a unitless coefficient measuring genotypic response and an environmental effect in terms of the physical unit of the concerned trait. Biplots can be used with the scores of both genotypes and environments for graphic examination of analytic results. Total tuber-yield data from potato genotypes tested in a series of international trials are used to illustrate the new analytic procedure. Key words: Genotype × environment interactions, AMMI, canonical variate analysis, potato
Effect of split application of sulphur and nitrogen on growth and yield attributes of Brassica genotypes differing in time of flowering
Authors: Ahmad Altaf , Abrol Y. P. , Abdin M. Z.
Published: April 2011

According to prevalent agronomic practices for cultivation of Brassica genotypes, N is applied in split doses, while S is applied as a basal dose. This may create imbalance in the supply of these nutrients during the growth and development of the crop because metabolism of N and that of S are closely linked and play a central role in protein synthesis. The requirement of one depends on the supply of the other, and the imbalance in their supply causes a reduction in the yield because of reduced uptake and assimilation of the two nutrients. In the present investigation, therefore, S was applied in split doses, along with N, to study its effect on growth and yield attributes of Brassica juncea (L.) Czern. and Coss. (V1) and Brassica campestris L. (V2). In the experiment, conducted in the field, 40 kg S ha−1 as CaSO4 (gypsum) was applied either in a single basal application (S1) or in two (S2) or three (S3) split applications; and 100 kg N ha−1 as urea was applied either in two (N2) or three (N3) splits. Biomass accumulation, leaf-area index (LAI), leaf-area duration (LAD), crop growth rate (CGR) and photosynthesis in the leaves were determined at various phenological stages. Split application of S and N (S2N2 or S3N3) resulted in significant improvement in growth and yield of both the genotypes compared with the application of S in a single basal application and N in two splits (S1N2). Genetic variability was observed between the two genotypes in response to split application of S and N. V1 responded better when S and N was applied in two split doses (S2N2) than when it was applied as S1N2 or S3N3 This S2N2 treatment resulted in 40.0, 39.7, 35.5, 48.2 and 18.1% enhancement in biomass accumulation, LAI, LAD, CGR and photosynthetic rate, respectively in comparison with S1N2. Seed yield, biological yield and harvest index were improved by 38.3, 26.3 and 9.5%, respectively, by S2N2 over the results obtained with S1N2. In the case of V2, three split applications of S and N (S3N3) resulted in maximum growth and yield. Increases in biomass accumulation, LAI, LAD, CGR and photosynthetic rate due to application of S3N3 were 48.4, 81.3, 77.9, 101.1 and 28.6% respectively, over the results of S1N2. Seed yield, biological yield and harvest index improved by 41.3, 26.9 and 11.6% respectively, with this treatment.On the basis of results obtained in this study, it can be concluded that S must be applied in split doses for optimum growth and yield of Brassica genotypes. The variability in response of these genotypes to split application of S and N was due to differences in flowering time, as V1 flowered earlier (just after the application of the second dose of S and N) than V1 (just after the application of the third dose of S and N). Key words: Brassica genotypes, nitrogen, sulphur, split application, growth, yield
Leaf and stem nutritive value of timothy grown with varying N nutrition in spring and summer
Authors: Bélanger G. , McQueen R. E.
Published: April 2011

Nitrogen fertilization is known to have a limited effect on the digestibility of grasses. In a previous paper, however, we reported that N deficiency increased the proportion of leaves in the shoot biomass, and hence, indirectly increased the digestibility of timothy (Phleum pratense L). This was mitigated by the direct negative effect of N deficiency on the digestibility of leaves or stems or both early in the regrowth. The objective of this study was to determine the direct effect of N deficiency on three parameters of nutritive value of leaves and stems of timothy cv. Champ. The evolution of leaf and stem in vitro true digestibility (IVTD), in vitro cell wall digestibility (IVCWD), and neutral detergent fiber (NDF) concentration of field-grown timothy fertilized with four rates of N was studied during a spring and summer regrowth cycle by sampling at weekly intervals. The rate of decline in leaf nutritive value in spring was greater than that in summer, and was less than the rate of decline in stem nutritive value during spring. Nitrogen deficiency consistently increased the NDF concentration of leaves but had a lesser effect on the NDF concentration of stems. Nitrogen deficiency decreased leaf IVCWD when the leaf-to-weight ratio (LWR) was high early in the spring and summer regrowth cycles. At the end of regrowth when LWR values were low, leaf IVCWD was greatest when no N was applied. As a result, the negative effect of N deficiency on the leaf IVTD during the early part of the spring and summer regrowth cycles diminished as the regrowth cycles progressed. Nitrogen deficiency had a limited effect on stem IVCWD. We concluded that the direct negative effect of N deficiency on the digestibility of the timothy shoot biomass can be attributed primarily to its effect on the NDF concentration and cell wall digestibility of leaves. Key words: Phleum pratense L., grasses, digestibility, cell wall, nitrogen
Yield and injury effects on vegetable crops planted in flumetsulam-treated soil
Authors: O'Sullivan J. , Thomas R. J. , Bouw W. J.
Published: April 2011

