bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth, competitiveness, and seed germination of triallate/difenzoquat-susceptible and -resistant wild oat populations
Authors: O'Donovan J. T. , Newman J. C. , Blackshaw R. E. , Harker K. N. , Derksen D. A. , Thomas A. G.
Published: April 2011

Understanding the relative competitiveness and seed germination patterns of herbicide-resistant weeds has implications for integrated weed management. Replacement series experiments were conducted in the greenhouse to compare interspecific competition among two triallate/difenzoquat susceptible (S) and 10 resistant (R) wild oat (Avena fatua L.) populations. Each series included monocultures of each of the populations and three mixtures at relative S:R proportions of 3:1, 1:1 and 1:3. Shoot dry weight tended to be greater in the R than S populations, but results were not always statistically significant at the 5% level. Leaf area was more variable, but in most cases did not differ between R and S populations. With a few exceptions, relative crowding coefficients for shoot dry weight and leaf area were similar for S and R populations indicating little or no differences in competitiveness. In field experiments where two S and five R populations were grown in competition with wheat (Triticum aestivum L.), two of the R populations produced significantly (P < 0.05) greater shoot dry weight and seed yield than the S populations. Otherwise populations did not differ significantly. In seed germination studies, the S populations consistently displayed lower cumulative germination than the R populations. The higher seed germination associated with the R populations suggests that producers should be able to manage these populations effectively with a combination of alternative herbicides and cultural practices. Key words: Avena fatua, herbicide resistance, triallate, difenzoquat, relative competitiveness, seed germination
Quality changes occurring in stored solin, high linolenic acid and standard flaxseed (Linum usitatissimum L.)
Authors: White N. D. G. , Mills J. T. , Kenaschuk E. O. , Oomah B. D. , Dribnenki P.
Published: April 2011

Changes occurring in stored solin/flax cultivars over 6 mo at temperatures ranging from 10 to 35 °C and moisture contents of 8.0, 9.5, 11.0 and 12.5% were observed. The cultivars were NorLin, McGregor, FP1001 (high linolenic acid), LinolaTM 947 (solin) and LinolaTM 989 (solin). Oil composition in all cultivars changed only slightly over 6 mo with a significant increase in palmitic acid. Doubling of free fatty acid levels was considered an indicator of quality deterioration. The deterioration occurred in 6 mo at 8% MC and 20 °C in FP1001 and in NorLin, McGregor, and LinolaTM 947 at 25 °C; LinolaTM 989 could be stored at 30 °C. LinolaTM 989 could be safely stored at moderately higher temperatures at a given moisture level than LinolaTM 947. Visible mold with corresponding germination loss was usually associated with Aspergillus glaucus group infection. Stored-product insects that could survive and develop on the solin/flax were the red flour beetle, Tribolium castaneum (Herbst), the confused flour beetle, T. confusum J. du Val, the sawtoothed grain beetle, Oryzaephilus surinamensis (L.) and the merchant grain beetle, O. mercator (Fauvel).In general, LinolaTM 947 and FP1001 were slightly more difficult to store than the other cultivars but there was no consistent difference between solin and flaxseed. Key words: Flaxseed, solin, storage, quality
Changes in the essential oil constituents of fennel (Foeniculum vulgare) as influenced by soil and foliar levels of N and P
Authors: Khan M. Masroor A. , Azam Zake M. , Samiullah Samiullah
Published: April 2011

In a split-plotfield trial, the effect of foliar (F) application of 0 or 20 kg N, 2 kg P or 20 kg N + 2 kg P ha−1.was studied on the composition (analysed by GLC) and yield of fennel essential oil constituents grown with two soil (S) levels (60 kg N + 27 kg P and 90 kg N + 0 kg P ha−1). Camphene and dfenchone, both being bicyclic monoterpenes, and d-α-pinene, another bicyclic monoterpene showed a similar trend (R = 0.87) and their contents were maximum with FN20P2 at both soil levels. Methylchavicol and anethole (Phenylpropanoids) exhibited parallel trends (R = 0.56), with the control giving higher values at both soil levels. Interestingly, there was a negative correlation between some of the constituents, e.g. anethole versus d-fenchone (R = −0.99), anethole versus camphene (R = −0.87), and methylchavicol and d-α-pinene (R = −0.71), suggesting that the synthesis of the one constituent was at the expense of the other. Soil application of N and P enhanced the contents (%) of the phenylpropanoids (anethole and methylchavicol) while their foliar application increased the monoterpenes (d-fenchone, camphene and d-α-pinene). It is concluded that appropriate combinations of basal and foliar nutrients could be exploited to obtain higher yields of the desired constituents of fennel oil. Key words: Anethole, d-fenchone, d-α-pinene, camphene, methylchavicol, correlation
Crop density and seed production of tall fescue (Festuca arundinacea Schreber). 1. Yield and plant development
Authors: Fairey N. A. , Lefkovitch L. P.
Published: April 2011

