bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical properties of clay in relation to moisture loss
Authors: Russell Edward J.F. , Barker Ron D.
Published: March 2010

Subsidence of buildings situated on clay soils can be a serious insurance problem in dry summers. In order to investigate subsidence and monitor its progress, non‐invasive techniques that provide information on soil properties have enormous potential. To help assess the application of new electrical tomographic monitoring techniques, the electrical properties of seven geographically extensive clays and their relationships with moisture content have been determined. It is found that resistivity increases slowly as moisture content decreases to between 10–15% of the total saturation, beyond which resistivity increases rapidly. As electrical resistivity of clay is also dependent on ambient temperature, this must be monitored and corrected for. The results suggest that electrical resistivity could be a useful indicator of moisture content in clay soils.
Molecular cloning of the two very low-density lipoprotein receptor (VLDLR) subtypes in geese and the effect of overfeeding on their MRNA levels
Authors: Han C , Yao J , Wang J , Lu L , Li L
Published: March 2010

The objectives of this study were to verify the existence of two subtypes of the very low-density lipoprotein receptor (VLDLR) gene in geese, to investigate the effect of overfeeding on the plasma concentration of triglycerides (TG) and the very low density lipoprotein (VLDL), the activity of lipoprotein lipase (LPL), and the mRNA level of VLDLR in Sichuan White geese and Landes geese. The results indicate that there are two subtypes of the VLDLR gene in geese, and that they share a high similarity with those of other species. The expression of VLDLR I and VLDLR II was found in both tissues examined. After overfeeding, the expression level of VLDLR I in adipose tissue showed about a onefold increase (P < 0.05) in both breeds. Overfeeding induced a significant decrease of VLDLR I in skeletal muscle of both breeds, and a significant decrease of VLDLR II in Sichuan White geese (P < 0.05), but an obvious increase of VLDLR II in Landes geese (P < 0.05). In addition, overfeeding induced the increase of plasma VLDL, TG concentration and plasma LPL activity. It was concluded that VLDLR may participate in the metabolism of VLDL-TG by regulating the LPL-mediated TG hydrolysis in geese. Key words: Gene expression, geese, molecular cloning, overfeeding, very low-density lipoprotein receptor
Objective Bayesian vs. least squares estimation for by-products degradability with different rumen fluids
Authors: Martínez-Teruel A. , Megías M D , Hernández F. , Madrid J. , Salmerón D. , Cano J A
Published: March 2010

The degradation kinetic curves of different by-products have been obtained. The considered by-products were lemon and several types of treated and untreated barley straw, and they were degraded by in vitro incubation with rumen fluid extracted from two herds of Murciano-Granadina goats, one of them fed alfalfa hay and the other one fed barley straw. The feeds were incubated at 39ºC for 12, 24, 36, 48 and 72 hours with each rumen fluid. The resulting fitted exponential-type degradation curves obtained with a frequentist statistical analysis were compared with those resulting from an objective Bayesian statistical analysis. The use of the objective Bayesian analysis smoothed the estimates of the frequentist fit using least squares, which did not suitably process the involved restrictions and avoided biologically unacceptable results. On the other hand, the rumen fluid from goats fed alfalfa hay fomented the greatest effective degradability and the degradabilities of the different by-products were also compared, with the result that the lemon by-product was the best degraded one under both statistical analyses. Key words: In vitro fermentation, by-product, degradation curve
Growth performance, carcass traits and meat quality of heavy lambs reared in a warm or cold environment during winter
Authors: Pouliot É. , Gariépy C. , Thériault M. , Avezard C. , Fortin J. , Castonguay F W
Published: March 2010

The goal of this study was to evaluate the impact of winter rearing environment on the growth performance and meat quality of heavy lambs. Half of sixty-four Dorset lambs (32 males and 32 females) were raised in each of two different environments: warm and cold with average temperature of 10.9 ± 0.7 °C and -2.0 ± 5.2 °C, respectively. The lambs were slaughtered at live weights of 41-45 kg for females and 46-50 kg for males. Cold environment had no adverse effect on either growth performance or carcass quality. The rate of longissimus dorsi muscle deposition (P = 0.049) and its depth at slaughter (P = 0.027) were rather greater in lambs reared in the cold environment and a higher proportion of oxido-glycolytic fibres (P = 0.047) was also observed in this muscle. Rearing environment had only a minor effect on the organoleptic qualities, with the cold environment promoting juiciness of the meat (P = 0.043). Therefore, cold environment rearing such as used in this study represents an economic advantage for lamb producers by reducing the costs associated with the construction of insulated barns, while maintaining growth performance, as well as carcass and meat quality. Key words: Lamb, rearing environment, temperature, growth, carcass, meat quality
Calculating economic values for turkeys using a deterministic production model
Authors: Wood B J
Published: March 2010

Modern poultry breeding has been successful in achieving significant gains in production due to high fecundity, relatively short generation interval (in comparison with other species) and, last, the application of scientific processes in genetic evaluation. The objective of this paper was to document the development of an economic model relevant to the integrated turkey industry and to use the model to describe appropriate breeding objectives by calculating economic values for important production traits. The industry was modelled from the multiplier breeder down through to the processor. Each level in the production chain used a unit of production such as a live poult produced, a carcass delivered at the processing plant or a processed unit of meat to scale between different production divisions. Growth rate, feed consumption and breast meat yield all had similar relative economic value, while the reproductive traits (egg production, fertility and hatchability) had similar economic values to each other, but were smaller in comparison with the commercial production traits. The model was sensitive to assumed costs, such as feed price and, also for assumed returns in the form of breast meat value, and, as a consequence, care must be taken in the assumed pricing structure when calculating economic values for turkey breeding.Key words: Economic model, economic value, turkeys, breeding objectives
Use of corn distillers’ dried grains to reduce enteric methane loss from beef cattle
Authors: McGinn S M , Chung Y -H , Beauchemin K A , Iwaasa A D , Grainger C
Published: March 2010

