bluuebunny/crossref_metadata_2025 huggingface dataset:
A rapid method to detect Cryptolestes ferrugineus (Coleoptera: Cucujidae) larvae in stored grain
Authors: Minkevich J. M. , Demianyk C. J. , White N. D. G. , Jayas D. S. , Timlick B.
Published: April 2011

Modifications of three detection methods, based on the heat-gradient principle employed by the Berlese funnel method were investigated to extract larvae of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), developing under the seed coats of infested kernels in grain samples. One-kilogram samples of wheat, barley and corn were artificially infested with rusty grain beetle eggs, resulting in survival rates (to larval stage) of 71.1 ± 14.4, 58.9 ± 14.3, and 24.7 ± 11.8%, respectively. Sets of 10 infested kernels containing different-aged larvae (10 individuals × 4 instars) were added to 1-kg samples of hydrated grain, then heated on screens beneath heat sources (lights) at several heights in three different containers (Berlese funnel, with a 7-cm-deep grain layer, or square and rectangular screened boxes with a grain layer several kernels deep). There were no significantly different extraction rates between the rectangular and square containers for all heating trials. A larval extraction rate of 31% was produced by 1-h trials with wheat (15% moisture content wet basis) 5.5 cm below the lamp bank with a thermostat set at 50°C. This matched the efficiency of the Berlese funnel method (36% extraction in 6 h), but in much less time. Similar results were found for barley, bu t for corn the square and rectangle gave significantly better extraction than the Berlese funnel, although extraction efficiency was half that of wheat and barley. Considerably lower extraction rates were obtained from trials that did not use a thermostat. The results from this experiment show that there is a potential alternative detection method with the thermostatically controlled heating of a thin layer of grain that should be faster than the conventional 6-h Berlese funnel method. Key words: Cryptolestes ferrugineus, grain, larval extraction, Berlese funnel, grain monolayer
Physiological characteristics of recent Canada Western Red Spring wheat cultivars: Yield components and dry matter production
Authors: Wang H. , McCaig T. N. , DePauw R. M. , Clarke F. R. , Clarke J. M.
Published: April 2011

Genetic yield gains have been difficult to achieve within the Canada Western Red Spring (CWRS) wheat (Triticum aestivum L.) class because of stringent quality requirements and a short growing-season environment with low precipitation and high temperatures. Understanding the physiological basis of yield gains may provide breeders with better insight in selecting parents and screening tools to identify desirable genotypes. The objective of the present study was to compare four new CWRS wheat cultivars with two older cultivars, Neepawa and Marquis, for yield components and dry matter production. When grown at Swift Current, SK, for 3 yr, the average yield for the group of new cultivars was 34.3% higher than that of Marquis (P < 0.01), and 5.9% higher than that of Neepawa (P = 0.10). The new cultivars, as a group, had significantly increased kernel weight, kernels per spike, yield per spike, and spike-filling rate relative to either of the older cultivars. When cultivars were compared individually, all four of the new cultivars had significantly higher yield per spike and spike-filling rate than Neepawa or Marquis, suggesting that these factors may be closely related to the increased yields of the newer cultivars. The trend toward higher kernel weight and kernels per spike suggests that the new cultivars have increased the sink size of each tiller. The number of spikes per plant and the length of the grain-filling period do not appear to be associated with the increased yield. Harvest index of the group of new cultivars, while significantly higher than that of Marquis, has not increased significantly compared to Neepawa, probably because this group is similar in height to Neepawa. Key words: Triticum aestivum, wheat, Canada Western Red Spring, yield, quality
Morphological characteristics of crested wheatgrass populations of diverse origin
Authors: Mellish A. , Coulman B.
Published: April 2011

In crested wheatgrass, the species Agropyron cristatum includes populations that are diploid and tetraploid, either naturally or artificially induced. The species Agropyron desertorum is tetraploid and there are culitvars that are hybrids between A. cristatum and A. desertorum. The goal of this study was to compare the morphology (height, crown width, tiller density, tiller weight and tiller angle) of populations from the two species and hybrids, including S9240, a recently developed colchicine induced tetraploid A. cristatum. Data were collected in 1999 and 2000 from several different sward-seeded and spaced-planted trials. The four tetraploid crested wheatgrasses (A. cristatum “Kirk” and “S9240”, A. desertorum “Nordan”, and A. desertorum × A. cristatum “CD-II”) were significantly (P < 0.05) taller, narrower in row width, and produced fewer, heavier tillers than the diploid A. cristatum “Parkway”. Among the tetraploid populations, S9240 was significantly (P < 0.05) taller and produced fewer tillers. S9240 also produced significantly (P < 0.05) heavier tillers than CD-II and Nordan, and also than Kirk, one year of two. Row widths were variable among populations, but S9240 generally produced a narrower crown than other populations. Key words: Crested wheatgrass, polyploidy, plant height, crown diameter, tiller characteristics
Seedbed preparation, timing of seeding, fertility and root pathogens affect establishment and yield of alfalfa
Authors: Hwang S. F. , Gossen B. D. , Turnbull G. D. , Chang K. F. , Howard R. J.
Published: April 2011