The effect of flumetsulam on several vegetable crops grown following soybean was investigated over a 4-yr period. Flumetsulam was applied preplant incorporated to soybean at 0, 70 and 140 g a.i. ha−1 from 1992 to 1994. In trials 1 yr after flumetsulam application, cabbage (Brassica oleracea var. capitata), potato (Solanum tuberosum L.), tomato (Lycopersicon esculentum L.), and pepper (Capsicum annuum L.), showed visual injury symptoms and reduced yields in 1993, while only cabbage showed visual injury symptoms and reduced yields in 1994 and 1995. Cucumber (Cucumis sativus) showed injury symptoms only in 1993 and had no yield reduction. Cabbage also showed visual injury and reduced yields 2 and 3 yr following a 1992 flumetsulam application. Broccoli (Brassica oleracea var. italica) and cauliflower (Brassica oleracea var. botrytis) showed visual injury symptoms in 1995, 3 yr after flumetsulam application. Generally, crop tolerance decreased linearly as application dose increased from 0 to 140 g ha−1. Minor visual injury symptoms did not correspond with a reduced yield. Injury was most severe on sites with the lowest soil pH values. Based on these studies, effects of flumetsulam from normal use rates (70 g ha–1) will carry over to injure-sensitive crops like cabbage, in the rotation for up to 3 yr, especially in low pH soils (pH 6.1 or less). Otherwise, a 22-mo planting interval is adequate to protect other vegetable crops in the rotation from injury and yield reductions. Key words: Crop injury, herbicide carryover, flumetsulam, yield
Efficacy of chlorophyll fluorescence as a viability test for freeze-stressed woody grape tissues
Authors: Jiang Hongying , Howell G. S. , Flore J. A.
Published: April 2011

Woody-tissue cold hardiness and chlorophyll fluorescence of Concord (Vitis labruscana Bailey) grapevines were measured every 2 wk from late September to mid-December 1997. Plant efficiency analyser (Hansatech Ltd., King's Lynn, UK) was used to measure chlorophyll fluorescence after a laboratory controlled freeze stress. From five preliminary experiments, valid chlorophyll fluorescence measurements were obtained from the cane surface with periderm removed, under ∼ 2700 µ mol m−2 s−1 and 10 min dark adaptation after 24–30 h post stress. For large samples, dark adaptation was not necessary if only the Fv/Fm (ratio of variable fluorescence to maximum fluorescence) was of interest. This ratio was positively correlated with freeze-stress temperatures and negatively correlated with tissue injury. The Fv/Fm temperature inflection point was positively correlated with LT50 (temperature at which 50% of the sample is injured), calculated from the regrowth test. The Fv/Fm ratio was a sensitive, reliable, objective, and rapid method of assessing woody-tissue viability after a freeze–thaw episode during cold acclimation. An Fv/Fm50 was proposed as an indicator of the injury threshold. Key words: Concord (Vitis labruscana), cold hardiness, Fv/Fm, regrowth test
Competition between corn and a living mulch
Authors: Martin R. C. , Greyson P. R. , Gordon R.
Published: April 2011

Living mulches in row crops can reduce soil erosion, conserve soil moisture and control weeds; however, unless suppressed, they may also compete with the primary crop for light, nutrients and water. Therefore, the effects of mulch suppression were assessed on the development and yields of silage corn (Zea mays L.) in Truro, NS.In 1995 and 1996, silage corn was grown in a living mulch composed of white clover (Trifolium repens L.) and mixed grasses in a 2 × 5 factorial design with eight replications. There were 2 levels of applied N: 0 and 115 kg N ha−1. The mulch was suppressed by: herbicide bands, roto-tilled strips, a combination of herbicide and roto-tillage, applied straw, and complete eradication with conventional tillage and herbicide applications (unmulched control treatment). Mulch between the corn rows was mowed several times, early in the season, to reduce competition.In 1996, the control treatment yielded 11583 kg ha−1, significantly more than 6844 kg ha−1 in the combined herbicide and rototilled treatment, but in 1995 yields were not significantly different (P > 0.05) between these two treatments. Where only one method of mulch suppression was used (either roto-till or herbicide), corn yields in plots with living mulch were reduced by 39 to 72% relative to control plots. In both years, corn yields were higher at 115 kg N ha−1 than at 0 kg N ha−1. Yields in the mulched plots were 27% lower in 1996 than in 1995, probably as a result of a late June 1996 frost. In addition to the increased risk of frost damage, the living mulch also delayed corn emergence and development. While there may be some reductions in herbicide use with living mulch, the risk in cool temperate climates of delayed development and reductions in yield may limit the use of living mulches to cool season crops. Key words: Corn, frost, living mulch, reduced tillage, soil moisture
The effect of ice encasement and early snow removal on the survival of creeping bentgrass
Authors: Cattani D. J. , Miller P. R. , Smith Jr. S. R.
Published: April 2011

Field studies conducted in 1992–1995 evaluated turf injury to creeping bentgrass following winter ice encasement. During the 1995 winter, ice encasement accompanied by early snow removal caused high stand mortality for two of five cultivars/line, but ice encasement with snow cover had no effect. Our results suggest that dormancy of the cultivars affect bentgrass survival under ice encasement. Key words: Ice encasement, creeping bentgrass
Influence of annual forages on weed dynamics in a cropping system
Authors: Schoofs Allison , Entz Martin H.
Published: April 2011

