bluuebunny/crossref_metadata_2025 huggingface dataset:
Strategies and tactics for herbicide use reduction in field crops in Canada: A review
Authors: Nazarko Orla M. , Van Acker Rene C. , Entz Martin H.
Published: April 2011

There are many economic and health reasons for reducing pesticide use in Canada. Herbicide use on field crops is by far the most common pesticide use in Canada. This paper is a review of four topics related to herbicide use reduction on field crops in Canada: (1) broad strategies and (2) specific tactics for herbicide use reduction; (3) factors affecting adoption; and 4) research approaches for improving the implementation of herbicide use reduction. Numerous tactics exist to use herbicides more efficiently and herbicides can sometimes be replaced by non-chemical weed control methods. Many of these tactics and methods have been investigated and demonstrated for use on field crops in Canada. However, herbicide use reduction is fundamentally dependent upon preventative strategies designed to create robust cropping systems that maintain low weed densities. Diverse crop rotation forms the basis of preventative strategies as it inherently varies cropping system conditions to avoid weed adaptation. There is evidence that residual weed densities resulting from herbicide use reduction are manageable within competitive cropping systems. A great deal of research has been done on herbicide use reduction on field crops in Canada, and most projects report definite possibilities for herbicide use reduction in field crop production in Canada. Synthesizing and extending this information and customizing it for use on individual farms remain challenges. Collaboration between researchers and farmers can help to build successful strategies for herbicide use reduction which reflect the context of modern farming, the will of farmers and the culture of technology adoption among farmers. Key words: Pesticide use reduction, low-input agriculture, integrated pest management, integrated weed management
Response of mustard to fertilization, seeding date, and seeding rate in southern Alberta
Authors: McKenzie R. H. , Middleton A. B. , Bremer E.
Published: April 2011

Yellow mustard (Sinapsis alba L.), brown mustard (Brassica juncea L.), and oriental mustard (B. juncea) have been grown in Alberta since the 1950s, but limited agronomic information specific for this crop is available. The objective of this study was to determine the response of mustard to fertilization, seeding date and seeding rate in southern Alberta. Field experiments were conducted at 20 field sites over a 4-yr period (1999–2002) under irrigated and dryland (fallow and stubble) conditions. Five experiments were conducted with the following treatments: (1) N fertilizer rate (0, 30, 60, 90 and 120 kg N ha-1), (2) urea placement (seed-placed and side-banded urea at rates of 0 to 120 kg N ha-1), (3) P fertilizer rate (0, 6.5, and 13.1 kg P ha-1), (4) S fertilizer rate (0, 10 and 20 kg S ha-1), and (5) seeding date (three dates at approximately 10-d intervals) and seeding rate (target plant densities of 75, 125, 175, 225, and 300 plants m-2). Experiment 1 was conducted with yellow mustard (AC Pennant), oriental mustard (Forge), brown mustard (Commercial Brown) and canola (Q2) (Brassica napus L.), while the remaining experiments were only conducted with yellow mustard. For maximum seed yield, mustard required 95 kg of available N Mg-1 of potential seed yield. Potential yields were closely related to available moisture, increasing 7 to 8 kg ha-1 for every mm increase in available moisture above a minimum moisture requirement of 90 mm. Seed-placed urea reduced plant stand at rates as low as 30 kg N ha-1 and reduced seed yield at rates of 60 to 120 kg N ha-1. Fourteen of 20 sites had a greater than 3% positive yield benefit due to P fertilizer. Mustard did not benefit from S fertilizer application. Delay in seeding by 3–4 wk, compared with seeding in late April to mid-May, reduced seed yield of yellow mustard by an average of 37%. Seed yield increased with seeding rate, but the maximum gain in seed yield due to high seeding rates was only 200 kg ha-1, with significant increases obtained only under very dry conditions. Early seeding and adequate N fertility were the most important agronomic practices for achieving high yields of mustard in southern Alberta. Key words: Sinapsis alba, Brassica juncea, yield, oil, nitrogen, phosphorus, sulfur, water-use efficiency
A review of research progress on cicer milkvetch (Astragalus cicer L.)
Authors: Acharya S. N. , Kastelic J. P. , Beauchemin K. A. , Messenger D. F.
Published: April 2011

This review of cicer milkvetch includes both published and unpublished information regarding crop and seed characteristics, seed treatments, breeding, agronomic practices and nutritional value for livestock. Cicer milkvetch is a long-lived perennial, acid- and drought-tolerant crop providing high-quality forage throughout the growing season. It does not cause bloat in ruminants. Although it has caused photosensitization in ruminants, this was apparently due to specific environmental conditions and the cultivar used. Cicer milkvetch is compatible with other forage crops in mixed stands and is particularly suitable for pasture. Although the crop has many good qualities and was introduced in North America approximately 75 yr ago, it has not been utilized extensively, primarily due to slow establishment. However, stand establishment has been improved by elucidation of seed and seedling characteristics, followed by selection for heavy seed, rate of emergence, and mature plant vigor. Improved cultivars, developed through recurrent selection for rapid establishment, are now available. Seed scarification, inoculation with rhizobia, and shallow seeding into a pre-packed, warm seedbed are of great importance in cicer milkvetch establishment. Seeding later in the spring (without a companion crop) increases the probability of successful establishment of genetically improved cultivars. Development of cultivars with upright growth characteristics and long-term persistence under grazing stress, improved scarification techniques (to reduce seed loss), and a seeding protocol for successful establishment of the crop, have the potential to substantially increase utilization of this important forage legume. Key words: Cicer milkvetch, forage legume, hard seed, seed scarification, seedling vigor, stand establishment
Influence of prohexadione calcium (Apogee®) on shoot growth of non-bearing mature apple trees in two different growing regions
Authors: Privé J. -P. , Cline J. , Fava E.
Published: April 2011