A field study was conducted with tall fescue (Festuca arundinacea Schreber) to determine the effect of the initial population density and spatial arrangement of plants on crop development and seed yield. Individual seedling plants were transplanted at seven densities (1.6, 3.1, 6.3, 12.5, 25, 50, and 100 plants m−2) and three row spacings (20, 40, and 80 cm), and characteristics of seed production were determined for 3 yr (1991–1993). Over the 3 yr, heading commenced at dates differing by 15 d and was delayed, as density increased, by 8, 6, and 2 d, respectively, in the first, second, and third production years. The time of seed maturity differed among years (21 July to 4 August) but was generally unaffected by density or row spacing. In the first production year, seed yield increased with density up to 25 plants m−2 for each row spacing, then remained constant to at least 50 plants m−2 with both 20- or 40-cm rows; it decreased slightly at 100 plants m−2 with 20 cm rows. In the second production year, seed yield was relatively independent of plant density except that it decreased when the initial density was less than 6 plants m−2 with a row spacing of 80 cm, and tended to be greatest with the 40-cm row spacing at 6–25 plants m−2. In the third production year, seed yield was much lower than in the previous 2 yr but the pattern of response to the density and row spacing treatments was similar to that in the second production year. The seed yield of tall fescue can be optimized for at least 3 consecutive years by establishing an initial density of 20–100 plants m−2 in rows spaced 20–60 cm apart. If the maximization of first-year seed yield is a priority, then the initial establishment should be at a density of 25–50 plants m−2 in rows spaced 20–40 cm apart. Key words: Tall fescue, Festuca arundinacea Schreber, population density, plant spacing, seed production
Effects of storage conditions on quality loss of hull-less and hulled oats and barley
Authors: White N. D. G. , Hulasare R. B. , Jayas D. S.
Published: April 2011

Oat and barley cultivars were stored at various temperatures (10–30 °C) and relative humidities (35–80%) for one year to determine rates of seed deterioration. Two hulled oat cultivars (Robert and AC Marie), one hull-less oat cultivar (AC Belmont), one hulled barley cultivar (Bedford) and one hull-less barley cultivar (Condor) were stored. Experimental data were obtained at specified intervals for fat acidity values (FAV), germination and moisture content to determine the deterioration during storage. FAV were initially 69 mg KOH 100 g−1 dry seed for AC Marie, 43 for Robert, and 46 for AC Belmont oats. Values for barley were 8 mg KOH 100 g−1 dry seed for Bedford and 9 for Condor. The incidence of microfloral infection by Aspergillus glaucus group, Penicillium spp., Cladosporium spp., Rhizopus spp., and Alternaria alternata during the storage period was determined. Storage guidelines for barley and oat, based on grain moisture and temperature, were related to FAV increases of 1.5-fold for oats and two-fold for barley. Generally, hull-less cultivars of both crops stored as well as hulled cultivars at cool, dry conditions, but they deteriorated faster at high temperatures and high moisture contents. Key words: Oat, barley, hulled, hull-less, temperature, moisture, storage
Evaluation of the "fall rosette" procedure for perennial sowthistle control in fallow
Authors: Darwent A. L. , Harker K. N. , Broatch J. M. , Mills P.
Published: April 2011

Field experiments conducted near Grande Prairie, Alberta, compared the effectiveness of the fall rosette procedure to other procedures used in a year of fallow for the control of perennial sowthistle (Sonchus arvensis L.). The fall rosette procedure, which consisted of discontinuing normal cultivation in late July, allowing the perennial sowthistle plants to grow for 6 wk and then applying glyphosate plus dicamba at 0.6 + 0.6 kg ha−1 plus Agral 90 at 0.5% vol/vol of spray volume, reduced shoot density by 84, 90 and 96% approximately 1 yr after imposition in 1992, 1993 and 1994, respectively. By comparison, the bud stage procedure, which consisted of allowing plants to grow to the bud stage in the spring/early summer, applying the same herbicide treatment and conducting tillage for the rest of the year, reduced shoot densities by 58, 86 and 85% when imposed in the same years, respectively. The fall rosette procedure was also more effective than frequent tillage throughout the growing season without herbicide, or than chemfallow (glyphosate plus dicamba applied in early July and again in early September, with or without late fall tillage) in reducing perennial sowthistle shoot density. Mowing, whenever the perennial sowthistle reached 8–10 cm in height, did not reduce shoot density. Key words: Fall rosette, bud stage, Sonchus arvensis L., tillage, mowing, chemfallow
The Biology of Canadian Weeds. 111. Anthriscus sylvestris (L.) Hoffm
Authors: Darbyshire S. J. , Hoeg R. , Haverkort J.
Published: April 2011

Wild chervil, Anthriscus sylvestris (L.) Hoffm. (Apiaceae), is a weed of perennial crops, old fields, disturbed areas and roadsides. Introduced from Eurasia, it is widely naturalized in eastern Canada from Newfoundland to Ontario and at two sites in British Columbia. It is a monocarpic short-lived perennial, reproducing by seed and budding from the root crown. Dense populations achieved through vegetative reproduction can exclude most other vegetation. The rust, Puccinia pimpinellae subsp. pimpinellae, was detected on a population of wild chervil from Quebec. Key words: Wild chervil, Anthriscus sylvestris, weed biology
Q2 summer rape
Authors: Stringam G. R. , Degenhardt D. F. , Thiagarajah M. R. , Bansal V. K.
Published: April 2011

Q2 is a canola quality summer rape cultivar adapted to areas where Brassica napus is grown in western Canada. Q2 combines high seed yield, good lodging resistance, and excellent resistance to blackleg disease. Key words: Rape (summer), cultivar description, yield, blackleg resistant, lodging resistant
Plant mineral accumulation, use and transport during the life cycle of plants: A review
Authors: Liptay A. , Arevalo A.E.
Published: April 2011

