bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of desiccants to reduce frost damage in immature flax
Authors: Gubbels G. H. , Bonner D. M. , Kenaschuk E. O.
Published: April 2011

The desiccants diquat, glufosinate-ammonium, dimethipin and glyphosate were applied to flax when 44–84% of the capsules were green to reduce damage from subsequent frost. Beginning 3 d after desiccant application, plant samples were taken at 2–4 d intervals and exposed to a temperature at −20 °C overnight. Diquat application gave the most promising results, reducing the proportion of discolored seed and sometimes reducing loss of germinability, while resulting in a small yield loss compared with freezing of untreated plants. Key words: Flax, Linum usitatissimum L., desiccants, frost damage, seed quality, germination
OAC Shire soybean
Authors: Beversdorf W. D. , Tanner J. W. , Gostovic P. , Montminy W. , Hume D. J.
Published: April 2011

OAC Shire is a mid-Maturity Group I soybean (Glycine max [L.] Merr.) cultivar with excellent yield potential and moderate field tolerance to Phytophthora root rot. Key words: Soybean, cultivar description
OAC Frontier soybean
Authors: Beversdorf W. D. , Tanner J. W. , Montminy W. , Gostovic P. , Hume D. J.
Published: April 2011

OAC Frontier is an early Maturity Group 00 soybean (Glycine max [L.] Merr.) cultivar with excellent yield potential and high seed oil content. Key words: Soybean, cultivar description
AC Nordica alfalfa
Authors: Goplen B. P. , Gossen B. D.
Published: April 2011

AC Nordica alfalfa (Medicago sativa L.) was developed by the Agriculture Canada Research Station at Saskatoon, Saskatchewan. It is similar to Beaver alfalfa in having a broad crown and a tap root with many branches. AC Nordica is 1–2 d earlier in maturity than Beaver. It is shorter than Beaver at 10% bloom, is slightly slower in regrowth following harvest, and displays less spring vigor. However, it excels in winter hardiness, rating similar to Anik and Drylander alfalfa. AC Nordica is highly resistant to bacterial wilt (Clavibacter michiganense subsp. insidiosum [McCulloch] Davis, Gillaspie, Vidaver & Harris), and moderately resistant to snow mold (Coprinus psychromorbidus Redhead & Traquair). AC Nordica is intended as a special-purpose cultivar for the northern prairies, the Peace River area of Alberta, and other high snowfall areas where snow mold (winter crown rot) may occur and where extreme winter hardiness is required. Key words: Alfalfa, Medicago sativa, winter hardiness, winter crown rot, snow mold, cultivar description
Response of Eckespoint Lilo poinsettia to nitrite, substrate pH and etridiazole in a subirrigation system
Authors: Blom Theo J. , Piott Brian D.
Published: April 2011

Poinsettias (Euphorbia pulcherrima Willd. 'Eckespoint Lilo') were grown in pH-adjusted (4.5, 5.5 or 6.5) sphagnum peat substrates and subirrigated using a complete nutrient solution with three concentrations of nitrite (0, 1.75 and 3.5 mol m−3). The substrate also was either treated with a nitrification inhibitor (etridiazole) or remained untreated. There was a linear decrease in leaf and bract areas, top dry weight, plant height and root growth with increasing nitrite concentration. This response occurred at a rate of 10% mol−1 NO2− m−3 at a substrate pH of 4.5 or 5.5 and 6% mol−1 NO2 m−3 at a substrate pH of 6.5. Leaf and bract areas and top dry weight were greater at pH 4.5 than at pH 6.5. Etridiazole did not affect the response of plant growth to nitrite and (or) substrate pH. Key words: Aaterra, 5-ethoxy-3-trichloromethyl-1,2,4-thiadiazole, subirrigation, terrazole, truban
In vitro propagation and bulb formation of garlic
Authors: Seabrook Janet E. A.
Published: April 2011