Orchard experiments were conducted on mature non-bearing apple ( Malus × domesticaBorkh.) trees to determine the efficacy of prohexadione-calcium (PC), formulated as Apogee® [27.5% PC + 56.1% (NH4)2 SO4 +16.4% ot her proprietary additives] for shoot growth control on six cultivars grown in Ontario (ON) and one grown in New Brunswick (NB), Canada. Seasonal patterns of extension shoot growth among cultivars in both locations were also compared. Results indicate that PC applications are most effective at the beginning of the season, when relative growth rates were greatest in eastern Canada. Four applications of PC failed to significantly reduce shoot growth more than two applications in either location. However, the level of control might have been more effective in ON if treatment applications were initiated earlier in the season. Although tree vigor and shoot growth differed between cultivars and locations, PC significantly and consistently reduced shoot growth and relative shoot growth rates for all cultivars at both locations. Empire shoots treated with PC were approximately 33 and 37% shorter at the end of the season in NB and ON, respectively. Key words: Calcium 3-oxido-5-oxo-4-propionylcyclohex-3-enecarboxylate, anti-giberellin, plant growth regulator, relative growth rate, Malus
Cloning, molecular characterization, and expression analysis of several red clover cDNAs
Authors: Sullivan Michael L. , Thoma Sharon L.
Published: April 2011

To begin gathering information regarding nucleotide sequence similarity between red clover genes and other plant species, especially the model legume Medicago truncatula, several random red clover cDNAs were sequenced. The analyzed cDNAs included genes encoding actin; several proteins involved in photosynthesis including PsaH, PsbR, PsbX, early light-induced protein (ELIP), ferredoxin, chlorophyll a/b binding protein; fructose-bisphosphate aldolase;chloroplastic superoxide dismutase; and GTP-binding protein typA. The gene set had a median sequence identity of 92% with their counterparts from M. truncatula, suggesting its available genomics tools can be applied to red clover. An expression analysis of the gene set in various red clover tissues indicates the genes show a wide range of expression patterns. Consequently, this set of cDNAs and associated data are proving useful as controls in molecular genetic experiments involving red clover. Key words: Red clover, Trifolium pratense, Medicago truncatula, forage legume, genomics, inquiry-based learning
Response to inoculation in Illinois bundleflower
Authors: Beyhaut Elena , DeHaan Lee R , Byun Jaehyun L , Sheaffer Craig C , Graham Peter H
Published: April 2011

llinois bundleflower [Desmanthus illinoensis (Michx.) MacMillan] has potential as a pasture and grain legume in the Midwestern USA, but has proven to be somewhat problematic in inoculation response. We identified inoculant-quality Rhizobium strains from among 120 isolates trapped from 12 sites within the native range of Illinois bundleflower, then determined the effect of inoculation with four selected strains on plant dry matter and plant total N in growth chamber, greenhouse, and field experiments. We also studied nodule occupancy in the field. In field experiments at Salina (Kansas) and Becker (Minnesota) inoculated plants yielded 170% greater dry matter and total N on average than did uninoculated and N fertilized controls at each site in the seeding year. There were no differences in plant response among the Rhizobium strains used, uninoculated plants were devoid of nodules, and the response to inoculation was similar for the three plant accessions considered. In the second growing season, plant regrowth was different at Salina and Becker. At Salina, all plant accessions regrew and no differences were found between inoculated and control treatments in the second year. At Becker, toward the northern extreme of the range for Illinois bundleflower, only a MN ecotype regenerated in the second year, and inoculation was a requirement for plant persistence. Regrowth was similar with each of the four inoculant strains used. While 90% of the rhizobia recovered from nodules in the seeding year at Becker had genetic fingerprints similar to the inoculant strains, in the second year this percentage had declined to 70%. Our results highlight the importance of Rhizobium strain selection if the use of native legumes is to be increased. Key words: Herbage, Illinois bundleflower, inoculant, native plants, nitrogen fixation, rhizobia
Adventitious presence of GMOs: Scientific overview for Canadian grains
Authors: Demeke T. , Perry D. J. , Scowcroft W. R.
Published: April 2011

The global expansion in the development and cultivation of genetically modified (GM) crops has increased international concern about adventitious presence of GM materials in non-GM seeds and grains. GM events in canola, corn, soybean, cotton, flax, papaya, potato, squash, sugar beet, and tomato have received regulatory approval in Canada. However, GM cultivars are only in commercial production for canola, corn and soybean. More than 30 GM events have been approved in these three crops. Cases of unapproved adventitious presence of GM materials that have impacted grain trading and handling in Canada and other countries include StarLink™ corn, GT200 canola, GM canola in mustard and recently Bt10 corn. Some countries have established tolerance and traceability requirements for adventitious presence of GMOs, while others are in the process of developing or adopting legislation. The threshold for labeling of adventitious presence of approved GM material in non-GM grain varies from 0.9% (e.g., EU) to 5% (e.g., Japan). Progress has been made in the development of DNA- and protein-based GMO detection methods. However, only a limited number of these detection methods have been internationally validated. The challenges for detection methods include sampling, a lack of certified reference material, a lack of DNA sequence information for the design of event-specific primers, and the sheer number of individual events that may be present and tested for. Current efforts by ISO and CEN will be valuable for establishing harmonized and standardized GMO detection methods. Key words: List of GM events, cases of AP, tolerance, traceability, detection methods, challenges
OAC Rex common bean
Authors: Michaels T. E. , Smith T. H. , Larsen J. , Beattie A. D. , Pauls K. P.
Published: April 2011

