bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic control of rebaudioside A and C concentration in leaves of the sweet herb, Stevia rebaudiana
Authors: Brandle Jim
Published: April 2011

Stevia rebaudiana Bertoni produces steviol glycoside sweeteners in its leaves that are up to 240 times sweeter than sugar. Understanding the genetic basis of glycoside proportions will aid in their manipulation through plant breeding. The experiments conducted in this study were focused on the genetic control of the proportions of two of those glycosides, rebaudioside A and rebaudioside C. The study was conducted using F2 population from crosses between two sets of parents with divergent glycoside profiles. Segregation in the first set of F2s showed that the presence/absence of rebaudioside A is controlled by a single dominant gene, but that the actual proportions of rebaudioside A may be controlled by multiple loci or alleles. In a second cross, proportions of rebaudioside A and rebaudioside C were found to co-segregate and were shown to be controlled by a single additive gene. This result suggests that both rebaudioside A and C are synthesized by the same enzyme. The results were used to propose a model for glycosylation of steviol glycosides. Key words: Diterpene glycoside, genetic analysis, glycosylation, biosynthetic model
Une régie de trois coupes chez le dactyle (Dactylis glomerata L.) en régions agricoles du Moyen-Nord de l'Est du Canada
Authors: Drapeau R.
Published: April 2011

Orchardgrass (Dactylis glomerata L.) has good winter survival in the mid-north agricultural areas of eastern Canada. There is no information on the cutting management to use after the first harvest of orchardgrass under these climatic conditions. The objective of this study was to determine the required interval between harvests following a first harvest at heading stage to optimise the productivity and maintain the persistence of orchardgrass. An interval of 35 d between harvests was sufficient to obtain annual yields of 4 to 6 tonnes of dry matter per hectare. An interval of 28 d between harvests had no negative effects on orchardgrass persistence under our climatic conditions. A second harvest taken 42 d after the first one often had a negative effect on the dry matter yield of the third harvest. Each time this occurred, we observed that the second harvest had been taken after 20 July. Heading dates varied among years. In addition to the growth stage at the first harvest, the date of occurrence of the heading stage should be considered so that the second harvest will be taken before 20 July. Consequently, if heading is delayed in spring, the interval between the first and second harvest must be reduced to take the second harvest before 20 July. Delaying the third harvest had a negative effect on the dry matter yield of the first harvest of the following production year. These results indicate that it is possible to take three harvests before September under the climatic conditions of the mid-north of eastern Canada without affecting the persistence of orchardgrass. Key words: Dactylis glomerata L., orchardgrass, cutting stage, cutting intervals, cutting management, yield
Strategies for breeding a new greenhouse crop, the pepino (Solanum muricatum Aiton)
Authors: Prohens J. , Nuez F.
Published: April 2011

The introduction of pepino (Solanum muricatum Aiton) as a new greenhouse crop relies on the development of clones that produce high fruit yields with an increased soluble solids concentration (SSC). We have evaluated two breeding strategies aimed at obtaining new, improved clones of this heterozygous vegetatively propagated crop: selection in the segregating generation F1 (hybrids) or in the first generation of selfing (selfings). We recorded the total yield, SSC, fruit weight, shape, firmness, titratable acidity and ascorbic acid concentration in seven populations of hybrids and in five populations of selfings. Four populations of clonal replicates were used to estimate environmental variability. Total yield and its heritability were higher in the hybrids than in the selfings. Expected responses to selection showed that it might be possible to select clones with a yield higher than 80 t ha−1 with selection pressures lower than 5% in some hybrid populations. Heritabilities for SSC were moderate, but clones with a SSC higher than 9.0 °Brix could be selected. We also found an important variation in the other characters studied, indicating that improved clones could be selected for all of them. Values for genotypic correlations between characters were very variable. In most hybrid populations, however, we did not find negative genotypic correlations between yield and fruit quality characters. Our results indicate that new hybrid clones of pepino that exceed present clones in yield and fruit quality might be obtained. Key words: New crops, plant breeding, clonal propagation, hybrids, selfings
Dieback of pome fruit rootstocks caused by Pseudomonas syringae
Authors: Sholberg P. L. , Quamme H. A.
Published: April 2011

Dieback (bark necrosis) of pome fruit rootstocks occurred in cuttings, potted plants in the greenhouse, and plants in the nursery when the freshly cut stems were inoculated with bacterial isolate ARS4, identified as Pseudomonas syringae pv syringae. Isolate ARS4, originally isolated from a diseased Malling 9 (M.9) rootstock from a commercial nursery, also caused papery bark (bark shredding) on apple and pear rootstocks indicative of severe dieback. Isolate 980 also identified as P. syringae pv. syringae, isolated from a sweet cherry branch canker, was associated with dieback of pome fruit rootstocks in greenhouse trials but was generally less pathogenic than isolate ARS4. Isolate ARS4 labelled with resistance to nalidixic acidic was recovered from lesions on five of nine M.9 rootstocks at the lesion boundary indicating that the isolate was present in diseased rootstock tissue. Of nine apple rootstock cultivars tested for susceptibility to isolate ARS4, M.4 and M.9 were more susceptible than the other five rootstock cultivars. The effect of inoculation during thawing of frozen M.9 rootstocks in pots led to significantly more dieback than if rootstocks were not frozen. Contamination of buds did not lead to dieback but isolate 980 reduced McIntosh bud growth to 1.7% of the total number of buds that were tested. Leaving a stub above the scion bud on M.9 rootstocks to control dieback did not affect bud development or rootstock stem diameter. Key words: Pseudomonas cichorii, Pseudomonas fluorescens, necrosis, papery bark, lesions, blister spot
Genotype × environment interactions and underlying environmental factors for winter wheat in Ontario
Authors: Haji H. M. , Hunt L. A.
Published: April 2011