Alternatives to herbicides are needed for weed control. Field studies were conducted in 1994/1995 and 1995/1996 to investigate the nature of forage crop-weed dynamics and to test the effect of single year forage crops on the density and community composition of annual weeds in a following field pea (Pisium sativum L.) test crop. Five spring-seeded forage treatments were compared with wheat (Triticum aestivum L.) grain crops (with or without herbicides for grassy and broadleaved weeds): winter triticale (Triticosecale) (simulation grazed); spring triticale (silage); spring/winter triticale intercrop (silage, then simulation grazed); alfalfa (Medicago sativa L.) (hay); sorghum-sudangrass (Sorghum bicolor [L.] Moench × Sorghum sudanese [Piper]) (hay); and a weedy fallow (silage). A fall rye (Secale cereale L.) grain crop and a sweet clover (Melilotis officinalis L.)/winter triticale double crop (hay, then simulation grazing) were included in the 1995/1996 trial. All forage systems were at least as effective as the sprayed wheat control in suppressing wild oat (Avena fatua L.); however, effects on other weeds, especially broadleaved species, were variable. Biennial crops provided the best early season weed control, while long-season systems such winter triticale and the triticale intercrop provided the best late season weed control. Forages shifted the weed community composition away from wild oat and green foxtail (Setaria viridis L. Beauv.) to a similar or greater extent than herbicide-treated wheat. Forage systems that did not provide season-long crop competition tended to have more broadleaved weeds. Some forage systems increased pea grain yield the following year (relative to the sprayed wheat control); however, forages alone did not eliminate the need for herbicides in the pea crop. Annual forages may play an important role in integrated weed management, especially for wild oat, however further research to refine forage-based weed management systems is needed. Key words: Integrated weed management, alfalfa, intercropping, double cropping, organic farming
Genotype × environment interaction of potato chip colour
Authors: Tai G. C. C. , Coleman W. K.
Published: April 2011

Ten potato genotypes were tested in replicated trials over three sites in New Brunswick. Five of them were tested in 1991, 1992 and 1993, and another five in 1992 and 1993. Tubers were harvested and put in storage rooms with two temperature regimes: 7 °C and 13 °C. Prior to testing glucose content and chip colour, a portion of tubers stored in 7 °C was sampled and subjected to reconditioning for 2 and 4 wk in a storage room with the temperature regime of 21 °C. High relative humidity (>80%) was maintained in all storage rooms. Glucose and colour score of chips were determined during November in each of the three years. Analysis of variance revealed genotype × environment interactions for both traits. Since variation of chip colour is controlled primarily by glucose content in potatoes, this causal relationship was used as a basis to perform path regression analysis for each of the genotypes, based on all available data of the two traits. The regression equation is composed of two terms: an average chip score over environments (µ) and a multiplicative term with a genotypic coefficient (g) and an environmental index (r); µ measures the overall chipping ability, whereas g responds to environment and thus represents chipping stability. The 10 genotypes were different from one another on estimates of both parameters. The estimates of r showed lesser differences between the three test sites than between storage-temperature regimes. Storing potatoes at 13 °C and 7 °C gave the best and worst chip-colour scores, respectively. Reconditioning at 21 °C after storing at 7 °C improved the colour performance. No clear association was observed between chip colour, specific gravity and marketable yield. Good chipping genotypes tested in the experiment, however, had lower yields than others. The present results indicate that path regression analysis is an effective method for detecting the role of glucose content in the control of the expression of chip colour. Key words: Potato, Solanum tuberosum, chip colour, glucose content, storage
AC Carnduff flax
Authors: Kenaschuk E. O. , Rashid K. Y.
Published: April 2011

AC Carnduff, a medium-late maturing oilseed flax (Linum usitatissimum L.) was developed by Agriculture and Agri-Food Canada, Research Centre, Morden, Manitoba. This cultivar has medium-high oil content, high oil quality, medium seed size, good lodging resistance and high yield when seeded early in the Black and the Brown Soil zones of the prairies. It is immune to North American races of rust caused by Melampsora lini and moderately resistant to wilt caused by Fusarium oxysporum f. sp. lini. Key words: Flax, oilseed, Linum usitatissimum L., cultivar description
Arbuscular mycorrhizae and the phosphorus nutrition of maize: A review of Guelph studies
Authors: Miller Murray H.
Published: April 2011