OAC Rex is an upright indeterminate bush white bean (Phaseolus vulgaris L.) cultivar intended for use in areas with greater than 2800 crop heat units. It has good yield potential in either wide or narrow row production. It is resistant to races 1 and 15 of bean common mosaic virus and is the first common bean cultivar resistant to common bacterial blight (Xanthomonas axonopodis pv. phaseoli) in Ontario. Seed has acceptable cooking and canning quality. Key words: Phaseolus vulgaris L., white bean, common bean, common bacterial blight, cultivar description
Infinity hard red spring wheat
Authors: DePauw R. M. , Knox R. E. , Clarke F. R. , McCaig T. N. , Clarke J. M. , Fernandez M. R.
Published: April 2011

Infinity hard red spring wheat (Triticum aestivum L.) has exhibited adaptation to a wide range of growing season temperatures and moisture availability. Infinity averaged significantly more grain yield than most other presently registered cultivars, and its grain protein concentration was significantly higher than that of Superb in the Saskatchewan Advisory Council trials. It matured significantly earlier than Superb. The straw length and strength, and volume weight of Infinity was intermediate to the check cultivars. Its seed size was smaller than that of AC Barrie and Superb. Infinity expressed resistance to prevalent races of stem rust and loose smut, moderate resistance to leaf rust and common bunt, and susceptibility to fusarium head blight. Infinity is eligible for all grades of the Canada Western Red Spring (CWRS) wheat class. Key words: Triticum aestivum L., cultivar description, adaptation, grain yield, grain protein, disease resistance
Evaluation of Rhizobium inoculant formulations for alfalfa yield and N fixation
Authors: Diane Knight J.
Published: April 2011

Because of its small seed size, alfalfa (Medicago sativa L.) typically is seeded at a shallow depth, putting Rhizobium inoculated onto the seed coat at a high risk of desiccation. Granular inoculants may provide a superior delivery formulation for Rhizobium because the inoculant can be placed deeper in the soil than the seed, where it is protected from desiccation. Sinorhizobium meliloti cv. Beaver delivered as (1) pre-inoculated alfalfa seed from the inoculant manufacturer, (2) commercial peat-based, self-sticking inoculant applied on-site, and (3) granular inoculant placed with the seed or (4) banded below and to the side of the seed was evaluated against uninoculated alfalfa controls at three field sites in Saskatchewan. Overall, alfalfa inoculated with the granular formulation placed below and to the side of the alfalfa seed was among the highest biomass producer in the establishment year, although it did not exhibit superior nodulation or biological N fixation compared with the other treatments. Any advantage conferred by the granular inoculant in the establishment year did not persist through the first and second production years. Under the conditions of this study, the delivery formulation had no long-term affect on alfalfa productivity, nodulation and biological N fixation. Furthermore, none of the inoculant treatments were consistently superior to the uninoculated controls. Key words: Alfalfa, granular inoculant, peat inoculant, pre-inoculated seed, Medicago sativa L., Sinorhizobium meliloti
Genetic diversity for agronomic, morphological and seed quality traits in Sinapis alba L. (yellow mustard)
Authors: Katepa-Mupondwa F. , Gugel R. K. , Raney J. P.
Published: April 2011

The objective of this research was to study the amount and pattern of phenotypic diversity among 179 Sinapis alba accessions maintained in germplasm collections at Plant Gene Resources of Canada (PGRC) and the Saskatoon Research Centre of Agriculture and Agri-Food Canada (SRC-AAFC). Accessions were evaluated in five field trials at Saskatoon from 1994 to 1998. Observations were recorded on number of days to flower and to mature, plant height, 1000-seed weight, oil and protein content and selected fatty acids and glucosinolates. Analysis of variance and mean comparisons were used to characterize variation in the germplasm. There was significant variation among accessions for all traits except some minor fatty acids and glucosinolates. Principal component analysis indicated that five or six principal components provided a good summary of the data, accounting for 75–80% of the variation. In all trials, the first principal component axis separated accessions predominantly on the basis of erucic acid (C22:1) and oleic acid (C18:1), with associated C22 and C18 fatty acids. The relative importance of agronomic, morphological and other seed quality traits varied among the trials, but they were always less important than C22:1 and C18:1. Cluster analysis generated 10–13 groups of accessions in each trial except in 1997 (five clusters). Distinct clusters were identified that possessed high or low values for C22:1, C18:1, oil and protein content, maturity, plant height and seed weight. Seed colour was not used as a classification variable; however, brown-seeded accessions were grouped into one distinct cluster due to a significantly higher level of C22:1 in these accessions. This study demonstrates that the S. alba accessions maintained at PGRC and SRC-AAFC are a source of genetic diversity for breeding both condiment (high glucosinolate and C22:1 content) and vegetable (low glucosinolate and C22:1 content) oilseed yellow mustard and for conducting genetic studies. Key words: Sinapis alba, genetic diversity, cluster analysis, principal component analysis
Carbon isotope discrimination of two-rowed and six-rowed barley genotypes under irrigated and non-irrigated field conditions
Authors: Dominique Roche Qingzhen Jiang, , Hole David J.
Published: April 2011