Invasion by grasses and weedy species occurs when plant density in alfalfa fields falls below critical levels. Several soil-borne fungal pathogens can reduce stand density in alfalfa by impeding seedling establishment and by killing older plants weakened by other stresses. Surveys of alfalfa fields were conducted in 1997, and pathogenic fungi from rotted roots were isolated and identified. Isolates of selected pathogens were applied with the seed in field trials to assess the impact of fertilizer and seeding system (conventional vs. sod-seeding, spring vs. dormant-fall seeding) on seedling emergence and subsequent productivity when disease pressure was high. The impact of various fungicide seed treatments was also assessed. Seed treatment improved seedling emergence and initial forage productivity in one of three trials; however, it had little effect on long-term forage yield. Addition of sulphur fertilizer had little effect on seedling emergence or survival, but improved forage productivity at all three trial sites. Sod-seeded plots suffered more winterkill and were less vigorous than plots seeded into a tilled seedbed. Seedling emergence was lower when seedlings were planted in the fall than in the spring. However, fall-seeded treatments showed a less adverse response to inoculum treatments and, in some cases, these seedlings were able to take advantage of early-season moisture to produce higher yields than their spring-seeded counterparts. Key words: Medicago, Fusarium, Pythium, Phoma, fungicide, seed treatment, fertilizer, tillage
Selection for drought resistance in early generations of common bean populations
Authors: Terán Henry , Singh Shree P
Published: April 2011

Availability and use of high-yielding drought-resistant common bean (Phaseolus vulgaris L.) cultivars would reduce dependence on irrigation water and production costs, stabilize yield in drought-prone environments, and potentially increase profit margins for growers. Among various selection criteria, seed yield has been found to be the most effective to improve drought resistance in common bean. Our objective was to determine the effectiveness of selection for seed yield in drought-stressed (DS) and non-stressed (NS) environments in early generations of common bean populations under field conditions. One hundred thirty-four F2-derived F4 (F2:4) families from each of three double-cross populations (SX 12008, SX 12009, and SX 12010), four parents, and six checks were evaluated in replicated field trials in DS and NS environments at the Centro Internacional de Agricultura Tropical, Palmira, Colombia during the January to March growing season (1997A). The 30 highest yielding F2:5 families from each population and each environment, four parents, and two checks were again evaluated in replicated trials in their respective DS and NS environments during the June to August growing season (1997B). Three F5:7 lines from each of the four highest yielding F2:5 families from each population and each environment (a total of 72 lines), and nine parents involved in the three populations were evaluated in replicated trials in both DS and NS environments in 1998B and 1999B. Mean yieldof lines selected in the NS environment was significantly higher than the mean of parents in populations SX 12008 and SX 12010 when tested in the NS environment. In population SX 12009, lines selected in the DS environment had higher mean yield than their parents when tested in NS environment. The mean yields of lines selected in the DS and NS environments did not differ significantly when tested in the DS environment in any population. NS environment seed yields were positively correlated with DS yields, geometric mean yield (GM), percent reduction (PR) due to drought stress, and drought susceptibility index (DSI). In contrast, DS and GM yields were negatively correlated with PR and DSI, whereas the association between the latter two was positive. The 100 -seed weight was slightly reduced and mean maturity was accelerated by 2 to 4 d in DS versus NS environments. Considering the extra costs involved to test early generation selections for seed yield in DS environments, it does not appear to be advisable in common bean. Key words: Drought resistance in common bean, early generation yield test, F2-derived family selection, Phaseolus vulgaris, seed yield
Nitrogen management of spring milling wheat underseeded with red clover
Authors: Nass H. G. , Papadopolous Y. , MacLeod J. A. , Caldwell C. D. , Walker D. F.
Published: April 2011

The benefits of underseeding cereals with legumes and grasses have been established. However, research is required to determine the effects of underseeding spring wheat with red clover on yield and milling quality. The objectives of this study were: (1) to determine the rates of supplemental N required to obtain 13.5% or greater grain protein of three spring milling wheat (Triticum aestivum L. em Thell.) cultivars underseeded to red clover (Trifolium pratense L.); (2) to determine the effect of supplemental N on establishment of red clover , and (3) to relate the N status of the soil after harvest to grain protein. Field experiments were conducted from 1998 to 2000 on three sites: Hartland, New Brunswick; Truro, Nova Scotia; and Harrington, Prince Edward Island. Grain yield and protein content increased with increasing amounts of supplemental N. In most years, supplemental N above a base application of 55 kg N ha-1 applied at 52.5 kg N ha-1 at Zadoks GS 30 resulted in 13.5% protein in the grain of Grandin and AC Barrie, but 70 kg N ha-1 was r equired for AC Walton. Based on the N content of the straw, Grandin was less effective in partitioning N into the grain than AC Barrie and AC Walton. Increasing rates of supplemental N caused a reduction in red clover establishment. Soil pH decreased with increasing rates of supplemental N. Nitrate N in the soil at 0–5 and 0–20 cm depths increased with supplemental N, but there was no effect on ammonium N. Differences in pH or levels of soil N after harvest did not account for differences in grain protein. In the Maritime provinces, to reach a desirable milling protein level in spring wheat of 13.5%, producers will need to add supplemental N at a rate of at least 100 kg N ha-1 over and above background levels; however, this will be at the risk of reducing red clover establishment and increasing levels of soil N available for leaching. Key words: Spring wheat, Triticum aestivum, red clover, Trifolium pratense, underseeding, protein, nitrogen
Moisture in maize kernels at physiological maturity
Authors: Murray Brown D. , Bootsma Andrew
Published: April 2011