There are significant emissions of greenhouse gases (GHG) from agriculture, and a major source is enteric methane (CH4) from ruminants. Our study reports the impact on enteric CH4 emissions when barley grain (35% of the dietary dry matter (DM) was replaced by corn distillers’ dried grains with solubles (DDGS, adding 30 g fat kg-1 dietary DM) in the backgrounding diet of growing beef cattle. The addition of DDGS reduced CH4 emissions (g d-1) by 19.9%, and by 16.4% when adjusted for DM intake [g (DM intake)-1] or by 23.9% when adjusted for gross energy (GE) intake (% of GE intake). Adding DDGS to cattle diets reduced CH4 emissions, but the effects of higher N content of the manure on emissions of nitrous oxide and ammonia need to be accounted for to complete the evaluation of the environmental impact of feeding DDGS to feedlot cattle. Key words: Methane, beef cattle, corn distillers’ dried grains with solubles, lipid, greenhouse gas emissions, sulphur hexafluoride
Use of whole oat in feedlot diets
Authors: Gibb D J , Wang Y , Schwartzkopf-Genswein K S , McAllister T A
Published: March 2010

Replacing 9% silage and 6% barley with 15% whole oat (DM basis) had inconsistent effects on DMI, but increased (P < 0.04) eating rates and tended (P < 0.11) to increase meal size in all diets. Oat reduced (P < 0.008) gain/feed in the backgrounding diet, but increased gain/feed and ADG (P = 0.002) in the 0% forage finishing diet. Dressing percent, but not carcass weight, was reduced by inclusion of oat in the diet. No difference in liver abscesses or animal health were observed.Key words: Feedlot, forage, oat, eating behaviour
Dexamethasone reduces transport-induced weight losses in beef calves
Authors: Cook N J , Veira D , Church J S , Schaefer A L
Published: March 2010

Dexamethasone was administered intramuscularly at two dose levels (Trial 1 = 0.088 mg kg-1; Trial 2 = 10 mg per calf) to beef calves (Trial 1, n = 60; Trial 2, n = 58) prior to transport by road for 10 and 8 h, to test the effect on transport-induced weight losses. Calves lost significant weight over the transport periods (P < 0.001) but dexamethasone-treated calves lost significantly less weight than control animals (P < 0.004). The relationship between salivary dexamethasone concentrations and weight losses in Trial 1 exhibited a significant trend (r = 0.47, P < 0.06). The correlation of administered dose of dexamethasone (mg kg-1) with weight losses in Trial 2 was significant (r = 0.5, P < 0.006). Dexamethasone administration prior to long-haul transport reduced transport-induced weight losses, and may be an effective method of mitigating transport stress.Key words: Transport, beef calves, dexamethasone, weight losses, salivary cortisol, salivary dexamethasone
Performance and carcass characteristics of steers fed a low acid-detergent lignin hull, high-oil groat oat in growing and finishing diets
Authors: Zalinko G R , Racz V J , Rossnagel B G , Christensen D A , McKinnon J J
Published: March 2010

Two trials were conducted to evaluate the performance and carcass traits of steers fed a low acid detergent lignin hull, high oil groat (LLH-HOG) oat in cattle diets. In trial 1, 400 steers (275.4 ± 20.8 kg) were fed one of two diets with barley or LLH-HOG oat at 37.8% of the diet (DM basis). Dry matter intake (DMI) was lower (P = 0.02) (7.49 vs. 7.72 kg d-1) and gain to feed improved (P < 0.01) (0.171 vs. 0.159 kg) for steers fed the oat-based diet. Calculated NEm (1.80 and 1.71 Mcal kg-1) and NEg (1.17 and 1.09 Mcal kg-1) values were greater for the oat-based diet. In trial 2, 240 steers (341.7 ± 18.1 kg) were fed one of three diets consisting of 88.2% barley, corn or oat grain, 5.1% barley silage and 6.7% supplement (DM basis). During finishing, steers on the oat diet had lower (P < 0.01) Average daily gain than barley- or corn-fed cattle (1.40, 1.69 and 1.84 kg d-1, respectively) reflecting lower (P < 0.01) DMI (9.56, 10.84 and 11.56 kg d-1, respectively). Ultrasound fat and longissimus dorsi (l. dorsi) area, carcass weight and dressing percentage were lower (P < 0.01) for steers fed the oat diet. Stearic acid content of the l. dorsi of oat-fed cattle was greater (P < 0.01) than barley- or corn-fed cattle. The ratio of polyunsaturated to saturated fatty acids in the muscle of oat- and corn-fed cattle was greater (P = 0.01) than that of barley-fed cattle. Results indicate that the energy value of the LLH-HOG oat is equivalent or superior to that of barley for growing cattle; however, research is required to identify why feed intake of finishing cattle fed this grain source is reduced. Key words: Low lignin hull, high-oil groat oat, barley, corn, cattle performance, carcass traits
Determination of the digestible energy and prediction of the net energy content of toasted and non-toasted canola meals from Brassica junceae and Brassica napus in growing pigs by the total faecal collection and the indigestible marker method
Authors: Montoya C A , Leterme P
Published: March 2010