Many studies have dealt with the problem of varying genotype performance in different environments (GE interaction). Little is known, however, of the underlying causes of GE interaction. This study was undertaken to identify some of the environmental factors that are associated with GE interactions in winter wheat in Ontario, Canada.Grain yields were obtained from the 1992/1993 and 1993/1994 winter wheat (Triticum aestivum L. em. Thell.) recommendation trials in Ontario. In each year, trials were grown at nine sites. Variance components for the second-order interaction between genotypes × sites × years were considerably larger (22% of the phenotypic variance) than the first-order interactions between genotypes × years and genotypes × sites, which, respectively, accounted for only 5% of the total variation, suggesting that the genotypes were responding differentially to environmental factors at the various sites. Both linear and non-linear components of the regression of genotype grain yields on site mean grain yield were significant. Grain yield of many genotypes was associated with both the lowest and the mean minimum temperature in January and with precipitation during the vegetative stage (May) in 1992/1993 and during the grain-filling period (July) in 1993/1994. Interaction principal component analysis scores for the environment were associated with January minimum temperature in both years although winter survival differences were only apparent in 1992/1993.The results indicate that January temperatures, together with moisture supply before anthesis, are associated with some of the GE interaction noted with winter wheat in Ontario. Both of these aspects, but in particular January temperatures, should thus be taken into account when evaluating cultivar performance trials. Cultivars should be exposed to low January temperatures at some sites during the evaluation process, and weather records from evaluation sites should be examined to ensure that this has occurred. Key words: Genotype × environment interaction, wheat (winter), temperature, grain yield, stress, moisture
AC Christie red clover
Authors: Martin R. A. , Christie B. R. , Papadopoulos Y. A. , Martin R. C.
Published: April 2011

AC Christie red clover (Trifolium pratense L.) is a diploid cultivar of the double-cut type. It was developed by phenotypic selection at the Crop and Livestock Research Centre, Agriculture and Agri-Food Canada, Charlottetown, PEI. It is early flowering, very winterhardy and has no pubescence on the stems. In Atlantic Canada it has produced more forage than the check cultivars in the second and third harvest years. Key words: Red clover, Trifolium pratense, cultivar description
AC Westech barley
Authors: Choo T. M. , Ye J. M. , Martin R. A. , Ho K. M. , Atlin G. , Walton R. , Blatt R. , Rodd V.
Published: April 2011

AC Westech is a doubled-haploid derived, six-row, spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Canada Barley Breeding Group, Agriculture and Agri-Food Canada. It has high yield, good test weight, and lodging resistance. AC Westech performs well in the Maritime Region of Canada. Key words: Barley, Hordeum vulgare L., cultivar description, doubled haploid
Creston apple
Authors: Quamme H. A. , Lapins K. O. , Schmidt H. , MacDonald R. A. , Lane W. D. , Hampson C. R.
Published: April 2011

Creston is a new high-quality apple cultivar ripening 6 d before Red Delicious. It is large-fruited and similar to Jonagold in appearance but possesses better firmness and storage quality. It can be held for 8 wk in air storage (0 °C) and 4–5 mo in controlled-atmosphere storage. Key words: Malus domestica Borkh., dessert apple, cultivar descriptionnot available
Evaluation of hedonic scores and R-indices for visual, flavour and texture preferences of apple cultivars by British Columbian and Nova Scotian consumers
Authors: Cliff M. A. , Sanford K. , Johnston E.
Published: April 2011

Apple preferences were examined for regional, cultivar and order-of presentation effects. Seven apple cultivars, four (Honeycrisp, Fiesta, Cortland and Sinta) grown in Nova Scotia (NS) and three (Creston, Silken and Gala) grown in British Columbia (BC) were evaluated for visual, flavour and texture preferences using a nine-point hedonic scale. In both locations, 126 consumers evaluated all seven cultivars for their visual preferences and four of the seven cultivars for their flavour and texture preferences, using an incomplete-block design balanced for presentation order and carry-over effects. On average, the flavour and texture scores of NS consumers were higher than those of BC consumers. Regional differences were most pronounced for visual preferences, with BC consumers preferring Gala and Creston (BC-grown cultivars) and NS consumers preferring Fiesta and Cortland (NS-grown cultivars). Despite these differences, three of the four top-rated cultivars were identical (Gala, Fiesta and Cortland). Flavour preferences were the most similar, with Gala, Silken, Creston and Cortland being preferred by both NS and BC consumers. Regional differences for texture preferences were less pronounced than those for visual preferences, with Creston preferred by both groups. The BC consumers preferred the texture of Silken and Creston, while the NS consumers preferred the texture of Creston, Honeycrisp, Cortland and Gala. Results from the nine-point hedonic scale were correlated with results from the four-point R-index scale. Correlations were highest when discrimination among the cultivars was greatest. Both methodologies effectively quantified consumer preferences, with hedonic scores expressing results in relative terms and the R-index expressing results as probabilities. Key words: Sensory evaluation, consumer preference, apple-cultivar preference, R-index
Weed management in common buckwheat (Fagopyrum esculentum)
Authors: Wall David A. , Smith Majorie A. H.
Published: April 2011