Carbon isotope discrimination (Δ) has been widely used to estimate the water-use efficiency (WUE) of C3 cereals including barley (Hordeum vulgare L.). Genetic lines of barley belong to two phenotypic classes for ear morphology, either two-rowed or six-rowed, a simply inherited trait. We tested the value of Δ as a predictor of grain yield and WUE for these two types of barley under different conditions of water availability. We also investigated if differences in plant morphology and yield parameters between these two types resulted in different carbon dynamics and different Δ values for grain, awn and flag leaf. We conducted field experiments for 3 consecutive years with genetic lines of both ear types in northern Utah and southeastern Idaho under irrigated and non-irrigated conditions, including two line-source sprinkler experiments. Correlations between grain yield and Δ values of flag leaf, awn and grain were stronger in combined analyses across ear types than in analyses within two-rowed (2R) and six-rowed (6R) types. Nevertheless, we found that Δ of mature awns and grains were a good predictor of yield for both barley types under low to moderate water stress. However, Δ was not a reliable predictor for barley yield under severe water stress. Pearson’s correlations were used to test associations between Δ values and several yield parameters (heading date, above-ground dry matter, harvest index, grain mass per fertile tiller). Our data indicated that among the field-grown genetic lines tested, the two types of barley differed in Δ values for grain, awn and flag leaf. Values of Δ for 2R barley were usually lower, suggesting higher WUE, than those for 6R types. Fundamental differences in sink size or grain mass per fertile tiller between 2R and 6R cultivars probably have important consequences on carbon/water metabolism at the whole tiller level. Key words: Barley, carbon isotope discrimination, yield, awn, drought, irrigation
Seeding rate, fertilizer level and disease management effects on hybrid versus open pollinated canola (Brassica napus L.)
Authors: Brandt S. A. , Malhi S. S. , Ulrich D. , Lafond G. P. , Kutcher H. R. , Johnston A. M.
Published: April 2011

New canola cultivars have much higher yield potential than conventional canola cultivars and changes in production practices may be needed to achieve optimum yield from these cultivars. Studies were conducted to investigate the influence of seeding rates (2.8, 5.6 and 8.4 kg ha-1), fertilizer level (67% – low, 100% – medium, 133% – high of the commercial recommendation) and fungicide application on growth, dry matter accumulation, seed yield and seed quality using two high-yielding canola cultivars [cv. Quantum, open pollinated (OP), and cv. Invigor™, hybrid (HYB)]. The studies were conducted from 1999 to 2001 at three sites in the Parkland region of the Canadian prairies. The two cultivars did not differ in their responses to seeding and fertilizer rates, or fungicide application. Plant density was lower for the HYB than the OP because the HYB had larger seeds, with fewer seeds per kilogram. Emergence declined slightly at high fertilizer levels in some site-years due to fertilizer induced seedling damage, but increased with seeding rate. Time to onset of flowering and maturity showed no consistent influence of cultivar, and tended to be somewhat prolonged with an increase in fertilizer levels, but reduced by an increase in seeding rate. On average, the HYB produced 822 kg ha-1 more biomass and 200 kg ha-1 more seed yield than the OP. Sclerotinia stem rot incidence was very low, except at Melfort in 2000, and fungicide application generally failed to benefit the crop. Seed yield was generally increased when seeding rate was increased, with the largest increase occurring from 2.8 to 5.8 kg ha-1. Seed yield responses to the high rates of seeding or fertilizer only occurred where both inputs were at the highest level, indicating that the optimum level of one was dependent upon the level of the other input. Oil and protein concentration in the seed was higher for the HYB than the OP. High fertilizer levels generally increased the total yield of biomass and seed, and protein concentration in the seed, but usually reduced oil concentration in the seed. Increased seeding rate resulted in a small increase in oil concentration and a small reduction in protein concentration in the seed. Net returns were greatest and least variable for the HYB cultivar. Overall, the HYB performed better than the OP, and the full economic value of high-yielding canola cultivars was only realized when fertilizer and seeding rates were at or above the current recommended rates. Key words: Canola (Brassica napus L.), fertilizer rate, fungicide, hybrid canola, oil content, open pollinated canola, protein content, seeding rate, seed quality, yield
Reward field pea
Authors: Bing Deng-Jin , Sloan Al , Beauchesne Don , Conner Robert , Warkentin Tom , Gan Yantai , Vera Cecil , Gehl David , Turkington Kelly , Clayton George , McLaren Debbie , Chang Kan-Fa
Published: April 2011

Reward, a semi-leafless and powdery mildew resistant yellow cotyledon field pea (Pisum sativum L.) cultivar, has excellent lodging resistance, high yielding ability, round seed shape and medium seed size. It is adapted to field pea growing regions in western Canada. Key words: Pisum sativum L., field pea, powdery mildew resistance, cultivar description
Effect of leaf nitrogen concentration versus CND nutritional balance on shoot density and foliage colour of an established Kentucky bluegrass (Poa pratensis L.) turf
Authors: Badra Abdo , Parent Léon-Étienne , Allard Guy , Tremblay Nicolas , Desjardins Yves , Morin Nancy
Published: April 2011