The study aimed to compare the digestible and net energy (DE and NE) contents of three canola meals (CM) toasted (95°C) or not after desolventization from yellow Brassica junceae (YBJ) and yellow and black Brassica napus (YBN and BBN) in growing pigs. A basal diet and six CM-based diets (2/3 basal diet and 1/3 CM) supplemented with acid-insoluble ash (indigestible marker) were prepared. The growing pigs (28 kg; six per treatment) were kept in metabolic cages for 18 d and their faeces were collected for the last 10 d. The digestibilities and DE content of the CM were determined based on the total faecal excretion and the indigestible marker method. NE was estimated with a prediction equation. The DE and NE contents of the YBN meal (3.98 and 2.73 Mcal kg-1 DM) were higher (P = 0.007) than that of the YBJ (3.76 and 2.59 Mcal kg-1 DM) and BBN (3.64 and 2.43 Mcal kg-1 DM) meals. Toasting had no effect (P > 0.05) on the DE and NE contents. Inconsistent values were obtained with the indigestible marker, as compared with the total faecal collection method. In conclusion, YBN canola presents the highest energy content, and toasting of CM does not affect its energy values in growing pigs.Key words: Canola meal, growing pigs, toasting, digestible energy, net energy
Expression and localisation of glucose transporter 1 (GLUT1) in dairy goat mammary gland at different physiological stages
Authors: Na Z , Qingzhang L , Xuejun G , Xuemei N , Hongbo Y , Chun L
Published: March 2010

Glucose is the major energy source for mammary epithelial cells, as well as an important substrate for lactose synthesis. Mammary epithelial cells take up glucose from extracellular fluid into the cell through glucose transporter (GLUT). This study was aimed at investigating the expression of GLUT1 glucose transporter in dairy goat mammary gland during puberty, pregnancy, lactation, and involution. Using real-time reverse transcription PCR (qRT-PCR) and Western blotting, we analyzed the expression of GLUT1 mRNA and protein in dairy goat mammary gland. GLUT1 mRNA and protein expression increased during pregnancy and lactation, especially at peak lactation, and decreased strongly after weaning. Furthermore, the location of GLUT1 protein was determined by immunofluorescence laser confocal microscopy. GLUT1 protein localised to the basal and apical plasma membrane of epithelial cells, and also in the cytoplasm. The results from this study showed that GLUT1 is expressed in the dairy goat mammary gland with the greatest expression found in mammary epithelial cells during pregnancy and lactation.Key words: Expression, glucose transporter, goat, mammary gland
Feeding amount affects the sorting behavior of lactating dairy cows
Authors: Miller-Cushon E K , DeVries T J
Published: March 2010

The objective of this study was to determine whether feed sorting behavior in dairy cattle is influenced by the amount of feed provided. Six lactating Holstein cows, individually fed a total mixed ration once daily, were exposed to two treatments in a crossover design with 7-d periods. The treatments were: (1) lower feed amount (LFA; target 10% orts), and (2) higher feed amount (HFA; target 20% orts). Dry matter intake (DMI) was monitored daily for each animal. On the final 4 d of each treatment period, fresh feed and orts were sampled for particle size analysis. The particle size separator had three screens (19, 8, 1.18 mm) and a bottom pan, resulting in four fractions (long, medium, short, fine). Sorting was calculated as the actual intake of each particle size fraction expressed as a percentage of the predicted intake of that fraction. Actual orts percentage averaged 11.5% for the LFA and 18.0% for the HFA treatments. When on the HFA cows sorted for the medium particles to a greater extent than on the LFA (103.0 vs. 101.1%). Further, when on the HFA treatment cows sorted against short particles to a greater extent than on the LFA (95.2 vs. 98.6%). Despite greater sorting on the HFA treatment, the concentrations of neutral detergent fiber (NDF; 29.6%) and starch (27.1%) in the feed consumed were similar between treatments. Given this, and that DMI was greater on the HFA treatment compared with the LFA treatment (29.7 vs. 26.5 kg d-1), greater intakes of NDF (8.7 vs. 7.8 kg d-1) and starch (8.0 vs. 7.2 kg d-1) were also observed on the HFA treatment. The results suggest that, despite causing greater feed sorting, increasing the feeding amount for lactating dairy cows promoted higher DMI and did not prevent the consumption of a ration balanced to meet their nutritional requirements.Key words: Feeding amount, sorting behavior, dairy cow
Effect of dietary citric acid, flavomycin and their combination on the performance, tibia ash and immune status of broiler
Authors: Haque M N , Islam K M.S. , Akbar M A , Chowdhury R , Khatun M , Karim M R , Kemppainen B W
Published: March 2010