The role of mycorrhizae in phosphorus nutrition of maize (Zea mays L.) is related to the fact that the P concentration in maize shoots at the four- to five-leaf stage affects final grain yield.In the early 1980s we observed greater early-season shoot-P concentration (mg g−1) and P absorption (mg plant−1) from a no-till compared to a conventional tillage system. Further studies established that the greater P absorption is due to a more effective arbuscular mycorrhizal (AM) symbiosis when the soil is not disturbed. The greater P absorption is largely a result of the undisrupted mycelium present in an undisturbed soil, rather than to increased colonization. This mycelium retains viability through extended periods in frozen soil. In the spring this mycelia network is able to acquire P from the soil and deliver it to the plant immediately upon becoming connected to a newly developing root system. Increased P absorption has not resulted in increased grain yield in field trials. Some additional factor limits yield with no-till maize preventing the advantage of early P absorption from being realized as yield. When maize follows a non-mycorrhizal crop such as canola (Brassica napus L.), mycorrhizal colonization is delayed, reducing early-season P absorption. Yield reductions may occur.In summary, AM mycorrhizae are involved in P nutrition of maize and an understanding of their functioning will assist us in modifying management practices to maximize economic returns through increased fertilizer efficiency. Key words: Maize, arbuscular mycorrhizae, phosphorus nutrition, tillage, canola
AC Intrepid hard red spring wheat
Authors: DePauw R. M. , Clarke J. M. , Knox R. E. , Fernandez M. R. , McCaig T. N. , McLeod J. G.
Published: April 2011

AC Intrepid, a hard red spring wheat (Triticum aestivum L.), is adapted to the Canadian prairies. It expressed high grain yield, early maturity, and heavy kernels. It has resistance to prevalent races of leaf rust, stem rust, and common bunt. AC Intrepid is eligible for grades of Canada Western Red Spring wheat. Key words: Triticum aestivum L., red spring wheat, yield, maturity, disease resistance, seed size
Vineland plum cultivars perform well on dwarf and vigorous rootstocks in early production
Authors: Embree C. G. , Tehrani G. , McRae K. B.
Published: April 2011

European plum (Prunus domestica L.) cultivars, and selections developed at the Horticultural Research Institute of Ontario, Vineland Station, were evaluated, over a range of rootstocks of differing vigour, in the Annapolis Valley, Nova Scotia. Cultivars and number selections included: Vanette (V66071), Victory (V72331), Voyageur (V63002), V63015, Valerie (V70031), Valor, Veeblue, Vision, Verity, and the standards, Stanley and Italian Prune. The four prunus rootstocks were: Pixy (P. insititia L.), St. Julian A (P. insititia L.), Brompton (P. domestica L.), and Myrobalan B (P. cerasifera Ehrh.). The largest cultivars were Italian Prune, Vision, and Veeblue, particularly on St. Julien A, Brompton, and Myrobalan B. Trees on Pixy were the smallest and had the smallest range of sizes. Yield and efficiency was the greatest for Vision, for all rootstocks. Victory, Voyageur, Valor, and Veeblue performed well with some of the rootstocks. The cultivars Vision, Vanette, Victory, Voyageur, and Valerie were the most precocious. The three cultivars with the largest fruit size were Victory, Valerie, and Vision. Italian Prune produced the smallest fruit. The combination of Stanley/Pixy also produced small fruit. For the Annapolis Valley, Vision is highlighted as a very productive cultivar for which tree size can be contained by the rootstocks Pixy and St. Julien A. Key words: Plum, cultivars, rootstocks, yield, precocity
Anthocyanin content and profile within and among blueberry species
Authors: Kalt W. , McDonald J. E. , Ricker R. D. , Lu X.
Published: April 2011

Anthocyanins in ripe fruit of four Vaccinium species and genotypes within these species were compared, revealing substantial inter- and intra-species variability among these commercial and non-commercial blueberries. The highest total anthocyanin content occurred in the bilberry (V. myrtillus L.). Commercial lowbush blueberry clonal mixtures and wild velvet leaf blueberries (V. myrtilloides L.) had about 43% of the anthocyanin content of bilberries (fresh weight basis). Three commercial highbush cultivars (V. corymbosum L.) had about 30% of the bilberry level, while wild genotypes of highbush blueberries had almost 60% of the bilberry level. Acetylation of anthocyanins occurred widely among all species, except bilberries. Although the proportions of the five blueberry anthocyanidins varied substantially among the commercial blueberries, these differences probably do not contribute substantially to differences in their relative antioxidant capacity. Key words: Vaccinium, bilberry, acetylation, cluster analysis, antioxidant
Phenotypic diversity in four woody species on the Canadian prairies
Authors: Chowdhury M. A. , Jana S. , Schroeder W. R.
Published: April 2011

Genetic diversity is a prerequisite for plant adaptation and maintenance of a sustainable ecosystem. Not much information is available on the genetic diversity of woody species on the semi-arid Canadian prairies. We used RAPD fragments to assess the diversity of four woody species of the Elaeagnaceae family, sea buckthorn (Hippophae rhamnoides L.), Russian olive (Elaeagnus angustifolia L.), buffaloberry (Shepherdia argentea Nutt.) and silverberry (Elaeagnus commutata Bernh. Ex Rydb.) collected from several locations in southwestern Saskatchewan. The RAPD fragments were used to generate molecular data for this experiment. Of the total scorable RAPD fragments, 86, 80, 55.2, and 36.5% were polymorphic in sea buckthorn, buffaloberry, silverberry and Russian olive, respectively. Estimates of phenotypic diversity by AMOVA and Shanon's information index revealed that buffaloberry and sea buckthorn had relatively high phenotypic diversity and Russian olive had low phenotypic diversity. Key words: Sea buckthorn, silverberry, buffaloberry, Russian olive, RAPD, phenotypic diversity, Hippophae, Elaeagnus, Shepherdia
The inheritance of stem rust resistance in Thatcher wheat
Authors: Knott D. R.
Published: April 2011