A 3-yr field study was conducted in a loam and a sand site to determine the effects of N, P, and K application rates on N status, shoot density and foliage colour of Kentucky bluegrass clippings and to derive critical N values. The experiment was arranged in a completely randomized block design with four replicates and three nutrients, N (0 or 50 to 300 kg ha-1 yr-1), P (0 or 21.8 to 87.3 kg P ha-1 yr-1), and K (0 or 41.7 to 250 kg K ha-1 yr-1), equally broadcast six times per growing season. We examined N concentration values, log-transformed N concentration values, and CND values for compositional nutrient simplexes comprising one (VN1), three (VN3), five (VN5), or 11 (VN11) macro- and micro-nutrients. Critical values for N expressions were obtained from linear relationships with targeted visual shoot density and foliage colour ratings that were closely related to each other (R2 = 0.92). The highest coefficients of determination (0.975 to 0.980) were obtained with VN5 and VN11. The VN5 values were consistent with literature data and across experimental sites, and were the most successful (99% success) in diagnosing N sufficiency in 328 qualified specimens from commercial sod farms. Compared with raw concentrations, the CND transformation reduced from 0.6 to 0.1 the degree of inter-correlation among nutrients in principal component analysis and was amenable to a χ2 distribution of CND indices. Using a critical imbalance index (CNDr2) of 5.6as χ2 value, and a critical CND IN2 index of 1.5 for a 5-nutrient simplex, we diagnosed as imbalanced 179 qualified specimens of which 110 specimens presented excessively high N level among the 328 qualified specimens in commercial stands. The proposed five-nutrient CND norms proved to be effective in diagnosing N status in Kentucky bluegrass clippings across experimental, literature, and survey data sets. Key words: Plant tissue nutrient diagnosis, DRIS, CND, Kentucky bluegrass nitrogen fertilization, turfgrass shoot density, turfgrass foliage colour
Furlong Oat
Authors: Mitchell Fetch J. W. , Brown P. D. , Duguid S. D. , Fetch T. G. , Ames N. , Chong J. , Haber S. M. , Menzies J. G. , Noll J.
Published: April 2011

Furlong is a high-yielding, tan-hulled oat (Avena sativa L.) cultivar postulated to carry the crown rust resistance combination Pc38, Pc39 and Pc68, which is effective against most of the current crown rust races on the Canadian prairies. It has very good resistance to loose and covered smut, good resistance to stem rust (likely due to Pg2 and Pg13) and moderate tolerance to barley yellow dwarf virus (BYDV). Furlong has very high kernel weight, high percent plump kernels and low percent thin kernels. According to its grain characteristics, including hull-to-groat ratio, protein content and milling yield, Furlong should be acceptable for milling purposes. Furlong is adapted for the oat-growing areas of western Canada and in particular the Black Soil Zone of Manitoba and Saskatchewan, where oat crown rust is prevalent. Key words: Oat, Avena sativa L., cultivar description, milling oat
Irrigation and fertilizer management effects on processing cucumber productivity and water use efficiency
Authors: Beyaert R. P. , Roy R. C. , Ball Coelho B. R.
Published: April 2011

Experiments were conducted to evaluate the response of processing cucumber (Cucumis sativus L.) to irrigation and fertilization strategies on a loamy sand in southwestern Ontario from 2001 to 2003. Dry matter accumulation, fruit yield, economic returns and water use efficiency were compared for (a) non-irrigated with conventional broadcast fertilizer applications (NI/B), (b) overhead sprinkler irrigated with conventional broadcast fertilizer applications (OHI/B), (c) surface drip irrigated with fertigation (DI/F) and (d) subsurface drip irrigated with fertigation (SDI/F). All irrigation methods enhanced yields, with drip irrigation coupled with fertigation showing significant advantages in terms of yield and economic returns compared with overhead irrigation and conventional fertilization practices. Irrigation increased dry matter accumulation, fruit yield and economic returns over non-irrigated treatments in a dry year, but only DI/F and SDI/F irrigation with fertigation increased these parameters in a wet year. Irrigation water use efficiency was greatest with SDI/F in 2 of 3 yr. This study indicates that processing cucumbers in Ontario benefit from irrigation, with drip irrigation/fertigation being more beneficial than overhead sprinkler irrigation. Subsurface drip irrigation systems increase irrigation water use efficiency over sprinkler and surface drip systems when higher than average temperatures coupled with lower than average rainfall are experienced on coarse-textured soils. Key words: Irrigation, fertigation, Cucumis sativus, yield
Effect of ammonium/nitrate ratio on growth and development of avocado plants under hydroponic conditions
Authors: Lobit P. , López-Pérez L. , Cárdenas-Navarro R. , Castellanos-Morales V. C. , Ruiz-Corro R.
Published: April 2011