The goal of this research was to investigate the effect of citric acid (CA), the antibiotic growth promoter flavomycin (FL) and their combination on the growth performance, tibia ash and immune status of broilers. One hundred and sixty straight run day-old broiler chicks (Hubbard Classic) were randomly distributed into four dietary groups, with four replicate cages having 10 birds in each. Standard corn-soybean-based basal starter diet was given to control birds. Diets for other groups were further fortified by 0.5% CA, 0.001% FL and their combination (0.5% CA plus 0.001% FL). On day 35, CA and its combination (CA + FL) group had 17 and 12% increase in live weight compared with control, respectively (P < 0.05). Total live weight on day 35 was 1141, 1337, 1169, and 1275 g bird-1 in different groups, respectively (P < 0.05). Cumulative feed intake was higher (P < 0.05) in CA and its combination (CA + FL) compared with the control and FL groups on day 28. Supplementation with CA improved (P > 0.05) feed conversion ratio [FCR; feed intake (kg):weight gain (kg)] compared with FL and its combination (CA + FL). Carcass yield was increased (P > 0.05) due to the addition of CA and its combination (CA + FL). Tibia ash content in the CA group (59.0) was higher (P < 0.05) than in the control (53.6%), FL (53.1%) and their combination (57.1%). The lymphocyte cells associated with immunity in the lymphoid organs (caecal tonsil, bursa Fabricius and ileum) were more densely populated, suggesting an increased level of innate immunity in the CA group. Overall mortality was low (1.25%), and there were no treatment-related effects on mortality. Citric acid reduced the pH of formulated feeds, but mild reduction was found in the pH of the faeces. Dietary supplementation of 0.5% CA increase weight gain, feed intake, tibia ash deposition and non-specific immunity (P < 0.05) as well as feed efficiency and carcass yield (P > 0.05) of broilers. Citric acid has potential as a growth promoter to replace the antibiotic growth promoter FL.Key words: Citric acid, flavomycin, growth performance, immunity, tibia ash, broiler
Effect of crop residues in haylage-based rations on the performance of pregnant beef cows
Authors: Wood K M , Kelly M J , Miller S P , Mandell I B , Swanson K C
Published: March 2010

Seventy-one individually fed multiparous, pregnant crossbred beef cows [body weight (BW) ± SD; 730 ± 77.9 kg] were used to examine the effects of including crop residues in alfalfa/grass haylage-based rations on BW gain, fat deposition/loss and plasma metabolites. The haylage control ration (CON; n = 23) was modified to include either 40% (dry matter basis) wheat straw (WS; n = 24) or 40% corn stalklage (CS; n = 24). Cows were blocked by calving date and randomly assigned to each treatment and fed for 82 d leading up to the earliest calving date. On days 1, 40, and 82, cows were weighed, ultrasounded to measure subcutaneous backfat (BF) over the ribs, body condition scored (BCS) and plasma was collected. Calves from cows fed WS had greater (P = 0.02 ) weaning weights than cows fed CS, but did not differ (P = 0.23) from CON. CS cows had the lowest ADG (P < 0.03), lost the most body condition (P < 0.04), and had the lowest dry matter intake (P ≤ 0.001). These data indicate that diets containing crop residues can be used to dilute high-quality haylage rations for wintering beef cows; however, diets containing 40% corn stalklage used in this experiment may not be advisable, since cows lost BW and fat, and their calves had the poorest calf performance up to weaning. Key words: Beef cattle, wheat straw, winter feeding, corn stalklage, crop residues
Nitrogen release from field pea residues and soil inorganic N in a pea-wheat crop rotation in northwestern Canada
Authors: Lupwayi N. Z. , Soon Y. K.
Published: March 2010

Pea (Pisum sativum L.) varieties can differ in morphology, N2 fixation and straw N content. A study was conducted over 3 site-years to evaluate the influence of pea variety and inoculation with Rhizobium on N release from decomposing pea residues. The litterbag technique was used to measure N release over a 52-wk period starting from the time of pea harvest in one season through part of the following season when wheat was grown. Experimental treatments comprised factorial combinations of three pea varieties and either inoculation with 5 kg ha-1 of a granular inoculant or none, arranged in a randomized complete block design. Neither pea variety nor inoculation affected amounts or patterns of N released. Patterns of N release over time showed mostly net N mineralization in two of 3 site-years, and some net N immobilization in one site-year. The percentages (up to 19 to 24% over time) and amounts (up to 2.3 to 7.5 kg N ha-1) of N released were low, probably due to the combination of low N concentrations (mostly < 1%) in the residues and below-normal rainfall in all 3 site-years. Soil NO3-N and NH4-N (0- to 80-cm depth) in the fall after pea harvest (20 to 39 and 27 to 55 kg N ha-1, respectively) and in spring before wheat seeding (23 to 51 and 16 to 40 kg N ha-1, respectively) were not affected by pea variety or inoculation. However, soil NO3-N was mostly higher after peas than after barley (the control). There is need to measure patterns of N release over several subsequent crops to check if more N is released in the long term. Key words: Crop residue, N mineralization, Rhizobium inoculation, soil inorganic N
Broccoli growth in response to increasing rates of pre-plant nitrogen. II. Dry matter and nitrogen accumulation
Authors: Bakker C. J. , Swanton C. J. , McKeown A. W.
Published: March 2010