Minerals accumulated during each stage of plant development are important, especially for the initial portion of subsequent stages of growth. For example, minerals acquired during seed ontogeny are largely responsible for the earliest stage of seedling growth. Without these minerals, seedling development would be arrested or impossible. Thus, even though the amount of minerals may be relatively small in the seed, their presence is absolutely essential. Similarly, although the mineral nutrient content of a seedling used as a transplant in establishing a crop in the field may seem rather minuscule, the importance to the initiation of development of the successive stage of growth is critical. Moreover, seedling-mineral content, plant performance and seed production can be improved by the selection of optimal cultural practices. This review examines acquisition, content and use of minerals in the various stages of plant development and growth as well as agricultural approaches to enhance mineral accumulation. Key words: Nutrient uptake, field crop establishment, seed mineral content, seed yield, crop growth
Distribution of carbohydrate during grainfill in Leafy and normal maize hybrids
Authors: Andrews C. J. , Dwyer L. M. , Stewart D. W. , Dugas J.-A. , Bonn P.
Published: April 2011

The Leafy (Lfy) genotype in corn has extra leaves above the ear in comparison to normal non-leafy genotypes and has been shown to increase yields in some geographical areas. In this study, carbohydrate distribution in three Lfy hybrids (two of which were "staygreen") and a normal check (Pioneer 3790) were analyzed in a short-season area (2800 Crop Heat Units, suitable for 85 day Relative Maturity hybrids). Total sugar and starch were determined at all aboveground levels of leaf and stem on 1 August 1990 and this distribution was used to calculate total canopy carbohydrates in two subsequent years from samplings of leaf and stem at only three or four canopy levels bracketing the ear level. Husk, cob and kernel components were also analyzed at three sampling times during grainfill. Major differences in the 2 yr were observed, but in general there was approximately twice the carbohydrate in the canopy at and above the ear in the Lfy genotypes compared to the check. There was also more carbohydrate in the husk and cob in the Lfy lines, but substantially less carbohydrate below the ear in these lines. Rates of grainfill were generally higher in the Lfy hybrids, but the rate of Lfy hybrid A, the early senescent hybrid, was slower in the cooler growing season. Despite the greater amount of carbohydrate in the Lfy hybrids in comparison to the traditional check, their grain yields were not greatly increased, indicating that the kernel component provided a weak sink. This characteristic is probably associated with the long season and tropical origin of the Lfy germplasm. Key words: Maize, grainfill, leafy, carbohydrate distribution, phenology, sink size
Nitrogen pools and processes in agricultural systems of Coastal British Columbia — A review of published research
Authors: Kowalenko C. G.
Published: April 2011

A significant amount of research on nitrogen (N) dynamics has been conducted within the past 20 yr in south coastal British Columbia. This succinct set of data has practical and environmental information on N cycling particularly focusing on gains to and losses from agricultural fields, and transformations of soil N pools. Coastal British Columbia fields have received large annual additions by application of fertilizer and manure. Some of the manure N from animals using locally grown forages is recycled within the farm operation, but a large amount of N is imported as feed especially for intensive animal production. Budget calculations estimated that there may be substantial losses of N through volatilization from manure, particularly from housing and storage areas, and during application to fields. Some of the volatilized ammonia in holding areas may be recycled to fields via precipitation. Direct measurements of these losses and returns of N have not been made. Studies have shown that there is limited risk of leaching of nitrate beyond the root zone during the growing season because most of the annual rainfall occurs over the winter and because nitrate can be adsorbed to soil particles. However, any extractable inorganic N (nitrate directly and ammonium after nitrification) in the profile at the end of the growing season will be lost over the winter. Most of that loss is due to nitrate leaching, but conditions are also favorable for denitrification. There is considerable (> 200 mg N k−1 in some soils) ammonium-N fixed in Fraser Valley soils, but the impact of this phenomenon to crop growth is still poorly understood. Wetting and drying cycles have a great influence on the dynamics of this pool of soil N. The response of spring growth of grass to the time of N application was influenced by the relative competitiveness of microorganisms and plants for available soil N. A study comparing short-season (broccoli) and long-season (sweet corn) crop responses to N applications showed that the rate at which the plants require N influences their response to N amendments. Raspberries were found to require relatively small quantities of N on a land area basis because of the wide inter-row distances. An autumn soil nitrate test has been proposed for making fertilizer N recommendations for raspberries. Although knowledge gained from this research has provided a basis for interpreting studies for the development of N management practices and for making interim recommendations, a method to predict the amount of N mineralized from soil organic matter is key to the development of soil-analysis-based N rate recommendations. Key words: N cycling, nitrate, ammonium, fixed ammonium, soil organic N, mineralization
Influence of soil mulches and method of crop establishment on growth and yields of pumpkins
Authors: Waterer D.
Published: April 2011

Management methods that speed crop establishment, growth and maturity are essential to the efficient production of warm season vegetable crops in regions with short, cool growing seasons. This study examined the influence of method of crop establishment and the use of plastic soil mulches on yields and crop maturity of two cultivars of pumpkins over two cropping seasons in central Saskatchewan. Transplanting did not improve stand establishment over direct seeding but enhanced yields without influencing crop maturity. Plastic mulches improved stand establishment and fruit yields relative to a non-mulched control. Clear mulch was superior to black plastic in some cases. Both cropping seasons were unusually favorable for pumpkin production, which may have obscured the benefits expected for transplanting or mulching. Key words: Pumpkins, Cucumis pepo, seeding, transplanting, mulches, maturity, yields
Effect of preharvest applications of glyphosate on the drying, yield and quality of canola
Authors: Darwent A. L. , Kirkland K. J. , Townley-Smith L. , Harker K. N. , Cessna A. J.
Published: April 2011