An experiment was carried out to study the effects of the proportion of ammonium (NH4+) and nitrate (NO3−) in the nutrient solution on avocado plants in a hydroponic system. Five treatments were applied, consisting of the following proportions of ammonium to nitrate ions in the solution: T0 = 0:4, T1 = 1:3, T2 = 2:2, T3 = 3:1 and T4 = 4:0 at a constant nitrogen concentration of 4 mM. After 4 months, the plants were harvested and fresh and dry matter accumulation, leaf area, and leaf nitrogen and carbon content were measured. An architectural description of the shoot (length, number of nodes and branching) was made. Dry matter of shoots and leaves all decreased with increasing NH4+ concentrations. In contrast, water content in aerial organs increased with NH4+ concentration. Nitrogen and carbon content and the relationship between dry matter production and leaf nitrogen were not significantly affected by the treatments. The architectural analysis showed that the shoots developed over time in one or two distinct growth units. While nitrogen form affected both growth units, the second one was more severely affected, showing decreased length, number of nodes, and branching when NH4+ concentration increased. Key words: Avocado, nitrogen, nitrate, ammonium, development
Possible cause of low fruit set in the sweet cherry cultivar 0900 Ziraat
Authors: Mert Cevriye , Soylu Arif
Published: April 2011

The possible cause of low fruit set in 0900 Ziraat sweet cherry (Prunus avium L.) was investigated. Pollination conditions, ovule development, incompatibility, and fruit set were evaluated under natural conditions. Results indicated that pollen transfer to the stigmas was sufficient, and pollen tube growth was normal. Ovule development in most pistils examined was not normal, and this was likely the cause of the low set in this cultivar. Key words: Fruit set, incompatibility, ovule, pollination, sweet cherry
Analysis of dwarfing genes in Zhepi 1 and Aizao 3: Two dwarfing gene donors in barley breeding in China
Authors: Zhang Jing , Li Zhen , Zhang Chihong
Published: April 2011

Inheritance of plant height was studied in Zhepi 1 and Aizao 3, two dwarfing gene donors used in barley (Hordeum vulgare L.) breeding programs in China. With direct cross and para-backcross methods, allelism tests were conducted for Zhepi 1 and Aizo 3 with barley entries carrying either brh 1, uzu 1, sdw1, or six new dwarfing genes recently identified in Chinese barley accessions. Plant height in both Zhepi 1 and Aizao 3 was controlled by the same recessive dwarfing gene. The dwarfing gene carried by both of these cultivars is different from the three known and the six new dwarfing genes. Based on the results of this study, only two dwarfing genes have predominantly been used in barley breeding in China since 1950. Key words: Hordeum vulgare, dwarf source, dwarfing gene
A method for screening soybean seedlings for resistance to northern stem canker caused by Diaporthe phaseolorum var. caulivora
Authors: Thickett K. , VanDerWal J. , Lovett-Doust L. , Anderson T. R.
Published: April 2011

Five soybean varieties, Williams, Harosoy, AC Hime, Coles and Leo were inoculated 2 and 4 wk after planting with Diaporthe phaseolorum var. caulivora to determine if differences in resistance to stem canker could be detected in the early stages of plant development. Seedling stems were severed above the unifoliolate leaves and inoculum was applied to the cut surface. Stem lesion lengths were measured at 1, 2 and 3 wk following inoculation. The mean lesion length on seedlings inoculated 2 wk after planting (27.2 mm) was significantly less than seedlings inoculated 4 wk after planting (44.5 mm). Based on mean lesion length, Williams was the most susceptible variety followed by Harosoy. AC Hime, Coles and Leo were equally resistant. Stem canker development measured at 2 and 3 wk following inoculation was negatively correlated with stem moisture at the time of inoculation suggesting that stem moisture is important in the development and severity of stem canker. Key words: Diaporthe phaseolorum var. caulivora, Glycine max, inoculation method, northern stem canker, resistance, screening method
Vine desiccation characteristics and influence of time and method of top kill on yields and quality of four cultivars of potato (Solanum tuberosum L.)
Authors: Waterer D.
Published: April 2011

Potato crops are typically flailed or chemically desiccated several weeks prior to harvest to promote tuber maturity and facilitate harvest operations. This study evaluated how yields and processing quality of several potato cultivars responded to mechanical top kill versus desiccation with diquat at four different treatment dates. The influences of year and cultivar on the rate and extent of vine desiccation were also evaluated in the chemically desiccated crop. The cultivar Ranger Russet was slower to desiccate than Russet Burbank, Shepody or Russet Norkotah, likely because of its larger canopy. Averaged over 3 yr and four treatment dates, flailing reduced yields of the four cultivars tested by an average of 4% relative to chemical desiccation of the tops. The yield difference between flailed and chemically desiccated crops increased if conditions after application of the desiccant favored a gradual die down of the canopy. Specific gravities of the chemically desiccated treatments were equal to or higher than treatments killed by flailing. Fry colors were not influenced by either the method or timing of top kill. Although chemical desiccation enhanced yields relative to a crop flailed at the same time, the dry down period required for the chemically treated crop was at least 3 wk in this study. By contrast, crops killed by flailing are ready for harvest immediately, as long as skin set is not critical. Early in the season, if flailing allowed top kill of Russet Burbank to be delayed by as little as a week, the result was a 9% yield gain. As growing conditions became less favorable later in the season, there was little potential for yield gain by opting to flail instead of using the chemical desiccant. Key words: Diquat, flailing, Russet Burbank, Shepody, Ranger Russet, Russet Norkotah
Galley common bean
Authors: Park S. J. , Rupert T. , Yu K.
Published: April 2011