Garlic (Allium sativum and A. ampeloprasum) shoot cultures were established in vitro for cultivars Block, Chets, Shaw, #72 and Elephant garlic. Explants comprised a small (1–3 mm) piece of basal plate, an axillary bud and one or two subtending bulb scales. A medium containing MS salts and 0.1 mg L−1 (0.5 μM) NAA and 2.0 mg L−1 (8.8 μM) BAP or 2iP promoted axillary shoot multiplication., Bulb formation of garlic shoot cultures was obtained on a medium containing a lower concentration of macro- and minor elements. The substitution of glucose and manitol for sucrose resulted in a bulbing medium with higher carbohydrate levels than the multiplication medium. Genotypic differences for both shoot multiplication and bulb formation in vitro were observed. The mean number of shoots produced were: Chets (9.5), #72 (8.0), Elephant (7.2), Shaw (7.1) and Block (6.1). The mean numbers of bulbs per 50 shoot explants were: Chets (62), Elephant (44), #72 (43), Shaw (26) and Block (9). Key words:Allium sativum, Allium ampeloprasum, genotypic responses, micro-propagation, tissue culture
Seeding-date effects on yield, quality and maturity of safflower
Authors: Mündel H.-H. , Morrison R. J. , Blackshaw R. E. , Entz T. , Roth B. T. , Gaudiel R. , Kiehn F.
Published: April 2011

Experiments were conducted for 4 yr at Lethbridge and Brooks, Alberta, and at Morden, Manitoba, to determine the effect of seeding date, cultivar (Saffire, S-208 and Cargill-3) and location on safflower (Carthamus tinctorius L.) yield, oil content, test weight and maturity; and the effect of accumulated degree–days (DD) on yield, oil content and test weight. The early-maturing cultivar, Saffire, produced the least variable yields across seeding dates. For locations and years where fall frosts did not occur before maturity, Cargill-3 produced good yields, even with late seeding; S-208 yielded less in similar situations; however, S-208 generally outyielded Saffire. Highest yields were obtained at Brooks by seeding in late April, at Lethbridge, by seeding in late April or early May. However, at both Alberta locations, Saffire could usually be seeded to mid-May without major yield reduction. At Morden, seeding during the third week of May provided optimum yields. Seeding date had little influence on oil content. Later seeding dates tended to reduce days to maturity and test weight. Safflower matured 3 wk earlier at Morden (earliest site) than at Lethbridge (latest site), with maturity at Brooks averaging 4–8 days earlier than at Lethbridge. Plants required more DD to reach maturity at Morden than at either Alberta location. DD was positively associated with yield of S-208 at both Lethbridge and Morden; for Saffire, only at Lethbridge; and for Cargill-3, only at Morden. DD generally did not significantly affect oil or test weight. Key words: Safflower, Carthamus, agronomy, seeding dates, yield, oil, test weight, maturity, degree–days
Effets de régies culturales sur le rendement et la biomasse aérienne de trois cultivars de blé de printemps
Authors: Tremblay G. , Vasseur C.
Published: April 2011

Although bioclimatic conditions of the Saint Lawrence Lowlands are generally good enough to grow wheat for bread, management of this wheat production is poorly known in Quebec. Yields and total above-ground dry-matter biomass of three spring wheat (Triticum aestivum L.) cultivars (Max, Columbus and Katepwa) were measured in 1991 and 1992 under three management systems on a clay loam soil of the Saint Lawrence Lowlands. Reduced (50 kg N ha−1 and 375 plants m−2), conventional (100 kg N ha−1 and 375 plants m−2) and intensive (150 kg N ha−1 and 450 plants m−2) management systems were compared. In 1991, significant differences were observed among cultivars for four variables: stem weight, harvest index, tillers per square metre, and 1000-kernel weight. The management effect is less important than the cultivar effect. In 1992, significant differences among cultivars were observed for six of the nine variables measured, and seven of the nine variables measured differed with management. No significant cultivar × management interactions were observed in either year. Increasing input levels did not increase yield in 1991, probably because of the drier conditions. In the cooler and rainy growing season of 1992, intensive management increased wheat yield compared with that of reduced and conventional management. In both years, grain yield under reduced management was not significantly different from that under conventional management. Grain yield under intensive management was significantly higher than under reduced and conventional management in 1992 but not in 1991. The results of this study did not clearly show that intensive management was really better in the climatic conditions of the Saint Lawrence Lowlands than conventional or reduced management. Key words: Spring wheat, management, nitrogen, yield, dry matter, harvest index
Jay orchardgrass
Authors: Bowley S. R. , Hancock D. , Wood D.
Published: April 2011