There are currently no broadleaf herbicides registered in Canada for use in common buckwheat (Fagopyrum esculentum Moench.). Greenhouse and field studies were conducted from 1994 to 1997 at Morden and Brandon, Manitoba, to investigate potential herbicide treatments for buckwheat when cultural methods fail to control broadleaf weeds. Dose-response studies conducted in the greenhouse showed that buckwheat tolerance to desmedipham was three to five times greater than that of volunteer canola (Brassica napus L. and B.rapa L.), lamb's-quarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.) and wild mustard (Sinapis arvensis L.). A separate experiment showed that buckwheat cultivars did not differ in tolerance to desmedipham. Another greenhouse study demonstrated that low dosages of bentazon caused severe injury in buckwheat. In field studies, 500 to 700 g a.i. ha−1 of desmedipham effectively suppressed the annual broadleaf weed biomass in buckwheat without reducing seed yields. At a low dosage of 300 g a.i. ha−1 of desmedipham there were no yield losses even though no weed biomass reduction was evident. Imazamethabenz at 150 to 250 g a.i. ha−1 and metribuzin at 140 and 210 g a.i. ha−1 severely injured buckwheat and usually reduced yields. 2,4-D at 140 g a.i. ha−1 suppressed weed biomass, but caused severe injury and often reduced buckwheat yield. At 70 g a.i. ha−1, 2,4-D suppressed weed growth as effectively as the higher dosage with less visual injury, but sometimes reduced buckwheat yields. Thus, desmedipham is the most promising postemergence broadleaf herbicide for use in common buckwheat. Key words: Common buckwheat, crop tolerance, dose response, weed management, yield
Control of volunteer flax in wheat
Authors: Wall David A. , Smith Marjorie A. H.
Published: April 2011

Volunteer flax (Linum usitatissimum) can interfere with harvesting operations in cereals, especially at high flax densities. Field experiments were conducted in 1996 and 1997 at Morden and Brandon, Manitoba, Canada, to evaluate tribenuron and thifensulfuron plus tribenuron (2:1) alone and in mixtures with 2,4-D, quinclorac, flamprop-methyl and fluroxypyr for their ability to control volunteer flax in spring wheat. Volunteer flax cvs. NorLin and CDCTriffid, a transgenic, sulfonylurea-tolerant cultivar, were cross-seeded to plots of spring wheat cv. AC Domain. Herbicides were applied at rates recommended for their use in spring wheat, when wheat was at the three- to four-leaf stage and flax was 5–8 cm tall. When left uncontrolled, volunteer flax reduced wheat yields by up to 27%. Tribenuron and thifensulfuron plus tribenuron (2:1) provided poor control of NorLin flax and almost no control of Triffid flax. Flax density was not reduced, but biomass was reduced to some extent, more for NorLin than for Triffid. The addition of 2,4-D to the tank-mixes of the sulfonylurea herbicides had some effect on flax biomass reduction but results were not consistent. Wheat yields were reduced in three of the five field trials. The other herbicides controlled NorLin and Triffid flax equally well. Quinclorac at 100 and 200 g a.i. ha−1 provided consistently good flax control, generally without yield loss to the wheat crop. Fluroxypyr plus 2,4-D and fluroxypyr plus clopyralid plus MCPA were as effective as quinclorac, but were tested only in 1 yr. Flamprop-methyl reduced flax biomass and provided good control in 1997, but control was poor in 1996 and resulted in wheat yield losses. Recently, quinclorac has been registered for use against volunteer flax in spring wheat. Key words: Volunteer flax, sulfonylurea resistant flax, spring wheat, control, yield loss
Genotype and environment effect on canning quality of dry bean grown in Saskatchewan
Authors: Balasubramanian P. , Slinkard A. , Tyler R. , Vandenberg A.
Published: April 2011

Canning quality traits of dry bean are affected by both the genotype and the environment. This study was conducted to determine the effects of genotype, environment and the genotype × environment interaction on canning quality traits of selected navy bean, black bean and pinto bean cultivars. Three cultivars each of navy bean and black bean and two cultivars of pinto bean were grown at several sites across Saskatchewan in the summer of 1995 and 1996. Dry bean seed samples from five sites for navy bean, four sites for black bean and six sites for pinto bean grown over 2 yr were evaluated for canning quality traits using a modified laboratory canning protocol. The cultivar effect was significant for most canning quality traits in all three bean classes. For most canning quality traits, the cultivar × year × site interaction variance predominated over the corresponding cultivar × year or cultivar × site variances and, hence, the first order interactions were considered relatively unimportant. The occurrence of early fall frost at several sites resulted in frost-damaged seed, which affected both the genetic and environmental effects on the canning quality traits. Identification of cultivar × site interactions for a few canning quality traits does not justify dividing the province into subareas for breeding and testing purposes. Key words: Phaseolus vulgaris, common bean, genotype, environment, canning quality
Control of postharvest gray mold rot of modified atmosphere packaged sweet cherries by fumigation with thymol and acetic acid
Authors: Chu C. L. , Liu W. T. , Zhou T. , Tsao R.
Published: April 2011