Galley, white bean (navy bean) (Phaseolus vulgaris L), has good yield potential with dull white seed coat luster and semi-determinate growth habit with upright plant type. It is resistant to lodging, early medium season maturity in southwestern Ontario. Key words: Phaseolus vulgaris, dry bean, cultivar description, plant type, white mould
Effects of agricultural practices on the flora of hedgerows and woodland edges in southern Quebec
Authors: Jobin Benoît , Boutin Céline , DesGranges Jean-Luc
Published: April 2011

The structure and distribution of herbaceous species were examined in cultivated fields and in adjacent habitats in light of herbicide use and tillage. The diversity and vegetation cover of the herbaceous layer of hedgerows and woodland edges were lower on sites at which herbicides had been sprayed in recent years, probably due to herbicide drift during application on adjacent fields. Herbicide use and tillage had an impact on the species composition of the cultivated fields: there was a higher proportion of annual and introduced species in cultivated fields subjected to herbicide use and tillage than in fields that were not regularly treated or tilled. The species that were found only in non-crop habitats were primarily native and perennials, few of which were weed species, whereas a high proportion of the species found only in cultivated fields were annual and introduced species, several of which were considered weeds. Key words: Woodland edge, hedgerow, herbicide, tillage, weeds, life span
In vitro selection for improved seedling vigour in birdsfoot trefoil (Lotus corniculatus L.)
Authors: McLean N. L. , Nowak J.
Published: April 2011

Establishment of productive stands of birdsfoot trefoil (Lotus corniculatus L.) is often difficult due to poor seedling vigour. Objectives of this study were to evaluate the relative effectiveness of in vitro selection conditions for seedling vigour and to choose the best lines for further evaluation. Birdsfoot trefoil seedlings from cvs. Leo and Upstart were selected on the basis of in vitro rate of germination at 5, 12 and 20 °C and subsequent seedling growth at 20 °C. Two cycles of recurrent selection were carried out. Progeny from both cycles of selection were evaluated under controlled and field conditions. In general, selection temperatures did not significantly affect emergence, individual shoot dry matter production or total shoot dry matter production. Emergence and total shoot dry matter yield were higher for selections within cv. Upstart than for selections within cv. Leo. Seedling vigour of cycle-2 selections was not superior to cycle-1 selections. Failure to make gains during the second cycle of selection is believed to be due to seed sterilization procedures during cycle-2 selection. Germplasms chosen for further evaluation include the 12 °C and 20 °C cycle-1 selections and the 20 °C cycle-2 selection from cv. Upstart. Key words: Lotus corniculatus L., birdsfoot trefoil, seedling vigour, in vitro selection, temperature
Inheritance of condensed tannins in birdsfoot trefoil
Authors: Miller Perry R. , Ehlke Nancy J.
Published: April 2011

Neither the inheritance of condensed tannins (CT) in tannin-positive birdsfoot trefoil (Lotus corniculatus L.), nor the quantitative genetic analysis of CT concentration in a forage legume have been previously reported. The objective of this study was to determine the inheritance of CT concentration in tannin-positive birdsfoot trefoil. High-, medium-, and low-tannin parents were selected from NC-83 birdsfoot trefoil germplasm and intercrossed in two independent six-parent diallel sets to generate progenies for quantitative genetic analyses. Maturity, herbage yield, leaf fraction (LF) and CT concentration were analyzed for 1067 individual F1 plants from 30 progenies in both diallel sets. Mean CT concentrations of the 30 progenies ranged from 6.1 to 93.4 g catechin equivalent (CE) kg−1 DM. General combining ability (GCA):specific combining ability (SCA) ratios of 0.93 and 1.0 were observed for CT concentration in both diallel sets, at or near the theoretical maximum of unity, indicating a predominance of additive genetic effects for CT concentration. Specific combining ability effects were detected in one diallel set where 3 of 15 progenies exhibited significant SCA effects. The evidence from this study indicated that CT concentration in birdsfoot trefoil was controlled primarily by additive genetic effects. Key words: Birdsfoot trefoil, condensed tannins, forage legume, inheritance, Lotus corniculatus, quantitative genetics
Irrigation frequency and quantity affect root and top growth of fertigated 'McIntosh' apple on M.9, M.26 and M.7 rootstock
Authors: Neilsen G. H. , Parchomchuk P. , Berard R. , Neilsen D.
Published: April 2011

A study was undertaken in order to quantify the effects of rootstock and irrigation level on the rooting pattern of fertigated apple trees. A profile trench observation method was used to map the number and location of root intersections at two planes relative to drip emitters for NP-fertigated McIntosh apple trees (Malus domestica Borkh). Four replicates of all combinations of three rootstocks (M.9, M.26 and M.7, planted in 1990) and two irrigation treatments [F1 (daily, watered to field capacity) and F2 (weekly, watered to 50% available soil water capacity, imposed in 1991)] were investigated after the 1994 growing season. Dwarfing rootstocks and F2-irrigation had lower top vigour and yield per tree. Cumulative yield efficiency was greater for trees on dwarfing rootstock but was unaffected by irrigation treatment. Root numbers per observation plane paralleled rootstock vigour, being lowest for M.9 and greatest for M.7. No effect of irrigation on root number was observed. Root distribution was affected by an interaction between rootstock and irrigation treatment with average root location moving closer to the surface and emitter for the dwarfing rootstocks M.9 and M.26 but not for M.7 under F1-irrigation. Key words: Vigour, yield, drip emitter, root number and distribution
Inheritance and characterization of two low linolenic acid EMS-induced McGregor mutant flax (Linum usitatissimum)
Authors: Ntiamoah Charles , Rowland Gordon G.
Published: April 2011