Thatcher was the predominant wheat (Triticum aestivum L.) cultivar on the Canadian prairies in the 1950s. Until race 15B (TMH) of stem rust (Puccinia graminis pers. f. sp. tritici Eriks. & Henn.) became widespread, Thatcher had good resistance to stem rust, but was susceptible to leaf rust (P. recondita f. sp. tritici Rob. ex Desm.). Although genes for stem rust resistance have been identified in Thatcher, the inheritance of its resistance has never been fully understood. The objective of this research was to attempt to elucidate the inheritance of the resistance of Thatcher and to determine why it had a reputation as a poor parent for rust resistance. Over a period of 40 yr, crosses and backcrosses to a susceptible genotype and two sets of single seed descent (SSD) lines were studied. The second set of SSD lines was tested with isolates of six races of stem rust to which Thatcher is resistant. The data showed that Thatcher is a very heterogenous cultivar with individual plants differing widely in the genes for stem rust resistance that they carry. The inheritance of rust resistance varied greatly from race to race and was often quite complex. Either complementary genes or a gene plus a suppressor appeared to condition resistance to one race. Most genes gave resistance to only one race. The presence of Sr5, which Thatcher is known to have obtained from Kanred, was confirmed. Most of its many additional genes probably came from Iumillo durum wheat. Key words: Stem rust, Thatcher wheat, single seed descent
CDC Falcon winter wheat
Authors: Fowler D. B.
Published: April 2011

CDC Falcon is a high-yielding, lodging-resistant, semidwarf winter wheat (Triticum aestivum L.) with good winter hardiness and excellent stem and leaf rust resistance. CDC Falcon is the first winter wheat cultivar with a high level of leaf and stem rust resistance to be registered for production in western Canada. It is especially well adapted to the high-moisture and rust-hazard regions of the western Canadian prairies. CDC Falcon is eligible for grades of the Canada Western Red Winter Wheat class. Key words: Triticum aestivum L., cultivar description, wheat (winter)
CDC Harrier winter wheat
Authors: Fowler D. B.
Published: April 2011

CDC Harrier is a winter-hardy, strong-strawed, semidwarf winter wheat (Triticum aestivum L.) with the high grain yield and agronomic performance of CDC Kestrel. CDC Harrier is the first winter wheat cultivar with a high level of stem rust resistance to be registered for production in western Canada. The grain quality characteristics of CDC Harrier are similar to thos of CDC Kestrel. CDC Harrier is eligible for grades of the Canada Western Red Winter Wheat class. Key words: Triticum aestivum L., cultivar description, wheat (winter)
Analyse de l'étalement temporel de la floraison et influence sur la variabilité intra-arbre de la chute et de la croissance précoce des pêches
Authors: Lescourret Françoise , Inizan O. , Génard M.
Published: April 2011

This study attempted to explain peach abscission and early growth variabilities. We assumed that flower anthesis variability was indicative of early competition for carbohydrates, presumedly determinant for fruit set and early growth. From this viewpoint, the fruits resulting from early flowers should be advantaged. In a first step, we described and analysed the pattern of flowering dates within peach trees. In a second step, we studied the relationship between this pattern and the variability of fruit abscission and growth. At the tree level, the flowers started opening from the base towards the top, but at the shoot level the flowers opened from the apex down to the base. Single flowers opened 1 d earlier than associated flowers, which opened independently. However, the relationships between either fruit set or growth and date of flowering did not fit our hypothesis. For example, fruits from the late flowers had the best set. Thus, the initial hypothesis should be rejected while the influence of other factors should be considered. Our observations suggest that post-bloom temperatures could affect fruit set and early growth. Key words: Peach, Prunus persica, flowering, fruit abscission, fruit growth, early stage of development
Nitrogen cycling in silvopastoral systems in the Pacific Northwest: A review
Authors: Thompson D. J. , Newman R. F. , Hope G. , Broersma K. , Quinton D. A.
Published: April 2011

Clearcuts in interior British Columbia are often aerially seeded with domestic forages such as orchardgrass and alsike clover to prevent erosion and help control understorey vegetation during establishment of lodgepole pine plantations. These seeded clearcuts provide valuable mid-summer range for cattle and with careful management there is little damage to planted trees. There is growing concern about N losses due to clearcutting and site preparation and what effect these might have on long-term forest productivity. The literature indicates that without cattle or forage seeding natural N inputs from the atmosphere and N fixation are barely sufficient to provide adequate nutrition for a lodgepole pine stand. This literature review addresses what effect introducing domestic forages and cattle grazing can have on N cycling on clearcuts. Forage seeding alone may reduce N losses due to runoff and leaching and legumes can fix atmospheric N, but grazing by cattle can counteract some of these benefits. Estimates of N losses due to cattle grazing were calculated using summary data from a long-term grazing trial conducted in interior British Columbia where experimental pastures were either aerially seeded with clover-orchardgrass mixtures or left unseeded. Using forage yields, cattle gains, and a number of assumptions, N losses due to cattle grazing on the seeded pastures were calculated as 2.4 kg N ha−1 yr−1 compared with 0.8 kg N ha−1 yr−1 on native vegetation. Losses were from N in new cattle tissue and N volatilized from urine as ammonia. Increased losses due to grazing seeded forages were short-lived as the forage production of seeded pastures was equal to that of native vegetation by the seventh year. During this period, the losses due to grazing seeded forages may be balanced by increased capture of labile N by the forages. Key words: N cycling, seeded clearcuts, cattle grazing
Effect of varying seeding date on crop development, yield and yield components in canaryseed
Authors: Miller Perry R.
Published: April 2011

