bluuebunny/crossref_metadata_2025 huggingface dataset:
Stem and canopy attributes that affect lodging resistance in lentil
Authors: Ball R. A. , Hanlan T. G. , Vandenberg A.
Published: April 2011

Many lentil (Lens culinaris L.) cultivars currently grown in Western Canada are susceptible to lodging. The objective was to determine if plant traits associated with lodging but independent of environmental influences could be used for indirect selection of lodging resistance. For a range of canopy variation, eight genotypes were grown at three plant population densities in the field in 2001 and 2002 at five locations. Four unadapted genotypes (designated FLIP), varying in plant profile and stem stiffness, were compared with locally adapted cultivars. Lodging is a complex trait and was influenced by both genetic differences among the genotypes and environmental conditions. Large green market class cultivars had weak stems and lodged easily. As the canopy’s ability to recover from crushing increased, lodging increased due to greater plant biomass. The greater the fiber content in the plant stems, the more biomass and more lodging occurred. Genotypic ranking of stem diameter was consistent across locations, and stem diameter may be used to indirectly select for lodging resistance. From regression analysis, stem diameter and lodging were described by branch number, recovery from canopy crushing, plant density, height, stem fiber content and lignin content; branch number, plant density and plant height were the most influential terms. For screening lodging resistance in crosses made from a lodging resistant genotype and a highly lodging susceptible genotype, selection of progeny with the smallest stem diameter should be the most lodging resistant, although yields will be reduced. Selection procedures would involve seeking large diameter stems but with similar stem traits of the small-stemmed FLIP lines. Key words: Lodging, stem diameter, biomass, branch, lentil, fiber
Inheritance of herbicide resistance in two germplasm lines of Clearfield* rice (Oryza sativa L.)
Authors: Wenefrida Ida , Utomo Herry S , Meche Mona M , Nash Jennifer L
Published: April 2011

Inheritance of imidazolinone resistance in two germplasms of Clearfield rice lines, 93AS3510 and PWC-16, was studied using parents, F1 hybrids, F2 populations , and F2:3 families. Germination tests were conducted in Petri dishes under controlled environments to reveal any discrete phenotypic responses to herbicide treatments. PWC-16 has a herbicide resistance level 4.9 times higher than that of 93AS3510. A concentration of 1 mg L-1 a.i. (active ingredient) of imazethapyr herbicide produced three distinctive response types in 93AS3510 crosses, while a concentration of 10 mg L-1 was required to differentiate the three response types in PWC-16 crosses. The segregation of the herbicide-resistant gene from both Clearfield rice lines fit into the Mendelian 1:2:1 (susceptible:intermediate:resistant) ratio. There was no maternal effect associated with the inheritance of the trait. The imidazolinone resistance, therefore, is governed by a single incomplete dominant nuclear gene. The F1 hybrid from a cross between resistant and non-resistant lines will produce resistant plants. Clearfield rice provides an effective use of imidazolinone herbicides to control red rice, the most troublesome weed of rice, along with other rice weeds. Preventing transfer of the herbicide-resistant gene into red rice is crucial to maintain its effectiveness. Key words: Rice, Oryza sativa, imazethapyr, herbicide resistance, imidazolinone, incomplete dominance, heritability
Agronomic performance of soybean with seed lipoxygenase nulls and low linolenic acid content
Authors: Vaino W. Poysa Yarmilla Reinprecht, , Gary R. Ablett Istvan Rajcan, , Peter Pauls K.
Published: April 2011

Oxidation of linolenic acid (LA) is catalyzed by lipoxygenase (LX) and is associated with off-flavours of soybean [Glycine max (L.) Merrill] products. Low LA (LLA, <50 g kg-1 LA) and LX triple null (3lx) soybean lines have been developed to improve the oxidative stability of soybean oil and reduce off-flavours. The objective of this study was to evaluate the agronomic performance of recombinant inbred line (RIL) soybean population derived from the reciprocal crosses between a LLA line, RG10, and a 3lx line, OX948 and low LA, LX triple null (LLA.3lx) lines selected from these populations. Evaluation of RIL populations for seed and agronomic characteristics at three Ontario locations (Harrow, Ridgetown and Woodslee) in 2000 and 2001 indicated that reduction of LA and removal of seed LX did not cause any obvious detrimental effects agronomic traits including yield. Several RILs that combine LLA content (<30 g kg-1) with 3lx were obtained from these crosses and evaluated for a number of seed and agronomic traits at four Ontario locations (Harrow, Ridgetown, Woodslee and Woodstock) in 2001. The LLA.3lx lines had higher than average seed weight and protein content, but were 21 to 31% lower yielding than typical cultivars for these regions. Compared with parental lines, the LLA.3lx lines were 5 to 18% lower yielding. However, comparisons of LLA.3lx lines with lines combining high linolenic acid and all three seed lipoxygenases (HLA.3LX) indicated no yield difference between the two groups of lines in these populations. The results suggest that it should be possible to use this novel germplasm to develop competitive soybean cultivars that are resistant to oxidative degradation. Key words: Soybean, lipoxygenase null, low linolenic acid, performance
Selection for seed size and its impact on grain yield and quality in kabuli chickpea
Authors: Gan Y. , Jayakumar P. , Zentner R. P. , McDonald C. L.
Published: April 2011