Hedelfingen sweet cherries (Prunus avium L.) were inoculated with spores of Botrytis cinerea and then fumigated with 30 mg L−1.of thymol, acetic acid, or ethanol for 25 min before sealing in modified atmosphere packages and placing into cold storage. After 10 wk of storage, thymol or acetic acid reduced gray mold rot of B. cinerea inoculated cherries from 36 to 0.5% or 6%, respectively. Ethanol was not effective in controlling gray mold rot. Sweet cherries inoculated with B. cinerea and fumigated with thymol had lower total soluble solids, higher titratable acidity and higher stem browning than other treated or non-treated cherries. Key words: Cherry, fumigation, modified atmosphere packaging, storage, Botrytis cinerea
Effects of pre-anthesis moisture stress on floret sterility in some semi-dwarf and conventional height spring wheat cultivars
Authors: Briggs Keith G. , Kiplagat Oliver K. , Johnson-Flanagan Anne M.
Published: April 2011

This study was conducted to investigate the response of some semi-dwarf Canada Prairie Spring wheat (Triticum aestivum) and conventional height (tall) cultivars of Canada Western Red Spring wheat to moisture stress at the booting stage. The effect on the frequency of sterile florets was determined in the two height groups. Drought tolerance was investigated using the electrolyte leakage test. The association of floret sterility with pollen viability under moisture stress conditions was also investigated. When fully watered, several of the semidwarf cultivars had a lower frequency of sterile florets compared with the tall cultivars. Moisture stress increased the frequency of sterile florets in both semi-dwarf and tall wheat cultivars. As moisture stress increased, the resulting sterility was significantly higher in semidwarf cultivars, relative to the tall cultivars (P ≤ 0.01). Comparisons between floret sterility and desiccation injury (estimated by electrolyte leakage tests) suggest that a high degree of floret sterility was not associated with lower levels of desiccation tolerance. Cultivar differences in pollen fertility and for electrolyte leakage in response to moisture stress were evident, but were distributed independently of height class. Key words: Wheat cultivars, moisture stress, floret sterility, pollen sterility
Effect of barley plant density on wild oat interference, shoot biomass and seed yield under zero tillage
Authors: O'Donovan J. T. , Newman J. C. , Harker K. N. , Blackshaw R. E. , McAndrew D. W.
Published: April 2011

There has been little research aimed at developing regression models to describe the effects of barley and wild oat plant density on barley yield loss, or wild oat biomass and seed yield. Such models are an important component of integrated weed management systems, and can help determine when weed control with herbicides is economical. Field experiments were conducted over 4 yr at Vegreville, Alberta, to determine the interactive effects of wild oat and barley plant density on barley and wild oat variables in a zero tillage system. A nonlinear regression model in most cases provided good descriptions of barley yield loss, wild oat shoot dry weight, and wild oat seed yield as functions of wild oat and barley plant densities. The interactive effect of wild oat and barley plant density on percentage barley yield loss did not differ significantly (P = 0.05) among years. A pooled regression model describing barley yield loss accounted for 57% of the variation, and provides a means of estimating yield loss due to wild oat in barley grown under zero tillage. Barley yield loss increased as wild oat density increased but the magnitude of the yield loss diminished with increasing barley plant density. Wild oat economic threshold densities varied among years, and were strongly influenced by barley price and expected wild oat-free yield. Economic thresholds were greater at higher barley plant densities. Barley seed weight decreased with increasing barley plant density, and to a lesser extent with increasing wild oat density. The interactive effect of wild oat and barley plant density on wild oat seed yield varied significantly with year, and appeared to be influenced by climatic conditions. The cooler, wetter spring of 1996 favored wild oat seed production (by several orders of magnitude) compared with the relatively warmer and drier spring of 1995. Each year wild oat seed yield and shoot dry weight decreased as barley plant density increased. The results suggest that seeding barley at relatively high rates may reduce the need for wild oat control with herbicides in zero tillage systems. Key words: Zero tillage, wild oat interference, barley seeding rate, nonlinear regression
Effect of subsoil tillage in the previous crop year on soil loosening and potato yield performance
Authors: Holmstrom D. A. , Carter M. R.
Published: April 2011

Soil compaction under potato rotations can be a common problem in Prince Edward Island. This can be further aggravated by naturally occurring compact subsoils. A study was conducted at eight sites on sandy loam soils in three regions of Prince Edward Island to determine whether the recommended practice of subsoiling the fall prior to the potato crop would improve the physical condition of the soil and result in improved yields. The study found that subsoiling provided only a marginal improvement in soil physical conditions. Soil loosening did not increase potato yield or quality. Key words: Potato, subsoiling, yield response, potato quality
Farm-level profitability analysis of alternative tillage systems on clay soils
Authors: Yiridoe Emmanuel K. , Vyn Tony J. , Weersink Alfons , Hooker David C. , Swanton Clarence
Published: April 2011