Jay is a cultivar of orchardgrass (Dactylis glomerata L.) developed by the Crop Science Department, University of Guelph. It was developed by half-sib progeny testing for yield, leafiness, and late-maturity. It is similar in herbage yield and plant height but slightly later maturing than the cultivar Kay. Jay is suited for situations where a late-maturing orchardgrass is desired. Key words: Orchardgrass, Dactylis glomerata, cultivar description
Long-term effects of herbicide and fertilizers on lowbush blueberry growth and production
Authors: Eaton Leonard J.
Published: April 2011

Effects of herbicide and herbicide-fertilizer combinations on vegetative and reproductive growth of the lowbush blueberry (Vaccinium angustifolium Ait.) were assessed over a 12-yr period (six production cycles). All treatments stimulated stem lengths, fruit buds per stem and fresh fruit yields compared with untreated controls, but only after 3–6 yr. After the second cycle, stem lengths and fruit bud numbers were greater in herbicide + NPK-treated plants than in all others. Fresh fruit yields were variable throughout the study but were higher in herbicide and herbicide + fertilizer plots than in untreated controls after 1982, except in 1988. Nitrogen levels were greater in leaves and rhizomes of plants in all herbicide and herbicide + fertilizer plots than in control plots after 10 yr, whereas phosphorus was higher only in plants fertilized with NPK. These results suggest the lowbush blueberry responds slowly to herbicide and fertilizer applications. Increased vegetative and reproductive development, as well as denser plant stands, resulted from repeated herbicide and fertilizer applications. Fertilizers applied in conjunction with herbicides stimulate vegetative growth (and fruit buds if an NPK fertilizer), but appear to have no consistent effect on fresh fruit yields. Key words:Vaccinium angustifolium, fertilizer, herbicide, fruit buds, yield
Response of apple trees to fertigation-induced soil acidification
Authors: Neilsen G. H. , Parchomchuk P. , Hogue E. J. , Wolk W. D. , Lau O. L.
Published: April 2011

Summerland McIntosh apple trees (Malus domestica Borkh.)on M.9 rootstock were fertigated for the first 3 yr after planting with all combinations of two rates of N (23.5 and 47.0 g tree−1) and three rates of P (0, 17.5 and 35 g tree−1). During this period, soil pH (0.01 M CaCl2) beneath and near the drip emitters declined from 5.8 to < 4.0. Rate of fertigated N had few measurable effects on the trees. In contrast, fertigated P increased first-year tree vigour, second-year tree yield, and sometimes leaf Ca and Mg and leaf and fruit P concentrations. None of these nutrient concentrations were near critical values. Fertigated P also decreased leaf concentrations of K and Cu, which reached deficiency after 3 yr, and did not ameliorate the decline in tree vigour attributed to soil acidification. Increased Mn concentration in leaves was the most distinctive plant indicator of soil acidification, while decreased leaf K was the most important basic cation affected. Fruit Ca was not affected by the decrease in soil Ca availability. Key words: Vigour, yield, fruit Ca, leaf K, Mn and Cu
Zero-tillage influence on canola, field pea and wheat in a dry subhumid region: Agronomic and physiological responses
Authors: Borstlap Sylvia , Entz Martin H.
Published: April 2011