Seed cost is a major input expense for the production of kabuli chickpea (Cicer arietinum L.) due to its large seed size. Use of small seeds could reduce production costs because a lower volume of seeds would be needed per unit area. This study determined the effects of seed size, and selective use of small seeds, year after year, on the field performance of kabuli chickpea in Swift Current, Saskatchewan from 2000 to 2003. Separated large (9.1–11.0 mm diameter) and small (8.1–9.0 mm) seeds of certified CDC Xena were compared with the original, unseparated seeds during the 4-yr study period. Also, small seeds separated from small-seeded previous crops and large seeds separated from large-seeded previous crops were compared with the respective generations of unseparated seeds. Year significantly affected plant biomass, seed yield, and the proportion of ≥ 9-mm-diameter seeds (9DSeeds) in the harvested seed lot, and crops grown from large and small seeds separated from the original seed lot (i.e., 1st year of separation) did not differ in a given year. The 2nd year of selection for small seeds affected seed yield and 9DSeeds, although the effect was minimal. With 3 consecutive years of selection, small seeds lowered seed yield by 23% and decreased 9DSeeds by 10% compared with the unseparated seeds. Selective use of large seeds improved biomass, but did not increase seed yield or 9DSeeds compared with the unseparated seeds. Small seeds of a certified kabuli cultivar can be selectively used for up to 2 consecutive years before incurring a yield penalty, but the use of small seeds will decrease the percentage of large seeds in the harvested seed lot. Key words: Seed weight, selection pressure, Cicer arietinum L.
Monitoring leaf nitrogen in wheat using canopy reflectance spectra
Authors: Zhu Yan , Li Yingxue , Feng Wei , Tian Yongchao , Yao Xia , Cao Weixing
Published: April 2011

Non-destructive monitoring of leaf nitrogen (N) status can assist in growth diagnosis, N management and productivity forecast in field crops. The objectives of this study were to determine the relationships of leaf nitrogen concentration on a leaf dry weight basis (LNC) and leaf nitrogen accumulation per unit soil area (LNA) to ground-based canopy reflectance spectra, and to derive regression equations for monitoring N nutrition status in wheat (Triticum aestivum L.). Four field experiments were conducted with different N application rates and wheat cultivars across four growing seasons, and time-course measurements were taken on canopy spectral reflectance, LNC and leaf dry weights under the various treatments. In these studies, LNC and LNA in wheat increased with increasing N fertilization rates. The canopy reflectance differed significantly under varied N rates, and the pattern of response was consistent across the different cultivars and years. Overall, an integrated regression equation of LNC to normalized difference index (NDI) of 1220 and 710 nm of canopy reflectance spectra described the dynamic pattern of change in LNC in wheat. The ratios of several near infrared (NIR) bands to visible light were linearly related to LNA, with the ratio index (RI) of the average reflectance over 760, 810, 870, 950 and 1100 nm to 660 nm having the best index for quantitative estimation of LNA in wheat. When independent data were fit to the derived equations, the average root mean square error (RMSE) values for the predicted LNC and LNA relative to the observed values were no more than 15.1 and 15.2%, respectively, indicating a good fit. Our relationships of leaf N status to spectral indices of canopy reflectance can be potentially used for non-destructive and real-time monitoring of leaf N status in wheat. Key words: Wheat, leaf nitrogen concentration, leaf nitrogen accumulation, canopy reflectance, spectral index, nitrogen monitoring
Information systems for crop performance data
Authors: Tinker N. A. , Yan W.
Published: April 2011

An increased need for efficient storage and retrieval of crop performance data is driven by a desire to increase the value of crop performance tests, opportunities in crop modelling, opportunities to facilitate cross planning, opportunities to discover genes that affect economic traits, and data mining applications that require better integration of data from multiple sources. Thus, an increased number of stakeholders need access to crop data that are current, accurate, and complete. There is also a growing sophistication and awareness of the role and capabilities of modern informatics techniques in biological research – an area that has become known as “bioinformatics”. Bioinformatics, in partnership with statistics, can play a vital role in increasing the value of crop performance data. However, much of this role remains to be developed and adopted by the communities that gather and use these data. Part of the challenge is that phenotypic data are complex, and extensive information about the context under which the data were collected is required. This can include information about experimental design, soil and climatic conditions, treatments applied, germplasm tested, plant growth stages, and traits measured. If context is neglected, data are useless, but if context is overly complex, it may be ignored or used improperly. Several solutions have been developed to address these needs. These include commercial software packages, open-source collaborations, and a new application developed by the authors. Each solution has strengths and weaknesses, and each addresses different types of needs. This review will discuss the motivations for developing and using crop information systems, the current status and availability of crop information systems, and the challenges that must be met to achieve future potential. Key words: Bioinformatics, database, software, statistics, ontology, variety trial
Control of common bunt (Tilleta tritici and T. laevis) of wheat (Triticum aestivum cv. ‘Laura’) by fumigation with acetic acid vapour
Authors: Sholberg Peter L. , Gaudet Denis A. , Puchalski Byron , Randall Paul
Published: April 2011