The effects of varying seeding date on crop development, yield and yield components in canaryseed (Phalaris canariensis L.) have not been previously reported. In 1996 and 1997, a seeding date study was conducted at Swift Current, SK, which included barley (Hordeum vulgare L.), canaryseed and wheat (Triticum aestivum L.) sown at three dates in separate tilled fallow and untilled wheat stubble sites. Terminal summer drought occurred in both years of this experiment. Cumulative degree days (DD0) to reach maturity did not differ significantly among seeding dates for barley, or for wheat in 1997, while cumulative degree days to reach maturity decreased by 60 DD0 with delayed seeding for wheat in 1996. In contrast, cumulative degree days to reach maturity in canaryseed increased by 70 DD0 in 1996 and by 90 DD0 in 1997 with delayed seeding. Delaying seeding from the early to the late date decreased canaryseed yield by 29%, while barley and wheat yields decreased only 14 and 11%, respectively. Panicle density in canaryseed was reduced 24% between the early and late seeding dates, while barley and wheat spike densities were reduced only 2 and 6%, respectively. The large yield reduction in canaryseed was likely due to slowed crop development with delayed seeding, which intensified late-season drought stress. The slowed crop development with delay in seeding date in canaryseed may be due to vernalization requirement in this crop. In the semiarid prairie region, canaryseed should be seeded early to maintain a rapid crop development rate to minimize yield loss due to drought stress. Key words: Canaryseed, Phalaris canariensis L., seeding date, drought stress
Bloat in cattle grazing alfalfa cultivars selected for a low initial rate of digestion: A review
Authors: Berg B. P. , Majak W. , McAllister T. A. , Hall J. W. , McCartney D. , Coulman B. E. , Goplen B. P. , Acharya S. N. , Tait R. M. , Cheng K.-J.
Published: April 2011

The occurrence of frothy bloat limits the practice of alfalfa grazing in spite of the availability of strains bred specifically for pasture. Bloat is a chronic condition, endemic to cattle. Prophylactics and management techniques are available to reduce its incidence but they are expensive, difficult to administer, conflict with traditional grazing management regimens and do not eliminate bloat in all circumstances. A program to breed and evaluate a bloat-reduced strain of alfalfa was initiated in 1980 to overcome some of these limitations. A review of the results of grazing and feeding trials using alfalfas with low initial rates of digestion (LIRD) shows that this new strain reduces the incidence and severity of frothy bloat on pasture. Their effectiveness in controlling bloat was related to feeding or grazing management practices, the maturity of the plants and the season of use. Graziers may reduce the risk of occasional livestock losses from bloat by using LIRD cultivars, like AC Grazeland, or managing species/cultivar mixtures in ways that reduce the initial rate of digestion. Other bloat preventive strategies, including co-seeding with bloat-free legumes and using bloat-controlling prophylactics in combination with a LIRD alfalfa, are being investigated. Key words: Bloat, alfalfa, lucerne, legume, low initial rates of digestion, cattle, grazing
Transient expression of a reporter gene changes significantly during somatic embryogenesis in alfalfa
Authors: Tian Lining , Brown Daniel C. W. , Webb John
Published: April 2011

Transient expression of the β -glucuronidase (GUS) gene driven by a 35S constitutive promoter was investigated during somatic embryo development in alfalfa (Medicago sativa L.) following micro-projectile bombardment. The level of gene expression varied with the different developmental stages and changed dramatically within the stages. During embryogenic callus induction (stage I), expression was low in explants freshly transferred to culture, but increased when cells started to divide and show competence for somatic embryogenesis. Gene expression, however, decreased when extensive callus formation began and reached the lowest observed level when callus was fully developed. Reporter gene expression was consistently low during embryogenic cell proliferation (stage II). In contrast, high levels of reporter gene expression were detected in non-embryogenic suspension cultures during cell proliferation. Extremely low reporter gene expression was detected in embryonal tissues and young embryos at the embryo development and maturation stage (stage III). Expression increased as the somatic embryos developed and reached the highest level when the embryos reached maturity. Transient expression levels were similar in excised petiole tissue across 10 alfalfa genotypes, which included both diploid and tetraploid genotypes. In general, reporter gene expression was found to be higher in more organised mature tissues and organs than in less-organised or young tissues. The developmental status of the cells and tissues appears to be an important factor in the degree of transient expression of the introduced gene. Changes of gene expression during embryogenesis and factors affecting gene expression are discussed. Key words: GUS expression, Medicago sativa, bombardment, forage
Evaluation of two self-incompatibility alleles in three summer rape (Brassica napus L.) cultivars by UV fluorescence microscopy, seed set and outcrossing rates
Authors: Lewis L. J. , Woods D. L. , Klein-Gebbinck H. W.
Published: April 2011