The “desirable” kernel moisture that was used for the original heat unit rating of the “check” corn hybrids in Ontario for 30 yr was replaced with a kernel moisture of 32% in 1993. This level of moisture at physiological maturity was confirmed in a study by Ma and Dwyer (2001) that related the progression if the kernel “milk” line with the decrease in moisture content during grain filling. This communication discusses an interpretation of these results. Key words: Crop heat units, milk line, kernel moisture
Opener, packer wheel and packing force effects on crop emergence and yield of direct seeded wheat, canola and field peas
Authors: Johnston A. M. , Lafond G. P. , May W. E. , Hnatowich G. L. , Hultgreen G. E.
Published: April 2011

An understanding of the effects of different opener designs and on-row packing force would help producers in their selection of appropriate direct seeding implement options for their soil conditions. A field trial was conducted at three locations (Indian Head, Sylvania and Watrous) in Saskatchewan from 1997 to 1999 to evaluate the effect of opener-packer design (spoon-steel V packer; spoon-flat rubber packer; paired row-steel V packer; paired row-flat rubber packer; sweep-pneumatic tire) in combination with a range of on-row packing forces [0, 333, 549, 746, and 1000 Newton (N) per press wheel] on crop emergence and grain yield with direct seeding. The differences observed between opener-packer combinations in this study varied by less than 10% for grain yield, and were almost always associated with the opener design and not the packer type. Despite the variable results, there was a tendency for higher pea and wheat emergence with the sweep + tire compared with other opener types at those locations that tended to be drier in the spring. Also, grain yield tended to be greater for the sweep + tire in 1999 at Indian Head, when the heavy-textured soil at this site had high soil moisture conditions at seeding. The responses to packing force varied with different years and among the crops. Generally, 333 N per press wheel provided adequate emergence and grain yield across the environmental conditions encountered in this study, regardless of the opener-packer combination. In 1997, 5% more pea seedlings emerged with some amount of packing compared with no packing. Relative to the check, some packing resulted in wheat grain yield that was 13% greater at three of the location-by-year combinations, and wheat emergence that was 9% greater in 1998. However, with canola excessive packing force (i.e., the two highest vs. lower packing forces) resulted in 11 fewer seedlings m-2 in 1999. A packing pressure of 333 N per press wheel provided adequate emergence and grain yield across varied environmental conditions, with higher packing force only negatively influencing emergence in canola, and not yield. Key words: Furrow opener, packing force, emergence, direct seeding, zero till
The biology of Canadian weeds. 125. Symphyotrichum ericoides (L.) Nesom (Aster ericoides L.) and S. novae-angliae (L.) Nesom (A. novae-angliae L.)
Authors: Chmielewski J. G. , Semple J. C.
Published: April 2011

Symphyotrichum ericoides, the heath aster, is a herbaceous perennial, arising from woody, corm-like rootstocks or herbaceous rhizomes. This facultative upland species occurs in open, dry ground in plains, railway sidings, prairies, ranges, glades, grassy hillsides, dunes, sand bars, river banks, shore salt flats, and thickets. A weed in Canada, and sometimes declared so in the United States and other times not, S. ericoides has an extensive North American distribution, occurring from Nova Scotia and Maine in the east, westward to southern British Columbia, and southward to northern Mexico. No infraspecific taxa are recognized in this treatment of the species. Symphyotrichum novae-angliae, the New England aster, is a herbaceous perennial, arising from thick, short-branched, woody rootstocks. This facultative wetland species occurs in open places such as along roadside ditches and fence rows, on dry ground in plains, prairies and glades, in clearings, meadows and abandoned fields, and along stream banks and swamps, or in moist open or sometimes wooded places. A weed in both Canada and the United States, S. novae-angliae occurs commonly throughout the northern two-thirds of the eastern deciduous forest region of North America and onto the Great Plains. In the east, Nova Scotia populations are likely escaped cultivars, but in the west, isolated natural populations occur from the Black Hills region of South Dakota south to New Mexico. No infraspecific taxa are reco gnized in this treatment of the species. In those habitats where the two species co-occur, the morphologically intermediate F1hybrid S. amethystinum is often found. Key words: Symphyotrichum ericoides, Aster ericoides, Aster multiflorus, heath aster, Symphyotrichum novae-angliae, Aster novae-angliae, New England aster
Effect of water on common lambsquarters (Chenopodium album L.) and barnyardgrass [Echinochloa crus-galli (L.) Beauv.] seedling emergence in corn
Authors: Leblanc M. L. , Cloutier D. C. , Hamel C.
Published: April 2011