Common bunt caused by Tilletia tritici and T. laevis remains an important disease of wheat, particularly in organic production where effective fungicides are not available. Acetic acid (AA), a potential organic seed fumigant, was evaluated for control of common bunt of wheat. The highly susceptible spring wheat cultivar Laura was inoculated with bunt spores and then fumigated with 2 and 4 g kg-1 AA vapour in 23 L chambers for 1 h at 20°C. Fumigation reduced field infection levels of common bunt in trials conducted at Lethbridge, AB during 2000, 2001, and 2003. The 4 g kg-1 rate was more effective than the 2 g kg-1 rate in reducing bunt infection, although both rates were as effective as Vitavax, the standard seed-treatment fungicide treatment. Some reduction in tiller numbers was associated with the AA treatments especially at the 4 g kg-1 rate. In vitro tests on artificial growth media showed that AA significantly decreased seed-borne mold contamination caused by several species of fungi. Acetic acid fumigation could be an important organic alternative to fungicides for control of common bunt. Key words: Covered smut, organic, seed treatment, stinking smut, vinegar
Roland soybean
Authors: Cober Elroy R. , Voldeng Harvey D. , Guillemette Ronald J.D.
Published: April 2011

Roland is a 2500 crop heat unit soybean [Glycine max (L.) Merr.] cultivar with good yield potential. Key words: Soybean, cultivar description
DH3604 soybean
Authors: Cober Elroy R. , Voldeng Harvey D. , Frégeau-Reid Judith A. , Guillemette Ronald J. D.
Published: April 2011

DH3604 is a 2700 crop heat unit soybean [Glycine max (L.) Merr.] cultivar developed for natto soyfood production. Key words: Soybean, cultivar description, natto
Foliar application of elicitors alters isoflavone concentrations and other seed characteristics of field-grown soybean
Authors: Al-Tawaha A. M. , Seguin P. , Smith D. L. , Beaulieu C.
Published: April 2011

Soybean [Glycine max (L.) Merr.] is a key species used by the nutraceutical industry, as it contains isoflavones that have beneficial effects on human health. A 2-yr field study was conducted in Sainte-Anne-de-Bellevue, QC, to determine the effects of foliar application of elicitor compounds on isoflavone concentrations of seeds, seed yield, and other important seed characteristics. Two soybean cultivars (AC Proteina and AC Orford) were treated with one of four elicitors: lipo-chitooligosaccharides (LCO) Bj V (C18:1 MeFuc) and Bj V (Ac, C16, MeFuc), chitosan, and actinomycetes spores (Streptomyces melanosporofaciens strain EF-76), each applied at two soybean stages of development [vegetative (V4), and early podding (R3)]. Untreated controls were also included. Total and individual isoflavone concentrations were determined by HPLC. Seed yield, 100-seed weight, seeds per pod, pods per plant and oil and crude protein concentrations were concurrently determined. Total and individual isoflavone concentrations were affected by year and cultivar, which also interacted with elicitors. Interactions indicated that plant response to elicitors varied greatly depending on cultivars and years. Compared with an untreated control, some elicitors resulted in total isoflavone concentration increases ranging between 67 and 87%. No single elicitor treatment, however, consistently increased isoflavone concentrations. There were three-way interactions (year, cultivar and elicitors) for seed yield and number of pods per plants indicating, again, substantial variation in response to elicitors. Response was much greater in 2004, where elicitors consistently increased seed yield and number of pods per plant. Elicitors did not affect crude protein and oil concentrations. The use of elicitor compounds seems promising as a means of increasing isoflavone concentrations and seed yield; evaluations in a greater number of environments are now required. Key words: Soybean, isoflavone, daidzein, genistein, glycitein, protein, oil, seed yield, chitosan, actinomycetes, lipo-chitooligosaccharides
Changes in sugars and phenolics concentrations of Williams pear leaves during the growing season
Authors: Colaric Mateja , Stampar Franci , Hudina Metka
Published: April 2011

Leaves of Williams pear were collected during the growing season from May to October and the contents of sugars and phenolic compounds were analyzed by high-performance liquid chromatography method. Sorbitol was the major sugar (up to 83.8 g kg-1 DW), followed by sucrose (up to 22.1 g kg-1 DW). Concentrations of glucose and fructose were as high as 12.9 and 9.0 g kg-1 DW, respectively. Leaves contained up to 29 471.9 mg kg-1 DW of chlorogenic acid, followed in concentration by rutin (up to 6789.2 mg kg-1 DW), epicatechin (up to 7378.0 mg kg-1 DW), catechin (up to 3846.5 mg kg-1 DW), vanillic acid (up to 1832.1 mg kg-1 DW), syringic acid (up to 1123.5 mg kg-1 DW), caffeic acid (up to 122.5 mg kg-1 DW) and sinapic acid (up to 94.1 mg kg-1 DW). The significant differences in concentration of sorbitol, sucrose, glucose, and in all analyzed phenolics were observed during the growing season (six sampling dates). The lowest concentrations in the leaf were found at the beginning of the growing season in May and June. The highest contents of sugars were in October, with the exception of sorbitol. During the growing season, total phenolic content first increased, then declined. Chlorogenic acid, rutin and caffeic acid contents increased until July, vanillic acid and sinapic acid until August, and catechin, epicatechin and syringic acid until September. However, total phenolic content dropped by 50% from September to October. Key words: Pear leaves, sugars, phenolics, growing season
Azur red clover
Authors: Coulman Bruce
Published: April 2011