Crop yields, production costs, and net returns for seven alternative conservation tillage (including five reduced tillage and two no-till) treatments were compared with a conventional tillage (CT) treatment for a corn (Zea mays L.) – soybean (Glycine max L. Merr) rotation for two clay soils in southwestern Ontario. There was no significant difference in corn and soybean yields between the CT and the conservation tillage systems at either location, although actual yields tended to be highest for CT management. Tillage treatments that used a common set of machinery for corn and soybean production generated savings in annual machinery costs. Variable costs were lowest for the reduced-tillage treatments and highest for the two no-till treatments due to higher equipment expenditures and additional herbicide requirements. For a given location, there was often no significant difference in net returns between CT and the conservation tillage treatments, although average net returns for the corn–soybean cropping systems tended to be highest for CT and lowest for no-till. Key words: Net returns analysis, conservation tillage systems, clay soils, corn, soybeans
Influence of tillage type on vertical weed seedbank distribution in a sandy soil
Authors: Swanton Clarence J. , Shrestha Anil , Knezevic Stevan Z. , Roy Robert C. , Ball-Coelho Bonnie R.
Published: April 2011

The vertical distribution of weed seeds in the seedbank of a sandy soil under three tillage systems (moldboard plow, chisel plow, and no-till) was estimated by a seedling-emergence method. The vertical distribution of the weed seedbank differed with tillage type and depth of tillage. The no-till system had the largest portion (90%) of the seedbank in the 0- to 5-cm layer. Chisel plowing distributed most of the seeds (66%) in the 5- to 10-cm layer. Moldboard plowing concentrated 71% of the seeds at the 10- to 15-cm depth. Our results suggest that the vertical distribution of the weed seedbank will be influenced by tillage type, depth of tillage, and soil type. Key words: Soil structure, moldboard plow, chisel plow, no-till
Effects of day and night air temperature on growth, productivity and energy use of long English cucumber
Authors: Papadopoulos Athanasios P. , Hao Xiuming
Published: April 2011

To determine the optimum air temperature regime for greenhouse seedless cucumber production under North American conditions, the cvs. Corona (in the spring of 1990 and 1992) and Aramon (in the spring of 1992) were grown under nine day/night temperature regimes composed of a factorial combination of three day (18, 21 and 24 °C; DT) and three night (16, 18 and 20 °C; NT) heating temperatures, at a common 24 °C ventilation temperature. Plant development rates (leaf and flower number) were linearly increased with increasing daily average air temperature (MT), but not affected by day–night air temperature difference (DIF), indicating that plant development rates increased with increasing air temperature regardless of DT or NT. Specific leaf weight decreased with increasing DT or NT, and leaf photosynthesis rates decreased with increasing DT. Therefore, high DT or NT promoted the growth rates of young cucumber plants mainly through increasing leaf area ratios. Early and final yields of Corona were mainly affected by MT, not by DIF, while early and final yields of Aramon were mainly increased by DIF. Fruit size increased with increasing MT. Optimum MT for Corona fruit production was 19 °C heating temperature, at a 24 °C ventilation temperature. Optimum day/night air temperature regime for Aramon fruit production was at 21/16 °C day/night heating temperature, at a 24 °C ventilation temperature. Key words: Cucumis sativus, growth, yield, fruit size, daily average air temperature, day-night air temperature difference
AC Legend barley
Authors: Ho K. M. , Seaman W. L. , Choo T. M. , Martin R. A. , Rowsell J. , Guillemette L. , Dion Y. , Rioux S.
Published: April 2011

AC Legend is a six-rowed spring feed barley (Hordeum vulgare L.) cultivar bred at the Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, and evaluated by the Easter Canada Barley Breeding Group. It was selected from a Chapais/CIMMYT-6 cross and is suitable for growing in eastern Canada, where it out-yielded the check cultivars AC Stephen, Chapais, Myriam, ACCA and AC Westech. AC Legend is resistant to scald. Key words: Hordeum vulgare L., six-rowed barley, feed barley, high yield, scald resistance
Molecular analysis of genetic relatedness among alfalfa clones differing in levels of self-incompatibility
Authors: Campbell T. A.
Published: April 2011

The possibility of increasing hybridity in alfalfa (Medicago sativa L.) cultivars through the use of self-incompatible (SI) parents is being investigated. Prior research has demonstrated that self-incompatibility is a heritable trait and that environmentally stable SI clones can be selected. However, inbreeding depression is very severe in alfalfa, and a potential problem associated with utilizing self-incompatibility to increase hybridity is the purported positive relationship between self-incompatibility and inbreeding. Fifteen stable, partially to fully self-incompatible clones and 18 stable self-compatible (SC) clones were selected from the broad-based population W10-AC3. RAPD, Anchored Microsatellite Priming (AMSP), and Simple Sequence Repeat (SSR) analyses were performed on genomic DNA using 9, 10-mer RAPD primers; the AMSP primers (from the 5' end) CAA(CA)5, CCCC(GA)5, CCG(GA)5, and GCC(GA)5; and eight SSR primer pairs. Based on genetic distance (GD) estimates (computed from RAPD and AMSP markers) and numbers of tri-allelic and tetra-allelic loci from SSR analysis, there is no evidence that SI clones were more closely related than SC clones. Assuming parental GD is positively correlated with heterosis, environmentally stable SI clones with acceptable specific combining ability and separated by large GD's would be a good basis for a hybrid alfalfa system, or for use in other breeding schemes designed to minimize inbreeding while maximizing heterosis. Key words: Anchored microsatellite-priming, heterosis, inbreeding, RAPD, self incompatibility, SSR
AC Queens barley
Authors: Choo T. M. , Beek S. ter , Martin R. A. , Ho K. M. , Caldwell C. D. , Walker D. , Rodd V.
Published: April 2011