A 2-year field study was conducted in corn to determine the influence of rainfall, irrigation and soil water content on common lambsquarters and barnyardgrass emergence. Rainfall or irrigation had no influence on the final weed density and little on the pattern of weed emergence because the soil water content was at or greater than field capacity during the main weed emergence period. Irrigation may hasten the first weed emergence by warming the soil when temperature is limiting for germination. In southwestern Quebec, temperature appears to be the most important factor regulating germination in the spring since soil moisture is normally at field capacity for a long period, in part because of the melting of snow. Key words: Irrigation, weed emergence, soil moisture
Preharvest glyphosate in alfalfa for seed production: Control of Canada thistle
Authors: May W. E. , Myhre C. D. , Loeppky H. A. , Murrell D. C. , Soroka J. J.
Published: April 2011

Canada thistle [Cirsium arvense (L.) Scop.] is increasing in both frequency and density in Saskatchewan alfalfa (Medicago sativa L.) seed fields. Application of preharvest glyphosate is an effective means of controlling Canada thistle in annual crops. This study was conducted to determine the effects of preharvest glyphosate on Canada thistle control and crop tolerance in alfalfa seed fields. Five field experiments were conducted in northeast Saskatchewan between 1995 and 1997 in which preharvest glyphosate was applied at 0, 220, 440, 660, 880, and 1760 g a.i. ha-1 when 60–70% of alfalfa seed pods were brown. Glyphosate did not affect seed yield in the year of application at any application rate, nor germination and subsequent emergence of the harvested seed. Alfalfa regrowth in the year following application declined linearly as the rate of preharvest glyphosate increased. Seed yield was also reduced in the year following glyphosate application. Glyphosate application at 220 g a.i. ha-1 significantly reduced Canada thistle regrowth in the year following application. Canada thistle density decreased in 2 of 4 site years with increasing rates of preharvest glyphosate. Using preharvest glyphosate at rates higher than 220 g a.i. ha-1 in seed alfalfa is not recommended when future seed harvest is planned. However, higher rates of preharvest glyphosate could be used in the final year of seed production to facilitate alfalfa removal. Key words: Preharvest glyphosate, abnormal seeds, seed quality, germination, hard seed and emergence
Effect of drought on ericoid mycorrhizae in wild blueberry (Vaccinium angustifolium Ait.)
Authors: Jeliazkova and D. Percival E.
Published: April 2011

To evaluate the influence of water exclusion on the mycorrhizal coloni zations in wild blueberry, and to examine the spatial distribution of mycorrhizae among roots of wild blueberry plants that were in both the vegetative and cropping stages of production, a randomized complete block design was used. The mycorrhizal coloniz a tions were equally distributed throughout upper and lower soil profiles in both stages of production. Nevertheless, soil moisture levels in water exclusion treatments were as much as 50% lower than the control, drought stress had no effect on mycorrhizal colonization levels or on any other of the measured responses. Root weight and volume decreased as soil depth increased from 0-7.5 to 7.5-15 cm. Key words:
Seed yield and yield components of creeping bentgrass cultivars
Authors: Cattani D. J. , Smith S. R. , Miller Jr., P. R. , Feindel D. E. , Gjuric R.
Published: April 2011

Creeping bentgrass (Agrostis stolonifera L.) is a high-value turfgrass species that offers opportunities for western Canadian seed companies and producers. The objective of this study was to evaluate creeping bentgrass seed yield and the relationship between seedhead density and seed yield across a diverse range of cultivars. A series of four trials was established in Manitoba between 1992 and 1994 and included 18th Green, Cobra, Emerald, National, Penneagle, Pennlinks, Putter, Southshore, UM86-01 and UM86-02. Seed production and seedhead density were measured for 2–3 yr at each location. Additional yield component measurements included harvest index and thousand seed weight. The three cultivars developed within the region consistently showed high seed yield, seedhead density and harvest index and were numerically ranked in the top four for seed yield across all 11 location years. UM86-01 was in the highest grouping for seed yield across all harvests with yields ranging from 312 to 582 kg ha-1. Seedhead density was strongly related to seed yield (highly significant in five of six comparisons) and therefore has the potential to be a valuable indicator of relative seed yield in creeping bentgrass. These results indicate that creeping bentgrass seed yield is variable across cultivars and that seedhead density can serve as a good predictor of seed production potential across cultivars. Key words: creeping bentgrass, harvest index, seedhead density, seed yield, yield components.
DS Admiral field pea
Authors: Andersen L. , Warkentin T. , Philipp O. , Xue A. , Sloan A.
Published: April 2011

DS Admiral, a yellow cotyledon field pea (Pisum sativum L.) cultivar, was released in 2000 by Agriprogress Inc., Morden, Manitoba. DS Admiral has a semileafless leaf type, powdery mildew resistance, medium sized, round seeds, and good yielding ability. DS Admiral is adapted to the field-pea-growing region of western Canada. Key words: Field pea, Pisum sativum L., cultivar description, powdery mildew resistance
Weed management in irrigated fenugreek grown for forage in rotation with other annual crops
Authors: Moyer J. R. , Acharya S. N. , Mir Z. , Doram R. C.
Published: April 2011