An understanding of plant nitrogen accumulation and soil nitrogen dynamics is needed to develop management practices that balance nitrogen requirements of vegetable crops with environmental protection. Field trials were conducted in 2001 and 2002 to determine the interaction of increasing rates of pre-plant nitrogen fertilizer with broccoli tissue nitrogen accumulation and soil nitrogen dynamics. Broccoli cultivars Decathlon and Captain were grown with seven rates of nitrogen (0, 50, 100, 150, 200, 300, 400 kg N ha-1) applied pre-plant as ammonium nitrate. Rate of nitrogen accumulation by the above-ground tissue biomass varied over time and among nitrogen treatments, ranging from 1 to 16 kg N ha-1 d-1. At harvest, tissue nitrogen was high, but nitrogen use efficiency was low when high rates of nitrogen were applied. Soil NO3--N content decreased from planting to harvest. At harvest, soil NO3--N increased with increasing rates of nitrogen, with the majority of NO3--N found in the top 0 to 30 cm of the soil. At 200 kg ha-1 applied nitrogen, plants recovered essentially all of the estimated available nitrogen and there appears to be little risk of nitrogen loss during the growing season. Approximately 130 kg N ha-1 was supplied by the soil during the cropping season. Soil and crop residues at harvest ranged from 96 to 330 kg N ha-1. This residual fertility poses a risk for nitrogen loss. Practical and cost-effective strategies are needed to manage residual nitrogen in the soil and crop residues to minimize loss and retain this nitrogen for subsequent crops. Key words: Brassica oleracea L. italica Plenck, nitrogen budget, nitrogen rates, nitrogen use efficiency, nutrient management
Broccoli growth in response to increasing rates of pre-plant nitrogen. I. Yield and quality
Authors: Bakker C. J. , Swanton C. J. , McKeown A. W.
Published: March 2010

Nitrogen management is critical to the production of broccoli (Brassica oleracea L. italica Plenck). Field trials were conducted in 2001 and 2002 to determine the rate of pre-plant nitrogen required to optimize broccoli yield and quality. Seven rates of nitrogen (0, 50, 100, 150, 200, 300, 400 kg N ha-1) as ammonium nitrate were broadcast and incorporated before transplanting two broccoli cultivars, Captain and Decathlon. Maturity of the heads was delayed by 5 d at 0 kg N ha-1 compared with the other rates of applied N. Marketable yield was maximized at 243 to 272 kg N ha-1 for yield expressed in t ha-1 and 171 to 187 kg N ha-1 for yield expressed as cases ha-1. Averaged over cultivar and year the most economical rate of nitrogen (MERN) ranged from 298 to 309 kg ha-1, 50 kg higher than estimates for the maximum marketable yield derived from quadratic plateau models. The incidence of misshapen heads decreased and floret color improved as nitrogen rate increased, but hollow stem and head rot also increased with high rates of nitrogen. Floret NO3--N concentration increased and vitamin C concentration decreased at high nitrogen rates. Applying the rates of nitrogen required to maximize yield may have negative economic and environmental consequences. However, restricting nitrogen also jeopardizes both yield and quality. Hence, the optimum amount of pre-plant nitrogen to apply to broccoli that balances yield, quality, economics and environmental concerns remains a complex issue. Key words: Brassica oleracea L. italica Plenck, color, postharvest, nutrition, hollow stem, vitamin C
Colonization of the nitrogen-fixing bacterium Gluconacetobacter diazotrophicus in a large number of Canadian corn plants
Authors: Tian G , Pauls P , Dong Z , Reid L M , Tian L
Published: March 2010

Gluconacetobacter diazotrophicus is a nitrogen-fixing bacterium originally found in sugarcane. In this report, we studied colonization of this bacterium in corn (Zea mays) using 17 inbred grain corn lines and 10 sweet corn varieties. Gluconacetobacter diazotrophicus was inoculated to roots of different corn plants. Thirty days after inoculation, the presence of the bacterium in plant tissues was evaluated via polymerase chain reaction using specific primers. The research showed that it was possible to introduce G. diazotrophicus into a large number of corn genotypes. The bacterium was detected in 11 grain corn lines and 9 sweet corn varieties and the overall colonization in corn was 74.1%. The bacterium was detected in stems and leaves from the primary site of inoculation, indicating the bacterium could move to other organs and the bacterium showed a positive adaptation to the new host plant. The bacterium population size in colonized plants ranged from 200 to 3000 per fresh gram of tissues. Some grain and sweet corn genotypes were not colonized by the bacterium, indicating that genetic difference exists in corn plants which influences colonization. Sucrose content in stem tissues of sweet corn varieties was higher than that in grain plants. Analysis of all the corn genotypes showed that there was a positive correlation between plant sucrose content and colonization efficiency. The study indicates that corn can be a potential new host plant for G. diazotrophicus.Key words: Grain corn, nitrogen-fixing bacterium, sugar content, sweet corn
The Biology of Canadian Weeds. 141. Setaria faberi Herrm.
Authors: Nurse R. E. , Darbyshire S. J. , Bertin C. , DiTommaso A.
Published: March 2010

Setaria faberi, commonly known as giant foxtail, is an annual graminaceous weed that is native to eastern China, has colonized eastern North America and is expanding its range westward. This species is primarily self-pollinated and the only mechanism of reproduction is by seed. Adult plants may reach 2 m in height and produce over 2000 seeds per panicle. Seeds may possess non-deep physiological dormancy when freshly produced, and can form small persistent seed banks. If not controlled, S. faberi populations can cause severe yield reductions in corn and soybean crops. Several herbicides are available to provide chemical control; however, resistance to some modes of action, (ALS, ACCase, and Photosystem II) have been identified in Canada and the United States. Leaves and seeds of this species provide a food source to several species of mammals, birds, and insects. Key words: Setaria faberi, giant foxtail, growth, development, seed germination, diseases, herbicide
The performance of dry bean cultivars with and without common bacterial blight resistance in field studies across Canada
Authors: Gillard C. L. , Conner R. L. , Howard R. J. , Pauls K. P. , Shaw L. , Taran B.
Published: March 2010