Potential use of preharvest applications of glyphosate in canola (Brassica rapa L.) in western Canada both as a harvest aid and to control weeds prompted this study. Experiments were conducted from 1988 to 1990 at four locations in the region to document the effectiveness of preharvest applications of glyphosate to enhance canola seed and foliage drydown and to measure the effect of such applications on seed yield and quality. Glyphosate was applied in early August to early September at rates of 0.45, 0.90 and 1.70 kg acid equivalent ha−1 to canola with seed moisture contents ranging from 79 to 12%. Seed and foliage moisture drydown were not enhanced by glyphosate treatment. Glyphosate treatments generally had little or no effect on canola seed yields, seed weight, seed germination, green seed content or oil content except when applied when the pods were green and when seed moisture contents were high. Seed/pod moisture was not a reliable indicator of stage of canola development and thus, should not be used alone as an indicator of when preharvest applications of glyphosate can be applied to canola without decreasing seed yield and quality. Key words: Glyphosate, canola, Brassica rapa L., preharvest application, desiccation, seed quality
The influence of harvest management and fertilizers on herbage yields of cool-season grasses grown in the Aspen Parkland of northeastern Saskatchewan
Authors: Bittman S. , McCartney D. H. , Horton P. R. , Hiltz M. , Nuttall W. F.
Published: April 2011

This study was conducted to evaluate the impact of harvest and fertilizer management on the herbage yield of various grass cultivars grown in the Aspen Parkland region of northeastern Saskatchewan. A series of three experiments were set out: site 1 at Pathlow, Gray Luvisolic soil, 1980; site 2 at Melfort, Deep Black Chernozemic soil, 1979; and site 3 at Pathlow, 1986. At site 1, the design was a split-split plot with fertilizer treatments as mainplots (unfertilized and fertilized, initially with 11N-22P kg ha−1 incorporated 5 cm into soil and thereafter, 50N-13P kg ha−1 broadcast each year). Ten grass cultivars were seeded as subplots and harvest systems as subsubplots (two-cut and four-cut). At site 2 Melfort, the experimental design was similar to site 1, but without the fertilizer treatments. Fertilizer was applied to all plots at the same rates as site 1. At site 3, Pathlow, 14 grass cultivars were seeded with the same experimental design as site 2, but 10 kg S ha−1 was applied each year with the N and P fertilizer. At site 1 Pathlow, the only experiment with the unfertilized control, fertilizer increased the average herbage yield to 2.47 t ha−1 from 1.42 t ha−1 for unfertilized control plots. Frequent cutting (four-cut system) showed reduced annual yields of 1.70, 5.28 and 1.93 t ha−1 compared with 2.19, 7.08, and 2.87 t ha−1 (two-cut system), respectively, for sites 1, 2 (5-yr period) and 3 (7-yr period). A greater response to fertilizer was observed with the 2-cut system, 1.19 t ha−1, than with the four-cut system, 0.91 t ha−1, which resulted in a fertilizer × cutting management interaction at site 1. With some exceptions, most of the species were not significantly different in ranking based on herbage yield over the three test sites, but meadow bromegrass [Bromus biebersteinii (Roem & Schult.)] ranked higher in yield on the less fertile Pathlow Gray Wooded soil sites than on the more fertile Melfort Deep Black soil site. Crested wheatgrass (Agropyron cristatum L.) ranked high in herbage yield at all three sites. Crested wheatgrass, smooth bromegrass (Bromus inermis Leyss.) and meadow bromegrass, the most commonly grown species in Saskatchewan, yielded well under the simulated hay and pasture conditions. Other cultivars such as Clarke intermediate wheatgrass [(Elytrigia intermedia (Host) Nevski], Elbee northern wheatgrass [Elymus lanceolatur (Scribn. and Smith)] and Lodorm green needlegrass (Stripa viridula Trin.) should be considered for pasture and hay by farmers and ranchers in northern Saskatchewan. Key words: Grass, harvest management, pasture, hay, fertilizer
Single-cut red clover combined with late timothy may be valuable in short-term rotations
Authors: Kunelius H. T. , McRae K. B. , Fillmore S. A. E. , Dürr G.
Published: April 2011

Late-maturing cultivars of red clover (Trifolium pratense L.) and timothy (Phleum pratense L.) may be grown in short-term rotations with other crops and harvested for hay and silage. Harvesting forage in mid-summer is often advantageous for field curing, but the quality of mature forage may be low. We studied how harvests at different developmental stages affected yield, composition of herbage, and species persistence. The late-maturing single-cut red clover cultivar Altaswede and late timothy cultivar Farol were grown alone and in combination with and without applied N. Total forage, and red clover and timothy dry matter yields, increased between the first (27 June) and third (11 July) dates of harvest. Timothy grown alone or combined with red clover and fertilized with N produced greater forage yields than red clover alone or red clover + timothy without applied N. The in vitro digestibility of dry matter declined from 670 to 625 g kg−1 and crude protein from 134 to 109 g kg−1 between 27 June and 11 July. Water soluble carbohydrates in forage were low (36–66 g kg−1) in cuts 1 and 2. Macronutrient and micronutrient concentrations were generally highest at the first date of harvest on 27 June. Nutrient concentrations in cut 2 were similar for the three harvest schedules. We conclude that growing late-maturing single-cut red clover combined with late timothy produced high yields with good nutritional quality even at advanced stages of maturity. Single-cut red clover persisted for the first production year making this combination suited for short-term rotations that involve late harvesting of the primary growth. Key words: Red clover, Trifolium pratense, timothy, Phleum pratense, composition
Alfalfa resistance to post-harvest Aspergillus species: Response to selection
Authors: Kimbeng C. A. , Smith Jr. S. R. , Babij V. , Wittenberg K. M.
Published: April 2011