S-alleles W1 and T2 and an incompletely dominant white petal character were introgressed into the self-compatible (SC) summer rape (Brassica napus L. ssp. oleifera {Metzg.}) cultivars Global, Topas and Westar. The derived self-incompatible (SI) lines were evaluated for strength of incompatibility by ultraviolet fluorescence of pollen tubes, and by seed set. Pollen tube and seed set analyses showed the W1 and T2 alleles were strongly, moderately and weakly expressed in Topas, Global and Westar, respectively. Seed set data showed a significant difference between SI lines, but not between S-alleles, or between homozygous or heterozygous lines from the same SI cultivar. SI cultivar yellow petal (wild type) lines were field pollinated with SC white petal lines. Seed collected from the SI cultivars were evaluated for proportion of outcrossed progeny by recording the frequency of yellow petal and cream petal plants, which were the result of self- and cross-pollination, respectively. The proportion of outcrossed progeny (i.e., outcrossing rates) ranged from 23% to 79%. Topas SI lines had significantly higher outcrossing rates than Global SI lines, which corresponded to SI line seed set data. Environment, S-allele selection and genotype significantly affected outcrossing rates. Key words: Brassica napus, sporophytic incompatibility, S-allele, outcrossing rate
Six years of adaptive and on-farm spring cereal research in Newfoundland
Authors: Spaner D. , McKenzie D. B. , Todd A. G. , Simms A. , MacPherson M. , Woodrow E. F.
Published: April 2011

Livestock farmers in Newfoundland use most available land for forages. The local production of feed grains is negligible and expensive imported feed accounts for almost one half of farm operating expenses. Here, our objectives were to develop basic agronomic principles of mechanized spring grain production and to demonstrate grain production techniques to the Newfoundland farming community. Barley seeding date trials were conducted at five environments in eastern and western Newfoundland between 1996 and 1998. The relationship between soil pH and barley grain yield was explored through grid soil and yield sampling in two large fields in both 1997 and 1998. Between 1993 and 1998 over 20 livestock farmers throughout Newfoundland cooperated with the Newfoundland Grain Project, growing and comparing varieties of barley (Hordeum vulgare L.), spring wheat (Triticum aestivum L.) and oats (Avena sativa L.) on their farms. Late seeding of barley in the spring/summer resulted in linear grain yield reductions. A levelling off of yield response did not occur at greater cumulated growing degree days, possibly because optimum accumulation for maximum barley yield potential does not occur in Newfoundland. Resistant regression lines, describing the relationship between soil pH and grain yield were developed for two barley varieties, indicated that Sterling reached a yield plateau around a soil pH 6 in 1998, while Chapais reached a yield plateau at soil pH 5.4 in 1997. Barley is well adapted to Newfoundland growing conditions, normally providing a high-yielding, mature grain of good feeding quality. Farmers collaborating with the project were generally impressed with the potential of growing barley for grain and some are now regularly doing so. Key words: Seeding date; barley; wheat; oats; precision farming research
Almonte barley
Authors: Ho K. M. , Choo T. M. , Martin R. A. , Rowsell J. , Guillemette L.
Published: April 2011

Almonte is a two-row, spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Canada Breeding Group, Agriculture and Agri-Food Canada. It has high yield and good lodging resistance. Almonte is well adapted to Ontario. Key words: Barley, Hordeum vulgare L., two-row barley, high yield, lodging resistance
Effect of mancozeb on the control of mycosphaerella blight of field pea
Authors: Warkentin T. D. , Xue A. G. , McAndrew D. W.
Published: April 2011

Mycosphaerella blight (MB) [Mycosphaerella pinodes (Berk. & Blox.)Vestergr.] causes substantial yield loss to field pea in western Canada in most seasons and is a disease for which genetic resistance is lacking. The objective of this research was to evaluate the effectiveness of foliar application of mancozeb for the control of MB of field pea. Field trials of split-plot design were conducted at two sites per year from 1996 to 1998 in southern Manitoba, with cultivars as main-plots and fungicide treatments as sub-plots. In most site-years, a single application of mancozeb at the early flowering stage was effective in reducing MB severity and in increasing yield. Mancozeb had similar efficacy to chlorothalonil, the only currently registered fungicide for control of MB in field pea. The beneficial effect of both fungicides was greater for the highly MB susceptible cultivars AC Tamor and Carrera than the moderately MB susceptible cultivar Radley. Key words: Pisum sativum, field pea, mycosphaerella blight, mancozeb, chlorothalonil
Évaluation de la tolérance du Thuja occidentalis L. et de huit de ses cultivars aux conditions climatiques du nord-est canadien
Authors: Rioux J. A. , Marquis P. , Richer C. , Lamy M. P.
Published: April 2011