Common bacterial blight (CBB) is a serious seed-borne disease in dry beans (Phaseolus vulgaris). Plant breeders have focused on genetic resistance to control this disease, and this led to the release of the first resistant cultivar (OAC Rex) in 2002. In 2003 and 2004, field studies were conducted at six sites across Canada to measure the impact of CBB resistance on dry bean seed yield. Two resistant and four susceptible cultivars were evaluated in noninoculated and inoculated experiments at each site. In the noninoculated experiments, the CBB incidence was very low and there were no treatment differences for measurements of leaf disease. Significant disease pressure occurred in the inoculated experiments at 7 of 12 site-years. Both resistant cultivars usually had less leaf disease than the susceptible cultivars. Yield comparisons between the inoculated and noninoculated experiments were conducted using a yield index calculation to estimate the impact of CBB on the yield of the cultivar. OAC Rex and HR67 had a mean yield advantage of 23.1 and 13.8%, respectively, compared with the mean of the four susceptible cultivars. This is similar to the yield advantage previously reported in the literature. Key words: Dry bean, Phaseolus vulgaris, Xanthomonas axonopodis pv. phaseoli, resistance, yield
CTH14 flue-cured tobacco F1 hybrid
Authors: Haji H M , Mishra S , DeVos M
Published: March 2010

CTH14 is the second flue-cured tobacco (Nicotiana tabacum L.) hybrid recommended for commercial release in Canada. The yield of CTH14 is significantly superior to that of CT157, one of two check varieties, while the grade index is superior to the other check variety Delgold. As a result, the economic return of CTH14 is significantly superior to both check varieties. CTH14 has uniform growth both in the greenhouse and in the field. Leaf quality traits of CTH14 are far superior to Delgold, as well as most other commercial varieties in Ontario.Key words: Nicotiana tabacum L., tobacco, hybrid, male sterility, black root rot, cultivar description
Nursery stock type, nitrogen fertilization and shoot pruning effects on the growth of juvenile hybrid poplar in Saskatchewan
Authors: Block R. M. A. , Knight J. D. , Booth N. W. H. , Van Rees K. C. J.
Published: March 2010

Increased demand for wood from the forest-products and bio-energy industries in Canada has generated interest in large-scale hybrid poplar production for the prairie-boreal transition region. Because of the harsh climate and short growing season, this region of Canada poses significant challenges for establishment and production of hybrid poplar plantations and currently little silviculture information specific to this region is available. Trials were established at two sites with different prior land use histories: a former alfalfa field and a mixed-grass pasture. Cutting (Ct), rooted cutting (RCt) and rooted plug (RPg) nursery stock of hybrid poplar [P. deltoides × (P. laurifolia × P. nigra) var. Walker] were established with two fertilization rates (0 and 100 kg N ha-1) and pruned and unpruned treatments. Despite the alfalfa site having higher amounts of available N than the pasture site and tree growth being superior at the alfalfa site, foliar N concentrations indicated an N deficiency at the alfalfa site in 2003. The difference in growth between sites was attributed to a higher degree of weed competition at the pasture site. Survival of saplings was affected by the nursery stocks. The presence of roots on the initial stock was key to early survival with approximately 92% of rooted stocks surviving over winter the first year of planting, and only 41% of unrooted cuttings surviving the same period. The short growing seasons (115 to 127 frost-free days) provided enough time for RCt to recover from pruning and produce stem volumes larger than unpruned trees. For reasons unknown, RPg did not fully recover from pruning and stem volumes in 2003 and 2004 were lower than unpruned trees. Although expectations of rates of growth of hybrid poplar are lower in the prairie-boreal transition region of Canada compared with regions of North America with more moderate climates, establishment of plantations can be realized with aggressive weed control and selection of rooted stock materials. Key words: Cuttings, rooted cuttings, rooted plugs, cultural practices, Walker
CDC Verona durum wheat
Authors: Pozniak C. J. , Fox S. L. , Knott D. R.
Published: March 2010

CDC Verona durum wheat is adapted to the durum production area of the Canadian prairies. This conventional-height durum wheat combines good yield and high grain pigment and protein concentrations and is low in grain cadmium. CDC Verona is strong strawed and has similar maturity and disease resistance as other registered durum cultivars. Key words: Triticum turgidum L. var durum, durum wheat, yield, yellow pigment, cadmium, cultivar description
Optical sensors have potential for determining nitrogen fertilizer topdressing requirements of canola in Saskatchewan
Authors: Holzapfel C. B. , Lafond G. P. , Brandt S. A. , Bullock P. R. , Irvine R. B. , James D. C. , Morrison M. J. , May W. E.
Published: March 2010

An important challenge in N management is matching fertilizer inputs to crop requirements for specific environmental conditions. Field experiments were completed over 3 yr at two locations in Saskatchewan to evaluate the feasibility of using optical sensors and high-N reference plots along with topdressed liquid urea ammonium-nitrate (UAN) to arrive at more optimal N rates for canola (Brassica napus L.). Treatments included N management strategies where the timing and methods of application were varied along with the total quantities of N applied. Sensor-based N management was compared with the predominant practice of banding predetermined amounts of N at seeding. On average, sensor-based N management resulted in a 34 kg N ha-1 reduction in fertilizer use with no effect on seed yields except at Indian Head in 2006 where dry conditions resulted in yield reductions of 370 to 454 kg ha-1 compared with applying canola's entire N requirements at seeding. Sensor-based N management or split-N applications never increased yields relative to applying all N at seeding. Adopting this technology in western Canada will more likely result in reduced N inputs without reducing yield than increased seed yield. While sensor-based N management did not reduce post-harvest residual soil NO3-N levels, agronomic N use efficiency (ANUE) was increased 33% of the time and was never lessened. When significant, the increase in ANUE ranged from 4.8 to 7.8 kg seed kg N applied-1. Overall, optical sensors have potential as a tool for managing N fertility more efficiently in canola production. Key words: Brassica napus, normalized difference vegetation index, urea ammonium-nitrate, nitrogen use efficiency, agriculture, precision
A review of the recruitment biology of winter annual weeds in Canada
Authors: Cici S. Z.H. , Van Acker R. C.
Published: March 2010