AC Queens is a two-row, spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Canada Barley Breeding Group, Agriculture and Agri-Food Canada. It has high yield, good test weight, good seed weight, and lodging resistance. AC Queens performs well in the Maritime Region of Canada. Key words: Barley, Hordeum vulgare L., cultivar description, high yield, high seed weight
AC Redbond small red bean
Authors: Mündel Hans-Henning , Saindon Gilles , Huang Henry C. , Kiehn Ferdinand A.
Published: April 2011

AC Redbond is a high-yielding, early-maturing, small red dry bean (Phaseolus vulgaris L.) cultivar with moderate resistance to white mold. It was developed from a series of crosses at the Agriculture and Agri-Food Canada Research Centre, Lethbridge, with cooperation from the Agriculture and Agri-Food Canada Research Centre Morden. AC Redbond, having an upright growth habit with moderate resistance to white mold, is particularly well adapted to the western Canadian prairies using the narrow-row production system, maturing on average 3 d before NW 63, with 10% higher seed yield. Key words: Phaseolus vulgaris, small red bean, cultivar description, high yield, narrow row
Sweet corn (Zea mays) cultivar tolerance to nicosulfuron
Authors: O'Sullivan J. , Sikkema P. H. , Thomas R. J.
Published: April 2011

Eleven sweet corn cultivars were evaluated to identify cultivar sensitivity to nicosulfuron in three field studies, conducted over a 2-yr period. Response to nicosulfuron varied, depending on cultivar and application dose. DelMonte 2038 was highly sensitive to nicosulfuron, resulting in very severe injury and in most cases the death of all plants at both locations each year. At Exeter in 1997 and 1998, injury was slight, with no yield reductions on other cultivars. At Simcoe in 1998, five cultivars showed severe visual injury, especially at 50 g ha−1 of nicosulfuron; however, this did not always result in a significant yield reduction. Cultivars with a yield reduction were Elite, GH 1703 and Calico Belle. The cultivars Bonus Bt, Reveille, Krispy-King, GSS 7831 and GH 2690 were classified as fully tolerant to field applications of nicosulfuron showing injury of 5% or less at 25 g ha−1 and with no yield reduction. Key words: Sensitivity, herbicide injury, cultivars, nicosulfuron, Zea mays
Managing crop losses from foliar diseases with fungicides, rotation, and tillage in the Saskatchewan Parkland
Authors: Bailey K. L. , Johnston A. M. , Kutcher H. R. , Gossen B. D. , Morrall R. A. A.
Published: April 2011

The effects of three tillage systems, three crop rotations, and fungicide applications were evaluated on diseases of barley, wheat, canola and pea at Melfort, SK, from 1994 to 1998. During these years, reduced tillage did not increase crop losses due to diseases. Four-year rotations with higher proportions of broad-leaved crops and more crop diversity (i.e., canola, pea, flax, and barley) had higher yields than rotations with fewer broad-leaved crops and less crop diversity (i.e., canola, wheat, barley, and barley). However, these rotations did not influence the severity of septoria leaf blotch of wheat, net blotch of barley, the incidence of sclerotinia stem rot and blackleg of canola, or the severity of mycosphaerella blight of pea. Interplot interference may have been a factor influencing some diseases in plots, as the size was only 270 m2. Fungicide application of propiconazole on Harrington barley decreased foliar disease severity and increased yield by 23%, seed weight by 13%, and kernel plumpness by 25%. Application of azoxystrobin decreased foliar disease and increased pea yield 29% and seed weight by 7% for the pea cultivars Express and Highlight. Foliar disease severity on AC Taber wheat was reduced by application of propiconazole in 2 of 4 yr, but the yield response was very inconsistent. Similarly, AC Excel canola had inconsistent disease and yield response to applications of propiconazole and benomyl, but levels of sclerotinia stem rot and blackleg were very low in all years. These results indicate that reduced tillage will not result in significantly higher levels of disease that require fungicide inputs to maintain yield. Moving from cereal-based rotations to more diverse, broad-leaved based rotations improves the yield of cereals. However, regardless of tillage or rotation, higher yields may be obtained in barley and pea with fungicides for control of leaf spot disease in susceptible cultivars. Key words: Plant disease, rotation, tillage, fungicides, yield loss
Pre-plant chilling requirements for cloving of spring-planted garlic
Authors: Bandara Manjula S. , Krieger Kristine , Slinkard Alfred E. , Tanino Karen K.
Published: April 2011

Fall-planted garlic (Allium sativum L.) has a higher number of cloves per bulb and higher bulb yield than spring-planted garlic. Many garlic growers, however, plant their crops in the spring to avoid losses associated with winterkill. Pre-plant storage temperature of cloves affects bulbing and cloving of the subsequent crop. Studies were conducted to determine the optimum duration of pre-plant chilling (4 °C) treatment for enhanced cloving and increased bulb yield of three spring-planted garlic cultivars (an unnamed local selection, California Early and California Late). In a greenhouse study, California Early and California Late cloves were planted after receiving low-temperature treatments of 4 °C for 0 (control), 30, 45, 60 or 75 days, whereas, for field studies, cloves from greenhouse-grown bulbs of all three cultivars were planted, and chilling treatments were similar to those for the greenhouse study.Pre-plant chilling treatments of cloves produced significant increases in cloving and bulb yield for all cultivars. In general, chilling treatment periods exceeding 30 d (for field) and 45 d (for greenhouse) resulted in improved cloving in bulbs of all cultivars. Improved cloving resulted in a significant increase in both bulb diameter and bulb yield per plant, particularly in greenhouse-grown garlic. Pre-plant chilling was not a pre-requisite for bulb formation, but it was essential for cloving. In conclusion, results indicate that better cloving and bulb yields are obtained if cloves have been stored at 4 °C for 45–60 d prior to field and greenhouse planting, respectively. Key words: Allium sativum, bulbing, low temperature treatment
CT166 flue-cured tobacco
Authors: Haji H. M. , Mishra S. , Devos M.
Published: April 2011