Azur is a diploid cultivar of red clover [Trifolium pratense (L.)], which was selected for vigor and growth habit in the year of seeding. In forage trials conducted in Québec, Azur was superior in dry matter yield to check cultivars, particularly in trials harvested in the second production year. In trials in Ontario and the Atlantic provinces, Azur was numerically superior in dry matter yield to the check cultivar, but not significantly so (P < 0.05). Key words: Red clover, Trifolium pratense (L.), cultivar description
How the introduction of late season sweet cherry cultivars and changing demand conditions impacted industry competitiveness: Evidence from British Columbia
Authors: Carew Richard , Looney Norman E
Published: April 2011

This paper discusses the importance of government research and innovation policies designed to reflect changing demand conditions and strengthen competitiveness of the British Columbia (BC) sweet cherry industry. Canadian plant breeding programs have responded to market demand by releasing cultivars that have extended the marketing season and resulted in higher export price premiums earned in European and Asian markets. Stronger Canadian intellectual property rights (IPR) legislation has facilitated the commercialization of a range of cultivars with valuable attributes. However, the combination of Canada being a net importer of sweet cherries and the rapid adoption of BC cultivars by Washington State orchardists has challenged Canadian policy makers to implement IPR policies that can contribute to maximizing royalty returns and sustain the Canadian plant breeding program. Key words: Sweet cherry cultivars, plant breeding, intellectual property rights
CO443 corn inbred line
Authors: Reid L. M. , McDiarmid G. , Zhu X. , Parker A. J.
Published: April 2011

CO443 is a short season corn (Zea mays L.) inbred line with excellent combining ability and average to superior lodging resistance in hybrids. This stiff stalk type inbred performed best as a parent with non-stiff stalk inbreds. Excellent yields were achieved with the commercial inbred LH176. Key words: Corn, maize, Zea mays, cultivar description
In-soil banded versus post-seeding liquid nitrogen applications in no-till spring wheat and canola
Authors: Holzapfel C. B. , Lafond G. P. , Brandt S. A. , May W. E. , Johnston A. M.
Published: April 2011

Delaying nitrogen (N) applications into the growing season as a risk management tool is a concept that has received considerable attention in recent years. A 3-yr field study with spring wheat (Triticum aestivum L.) and canola (Brassica napus L.) was conducted at two Saskatchewan locations, Indian Head and Scott. The effects of postponing N applications for up to 30 d after seeding and several application methods were evaluated against mid-row banded urea at seeding. Liquid urea ammonium-nitrate (UAN) was applied at four separate times relative to seeding, either as an in-soil coulter band or a surface band. The surface band applications were applied either with or without the addition of 5% ammonium thiosulphate (ATS), a potential urease inhibitor. The dependent variables considered included plant density and grain yield for both crops, and grain protein in wheat. The only effect on plant density occurred in canola, where the post-seeding coulter applications slightly reduced stands compared with the other treatments. Postponing N fertilization for up to 30 d after seeding compared with N fertilization at seeding did not affect the yield of canola or protein in spring wheat, but reduced the yield of spring wheat at Indian Head in 2003, which was a very dry growing season. The coulter applications only showed a slight advantage over the surface band applications. For the surface band applications, the addition of 5% ATS did not provide a noticeable advantage over UAN alone. Canola appeared to be less sensitive to post-seeding applications than spring wheat. Deferring the entire amount of fertilizer N into the growing season appears to be a viable option but it is not without risk, especially when dry conditions are encountered. Key words: Triticum aestivum L., Brassica napus L., nitrogen management, no-till, surface dribble, urea-ammonium nitrate
Scheduling drip irrigation for ginseng (Panax quinquefolius L.) grown under straw and bark mulch
Authors: Roy R. C. , Ball Coelho B. R. , Bruin A. J. , Reeleder R. , Capell B.
Published: April 2011

Responses of ginseng to drip irrigation regimes and organic mulches were determined in two experiments beginning in 1998 and 1999. Treatments were four soil water content thresholds for irrigation: 0, 0.08, 0.12 and 0.16 m3 m-3 (θ0, θ8, θ12, and θ16, respectively); combined with either straw or bark mulch. In its first growing season, ginseng did not require irrigation in 1999 or 2000. In subsequent years, irrigation was generally more frequent when applied at higher moisture threshold levels, but precipitation affected irrigation frequency under all treatments. Water use increased with crop age to 3yr, to about 65% of the requirement of unshaded horticultural crops. Seed yield from 3-yr-old plants under straw mulch in 2001 was greater in response to θ12 and θ16 than to θ8 or θ0. Root yield response to irrigation threshold was linear for 2- and 3-yr- old plants under straw mulch in 2001, and quadratic for 3-yr-old plants under bark mulch in 2002. The optimal threshold to initiate drip irrigation was approximately 65% of field capacity. Key words: Root, soil water, water use
Yield, quality and revenue of pickling cucumbers with irrigation and supplemental N fertilizer under a humid climate
Authors: Jenni S. , Rekika D. , Stewart K. A.
Published: April 2011