Fenugreek (Trigonella foenum-graecom L.) is an annual legume that has potential as a forage crop on the Canadian Prairies. Experiments were established to determine the tolerance of fenugreek to several herbicides and their efficacy on various weeds. Potentially, fenugreek could be grown in conservation tillage systems in rotation with other annual crops. Therefore, additional multi-factor experiments were conducted to determine the effect of herbicides, seeding method, and 11 previous crops on fenugreek yield. Without herbicide application, weeds contributed 37 to 86% to total dry matter production. When imazamox/imazethapyr, or combinations of imazamoz/imazethapyr or imazethapyr with ethalfluralin was applied, weed contents were about 5% of the total dry matter and the herbicides did not reduce fenugreek yield compared to the hand-weeded check. Total forage samples with a low weed content had lower fibre content and higher protein and digestible dry matter content than forages with a high weed content. When imazamox/imazethapyr was used for weed control, fenugreek yields and weed biomass were similar after direct seeding and after cultivation plus seeding. In addition, the effect of previous crop and the previous crop by seeding method interaction was not significant for fenugreek yield and weed biomass. Therefore, irrigated fenugreek can be successfully grown in conservation tillage systems in rotation with several crops provided an effective herbicide is used for weed control. Key words: Conventional tillage, crop rotation, redroot pigweed, wild oat, zero tillage
Response of field pea cultivars to chlorothalonil in the control of mycosphaerella blight
Authors: Xue A. G. , Charest J. , Davidson C. G. , McAndrew D. W. , Bing D. J. , Warkentin T. D.
Published: April 2011

The efficacy of chlorothalonil in controlling mycosphaerella blight in field pea was evaluated from 1998 to 2000 using 10 cultivars representing different leaf types, market classes, seed sizes, plant heights, and maturities. Significant differences ( P < 0.05) were observed among cultivars in disease severity, yield, 1000-seed weight (TSW), and seed infection each year. Cultivar × fungicide treatment interactions for these parameters were not significant in any of the 3 yr. Under both chlorothalonil treated and untreated conditions, Radley was the most resistant, while Carrera and Keoma were equally the most susceptible cultivars. A higher efficacy of chlorothalonil treatments was observed in 1999 when disease severity was greater than in 1998 or 2000. On average, chlorothalonil treatments reduced disease severity significantly in 1999 and 2000, but not in 1998. Overall, the fungicide increased yield by 6.4%, and TSW by 0.9–5.1%, which were significant in 1998 and 1999, but not in 2000. Based on 2-yr assessments of seed infection by Mycosphaerella pinodes, chlorothalonil reduced seed infection by 19.2%, which was significant in 1999, but not in 2000. Chlorothalonil treatments provide a greater benefit in years when disease pressure and yield potential are high. Key words: Field pea, Pisum sativum, mycosphaerella blight, Mycosphaerella pinodes, chlorothalonil
Lightning flax
Authors: Duguid S. D. , Kenaschuk E. O. , Rashid K. Y.
Published: April 2011

Lightning, a medium-late maturing oilseed flax (Linum usitatissimum L.) was released in 2001 by Agriculture and Agri-Food Canada, Morden Research Station, Morden, Manitoba. This cultivar has high oil content, high oil quality, large seed size, good lodging resistance and high yield when seeded in the Black, Brown and Dark Brown soil zones of the prairies. It is immune to North American races of rust caused by Melampsora lini (Ehrenb.) Desmaz, and resistant to wilt caused by Fusarium oxysporum Schlecht. f. sp. lini (Bolley) Snyder & Hansen. Key words: Flax, oilseed, Linum usitatissimum L., cultivar description
Row spacing and fertilizer nitrogen effects on plant growth and grain yield of maize
Authors: Ma B. L. , Dwyer L. M. , Costa C.
Published: April 2011

Conflicting reports have led to a renewed interest in the effects of narrow row spacing and high plant population densities on maize (Zea mays L.) grain yield. Field experiments were conducted to evaluate maize response to row spacing and N fertility over a 4-yr period (1997–2000). A randomized complete block design, arranged in a split plot was used with four replications each year with modifications of treatments over years. Row spacings of 0.51 m, 0.76 m and 0.76 m paired row alone or in combination with hybrid were tested in the subplot whereas combination of fertilizer N by population density (1997 and 1998) or N alone was assigned to the main plot. In 1997 and 1998, combinations of N by density consisted of 0 , 60, 120, 180 and 240 kg N ha-1 at 89 000 plants ha-1, and 60 and 180 kg N ha-1 at 69 000 plants ha-1 using a single hybrid, Pioneer 3893. In 1999 and 2000, N fertility levels of 0, 80 and 180 kg N ha-1 >were the main plots and six combinations of hybrids (Pioneer 3893 and Pioneer 38P06 Bt) by row spacing were grown in the subplots at 69 000 plants ha-1. Row spacing and fertility levels showed no significant interaction for any parameter at any developmental stage. In both 1997 and 1998, row spacing had no significant effect on yield (yield differed by 5% among row spacing treatments) or harvest index (varied from 0.45 to 0.53). For Pioneer 38P06 Bt in 1999, grain yield of the 0.51 m row spacing with the 80 kg N ha-1 fertilizer rate was 14.6% higher than the conventional 0.76 m row spacing. In 2000, the substantially lower (11%) yield of the 0.76 m paired row spacing than the other row spacing treatments was more likely the result of an exceptionally cool and wet season. In 1997 and 1998, plant density showed no effect on shoot or root DM. The lower density (69 000 plants ha-1) did, however, show a higher root to shoot ratio than the higher density. Shoot DM, root DM and root to shoot ratio did not differ between the 60 and 180 kg N ha-1 fertility treatments. While higher N levels increased above- and below-ground crop N contents, row spacing showed no consistent effects on maize plants at the early stages. Under the conditions of this study, narrow rows did not result in higher yield or N use efficiency even plant density and N fertility varied. Key words: Maize (Zea mays L.), nitrogen use, population density, root/shoot ratio, row spacing
Response of kabuli chickpea to seed size and planting depth
Authors: Gan Y. T. , Miller P. R. , McDonald C. L.
Published: April 2011