CT166 is a flue-cured tobacco (Nicotiana tabacum L.) cultivar with high yield, and matures earlier than the standard checks. Percent alkaloids in CT166 is significantly lower than the checks. Lower alkaloids is a desirable quality characteristic. Key words: Nicotiana tabacum L., tobacco, cultivar description
Persistence of herbicide resistance in wild oat (Avena fatua L.) populations after cessation of triallate or difenzoquat use
Authors: O'Donovan J. T. , Baig M. N. , Newman J. C.
Published: April 2011

In experimental plots, the proportion of resistant (R) to susceptible (S) wild oat (Avena fatua L.) increased between 1992 and 1996 and was highest in continuous wheat (2.4:1) and lowest in continuous barley (1.2:1). Conversely, the relative frequency of R plants decreased in most farmers' fields between 1990 and 1997 and varied from 12 to 100%. Frequency of resistance was positively correlated with the number of triallate or difenzoquat applications since 1988. Key words: Avena fatua, persistence of herbicide resistance, triallate, difenzoquat
Cereal cover crops for weed suppression in a summer fallow-wheat cropping sequence
Authors: Moyer J. R. , Blackshaw R. E. , Smith E. G. , McGinn S. M.
Published: April 2011

Cropping systems in western Canada that include summer fallow can leave the soil exposed to erosion and require frequent weed control treatments. Cover crops have been used for soil conservation and to suppress weed growth. Experiments were conducted under rain-fed conditions at Lethbridge, Alberta to determine the effect of short-term fall rye (Secale cereale L.), winter wheat (Triticum aestivum L.) and annual rye cover crops in the fallow year on weed growth and subsequent wheat yield. Under favorable weather conditions fall rye was as effective as post-harvest plus early spring tillage or herbicides in spring weed control. Winter wheat and fall rye residues, after growth was terminated in June, reduced weed biomass in September by 50% compared to no cover crop in 1993 but had little effect on weeds in 1995. Fall-seeded cover crops reduced the density of dandelion (Taraxacum officinale Weber in Wiggers) and Canada thistle [Cirsium arvense (L.) Scop.] but increased the density of downy brome (Bromus tectorum L.), wild buckwheat (Polygonum convolvulus L.), and thyme-leaved spurge (Euphorbia serpyllifolia Pers.) in the following fall or spring. Wheat yields after fall rye and no cover crop were similar but yields after spring-seeded annual rye were less than after no cover crop. Spring-seeded annual rye did not adequately compete with weeds. Cover crops, unlike the no cover crop treatment, always left sufficient plant residue to protect the soil from erosion until the following wheat crop was seeded. Key words: Allelopathies, fall rye, nitrogen, soil conservation, soil moisture, weed control, spring rye, winter wheat
AC Navigator 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 Navigator 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 is a semidwarf with shorter straw than all other registered cultivars in Canada, and has similar maturity to Kyle. Key words: Triticum turgidum L. var durum, durum wheat, cultivar description, yield, protein, disease resistance
Phosphorus restriction: control of transplant growth
Authors: Liptay A. , Sikkema P.
Published: April 2011

Control of tomato (Lycopersicon esculentum Mill.) seedling growth and height during production in the greenhouse is critical for efficient subsequent transplanting and acceptable field performance. Height can be reduced by P fertilisation. Eliminating P from nutrient solutions severely restricted growth. When fed a 10 mg P L−1 in the nutrient solution, seedlings were 11 cm tall after 49 d of growth, but only 3 cm tall without P. Intermediate P reduced height within this range. Transplanting was simulated after 49 d of seedling production by transferring the transplants to a temperature-controlled root chamber in larger volume cells plus fertilisation with a complete nutrient solution. Transplant growth with a complete nutrient solution caused differential growth according to the prior P feeding regime. New root growth in the various treatments was dependent on root growth during the transplant stage. However, shoot growth differed greatly among the P levels. Seedlings grown without any P during transplant production grew very slowly with only a 25% increase in leaf growth after 9 d. With the 2 mg L−1 feeding during transplant production of leaf dry weight increased over 200% during the 9-d period. In conclusion, seedling growth restriction can be achieved by P deprivation; the amount of P deprivation, however, affects subsequent seedling growth. Key words: Phosphorus, nutrients, tomato, transplant.
Jay Orchardgrass
Authors: Christie B. R. , Bowley S. R.
Published: April 2011