A 5-yr field experiment was conducted in southern Quebec to investigate yield, gross revenue and quality of pickling cucumbers (Cucumis sativus L. ‘Fancipak’) in response to sprinkler irrigation. In addition, supplemental nitrogen treatments (40 kg ha-1 foliar and granular) following application of 80 kg ha-1 N preplant, as well as non-fertilized and over-fertilized controls (80 kg ha-1 N preplant, 40 kg ha-1 N granular and 60 kg ha-1 N slow-release) were compared in a 2-yr trial under irrigated and non-irrigated conditions. During 1997 to 2000, rainfall was close to or above normal and irrigation did not increase marketable yields. In 1999 and 2000, irrigation reduced early marketable yields relative to non-irrigated treatments. In 2000, a relatively cool year with average rainfall, there was a positive yield response to supplemental N in the non-irrigated plots, but not in the irrigated plots. In 2001, a very hot and dry season, irrigation increased early yield by 66%, marketable yield by 160% and gross revenue by 164% compared with non-irrigated treatments. Non-irrigated treatments did not respond to supplemental N, but supplementing the irrigated treatments with 40 kg ha-1 of N increased marketable yields by 22%, generating 18% additional revenues. Applying N in either a foliar or granular form gave similar results. Overall, under a humid climate, irrigation only had a positive impact on gross crop revenue for pickling cucumbers in 1 out of 5 yr. Key words: Cucumis sativus, pickle, overhead irrigation, sprinkler, foliar nitrogen, granular nitrogen, slow release.
The suitability of cool- and warm-season annual cereal species for winter grazing in Saskatchewan
Authors: May William E , Klein Lorne H , Lafond Guy P , McConnell Jody T , Phelps Sherrilyn M
Published: April 2011

Winter grazing is a practice that can reduce feeding cost for cattle production. Current production has been utilizing traditional cool-season cereals for winter grazing. Warm season (C4) cereals also have the potential to be adapted to winter grazing in Saskatchewan. The objective of this study was to evaluate cool and warm season annual cereal species for adaptation, quality, and dry matter production in annual fall and winter grazing systems. Two seeding dates, nine treatments and two harvest times were used at sites across Saskatchewan over 3 yr. The crops in this trial have significant differences in maturity and dry matter yield. Seeding date did not consistently affect dry matter yield. Pearl millet [Pennisetum glaucum (L.) R. Br.] and sorghum-sudangrass [Sorghum bicolor (L.) × S. arundinaceum (Desv.) Stapf var. sudanense (Stapf) Hitchc.] had low dry matter yields and were poorly adapted to Saskatchewan. The proso millet (Panicum miliaceum) cultivar, Crown, and the foxtail millet (Setaria italica L.) cultivars, Red Siberian and Golden German, hadyields similar to oat (Avena sativa L.) and barley (Hordeum vulgare L.), but lower than high-input corn (Zea mays L.). Corn haddry matter yield that was similar to barley and oat but yield variability across sites and years was higher for corn. Delaying the harvest lowered the protein concentration of all the crops except pearl millet and sorghum-sudangrass. There were significant changes in acid detergent fibre (ADF), neutral detergent fibre (NDF), calcium (Ca) and phosphorus (P) due to a cultivar ×harvest timing interaction. Weathering in the windrow until December did not significantly reduce the quality of the forage. Golden German foxtail millet is well adapted for swath grazing in eastern Saskatchewan. More data are required to determine its adaptability in central and western Saskatchewan and the adaptability of corn in all of Saskatchewan. Key words: Avena sativa L., Hordeum vulgare L., Setaria italica L., Panicum miliaceum, Zea mays L., swath grazing
Neurotransmitters, neuroregulators and neurotoxins in the life of plants
Authors: Cao Jin , Cole Ian B , Murch Susan J
Published: April 2011

Recent evidence has shown that neurologically active compounds play an important role in the physiology of higher plants. The human neurotransmitter melatonin (N-acetyl-5-methoxytryptamine) has been found in more than 140 different plant species and is associated with flower and seed development, reproductive capacity and root growth. Hyperforin, once thought to be characteristic of St. John’s wort (Hypericum perforatum L.), has now been found in several other plant species and preliminary findings indicate that it may function as a modulator of plant cell polarity and ion flow. The excitotoxin, β-methylamino-L-alanine, has been used to selectively isolate glutamate receptor mutants in Arabidopsis, and these studies are leading to new understandings of plant cell development. The study of these and other plant neurochemicals may lead to a new understanding of plant signal transmission and the mechanisms by which plant cells sense, interpret and respond to environmental cues. Key words: Neurotransmitter, neurotoxin, medicinal plant, plant cell signalling, melatonin, hyperforin
Impact of cultivar, row spacing and seeding rate on ascochyta blight severity and yield of chickpea
Authors: Chang K. F. , Ahmed H. U. , Hwang S. F. , Gossen B. D. , Howard R. J. , Warkentin T. D. , Strelkov S. E. , Blade S. F.
Published: April 2011