Field trials were conducted over 4 site-years in southern Manitoba to compare the response of Katepwa wheat, Westar canola and Victoria field pea to zero tillage (ZT). The experimental design was a split plot with tillage system as the mainplot (ZT vs. conventional tillage (CT)) and crop species as the subplot. All crops received protection from insect, weed and disease pests. Tillage system had only a limited impact on crop dry matter accumulation or grain quality. Where differences were observed, crop performance was enhanced under ZT. Seasonal evapotranspiration (ET) was either reduced or unaffected by ZT, while ET efficiency (ETE: kg ha−1 mm−1 ET) was either increased or unchanged by the shift from CT to ZT. Higher ETE under ZT was attributed to less soil water evaporation. Significant tillage system × crop species (T × S) interactions for growth parameters, ET and ETE indicated that field pea often benefitted more than wheat or canola from ZT. A significant T × S interaction at one of the four sites indicated that water extraction between 30 and 90 cm was higher for pea and canola in the ZT compared with CT treatment, while soil water extraction by wheat was reduced under ZT. At a second site, lower ET for all three crops under ZT was attributed to reduced water use between 90 and 130 cm. Despite some effects of ZT on crop growth and water use, no significant tillage, T × S, or site × tillage interactions were observed for grain yield. It was concluded that under the conditions of this study (i.e. precipitation and temperature conditions close to the long-term average), Westar canola, Victoria field pea and Katepwa wheat were, for the most part, equally suited to ZT production. Key words: Soil water extraction, evapotranspiration efficiency, crop quality, grain yield, canopy development
Rye cover crop management impact on soil water content, soil temperature and soybean growth
Authors: Wagner-Riddle C. , Gillespie T. J. , Swanton C. J.
Published: April 2011

The optimum killing time of a rye (Secale cereale) cover crop is an important management decision and can determine the yield of the subsequent soybean (Glyane max) crop The objective of this research was to study a rye cover/soybean system. Soybeans were grown on sandy (Delhi) and loam (Woodstock) soils (1989/1990) with mulch on the soil surface obtained by killing rye approximately 1 and 2 wk before soybean planting. A conventional tillage treatment was used as a control. Soil water content, soil temperature, rye mulch amount and soybean growth were monitored over the season. Rye mulch amount for the late killing (LK) date was always larger than for the ear y killing (EK) date. LK decreased soil water content at soybean planting time at Delhi in 1989. The rye mulch produced with the LK increased soil water content early in the soybean growing season in 1990. A substantial decrease in the amount of mulch was observed during the growing season and resulted in little difference between mulch and no mulch soil water and temperature conditions later in the season. Extreme temperatures were more frequent under the bare soil, but these were limited to a small percentage of hours, and did not translate into differences in soybean development rates. Reduced soybean growth observed early in the season in one out of four location-years vanished as the season progressed. Number of seeds per pod and nodule number were increased due to rye mulch, but no difference in soybean yields were observed among treatments. Key words: Rye (Secale cereale), cover crop, mulch, soybean (Glycine max)
Resource allocation in Maritime cereal cultivar trials
Authors: Atlin G. N. , McRae K. B.
Published: April 2011

Research funding for cooperators in the cereal cultivar testing system in Canada is declining, and cooperators are under pressure to reduce their testing effort. The impact of reducing the number of years, test sites, and replications on the standard error of cultivar means (SE), predicted response to selection (R), and the probability of accepting inferior cultivars in Maritime spring cereal registration trials was examined using variance component estimates. Reducing the number of replications increased SE less than reducing the number of sites or years of testing. Reducing replicates per site from four to two increased SE by no more than 0.02 t ha−1 when the number of sites was three or more. Reducing the number of trial sites from five to three, however, increased SE by up to 0.06 t ha−1 and reduced R by as much as 16%. The probability that a cultivar with a true yield 5% less than that of a standard would equal or exceed the standard in a 3-yr series of trials conducted at five sites ranged from 6% in 2-row barley to 21% in winter wheat. Cost reductions in the Maritime cereal registration trials should be achieved, where possible, by reducing within-site replication rather than reducing the number of trial sites. Some reduction in the risk of registering inferior cultivars can be achieved by comparing test cultivars with the mean of several standards, rather than with a single standard. Key words: Replication, genotype × environment interaction, selection response, acceptance probability, variance components, residual maximum likelihood
Forage potential of Wapiti triticale mixtures in central Alberta
Authors: Jedel P. E. , Salmon D. F.
Published: April 2011