Typically, summer annual weeds have been the primary management target for field crop farmers in Canada, but with changes in cropping systems and with acknowledged global climate change there will be an increasing need to consider the management of species that are present very early in the spring, including winter annual weeds. Knowledge of weed recruitment biology and emergence patterns can be used to guide weed management practices. A review was conducted of the recruitment biology of winter annual weeds in Canada. The key finding was that all of the significant winter annual weeds in Canadian agriculture are facultative, with the majority of species emerging at two peak periods, April-May and September-October. For the weed species included in this review, the information available on recruitment and seed biology was far from comprehensive, and for some species there was very little published information, in particular on specific base temperatures for germination, documented field-based emergence periods and data that could be used to create simple predictive population dynamics models, including fecundity (× environment), seed longevity and overwintering probability. This is particularly true with respect to information in Canadian agricultural contexts. A number of questions result from this review, a key one being whether spring versus fall emergence creates significant differences in fundamental biological characteristics of winter annual weeds including seed dormancy status, microsite requirements, phenology, plant vigour and competitive ability. Given that none of the winter annuals in Canada are constitutive and given ongoing climate change, farmers in Canada should be careful not to encourage summer annuals to become winter annuals. Movement away from fall weed management, including tillage and repeated sowing of winter annual crops will encourage facultative winter annual behaviour. In addition, farmers should be wary of invasion by populations of persistent winter annuals including stinkweed, chickweed and American dragonhead.Key words: Facultative winter annual, dormancy, microsites, emergence pattern, seed rain, seed longevity, weed management
Immature barley seeds as a degrading factor for Canadian malting barley
Authors: Edney M. J. , Beswitherick D.
Published: March 2010

Canadian malt barley in the past was downgraded on visual detection of any immature barley kernels. The quality of malt made from immature barley has been investigated in the past, but conclusions were inconsistent. The factor, though, was removed from Canadian malting barley grades in August 2008. The present study used a different approach to investigate the effects of immature kernels on malt quality. A series of commercial malt barley samples were adulterated with varying levels of immature kernels. Samples were visually graded, malted and analysed for malt quality. Immature kernels were found to affect malt quality, but only significantly when samples contained 2% or more immature kernels. Soluble protein, which increased in samples with more immature kernels, was the quality factor of greatest concern. Canadian malt is often criticized for high soluble protein, which can lead to an unacceptably high wort colour. The research supported downgrading of samples on account of immature kernels, but only when the level was 2% or higher. However, grain inspectors consistently downgraded the experimental samples with as low as 0.2% immature kernels, as per the previous grade determinants. The new grade schedule has no tolerances for immature kernels, but this study supported reinstatement of a tolerance level of 2% immature kernels. Key words: Green seed, quality, malt, soluble protein, extract, wort colour
Root mass for oilseed and pulse crops: Growth and distribution in the soil profile
Authors: Gan Y T , Campbell C A , Janzen H H , Lemke R , Liu L P , Basnyat P , McDonald C L
Published: March 2010

Crop roots transport water and nutrients to the plants, produce nutrients when they decompose in soil, and provide organic C to facilitate the process of C sequestration in the soil. Many studies on these subjects have been published for cereal crops, but little is known for oilseed and pulse crops. This study was conducted at Swift Current, Saskatchewan, in 2006 and 2007 to characterize the root growth and distribution profile in soil for selected oilseed and pulse crops. Three oilseed [canola (Brassica napus L.), mustard (Brassica juncea L.), flax (Linum usitatissimum L.)], three pulse crops [chickpea (Cicer arietinum L), dry pea (Pisum sativum L.) lentil (Lens culinaris Medik.)], and spring wheat (Triticum aestivum L.) were grown in 100 cm deep × 15 cm diameter lysimeters pushed into a silt loam soil. Crops were studied under rainfed and irrigated conditions. Lysimeters were removed from the field and sampled for above-ground (AG) and root mass at different depths at five growth stages. Root mass was highest for canola (1470 kg ha-1) and wheat (1311 kg ha-1), followed by mustard (893 kg ha-1) and chickpea (848 kg ha-1), and was lowest for dry pea (524 kg ha-1) and flax (440 kg ha-1). The root mass of oilseeds and pulses reached a maximum between late-flowering and late-pod stages and then decreased to maturity, while wheat root mass decreased to maturity after reaching a maximum at boot stage. On average, about 77 to 85% of the root mass was located in the 0-40 cm depth. Canola, mustard, and wheat rooted to 100 cm, while the pulses and flax had only 4 to 7% of the root mass beyond the 60 cm depth. Irrigation only increased root mass in the 0-20 cm depth. Roots developed more rapidly than AG biomass initially, but the ratio of root biomass to AG biomass decreased with plant maturity. At maturity, the ratio of root biomass to AG biomass was 0.11 for dry pea, and between 0.20 and 0.22 for the other crops tested. Our findings on rooting depths and root mass distribution in the soil profile should be useful for modelling water and nutrient uptake by crops, estimating C inputs into soil from roots, and developing diverse cropping systems with cereals, oilseeds and pulses for semiarid environments.Key words: Root growth, root biomass, rooting depth, chickpea, lentil, pea, canola, mustard, flax, root:shoot ratio
Veldt cicer milkvetch
Authors: Acharya S. N.
Published: March 2010