Field trials to assess the impact of chickpea type (desi vs. kabuli), row spacing and seeding rate on ascochyta blight of chickpea were conducted over 2 yr at Brooks, Alberta. A compound-leaved desi chickpea cultivar and unifoliate kabuli cultivar were sown at 20, 30 and 40 cm row spacing, and at three seeding rates (20, 40 and 60 seeds per 3 m row). Most of the variation in disease severity was associated with differences between the cultivars. Seeding rate, row spacing and their interactions had substantially smaller effects on ascochyta blight in comparison with cultivar effects. Late in the growing season, blight severity was consistently lower in the desi than the kabuli cultivar. Wide row spacing and low seeding rate reduced ascochyta blight severity and increased seed yield per plant. Wide row spacing in the first year reduced the seed yield per hectare, but row spacing did not significantly affect yield in 2005. Low in-row seeding rates increased yield only in 2004. There was a positive linear relationship between plant density and blight severity, and a negative relationship between yield per plant and both plant density and disease severity. We conclude that reduced plant population density could be one tool in a program to manage ascochyta blight of chickpea. Key words: Cicer arietinum, plant population density, ascochyta blight, yield
The Biology of Invasive Alien Plants in Canada. 7. Cabomba caroliniana A. Gray
Authors: Wilson Claire E , Darbyshire Stephen J , Jones Rosita
Published: April 2011

The freshwater aquatic plant Cabomba caroliniana, or fanwort, was recently reported in a lake northeast of Peterborough, Ontario, where it has successfully established and survived winter conditions since at least 1991. This is the first documented occurrence of fanwort becoming naturalized in Canada. Fanwort is a popular aquarium plant that is native to South America and possibly the southeastern United States and has been introduced in several Asian, Pacific and European countries through the discarding or deliberate planting of aquarium plants in natural waterways. It is particularly invasive in China, Japan and Australia, and in parts of the United States, where its range is spreading. Fanwort grows rapidly and forms dense stands that clog waterways, impeding flow, obstructing navigation, altering fish habitat and excluding other vegetation. It does not produce mature seed in the northern parts of its North American range, but can multiply clonally and spread quickly by stem fragmentation. It produces turion-like stems at the end of the growing season, which assist in over-wintering under adverse conditions. Fanwort is difficult to control with herbicides and is resistant to mechanical management techniques as populations can quickly re-establish from plant fragments. Populations near the Trent-Severn Waterway in Canada are extensively established and management tools are not available to attempt eradication. An integrated management plan that focuses on early detection and rapid response in surrounding water bodies may succeed in mitigating the economic and environmental impacts and limiting the spread of fanwort. Key words: Cabomba caroliniana, fanwort, cabomba de Caroline, CABCA, aquatic plant, weed biology, invasive alien
Post-flowering dry matter accumulation and partitioning and timing of crop maturity in chickpea in western Canada
Authors: Tom Warkentin Yadeta Anbessa, , Albert Vandenberg Rosalind Bueckert, , Gan Yantai
Published: April 2011

A field experiment aimed at determining whether timing of crop maturity was related to patterns of dry matter (DM) accumulation and partitioning to reproductive organs in chickpea was conducted at different locations in Saskatchewan over two seasons, 2003 and 2004. Five genotypes 272-2, 298T-9, E100Ym, CDC Anna, and CDC Frontier were grown in a RCB design with four replications. Beginning at 60 d after seeding (DAS) and every 15 d following, plant samples were taken and separated into stem, leaf and pod fractions. Then dry weights of the sample fractions were determined. Total DM production showed an increasing trend over sampling dates, but the increase was at a decreasing rate beginning in mid-season. The early genotype 272-2 had a pattern of total DM accumulation similar to the others, but had significantly smaller vegetative (stem plus leaf) DM accumulation during the latter part of the growth period. This shows a relatively high proportion of DM partitioning to pod for 272-2. Also, the partitioning of resources to reproductive parts (allometric partitioning) and pod harvest index were each negatively associated with days to maturity, implying that assimilate partitioning for maximum pod DM is important for early maturity in chickpea in western Canada. Key words: days to maturity, post-flowering growth, dry matter, dry matter partitioning, pod harvest index
Thunderbird field pea
Authors: Bing Deng-Jin , Beauchesne Don , Sloan Al , Conner Robert , Gan Yantai , Vera Cecil , McLaren Debbie , Gehl David , Warkentin Tom , Chang Kan-Fa
Published: April 2011

Thunderbird, a semi-leafless field pea (Pisum sativum L.) cultivar with yellow cotyledons, has high seed yielding ability, excellent lodging resistance and improved seed shape compared with check cultivars. It is resistant to powdery mildew caused by Erysiphe pisi DC. var pisi. Thunderbird is adapted to all field pea growing regions in western Canada. Key words: Field pea, Pisum sativum, cultivar description, powdery mildew resistance
Effects of summer and fall applications of foliar boron on fruit bud winter injury in wild blueberry (Vaccinium angustifolium Ait.)
Authors: Eaton L. J. , Ju H-Y. , Sanderson K. R.
Published: April 2011

The effects of single and multiple applications of foliar B to two commercial wild blueberry sites during 1999 to 2001 were determined. The effects on tissue B concentrations and winter injury to developing fruit buds was evaluated. At one site, applications of foliar B in summer or fall or in both seasons increased tissue B levels in the first crop fruit buds, but the increases were not observed 1 yr later in the second crop fruit buds. At the other site, applications of foliar B in both the summer and fall of two successive cropping cycles reduced winter injury compared with untreated controls, indicating that multiple foliar B applications may be required to reduce winter injury to developing buds of wild blueberry. Key words: Extractable boron, bud damage, tissue boron concentration, Vaccinium angustifolium Ait.
The effects of land use intensification on soil biodiversity in the pasture
Authors: Mills Aaron , Sina Adl M.
Published: April 2011