Tests were conducted at Lacombe, AB, from 1989 to 1991 to determine the forage yield and quality of Wapiti triticale (× Triticosecale Rimpani Witt.) grown as a monocrop and in binary mixtures with Cascade oat (Avena sativa L.), Empress barley (Hordeum vulgare L.) or Johnston barley. The Cascade monocrop and mixtures with Wapiti had the highest DM yields (12.37–13.42 t ha−1). Yields of the barley monocrops and mixtures with Wapiti (6.60–9.10 t ha−1 in 1989 and 8.96–11.49 t ha−1 in 1990) were similar to the Wapiti monocrop (8.06 and 8.99 t ha−1). In 1991, yields for the Wapiti monocrop and 25:75 barley:Wapiti mixtures (14.54 and 14.99 t ha−1, respectively) were higher than those for the barley monocrops and 50:50 and 75:25 mixtures (11.98–12.79 t ha−1). The yields of the mixtures in 1989 and 1990 were 108 and 106% higher than expected based on the yield of the components, although in 1991 this enhancement was not observed. Moisture contents at harvest were variable and not always as expected based on the relative maturities of the species. However, mixtures with Wapiti could offer some flexibility in harvest for silage production. Protein contents were found to be highly variable and no trends were established. The Cascade monocrop and mixtures had the highest protein yields in 1990 and 1991. The acid detergent fibre (ADF) contents of the 50:50 and 25:75 Cascade:Wapiti mixtures (26.9 and 28.4 g 100 g−1) were lower than the Cascade monocrop (33.6 g 100 g−1). Lignin contents were found to vary between treatments only in 1989 when the Wapiti monocrop (3.90 g 100 g−1) was intermediate to the Empress (3.30 g 100 g−1) and Cascade (4.83 g 100 g−1). Yield stability and quality would make use of Wapiti mixtures for silage attractive choices for silage production. Key words: Silage, protein, ADF, lignin, cereal mixtures
Direct seeding of alfalfa into established Russian wildrye pasture in southwest Saskatchewan
Authors: Schellenberg M. P. , Waddington J. , King J. R.
Published: April 2011

Experiments were started in each of the three years 1989–1991 to examine the effect of severing near-surface roots of established Russian wildrye (Psathyrostachys juncea (Fisch.) Nevskii) on the establishment of two alfalfa cultivars (Medicago sativa L.) in semiarid Saskatchewan. In 2 of 3 yr, up to 75% more seedlings were established of the cultivar Rangelander, a creeping-rooted alfalfa of mixed ssp. sativa (L.) Lesins & Lesins and ssp. falcata (L.) Arcangeli parentage, than of SCMf3713, a tap-rooted ssp. falcata. Severing Russian wildrye roots significantly improved alfalfa establishment and dry matter production in 1990, only 1 of 3 yr. There were no benefits from severing Russian wildrye roots on more than the side adjacent to the alfalfa seedlings. Soil moisture levels in the top 15 cm of soil were at or below the permanent wilting point through much of the growing seasons of 1989 and 1991. Soil moisture was increased only occasionally where Russian wildrye roots were severed. Key words: Sod-seeding, Psathyrostachys juncea, Medicago media
Effects of harvest date on certain chemical and physical characteristics of sweet potato grown in southwestern Ontario
Authors: Reynolds L. B. , Rosa N. , McKeown A. W.
Published: April 2011

Effects of harvest date on yield, concentration of selected minerals and carbohydrates of two sweet potato cultivars (Ipomoea batatas Lam.) grown in Southwestern Ontario, Canada were measured over 3 yr. Harvest date for maximum yield of table grade roots was found to be mid to late September. Mineral concentrations were not consistently affected by dates of harvest. The concentration of Na in the roots was found to be lower than values reported for other production regions for both cultivars. In 2 of 3 yr, sucrose and total sugars increased and starch, percent dry weight and root growth rate decreased as harvest date was delayed from 27 September to 11 October. These effects of delayed harvest date were attributed to low temperatures late in the normal harvest time period for this production area. Key words: yield, mineral, sugar, starch, Ipomoea batatas
Évaluation de la rusticité et de la croissance d'arbustes ornementaux à feuillage caduc
Authors: Richer-Leclerc C. , Côté J. , Rioux J. A. , Lapointe D. , Guillemette L. , Drapeau R. , Auger M. , Fortin M.
Published: April 2011