Alfalfa (Medicago sativa L.) cultivar development programs routinely incorporate resistance to fungal diseases that limit forage yield, quality and stand longevity. "Hay molding", caused by saprophytic fungi, reduces forage quality during the post-harvest period, but genetic resistance has not been reported. The objective was to determine the response to selection for post-harvest fungal resistance in alfalfa. Initially, 1144 genotypes from 22 alfalfa cultivars were screened for post-harvest fungal resistance with a combination of Aspergillus species. Forty resistant and 40 susceptible genotypes were selected by measuring percentage of leaf area with fungal coverage. The selected genotypes and their maternally derived half-sib families were screened for resistance to Aspergillus repens. Mean leaf area with fungal coverage was significantly (P < 0.05) lower for resistant than susceptible parental genotypes and maternal half-sib families. Percent leaf area with fungal coverage ranged from 13.2 to 70.5% (mean, 41.7 ± 1.7) among resistant and 28.2 – 83.4% (mean, 50.2 ± 1.7) among susceptible parental genotypes. Among the maternal half-sib families, resistant families ranged from 14.0 to 51.3% (mean, 32.1 ± 1.8) and susceptible families from 18.8 to 60.1% (mean, 40.3 ± 1.9). These results show a positive response to selection for post-harvest fungal resistance in alfalfa. Key words: Alfalfa, Medicago sativa, post-harvest fungi, Aspergillus species, breeding, divergent selection
Herbicidal weed control and crop-year NPK fertilization improves lowbush blueberry (Vaccinium angustifolium Ait.) production
Authors: Penney B. G. , Mcrae K. B.
Published: April 2011

Past research has shown that fertilizer applied in the vegetative year can increase yield, but not always. Fertilizer applied in the crop year without weed control also has been shown to increase yield. The present study, conducted on a natural lowbush blueberry stand for 8 yr, compared the effects of factorial combinations of two rates each of N (0, 60), P (0, 26), and K (0, 50 kg ha−1) applied either in the vegetative or crop year, with or without weed control. Greatest production was obtained with weed control, which increased ripe fruit yield by 247% over that from plots without weed control. Nitrogen alone or P and K with N also increased yield, but only when applied in the crop year to weed-controlled plots. Phosphorous or K alone was of little benefit. Nitrogen increased ripe fruit yield from 3910 (unfertilized plots with weed control) to 4440 kg ha−1 and in combination with P and K to 5520 kg ha−1. Yield increases from weed control and N were due to increased berry weight and hastened maturity, but weed control also increased total berry number. The increase by P and K was due to an increase in total and ripe berry numbers. Nitrogen applied in the vegetative year, although producing more flower buds m−2 than when applied in the crop year, gave lower yields. Fruit abortion, due to insufficient nutrients in the crop year, particularly N, is suspected to be the reason for the reduced yield. Key words: Lowbush blueberry, Vaccinium angustifolium, yield flower buds, weed control, fertilizer, herbicide
CT681 flue-cured tobacco
Authors: Haji H. M. , Mishra S , DeVos M.
Published: April 2011

CT681 is a flue-cured tobacco (Nicotiana tabacum L.) cultivar with high yield and grade index, and provides significantly higher economic returns togrowers. Company evaluations are higher than the checks, and percent lamina is high. CT681 is resistant to black root rot [Thielaviopsis basicola (Berk. & Broome) Ferraris] disease. Key words: Nicotiana tabacum L., tobacco, cultivar description
Comparison of nitrogen application via a trickle irrigation system with surface banding of granular fertilizer on red raspberry
Authors: Kowalenko C. G. , Keng J. C. W. , Freeman J. A.
Published: April 2011

A field trial compared applications of ammonium nitrate N as soil-surface bands of granular fertilizer with applications as a solution through a trickle irrigation system (i.e., fertigation) on yield, plant growth and end-of-season extractable soil inorganic nitrogen of red raspberries (Rubus idaeous L.). The granular application was made once in early spring, and the fertigation was scheduled as eight weekly applications from early to late spring in each of 4 successive years. Three rates of N (33, 67 and 134 kg N ha−1) were applied by both methods and a zero N control was also included. The N treatments had relatively small effects on berry yields, being significant in the last 2 years (1988 and 1989) only. Applications of granular N resulted in equal or greater yields than the control, whereas the fertigation method resulted in equal or lower yields than the control. Granular applications tended to enhance cane growth and N concentrations in the fruiting cluster, laterals and leaves of fruiting canes. Leaching of N during the growing season was greater with the fertigation than with the granular method of application. The poorer performance of fertigation relative to granular application of N was due to the timing of application in relation to crop requirement. Raspberries require a majority of their N early in the growing season. The utility of applying fertilizer N via irrigation systems on crops such as raspberry in climatic regions where water deficits do not usually occur early in the growing season, as in coastal British Columbia, is limited. Key words: Fertigation, soil N, yield, soil inorganic N, leaching, Rubus idaeous L.
Effect of spermine and cyclohexylamine on in vitro pollen germination and tube growth in Helianthus annuus
Authors: Çetin Ergü , Yildirim Cansev , Palavan-Ünsal Narçin , Ünal Meral
Published: April 2011