Mutagens [e.g. EMS (ethyl methane sulphonate)] are sometimes used to generate variability in oil crops when variability is lacking in natural populations, or when strong interspecific crossing barriers prevent hybridization with relatives. It is imperative to conduct genetic studies on beneficial mutants before they can be effectively used in a breeding program. This study was conducted to study the inheritance, and characterize two "apparent" low linolenic acid EMS-induced McGregor flax mutants (E1929 and E1536) that appeared to be quite different from E1747, a linolenic acid deficient McGregor flax mutant which has been extensively studied. Diallele crosses involving 1) E1929, E1536, and McGregor, and 2) E1929, E1536, and E1747 were made. Gas chromatography analyses of fatty acids from seed oil of F1 and F2 populations indicated that E1929 resulted from a reduction in Δ15 desaturase activity, and that the control of the trait is by a single recessive gene. The E1929 gene appears to be allelic to one of the two genes possessed by E1747. E1929 was characterized as a "moderately low linolenic-high oleic acid mutant". E1536 could not be characterized with the available data. Key words: flax, fatty acids, linolenic, Linum
AC Juniper Oat
Authors: Kibite Solomon
Published: April 2011

AC Juniper is an early maturing oat (Avena sativa L.) cultivar with high grain yield and good lodging resistance. It has a higher kernel weight, a higher percentage of plump kernels, and a lower percentage of thin kernels than Jasper. Its hull content is significantly lower than Cascade, similar to Jasper and Dumont, and higher than Derby. AC Juniper is well adapted to Alberta and the rust-free areas of western Saskatchewan. Key words: Avena sativa, oat (spring), cultivar description
Photosynthetic function, lipid peroxidation, and α-tocopherol content in spinach leaves during exposure to UV-B radiation
Authors: DeLong J. M. , Steffen K. L.
Published: April 2011

Spinach (Spinacia oleracea L. 'Meridian') plants were irradiated for 9 h d−1 for 12 d with ultra-violet-B (UV-B) radiation [13.5 kJ m−2 d−1 of biologically effective UV-B radiation (UV-BBE) + 350 µmol m−2 s−1 of photosynthetically active radiation (PAR)] or PAR (350 µmol m−2 s−1) to determine if incipient UV-B-induced inhibition of photosynthetic function occurred in photosystem 2 (PS2) reaction centers or in the lipid matrix of thylakoid membranes. Chlorophyll concentrations (leaf area basis) in UV-B-irradiated spinach leaves were significantly lower than in PAR plants after 4, 8 and 12 d of exposure. A significant UV-B-induced rise in initial fluorescence (Fo) at days 8 and 10 was accompanied by a decline in the photochemical efficiency (Fv/Fm) ratio, indicating a reduction in the efficiency of PS2 energy harvesting and trapping. When based upon the chlorophyll content of thylakoid membranes, UV-B radiation did not alter lipid per-oxidation but did increase α-tocopherol content compared with the PAR treatment during the first 8 of the 12 exposure days. These data suggest that incipient UV-B damage to the photochemical apparatus did not occur in PS2 reaction center complexes nor in the lipid matrix of the thylakoid membranes. Photosynthetic function was more susceptible to UV-B-induced impairment than thylakoid membrane lipids were to UV-B radiation damage. Key words: ultra-violet-B radiation, chlorophyll fluorescence, lipid peroxidation, α-tocopherol
Greenhouse bedding plant production of Stevia rebaudiana (Bert) Bertoni
Authors: Carneiro J. W. P. , Muniz A. S. , Guedes T. A.
Published: April 2011

The purpose of this experiment was to determine the effects of 14 growing media on greenhouse bedding plant production of Stevia rebaudiana (Bert) Bertoni. The best mixture consisted of sand clay (LEd2) soil, laying hen manure (10% vol/vol), and lime. Key words: Natural sweetener, fertilizers, transplant production
AC Harper six-row feed barley
Authors: May K. W.
Published: April 2011

AC Harper is a six-row yellow aleurone, hulled, spring feed barley with smooth awns, suitable for the Canadian prairies. AC Harper was developed from a cross between a scald resistant backcross line of Galt and BT364, which has high grain yield and strong straw. It has a combination of high yield potential, good resistance to lodging, short straw, and resistance to scald. AC Harper has improved kernel plumpness, protein content, and kernel colour compared to the feed check, Brier.Key words: Hordeum vulgare L., barley (six-row spring feed)
Freezing media affect cooling rate and regrowth of KSC 28 apple rootstock
Authors: Privé Jean-Pierre , Embree Charlie
Published: April 2011

To examine the effect that media have on cooling rates and subsequent plant regrowth, bare-rooted Kentville Select Clone 28 (KSC28) apple (Malus domestica Borkh.) roots were placed in various media (water, sawdust, soilless mixture and plastic bag) and set in a controlled environment chamber preset to −12 °C. Cooling rates differed between media with water and the plastic bag requiring the most and the least time to reach −12 °C, respectively. Shoot and root regrowth were similar for all treatments except water, which was significantly reduced. The plastic bag treatment provided the most uniform temperature gradients throughout the root system and the fastest cooling rate, was the easiest to handle, and allowed good regrowth. Key words: KSC28 apple rootstock, sawdust, soilless mix, cold hardiness testing