The use of small seed can reduce the production costs of kabuli chickpea (Cicer arietinum L.) 15 to 25% by reducing the amount of seed needed per unit area, but little is known about the effects of seed size on stand establishment, plant growth, and seed yield in semiarid environments. We conducted a field study in southwest Saskatchewan from 1998 to 2000 and determined the chickpea responses to seed size under different planting depths. Crops grown from small (7.1–9.0 mm) diameter seed required the same number of days to emerge (16.7 d) and mature (106 d) as those from large (9.1–11.0 mm) diameter seed. There were no differences in plant establishment, shoot dry weight, pod production, or seed yield between the two seed sizes when planted at a 50-mm depth. However, the small-seeded crop produced 7% lower plant stand, 4% lower seed yield, and 3% less seed 1799-mm diameter compared to the large-seeded crop when planted at a 100-mm depth (P < 0.05). Large-seed ed chickpea plants were 20 mm (4%) taller, and the height of the lowest pods from the soil surface was 11 to 13 mm (5%) higher than those from the small seed, suggesting an improvement of harvestability. In general, planting depth did not affect seedling emergence, shoot dry weight, or seed yield, but when small seed was used, chickpea sown at the 50-mm depth increased seed yield by 6% compared to that at the 100-mm depth. Kabuli chickpea produced an average of >20 pods plant-1, with 77% of them containing one seed per pod, 10% with two seeds per pod, and the remainder containing no seed; this ratio of pod fertility was independent of seed size or planting depth. Our results indicate that the use of small seed and shallow planting can reduce the production costs of chickpea by $31 to $52 ha-1 without a seed yield penalty. This level of saving in production far exceeds the otherwise increased value of $4 to $6 ha-1 with the use of large seed which produces a higher (3%) proportion of ≥ 9-mm diameter seed. Key words: Seedling emergence, seed mass, pod production, Cicer arietinum L.
Harvest time and N fertilization effects on forage yield and quality of quackgrass (Elytrigia repens L.) in northeastern Saskatchewan
Authors: Malhi S. S. , Foster A. , Gill K. S.
Published: April 2011

Quackgrass [Elytrigia repens (L.) Beauv.] is a primary noxious weed, but some cattle producers are discovering its value as forage for early-season grazing and for winter feeding as hay. Little information is available on how its production and quality change with advancing maturity and on its response to improved management in the Parkland zone of the Canadian prairies. The objective of this study was to determine the effects of harvest date and N fertilizer (surface-broadcast ammonium nitrate at 0, 56, 112 and 168 kg N ha-1) on the forage yield and quality of quackgrass. The study was done on a 10-yr-old quackgrass (˜ 90%) dominated stand on a silty clay loam (Dark Gray Luvisol) soil near Tisdale in northeastern Saskatchewan. For the harvest dates between early June and early September, maximum dry matter yield (DMY) was in August and maximum protein yield (PY) occurred in July. A delay in harvest reduced protein concentration (PC) and total digestible nutrients concentration (TDN), while it increased acid detergent fiber concentration (ADF). The DMY, PC and PY increased with increasing N rate for both Cut 1 (in early July) and Cut 2 (in late September). Strong quadratic relationships were observed between DMY and N rate. The effect of N application was relatively greater on PY than DMY due to the cumulative effect of increases in DMY and PC, and was greater in Cut 1 than in Cut 2. With the increase in N rate, TDN showed a trend of small increase, while ADF tended to decrease. In summary, the results show that N fertilization increases both forage yield and quality of quackgrass. Harvesting in late July or August is likely to provide maximum DMY when one harvest per season is taken. Key words: Acid detergent fiber, dry matter, forage, harvest date, hay, N fertilization, protein, quackgrass, total digestible nutrients
Sulphur fertilizer and tillage management of canola and wheat in western Canada
Authors: Grant C. A. , Johnston A. M. , Clayton G. W.
Published: April 2011

A 3-yr field study in Manitoba, Saskatchewan and Alberta evaluated immediate and residual effects of source, timing and placement of sulphur fertilizers on canola (Brassica napus L.) and wheat (Triticum aestivumL.) under conventional (CT) and reduced tillage (RT). Sulphur fertilization did not increase wheat yield, even when soil sulphate was low. Ammonium sulphate (AS) and ammonium thiosulphate (ATS) increased canola yield in 2 of 3 yr at the Saskatchewan site while elemental S and Tiger 90™ did not. Residual S from AS and ATS increased canola yield on S-deficient soils in the second and third crops after application. Canola yield on the S-deficient soil was lower where broadcast Tiger 90 rather than AS or ATS was applied the previous year, indicating that broadcast Tiger 90 oxidation was insufficient to support canola yield in the second crop year after application. Banding or seed-placing Tiger 90 delayed oxidation further. In the third crop after application, canola yield was similar with broadcast Tiger 90, AS or ATS but was lower with seed-placed or banded Tiger 90 than AS or broadcast Tiger 90. Small particle size and broadcast application of elemental S are needed to hasten oxidation of S to sulphate-S. Key words: Elemental S, Bentonite S, zero tillage, reduced tillage
Effect of harvest period on the protein content in sea buckthorn leaves
Authors: Li T. S. C. , Wardle D.
Published: April 2011