Naturally occurring polyamines (PA) are known to play a key role in growth and development of plants and animals. However, the role of these polycations in the development and germination of the pollen grain is not well understood. The effect of different concentrations of spermine (Spm) on pollen tube growth in Helianthus annuus was investigated. Spermine treatments in the 10−7 to 10−5 M range stimulated pollen tube growth starting in the first 15 min of the incubation period, while 10−4 M Spm treatment resulted in inhibition of pollen tube elongation. The effect of cyclohexylamine (CHA), an inhibitor of Spm synthesis on pollen tube growth and germination percentage was also studied. Cyclohexylamine in the 0.5 × 10−3 M to the 1.5 × 10−3 M range inhibited pollen tube elongation. The relationship of B deficiency, excess B and PA effect on pollen germination and pollen tube growth were also investigated. Key words: Polyamines, pollen, cyclohexylamine, boron
Selecting for triallate resistance in wild oat
Authors: Beckie Hugh J. , Jana Sakti
Published: April 2011

Resistance in wild oat (Avena fatua L.) to triallate was monitored from 1996 to 1998 in plots of continuous spring wheat (Triticum aestivum L.) and wheat-fallow, with or without triallate applied from 1979 to 1997. Resistance in wild oat occurred after 18 yr where triallate was applied annually in continuous wheat, but not where triallate was applied 10 times in a wheat-fallow rotation over the same period. No resistance was detected in the continuous wheat or wheat-fallow plots where no herbicide was applied. Key words: Herbicide resistance, wild oat, triallate
Effectiveness of border areas in confining the spread of transgenic Brassica napus pollen
Authors: Staniland Beverly K. , McVetty Peter B. E. , Friesen Lyle F. , Yarrow Stephen , Freyssinet Georges , Freyssinet Martine
Published: April 2011

The development of transgenic Brassica napus L. cultivars requires field trials in agricultural settings. For field testing of transgenic constructs that have not been granted full environmental release, current Canadian Government regulations require either large isolation zones (200 m) or 10 m wide borders of synchronously flowering, non-transgenic B. napus to contain transgenic pollen. To investigate the effectiveness of border areas in containing transgenic B. napus pollen, border areas 15 to 30 m wide were planted around 30 m × 60 m central plots of bromoxynil-herbicide-resistant transgenic B. napus strains. Four field trials were conducted at Carman and Winnipeg, Manitoba, Canada in 1994 and 1995. Seed samples were harvested from the border area at 0, 2.5, 5, 10, and 15 m for the four cardinal directions and additionally at 20, 25, and 30 m for two cardinal directions. These seed samples were planted in the field in 1995 and 1996 and the seedlings screened for the presence of bromoxynil-resistant plants (i.e., from outcrossed seeds). Distance from the central plot significantly affected outcrossing rates while environment (site–year) and direction effects were non-significant. Outcrossing rates averaged 0.70% at 0 m and declined exponentially to 0.02% at 30 m. More than four-fifths of the total outcross events detected occurred in the first 10 m of border area indicating that border areas effectively reduce pollen-mediated gene flow in B. napus but cannot completely eliminate it. Key words: Transgenic canola; Brassica napus; pollen containment
Characterization of meadow × smooth bromegrass hybrid populations using morphological characteristics
Authors: Ferdinandez Yasas S. N. , Coulman Bruce E.
Published: April 2011

Three hybrid populations between meadow bromegrass (Bromus riparius Rehm.) and smooth bromegrass (Bromus inermis Leyss.) have been developed using recurrent selection for vigor, uniformity of growth and floret fertility. The objective of this study was to use morphological characters to characterize the three hybrid populations (S-9197, S-9073, and S-9183) and the two parental species. Tiller heights did not differ among the hybrids and the parental species. Leaf-to-stem ratio of the hybrids was intermediate to that of the parents. Tiller density, panicle density and dry matter yield of the hybrids were more similar to those of smooth bromegrass. Leaf pubescence densities of the hybrids were higher than the parental species, but pubescence lengths closely resembled meadow bromegrass. Leaf area index (LAI) of the hybrids was lower than smooth bromegrass, and resembled meadow bromegrass. Lowest brown leaf spot ratings were observed in meadow bromegrass, while the hybrids were similar to smooth bromegrass. In general, the hybrid populations showed some individual characteristics similar to each of the parental species and, thus, can be characterized as being intermediate to the parental species. Furthermore, several of the differences among the hybrid populations can be attributed to the selection criteria that were used to develop these populations. Key words: Bromus, smooth bromegrass, meadow bromegrass, hybrid bromegrass, morphological characteristics
The effect of rejuvenation of Aspen Parkland ecoregion grass–legume pastures on dry matter yield and forage quality
Authors: Lardner H. A. , Wright S. B. M. , Cohen R. D. H. , Curry P. , MacFarlane L.
Published: April 2011