Six successive plantations of Thuja occidentalis L. (from 1985 to 1990) were transplanted in different sites corresponding to different northeast Canadian climatic zones (2 to 5). Five cultivars of this species were planted in 1985 and three other cultivars in 1986. These plants were observed over a 5-yr period to validate the climatic zonal range attributed to the species and to determine the winterhardiness of the cultivars. Winter damage observed each spring indicated that Thuja occidentalis L. can survive in climatic conditions more severe than those suggested in the literature. However, survival varies among the cultivars studied. Woodwardii, Reidii, Wareana and Lutea showed a winterhardiness similar to the species. Pulcherrima showed the most damage. Little Champion, Smaragd and Fastigiata cultivars gave a response between the two other groups. Furthermore, growth in terms of height and width of the species and each cultivar was influenced by the different climatic conditions of each location. Key words: Thuja occidentalis L., hardiness, winter damages, growth, origin, cultivars
AC Pathfinder durum wheat
Authors: Clarke J. M. , McLeod J. G. , DePauw R. M. , Marchylo B. A. , McCaig T. N. , Knox R. E. , Fernandez M. R. , Ames N.
Published: April 2011

AC Pathfinder durum wheat is adapted to the Brown and Dark Brown soil zones of the Canadian prairies. It combines high yield with strong gluten properties. It has shorter, stronger straw than Kyle. Key words: Triticum turgidum L. var. durum, durum wheat, cultivar description, yield, protein, disease resistance
AC Malone barley
Authors: Choo T. M. , Li J. C. , Martin R. A. , Ho K. M.
Published: April 2011

AC Malone is a six-row, spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Canada Barley Breeding Group, Agriculture and Agri-Food Canada. It was derived from callus culture of Léger barley. To our knowledge, AC Malone is the world's first barley cultivar selected from somaclonal variation. AC Malone performs well in Ontario, Canada. Key words: Barley, Hordeum vulgare L., cultivar description, somaclonal variation, high yield
Évolution des calibres et des rendements de cultivars de haricot destinés à la transformation
Authors: Roy G. , LaFlamme L. , Tremblay N.
Published: April 2011

The evolution of sieve-size, yield and quality are all factors that contribute to the determination of an optimal harvest date for snap beans (Phaseolus vulgaris L.) destined for processing. The evolution of two of these parameters was evaluated in two cultivars of processing beans (Applause and Goldmine) over seven harvesting dates from 1996 to 1997. Three sieve size groups were compared: Small (P, categories 1, 2, 3), Medium (M, category 4) and Large (G, categories 5, 6). At the optimal harvest date, Goldmine had a significantly higher yield in 1997 (17.6 t ha−1) than in 1996 (10.9 t ha−1), whereas no significant difference was found for Applause. Total yields increased at a constant rate (13.2% d−1 for Goldmine and 8.4% d−1 for Applause) (weight for weight), which did not vary year to year. Sieve size evolution was generally linear except for size P in Applause, which exhibited a curvilinear pattern. The rate of change in sieve size varied from year to year, except in the case of size G in Goldmine. Key words: harvest, maturity, planning, Phaseolus vulgaris, quality
Grain yield and water use: Relative performance of winter vs. spring cereals in east-central Saskatchewan
Authors: Gan Y. T. , Lafond G. P. , May W. E.
Published: April 2011

Changing economic conditions have provided strong incentives for grain producers to choose the most profitable cereal crops to grow. We determined grain yield and water use efficiency (WUE) for winter wheat (Triticum aestivum L.), fall rye (Secale cereale L.), hard red spring (HRS) wheat, Canada prairie spring (CPS) wheat, amber durum (Triticum turgidum L.), and barley (Hordeum vulgare L.) under no-till systems. Over 60% of yield variability existing among site/years was due to water use or evapotranspiration (ET) in semiarid east-central Saskatchewan. Mean grain yield increased by 16.3 kg ha−1 with each millimetre of increase in ET. Barley produced 3748 kg ha−1 of grain on average, or 21% higher than winter wheat, 27% higher than CPS wheat, 39% higher than rye or durum, and 50% higher than HRS wheat. Average yields differed less than 5% between winter wheat and CPS wheat, but in water-stressed environments, CPS wheat had 19 to 34% lower grain yield than winter wheat. In one of the five cases where winter wheat was seeded much later than the recommended seeding date, CPS wheat yields were 16% higher than winter wheat. With every millimetre of increased ET, CPS or barley increased grain yield by 22 kg ha−1, while winter wheat increased yield by 17 kg ha−1. Winter wheat and rye had no yield differences in general, but in more moist environments, winter wheat produced higher (up to 28%) grain yield than fall rye, and in the year when winter wheat was seeded late, winter wheat yielded 11% lower than rye. As fertiliser N increased from 50 to 100 kg ha−1, barley grain yield increased by 347 kg ha−1, and durum grain yield increased by only 5 kg ha−1. Winter wheat, fall rye and barley had greater WUE than the other spring cereals, but soil profile (0–120 cm) water in the spring did not differ among crops. In maximising grain yield and water use in east-central Saskatchewan, barley, winter wheat, and CPS wheat would provide the best options. Key words: Water-use efficiency, protein, winter wheat, Triticum aestivum, Secale cereale, Triticum turgidum, Hordeum vulgare
Electron soybean
Authors: Voldeng H. D. , Frégeau-Reid J. A. , Cober E. R. , Guillemette R. J. D.
Published: April 2011

Electron is a 2675 crop heat unit soybean [Glycine max (L.) Merr.] cultivar developed for natto soyfood production. Key words: Soybean, cultivar description, natto