A long-term multidisciplinary study of pasture agroecology is currently being conducted in Nova Scotia, Canada. The objective is to examine the relationship between above -ground and below-ground functional diversity, and the effects on agroecosystem productivity. The experimental design consists of four treatments of decreasing land use intensity, applied in the context of management intensive grazing. Treatments include: (1) clipping and harrowing following each grazing rotation (intensive); (2) clipping only once following the first defoliation; (3) grazing every second rotation; (4) grazed only once a year (extensive). Samples were taken from each treatment once during May, July, and September 2005. Edaphic characteristics and plant diversity were measured, as well as microarthropod, nematode, protist, and bacterial functional group diversity and abundances. Significant (P < 0.05) effects of treatment were observed on percentage of bare soil, plant species and functional diversity, and bacterial functional diversity. There were also significant (P < 0.05) negative correlations observed between treatment, and both testate amoebae and flagellate abundances. The information obtained from this study may be used to test the relationship between biodiversity and land-use intensity, and how productivity is affected in the pasture. Key words: Soil ecology, pasture management, sustainable agriculture, biodiversity, forage grazing
Responses of a long greenhouse tomato crop to summer CO2 enrichment
Authors: Hao X. , Wang Q. , Khosla S.
Published: April 2011

While CO2 enrichment generally benefits tomato fruit production in winter its effects on summer tomato production (under high air temperature and strong ventilation) are still not clear, especially when the crop has been subjected to long-term CO2 enrichment in winter. Therefore, a study was initiated in 2005 to determine the feasibility of summer CO2 enrichment in southwestern Ontario, a major greenhouse vegetable production area in North America with very hot summers. The long tomato crop (cv. Rapsodie) was planted into rockwool slabs in six greenhouse compartments in January. From January to the middle of June, the tomato plants in all six greenhouse compartments were subjected to the same standard CO2 enrichment practice. From the end of June to August, three CO2 treatments (two compartments for each treatment) were applied: Control (ambient/no enrichment), Enrich1 (800 µL L-1 when ventilation was less than 10% and 400 µL L-1 when less than 50%) and Enrich2 (1200 µL L-1 when ventilation was less than 10% and 500 µL L-1 when less than 50%). In all treatments, CO2 enrichment ceased when ventilation requirement was more than 50%. Leaf photosynthesis, as indicated by the CO2 response curve, partially acclimated to the CO2 enrichment. Marketable fruit yield was reduced by the summer CO2 enrichment. Leaf deformation [short, thick, curled and somewhat crisp, dark grey-green leaves, so-called short leaf syndrome (SLS)] was observed in the greenhouse compartments with summer CO2 enrichment. SLS developed under high light intensity and high CO2 concentration might have limited response of the tomato crop to summer CO2 enrichment. Further investigation on the cause and mechanism of SLS is needed to improve the response of greenhouse tomatoes to summer CO2 enrichment. Key words: Photosynthesis, Lycopersicon esculentum, high temperature stress, acclimation
Response to added nitrogen of a continuous potato sequence as related to sand thickness over clay
Authors: Cambouris A. N. , Zebarth B. J. , Nolin M. C. , Laverdière M. R.
Published: April 2011

This study evaluated the effect of rate and timing of N fertilizer application on tuber yield, tuber size distribution and tuber specific gravity of potato (Solanum tuberosum L.) in two sites in a commercial field in 1999–2001. One trial was established at each of the two sites chosen to represent two management zones (MZ) previously delineated by soil electrical conductivity, and differing in soil water availability, as controlled by depth to a clayey substratum. Each trial had 21 treatments including five rates of ammonium nitrate (0–200 kg N ha-1 in 1999; 0–240 kg N ha-1 in 2000 and 2001), each applied according to five application timings (100, 75, 50, 25 or 0% of N applied at planting with the remainder applied at hilling). Increasing N rate increased total and marketable tuber yields in both sites. The N rates required to optimize economic return ranged from 167 to 239 kg ha-1 among years and between sites. Nitrogen fertilizer applied all at planting or all at hilling decreased tuber yields in both sites compared with split N application. The percentage of N rate applied at planting to achieve the maximum marketable tuber yield varied among years from 34 to 61% and allowed a yield increase of 2 to 20%. The proportion of large tubers was higher in the site with a greater depth to the clayey substratum (DMZ site) than in the site with a shallower depth to the clayey substratum (SMZ site). Tuber yield and tuber N uptake were higher in the SMZ site than in the DMZ site when no fertilizer N was applied, and tuber yield was more responsive to fertilizer N rate in the DMZ site than in the SMZ site in one year; however, these differences are not sufficient to justify different fertilizer N management for the two sites. The two sites frequently differed in terms of tuber yield, tuber size and specific gravity, which are important parameters in determining tuber processing quality but the optimal N rate and N timing were similar. These differences may be sufficiently large to justify different potato management practices (e.g., nutrient management, seedpiece spacing) to optimize potato production for the chip processing market. Key words: Solanum tuberosum, marketable yield, tuber size distribution, specific gravity, N economic optimum
Effect of gibberellic acid on fruit cracking and quality of Bing and Sam sweet cherries
Authors: Cline J. A. , Trought M.
Published: April 2011