A 3-yr study was conducted on Black and Gray Wooded soils at five different sites in the Aspen Parkland of Saskatchewan to determine the effect of spiking, burning, mowing, deep-banding (Trt) and applications of N, P, K and S liquid and granular fertilizers (Fert) on dry matter yield (DMY) and forage quality of primarily smooth bromegrass (Bromus inermis Leyss.) and alfalfa (Medicago sativa L.) pastures. Fertilizer application was a liquid form blended to provide 100 kg N ha–1, 45 kg P2O5 ha–1, 23 kg K2O ha–1 and 12 kg S ha–1 in 350 kg of fertilizer ha–1. The experimental design at each site was a randomized complete block in a split-plot arrangement. Main plots were spike, burn, mow, deep-band, deep-band liquid fertilizer and control. The split-plot treatment was granular fertilizer broadcast at 0 and 350 kg ha−1 (providing 100 kg N ha−1, 45 kg P2O5 ha−1, 23 kg K2O ha–1 and 12 kg S ha−1). All treatments were applied in the spring of 1994. Interaction effects of Trt × Yr and Fert × Yr were significant (P < 0.05) indicating a wide range of response to the rejuvenation methods among years. Spiking reduced (P < 0.05) DMY in year 1 at two sites. Deep-banding and mowing increased (P < 0.05) DMY at one site in year 3. Burning increased (P < 0.05) DMY in years 1 and 2 only at the Gray Wooded soil site. In year 1, liquid plus granular fertilizer (200 kg N ha–1) [deep-banded liquid fertilizer (DBLIQ at 100 kg N ha−1) + broadcast fertilizer (+F at 100 kg N ha−1] increased DMY at all sites by 84 to 185% over control plots. This effect carried over (P < 0.05) into year 2 at four sites but not the third and final year. The high rate of N (200 kg N ha−1) of the DBLIQ + F almost doubled (P < 0.05) crude protein content of year 1 forage, 170.3 g kg−1 compared with 96.4 g kg–1 for control. It was concluded that an application of broadcast or liquid fertilizer alone or combined with mechanical treatments will produce a significant effect on herbage yield and quality but only in the short term. Key words: Rejuvenation, fertilizer, spike, burn, deep-band, quality
Efficacy of low O2 and high CO2 atmospheres in maintaining the postharvest quality of saskatoon fruit (Amelanchier alnifolia Nutt.)
Authors: Rogiers Suzy Y. , Knowles N. Richard
Published: April 2011

Changes in fruit quality of saskatoon (cvs. Pembina, Smoky, Northline, and Thiessen) stored under three O2 levels (2, 10, and 21%) factorially combined with two CO2 concentrations (0.035% and 5%) were assessed during 56 d of storage at 0.5 °C. The 5% CO2 atmosphere combined with 21 or 10% O2 was most effective at minimizing losses in fruit soluble solids, anthocyanins, firmness, and fresh weight. Fungal colonization of fruit after 8 wk of storage was eliminated in 5% CO2 at all O2 concentrations. Storage of fruit in 0.035% CO2 and 21 or 10% O2 resulted in the highest titratable acidity and lowest ethanol concentrations. Ethanol did not exceed 0.03% in fruit stored in any of the atmospheres. While changes in some of the quality characteristics of fruit during storage were cultivar dependent, differences among cultivars were small, and all four cultivars benefited from controlled atmosphere storage. Key words:Amelanchier alnifolia, saskatoon fruit, controlled atmosphere, postharvest quality
Tillage, fertiliser and glyphosate timing effects on foxtail barley (Hordeum jubatum) management in wheat
Authors: Blackshaw R. E. , Semach G. , Li X. , O'Donovan J. T. , Harker K. N.
Published: April 2011

Foxtail barley (Hordeum jubatum L.) is becoming a more severe weed problem as conservation tillage becomes widely adopted on the southern Canadian prairies. A 5-yr field study was conducted to determine the combined effects of tillage, N rate, N placement and application timing of glyphosate to manage foxtail barley in spring wheat. Wide-blade tillage conducted in fall and spring, compared to zero-till, reduced foxtail barley biomass and seed production in all yr and increased wheat yield in 4 of 5 yr. Foxtail barley was highly competitive with wheat for added N. N fertiliser placed mid-row in 10-cm-deep bands reduced foxtail barley growth in 2 of 5 yr and increased wheat yield in 3 of 5 yr compared with soil surface broadcast N. Wheat yield sometimes was similar when N was banded at 60 kg ha−1 or broadcast at 120 kg ha−1, indicating the large advantage of banding N in some situations. Glyphosate at 800 g ha−1 applied preharvest or postharvest gave similar levels of foxtail barley control in 2 of 3 yr. Results indicate that foxtail barley can be adequately managed in wheat production systems utilizing conservation tillage. Key words: Foxtail barley, Hordeum jubatum, glyphosate, integrated weed management, nitrogen placement, zero tillage
Early tall determinate soybean genotype E1E1e3e3e4e4dt1dt1 sets high bottom pods
Authors: Cober E. R. , Madill J. , Voldeng H. D.
Published: April 2011

The height of bottom pods on soybean [Glycine max (L.) Merr.] plants can be a major factor affecting seed loss at harvest. Tall determinate lines have been observed to have bottom pods set higher compared with indeterminate cultivars. This study was conducted to compare bottom pod height and other agronomic characteristics of indeterminate cultivars and elite tall determinate lines. Ten indeterminate cultivars and ten tall determinate lines adapted to maturity group 00 to I were evaluated at Ottawa (45°23′N lat.) and Winchester (45°6′N lat.), Ontario, in 1996 and 1997. Bottom pods on tall determinate lines were set almost twice as high as bottom pods on indeterminate cultivars. While main stem height did not differ between the two stem types, indeterminate plants had 0.2 more main stem nodes and two additional reproductive nodes than the tall determinate lines. Tall determinate lines yielded only 90% of the indeterminate cultivars and had smaller seeds and increased lodging. These results suggest that tall determinate lines may be valuable in environments where harvesting losses result from low bottom pods, but they still require further agronomic improvement to overcome yield limitations. Key words: Soybean, determinate, pod height, Glycine max (L.) Merr.
Herbicide-tolerant canola: weed control and yield comparisons in western Canada
Authors: Harker K. N. , Blackshaw R. E. , Kirkland K. J. , Derksen D. A. , Wall D.
Published: April 2011