A study was conducted at Summerland, BC, in 2000 and 2001 to investigate the effect of harvest period on the protein content of sea buckthorn leaves. Leaves of both male and female plants were collected bi-weekly during the growing season and analyzed with a LECO FP-528 nitrogen analyzer after air- and freeze-drying. A conversion factor of kA = 5.7 was applied to obtain the protein content. Total protein content in sea buckthorn leaves showed very small differences between male and female plants and from either freeze-dried or air-dried materials. There were significant fluctuations among harvest periods in both years. Based on the results of this experiment, sea buckthorn leaves should be harvested from late July to early August since leaf protein content peaked around this period of time and started to decline significantly by the middle of August. Key words: Sea buckthorn, Hippophae rhamnoides L., leaf protein
Characterization of the loss of seedling vigor in pea (Pisum sativum L.)
Authors: Ozga J. A. , Reinecke D. M. , Knowles N. R. , Blenis P.
Published: April 2011

The physiological age of pea (Pisum sativum L.) seeds was accelerated using high temperature and relative humidity (RH), resulting in a range of vigor classes within one seed lot. This differentially aged seed was then used to determine the impact of seed vigor on plant growth and yield. For seeds incubated at 38°C for 2, 4, or 6 d at 100% RH prior to germination (accelerated aging), the percentage germination and rate of seedling emergence decreased with increasing time of aging. Aging at 38°C decreased seed vigor as indicated by reduced seedling root and shoot growth relative to higher-vigor seeds aged at 20°C. The respiration rate of seeds aged at 38°C was significantly higher than that of seeds aged at 20°C throughout the 6-d aging interval. However, no differences in respiration were evident during subsequent germination among the seeds aged at 38°C for 0, 2, 4, or 6 d. The higher-vigor seeds aged at 20°C had a higher respiration rate than those aged at 38°C during subsequent germination. Seeds that expressed high and low vigor in controlled-environment conditions showed similar trends in the field; however, seed vigor had no significant effect on total seed yield over two growing seasons. These data indicate that under certain conditions, the loss in seed vigor can be substantial without affecting overall yield, due to the plasticity of vegetative and reproductive growth in pea. Key words: Germination, pea, Pisum sativum, seeds, seedling vigor, respiration
Irrigation effects on quality characteristics of durum wheat
Authors: Güler M.
Published: April 2011

Water stress can affect the quality characteristics of durum wheat (Triticum durum Desf.). The responses of three cultivars of durum wheat to four irrigation regimes [no irrigation or irrigation applied at three growth stages (sowing, jointing, and anthesis)] were evaluated at Ankara, Turkey, from 1993 to 1995. Thousand-kernel weight and test weight increased with irrigation at all three stages, whereas irrigation at sowing and jointing resulted in high pigmentation and protein values. When irrigation was applied at sowing and jointing, but not at anthesis, with water stress occurring only at grain filling, the quality of the grain was positively affected. Key words: Wheat, durum, stress, water quality, grain, irrigation
Leaf absorption, withdrawal and remobilization of autumn-applied urea-N in apple
Authors: Guak S. , Neilsen D. , Millard P. , Looney N. E.
Published: April 2011

Six-year-old well-nourished Jonagold/M9 apple (Malus domestica) trees were sprayed 7 d after harvest with a 2% urea solution enriched with 9.9% atom 15N. Through 3 d of the absorption period, leaves absorbed 19.2% of the intercepted urea 15N. This low absorption could be in part due to unfavourable conditions, i.e., low temperatures (daily mean ≈5°C) and windy conditions following treatment. During leaf senescence, 48% of the urea 15N absorbed was withdrawn from leaves and most of that (95%) remained in the treated branch section. Of this portion, 65% of the urea 15N was found in dormant bark, 29% in wood, and 6% in flower buds. In the following spring, 46% of the stored urea 15N was remobilized for growth of the flower buds when sampled at the “pink” stage of bud development. This accounted for 3.8% of total N in these tissues. This contribution did not influence flower quality, estimated by the length of the period between flower opening and petal fall and the level of fruit set. Key words: Malus × domestica, urea-15N, flower bud growth, fruit set
The influence of harvest management and fertilizer application on seasonal yield, crude protein concentration and N offtake of grasses in northeast Saskatchewan
Authors: McCartney D. H. , Bittman S. , Nuttall W. F.
Published: April 2011