Jay is a cultivar of orchardgrass (Dactylis glomerata L.) developed by the Department of Plant Agriculture, University of Guelph. The nine parents of Jay were selected for general vigour, late maturity, plant height at heading, and aftermath vigour. It is similar in herbage yield and plant height but slightly later maturing than the cultivar Kay. Jay is suited for situations where a late-maturing orchardgrass is desired. Key words: Orchardgrass, Dactylis glomerata, cultivar description
CG104 and CG105 corn inbred line
Authors: Lee E. A. , Good B. , Chakravarty R. , Kannenberg L.
Published: April 2011

CG104 and CG105 are short seasoned corn (Zea mays L.) inbred lines. Both exhibit excellent combining ability and average to superior lodging resistance in hybrids. Key words: Corn, Zea mays L., cultivar description
Faucon soybean
Authors: Voldeng H. D. , Frégeau-Reid J. A. , Cober E. R. , Guillemette R. J. D.
Published: April 2011

Faucon is a 2550 crop heat unit soybean [Glycine max (L.) Merr.] cultivar developed for natto soyfood production. Key words: Soybean, cultivar description, natto
The effect of autoclaving wilt nursery soil on emergence in flax
Authors: Saeidi G. , Rowland G. G.
Published: April 2011

Emergence of flax (Linum usitatissimum L) is affected by seed colour and seed linolenic acid concentration. The role of soil and soil microorganisms in this relationship was studied in near isogenic populations for seed colour and linolenic acid level. In growth chamber experiments, the emergence of flax from autoclaved soil was greater than from non-autoclaved soil. This effect was greater for yellow seed than brown seed. Seed with high (50%) levels of linolenic acid had greater emergence than seed with low (2%) levels of linolenic acid in both soil types. The protective effect of brown seed and high seed linolenic acid levels on emergence in flax was confirmed. Key words: Seed colour, linolenic acid, soil microorganisms, flax
Physical properties of the mor layer in a Scots pine stand II. Air permeability
Authors: Laurén A.
Published: April 2011

Mor is a typical humus form in the boreal coniferous forests, but little is known about its air permeability and pore geometry. Thirty undisturbed core samples were collected from a mor layer under a mature Scots pine (Pinus sylvestris L.) stand. Air permeability (Ka) was measured in each sample at six different air-filled porosities (εA) using a constant-pressure air permeameter. The air permeability and the air-filled porosity were used to determine different indices of pore geometry and continuity. The average Ka increased logarithmically from 7.4 × 10−1 to 1.3 × 103 µm2 when εA increased from 0.1 to 0.8. Both the air permeability and pore continuity were high when compared with most other mineral soils and well-decomposed peats. The variations in air permeability and pore continuity with εA were very large. The studied properties had a very large spatial variation in the mor layer which could be caused by the variation in the quality of the debris and the environmental factors affecting the decomposition process during the development history of the mor layer. Key words: Aeration, humus, pore continuity
Effects of three fertility amendments on soil dehydrogenase activity, organic C and pH
Authors: Cooper J. M. , Warman P. R.
Published: April 2011

An Acadia silty clay and a Pugwash sandy loam were each fertilized with three rates of either composted chicken manure, fresh chicken manure, or synthetic fertilizer. The effects of these amendments on soil microbial activity (dehydrogenase enzyme activity, DHA), organic C and pH were monitored. The sandy loam soil, which was relatively high in organic C, did not experience increases in DHA due to organic amendments while compost produced higher DHA than manure or fertilizer treatments to the silty clay soil. There was no treatment effect on soil organic C in the sandy loam, while organic treatments increased organic C in the silty clay soil. Soil pH was affected by treatments to both soils with compost amendments producing the greatest increases in this parameter. The results emphasize the importance of considering initial soil organic C and soil texture when planning studies of the effect of organic amendments on soil microbial activity.

Key words: Dehydrogenase, compost, chicken manure, pH, soil organic carbon
Denitrification and nitrate leaching during the fall and winter following dairy cattle slurry application
Authors: Paul J. W. , Zebarth B. J.
Published: April 2011

Conditions in soils of south-coastal British Columbia during the fall and winter favor both NO3− leaching and denitrification. Estimates of NO3− leaching were made on a coarse-textured soil having a high water table (Sumas) and a well-drained, medium-textured soil (Agassiz) in each of 1991 and 1992, following application of 0, 300 and 600 kg total N ha−1 as dairy cattle slurry at the end of September. Leaching was calculated by measuring NH4+ and NO3− concentrations biweekly to 90 cm depth and subtracting denitrification losses. Denitrification estimates were made using the acetylene blockage technique on intact cores taken to 43 cm depth at biweekly intervals from the 0 and 600 kg N ha−1 treatments. Most of the NO3− disappeared from the 90 cm soil profile by January in both years. At the high rate of manure application, denitrification losses were 29 and 20 kg N ha−1 at Agassiz in 1991 and 1992, and 48 and 17 kg N ha−1 at Sumas in 1991 and 1992, respectively. Denitrification losses in the non-manured treatments ranged from 3 to 16 kg N ha−1 Significant denitrification losses occurred at the 15- to 28-cm and the 30-cm to 43-cm depths, indicating that denitrification measurements at these depths are important. Leaching losses ranged from 60 to 188 kg N ha−1 from the control treatments, and from 102 to 241 kg N ha−1 following the highrate of manure application. Denitrification accounted for up to 17% of the NO3− loss from the soil profile, indicating that the majority of the NO3− was leached.

Key words: Acetylene blockage technique, denitrification rate, air-filled porosity, manure