Field experiments were conducted at five western Canadian locations in 1996 and 1997 to compare weed control and canola (Brassica napus L.) seed yields in the three major her-bicide-tolerant canola (HTC) systems. The main objective of this study was to determine if significant weed control and yield advantages could be expected by using herbicides "designated" for HTC compared to a more "standard" application of sethoxydim plus ethametsulfuron. In 3 of 10 site-years, glyphosate in Quest canola and imazethapyr/imazamox in 45A71 canola provided a yield advantage over the standard treatment. The yield advantages were restricted to the Lacombe and Lethbridge sites and ranged from 13 to 39% increases over the sethoxydim plus ethametsulfuron treatments. Among the HTC, weed control was usually greatest with glyphosate, followed by imazethapyr/imazamox, and then glufosinate. Glufosinate efficacy was often restricted due to advanced growth stages on some weeds. The standard treatment of sethoxydim plus ethametsulfuron did not provide better weed control than glyphosate, but in some cases did improve weed control compared to imazethapyr/imazamox or glufosinate. The HTC provide growers with new opportunities for the control of difficult weeds along with the option to employ in-crop herbicides with new modes of action in canola. Key words: Weed management, transgenic canola
Efficacy of pasture rejuvenation through mechanical aeration or N fertilization
Authors: Malhi S. S. , Heier K. , Nielsen K. , Davies W. E. , Gill K. S.
Published: April 2011

Field experiments were conducted in 1991 and 1992 at five sites in central Alberta to determine if mechanical aeration with an Aer-WayTM aerator and/or N application would increase forage production on pasture or hayland. Mechanical aeration did not affect forage yield at any of the five sites. In contrast, forage yields increased significantly with N application in most cases. These results indicate that nutrient deficiency, particularly N, was the likely cause of reduced production on these pasturelands and haylands. Consideration of nutrient deficiency alleviation via inclusion of a legume or via N application may be an appropriate strategy for pastureland and hayland rejuvenation in central Alberta. Key words: Hayland, mechanical aeration, N fertilization, pasture, rejuvenation
The effect of seeding date, seeding rate and N fertilization on winter wheat yield and yield components in eastern Newfoundland
Authors: Spaner D. , Todd A. G. , McKenzie D. B.
Published: April 2011

Livestock farmers in Newfoundland presently import most of their feed grain, and local self-sufficiency in grain production is a desirable long-term goal. The overall objective of this work was to refine our understanding of winter wheat (Triticum aestivum L.) production in Newfoundland, with the aim of improving present cropping recommendations. We conducted trials near St. John's in 1998 and 1999 to examine the effect of seeding rate and topdress ammonium nitrate (N) fertilization rate on Borden winter wheat yield and yield components. We also conducted four seeding date trials in the same region. Optimum-treatment grain yields in our six trials ranged from 2.76 to 5.39 t ha−1. In years of variable winter kill, increasing seeding rate up to 450 seeds m−2 increased spikes m−2 at harvest, resulting in increased grain yield. Seeding rate, however, was not as important as N fertilization in maximizing grain yield. Increasing topdress fertilization to 60 kg N ha–1 increased spikes m–2 at harvest in years of variable winter kill, resulting in greater grain yield. In years of high winter survival, the main source of higher grain yield levels (through higher N application rates) was not achieved through greater spikes m−2 at harvest, but rather through an increase in kernel weight. Optimum grain yields occurred at seeding rates of 400 ± 50 seeds m−2, and at topdress fertilizer applications up to a rate of at least 30 kg N ha−1. Given the results of our seeding date experiments, in conjunction with previously developed climatic models, we now consider the optimum seeding date for the eastern region of Newfoundland to be August 31. Key words: Yield component analysis, two-dimensional partitioning, Triticum aestivum L., ammonium nitrate
Impact of one year crozier removal on long-term frond production in Matteuccia struthiopteris
Authors: Bergeron Michel E. , Lapointe Line
Published: April 2011

Matteuccia struthiopteris (L.) Todaro populations that had been subjected to crozier harvesting over the past 25 yr were investigated. The number of crowns harvested and the number of croziers harvested per crown varied annually, but most crowns were harvested at least once over 5 yr. In 1995, total and 50% defoliation impacts were tested on subsequent years’ frond production in understorey and open site populations. The effect of mineral fertilization on the understorey population was also investigated. Crowns in the open habitat produced more fronds annually than the understorey crowns and were less susceptible to partial defoliation. One year with total defoliation was sufficient to significantly reduce the number of fronds produced in both habitats over the next 4 yr. Defoliated crowns also accumulated less carbohydrates at the end of the first season. Mineral fertilization increased the number of fronds produced the following year but had no long-term benefit and did not significantly alleviate defoliation effects. Despite the fact that harvesting intensity was relatively low, it appears necessary to limit crozier harvesting per crown to less than 50% in understorey populations to preserve wild populations of M. struthiopteris. Key words: Defoliation, carbohydrate reserves, fertilization, fiddlehead, Matteuccia struthiopteris
Reply to: Preston, C.M. (2000): Comment on: "Application of 13C CPMAS NMR techniques in 'Petroleum residues as water-repellent substances in weathered nonwettable oil-contaminated soils' (Roy et al. 1999) and recent related studies"
Authors: McGill W. B. , Roy J. L.
Published: April 2011

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