The goal of pasture management is to match quantity and quality of herbage to the requirement of the grazing animal. The objective of this study was to examine the effects of harvest management and fertilizer application on annual and seasonal production, protein concentration and N-offtake by eight grass species adapted to the central Aspen Parkland. In this 3-yr splitsplit- plot experiment, grasses were either fertilized annually (50 and 13 kg ha-1 of N and P, respectively) or left unfertilized, and cut either twice annually (two-cut) in early July and late September, or three to four times annually (multi-cut), in early June, early July, early August and late September if there was sufficient herbage. The grasses used in this study were Altai wildrye [Leymus angustus (Trin.) Pilger], creeping red fescue (Festuca rubra L. var. rubra), meadow bromegrass [Bromus riparius (Rehmann)], Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski], smooth bromegrass (Bromus inermis Leyss.), crested wheatgrass (Agropyron cristatum L. Gaertn.), intermediate wheatgrass [Elytrigia intermedia (Host) Nevski] and green needlegrass [Nassella viridula (Trin.) Barkworth]. Fertilizer increased yield of the two-cut treatment 15% (P < 0.05) more than the multi-cut treatment. On average, the multi-cut treatment had 32% higher protein concentration than the two-cut treatment throughout the season. Fertilizer significantly increased protein concentration only in the first harvest of the multi-cut clipped plots, probably because the application rate was low. Nitrogen offtake of the multi-cut treatment averaged 24% higher than the two-cut treatment, even though the latter yielded more. Meadow bromegrass showed the most uniform seasonal distribution of yield among the high-yielding grasses under all management systems while smooth bromegrass and crested wheatgrass were generally the poorest. Crested wheatgrass had significantly more first cut production than all other grasses. Meadow bromegrass herbage also had the lowest protein concentrations throughout the growing season among the high producing grasses. Since the protein concentrations were generally higher than required by grazing beef cattle, the meadow bromegrass herbage was the most suitable for this class of cattle. Green needlegrass also showed potential for use in pastures. Key words: Pasture, hay, protein yield, Bromus, Elytrigia, Nassella, Agropyron, Festuca, Psathyrostachys, Leymus
Parent-offspring regression in meadow bromegrass (Bromus riparius Rehm.): Evaluation of two methodologies on heritability estimates
Authors: de Araujo Marcelo R. A. , Coulman B. E.
Published: April 2011

To determine the nature and extent of inflation of estimates of heritabilities by parent-offspring regression methods, 40 clones of meadow bromegrass (Bromus riparius Rehm.) and their half-sib progenies were studied in completely randomized block design trials, with six replications in Saskatoon and Melfort, Canada. Clones and progenies were evaluated for dry matter yield, seed yield, plant height, fertility index and harvest index. The results of the analysis showed a consistent inflation of heritability estimates derived from the simple parent-offspring regression, when compared to the regression estimate by variance-covariance analysis. The two methods successfully removed the environmental covariances from the estimates. However, in the simple regression analysis, error covariance was not removed from the numerat or; therefore, heritabilities estimated by this methodology were higher than those estimated by the variance-covariance method. It was concluded that estimates derived from variance-covariance analysis provide less biased estimates of heritability. Key words: Regression analysis, heritability, meadow bromegrass
Vegetative propagation of sugar maple: Relating stem water content and terminal bud developmental stage to adventitious rooting of stem cuttings
Authors: Tousignant D. , Richer C. , Rioux J. -A. , Brassard N. , Mottard J. -P.
Published: April 2011

The objective of this study was to define the optimum period for collecting sugar maple (Acer saccharum Marsh.) stem cuttings. In 1999 and 2000, shoot development was monitored on young trees from a plantation established in 1993. Stem base water content and the number of pairs of terminal bud scales changed over time, reflecting meteorological characteristics of both years. In 1999, rooting percentage was high regardless of collection date, within a 7-wk period. The 2000 rooting trial covered a longer time frame and identified an optimal window during which rooting percentages reached 60 to 83%. Rooting success dropped below 30% for cuttings har vested too early or too late. Thus the optimal time for collecting sugar maple cuttings spans several weeks, but with significant year-to-year variations. For both years, optimal rooting was associated with a stem base water content lower than 75% but higher than 55%, and with the presence of one to three pairs of apical bud scales. This stage is reached when at least 270 degree-days above 5°C are accumulated. Using these indicators, practitioners can consider local conditions and year-to-year climatic variations to harvest sugar maple cuttings at an optimum stage of development. Key words: Acer saccharum, bud scales, collection date, cutting propagation, stem water content, vegetative propagation
Plant-species identity of pollen collected by bumblebees placed in greenhouses for tomato pollination
Authors: Whittington R. , Winston M. L. , Tucker C. , Parachnowitsch A. L.
Published: April 2011

The seasonal variation of pollen collected from different plant species by greenhouse bumblebees was investigated to determine how frequently bumblebees forage outside of commercial tomato greenhouses. Pollen was collected from bumblebees at three greenhouses between February and September 2001 and the plant species identity of pollen collected was determined with light microscopy. A significant amount of non-tomato pollen was collected by bumblebees during one or more months from outside each of the three greenhouses studied. The bees brought back as little as an average of 5% non-tomato pollen between February and September at one greenhouse and as much as 73% during July at another. Therefore, greenhouse tomato growers are probably not obtaining maximum pollination benefit from bumblebee colonies and should address methods to reduce their foraging outside the greenhouse. Key words: Bumblebee, Bombus occidentalis, Bombus impatiens, pollen, greenhouse, tomato