Veldt cicer milkvetch (Astragalus cicer L.) was developed by the Agriculture and Agri-Food Canada Research Centre, Lethbridge, Alberta. This synthetic cultivar, tested as LRC 94-1 in Western Forage Trials, was developed for improved seedling vigor and high forage yield. Veldt cicer milkvetch produced 19% more dry matter yield in western Canada than Oxley (check cultivar). Under non-irrigated conditions the dry matter yield of this cultivar was 15% greater than Oxley, while under irrigation the dry matter yield was 21% greater. Veldt is well suited for pasture and hay production in western Canada in both pure and mixed stands with grasses and other legumes. The seed size and seed yield of the new cultivar are about 12% higher than Oxley.Key words: Cultivar description, cicer milkvetch, Astragalus cicer L., seedling vigor, forage yield
Growth, yield and shelf-life of isopentenyltransferase (ipt)-gene transformed broccoli
Authors: Chan L -F , Chen L. -F.O. , Lu H -Y , Lin C -H , Huang H -C , Ting M -Y , Chang Y -M , Lin C -Y , Wu M -T
Published: March 2010

Loss of chlorophyll leading to floret yellowing limits the post-harvest lifespan of broccoli (Brassica oleracea L. var. italica Plenck). Cytokinins are known to delay floral yellowing of plants. A transgene construct pSG766A, which results in the expression of isopentenyltransferase (ipt), the key enzyme for cytokinin synthesis, has been developed in broccoli. Expression of the ipt transgene is triggered by the senescence-associated gene promoter (SAG-13). Three selfed T5 lines of ipt transformed broccoli (lines 101, 102 and 103) have been obtained through selection for single copy insertion, acceptable horticultural traits and transgene ipt activity. These three transgenic inbred lines were evaluated in the field during 2004-2007 to determine their growth, yield and shelf-life after harvest, relative to a non-transgenic inbred line (104) and the parental variety Green King. For most of the vegetative growth parameters measured, year-to-year variability exceeded line-to-line variability. Inbreeding had little impact on the appearance or yield potential of the broccoli lines. Head yields of the transgenic inbred lines 102 and 103 were comparable to the parental variety Green King, but were significantly higher than the non-transgenic inbred line 104, as lines 102 and 103 produced more plants with heavier flower heads. Cytokinin content in the form of isopentenyladenosine was relatively higher in the transgenic lines than in the two non-transgenic controls. When flower heads were stored at 25 ± 2°C, the period required to cause 50% floret yellowing was 7.5 and 8.5 d for the transgenic lines 102 and 103, respectively, compared with 5.6 d for the non-transgenic line 104, and 5.1 d for the parental variety Green King. This study showed that the ipt-transformed inbred lines of broccoli combined acceptable appearance and yields with enhanced shelf-life.Key words: Brassica oleracea L. var. italica Plenck, transgenic broccoli, isopentenyltransferase gene, genetic characterization, shelf-life
Environmental impacts of organic agriculture: A Canadian perspective
Authors: Lynch D
Published: March 2010

Canada, in 2009, will enact a regulatory regime to oversee certified organic agricultural productions systems, based on a management standard. The overreaching goal of that standard is to develop farm enterprises that are “sustainable and harmonious with the environment”. However, empirical evidence to shed light on claims of environmental benefits from organic agriculture is particularly scarce in Canada and North America generally, and has not been comprehensively summarized. This review examines the literature of Canadian and US studies which relate to environmental impacts of organic agriculture within the selected indicators of: (i) soil organic matter storage and soil quality/soil health; (ii) plant and wildlife biodiversity; (iii) energy use; (iv) nutrient loading and off-farm nutrient losses; and (v) climate change and greenhouse gas emissions. The empirical evidence presented suggests organic farming system attributes regarding cropping, floral, and habitat diversity, nutrient intensity, soil management, energy and pesticide use, etc., are sufficiently distinct as to impart potentially important environmental benefits across the indicator categories examined. However, on average, crop yields under organic management regimes continue to lag behind those obtained by conventional management systems. More research is needed to validate these results, for the benefit of producers, consumers and policy makers as they decide the relative importance and contribution of organic farming systems to the Canadian food marketplace and agrifood sector. Key words: Organic agriculture, farming system, soil, biodiversity, energy, greenhouse gases
Brigade durum wheat
Authors: Clarke J. M. , Knox R. E. , DePauw R. M. , Clarke F. R. , Fernandez M. R. , McCaig T. N. , Singh A. K.
Published: March 2010

Brigade durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.] is adapted to the durum production area of the Canadian prairies. It combines yield similar to the checks, very strong gluten, and low grain cadmium concentration. Brigade has better straw strength than Strongfield, slightly later maturity, and Fusarium head blight resistance better than other currently registered Canadian durum cultivars.Key words: Triticum turgidum L. subsp. durum (Desf.) Husn., durum wheat, cultivar description, yield, protein, disease resistance