Rain-induced cracking of sweet cherries (Prunus avium L.) is a major problem in many cherry growing regions throughout the world. One method to reduce cracking is to grow cracking resistant cultivars; however, no completely effective control measures are currently available to eliminate this problem. Studies conducted in New Zealand to test the ameliorating properties of gibberellic acid sprays to reduce cracking were examined. The results revealed that repeated or singular foliar applications at 10 or 40 mg L-1 gibberellic acid (GA3), respectively, increased both fruit cracking, and fruit firmness, but delayed fruit colour development. Key words: Prunus avium, cherry splitting, cracking
Natto 3 soybean
Authors: Poysa V. , Voldeng H.
Published: April 2011

Natto 3 is a 3200 crop heat unit soybean [Glycine max (L.) Merr.] cultivar developed for natto soyfood production. Key words: Glycine max (L.) Merr., soybean, cultivar description, natto
Relative precision of linkage mapping in recombinant diploid populations
Authors: Helms Theodore C
Published: April 2011

With the increased effort in mapping linked loci, it is important to understand how the precision of the estimate of linkage intensity is influenced by the level of inbreeding and the sample size. For discreet traits, such as molecular markers, the standard error of linkage intensity has been determined for an F2 and backcross population. However, the standard error of linkage intensity has not been determined for discreet traits in the case of the F3 population, double haploid or recombinant inbred lines. The objective is to provide information to aid plant scientists in planning mapping experiments where a given level of precision is desired when estimating the intensity of linkage between two loci for F2 and F3 populations as well as double haploid and fully inbred lines. The precision associated with the estimate of the intensity of linkage is shown graphically as the type of population, the sample size, the intensity of linkage and the linkage-phase is varied. For discreet traits, such as molecular markers, the F2 population and use of co-dominant markers are the best choices to maximize precision when estimating any degree of coupling and repulsion-phase linkage. Key words: Linkage, precision, inbreeding, sample size, markers, molecular
Variation in morphology, plant habit, proanthocyanidins, and flavonoids within a Lottus germplasm collection
Authors: Gruber Margaret , Skadhauge Birgitte , Yu Min , Muir Alister , Richards Kenneth
Published: April 2011

Lotus species collec ted from a range of geographical locations were evaluated for relationships between plant habit and size, leaf proanthocyanidin (PA) content, flower colour, stem colour, leaf colour, trichome density, and geographic origin. No relationships occurred between leaf PA concentration and morphological trait or collection site. Trichome coverage was moderately correlated with plant size (r = -0.70). Several accessions, e.g., L. angustissimus L. and L. castellanis Boiss. & Reut., consisted of small, trichome-covered plants distinct from the large, glabrous plants typical of the model species L. corniculatus var. japonicus ecotype Gifu B129. These two morphology types were also represented among the tan mutants of Gifu B129. Due to the importance of trichomes and PA in plant defence, PA composition was compared between L. angustissimusand tan1 (both representing the small trichome-covered phenotype) and ecotype Gifu B129 and tan2 (both representing the large, glabrous phenotype). Both the tan1 and tan2 mutants accumulated substantial amounts of leaf PA similar in size to the small oligomers recovered from leaves of L. angustissimus. PA polymers were undetectable in Gifu B129 leaves, while floral PA extracts of this ecotype included a much larger PA polymer. Flavonoid composition in leaves of tan1 and L. angustissimus was complex, and differed from the simple profile in Gifu B129 leaves. Key words: Lotus, proanthocyanidin, flavonoids, trichomes, morphology, plant habit, variability
Further evidence on the inheritance of reproductive mode in Brachiaria
Authors: Miles J. W. , Escandón M. L.
Published: April 2011

The most important tropical forages are Brachiaria spp. Existing cultivars are natural, polyploid, aposporous apomicts. Breeding programs seek to combine attributes from the tetraploid apomicts B. brizantha and B. decumbens. Apomixis is monogenic and dominant. We sought to synthesize an allogomous, sexual, breeding population containing germplasm from selected apomicts. Apospory was not detected in a large open-pollinated progeny of sexual hybrids from sexual-by-apomictic crosses. Key words: Apomixis, apospory, Brachiaria, breeding methods
Quantitative genetic analysis of in vitro callus proliferation in alfalfa
Authors: Kielly G. A. , Bowley S. R.
Published: April 2011

Genetic variability exists for in vitro callus growth within plant species, including alfalfa (Medicago sativa L.). The objective of this study was to investigate, using diallel crosses, the genetic variance components of in vitro callus production in tetraploid alfalfa. Nine genotypes were randomly chosen from among 60 plants from the cultivar Saranac and the experimental population OAC81-120R, which were previously characterized as being able to initiate callus. The group of nine plants was divided and crossed to generate two, six-plant diallel sets (A and B) with reciprocals; and the progeny were evaluated for callus production. Significant (P < 0.01) differences were found among crosses and for general combining ability (GCA) effects in both diallels. Specific combining ability (SCA) and reciprocal effects were found to be nonsignificant (P < 0.05). Estimates of heritability (h2) for callus production on a plot mean basis were 73% and 61% for diallel A and B, respectively. Since the heritabilities were high, and no reciprocal effects were detected, breeding strategies employing recurrent selection should result in the development of high in vitro callus producing populations. Key words: Medicago sativa L., callus proliferation, tissue culture, quantitative genetics, heritability, alfalfa