The winter hardiness and growth potential of 10 cultivars of deciduous shrubs were evaluated to determine their adaptability to climatic conditions. Plants were grown at eight sites in Quebec and at one site in northeastern Ontario (zones 2, 4 and 5). Cornus alba 'Argenteo-Marginata' and 'Sibirica', Lonicera korolkowii var. Zabelli, Lonicera korolkowii var. morrowii, Lonicera × xylosteoides 'Clavey's Dwarf', Physocarpus opulifolius, Physocarpus opulifolius 'Aureus' and 'Nanus', Salix purpurea 'Nana' and Salix elaeagnos were used. Cornus alba 'Sibirica' and L. × xylosteoides 'Clavey's Dwarf' were not affected by winter conditions at any of the sites, whereas L. korolkowii var. Zabelli and L. morrowii were severely affected, particularly in zone 2. Our results indicated that S. purpurea 'Nana' was more frost resistant than S. elaeagnos. The two cultivars of Physocarpus were slightly less winter hardy than the species. None of the 10 species could be grown commercially in zone 2a. Growth of S. purpurea 'Nana', S. elaeagnos and P. opulifolius 'Aureus' was limited in zones 4b and 5. The hardiness zones of the 10 species were made more precise, established or modified. Key words: Hardiness, growth potential, winter damage, shrubs, hedges
The transfer of leaf rust resistance from Triticum turgidum ssp. dicoccoides to hexaploid wheat
Authors: Dyck P. L.
Published: April 2011

Accession 8404 of Triticum turgidum ssp. dicoccoides was shown to have excellent resistance to leaf rust. Genetic analysis of the F3 of 8404 and RL6089, a leaf rust susceptible durum, indicated that 8404 had three genes for leaf rust resistance. Two of these genes were transferred to hexaploid wheat (Thatcher) by a series of backcrosses. One of the genes transferred was the same as Lr33 (RL6057). The second gene, which gives a fleck reaction to avirulent P. recondita races, appears to be fully incorporated into the hexaploid where it segregated to fit a one-gene ratio. Backcross lines with this gene give excellent resistance to leaf rust, although race MBG is virulent to this gene. This may be a previously unidentified leaf rust resistance gene and should increase the genetic diversity available for wheat breeders. Key words:Triticum aestivum, wheat, Triticum turgidum ssp. dicoccoides, leaf rust resistance
A chilling resistance test for inbred maize lines
Authors: Hodges D. Mark , Charest Christiane , Hamilton Robert I.
Published: April 2011

A laboratory germination test based on exposure of seeds to a temperature regime derived from natural conditions was developed to determine chilling resistance in maize (Zea mays L.). Seven inbred lines were exposed to a temperature regime approximating Ottawa, Ontario's (Lat. 45° 24′N, Long. 75° 43′W) spring climate. Seeds were subjected to a range of maximum (16 h) and minimum (8 h) temperatures corresponding to the dates spanning 15 April (10.3/0.4 °C) to 30 May (21.0/9.1 °C) in controlled temperature germinators. A control germination test used a constant 25 °C. The percent germination, percent viability, and average time taken to germinate were measured. The results of all three parameters corresponded in indicating which line was chilling susceptible, and the percents germination and viability in which lines were chilling tolerant. Field trials were sown in Ottawa in the early spring of 1992 and 1993 and percent of emergence and average time to emergence were recorded. The line demonstrated to be most chilling susceptible by the laboratory germination test and those lines selected to be most chilling tolerant by the laboratory percent germination and viability assays corresponded to those classified as such by the field percent emergence. Key words: Maize, germination test, chilling tolerance and sensitivity
Comparison of the effect of nap and pol cytoplasms on the performance of three summer oilseed rape cultivar-derived isoline pairs
Authors: McVetty P. B. E. , Pinnisch R.
Published: April 2011

The pol cytoplasm is a male sterile cytoplasm with potential for use in hybrid summer rape (Brassica napus L.) seed production while the nap cytoplasm is the one most commonly encountered in summer rape cultivars. The objective of this study was to compare the performance of three cultivar-derived summer rape isoline pairs in the nap and pol cytoplasms to determine the relative effect on performance of these two cytoplasms. One nap line yielded significantly more than its corresponding pol line, three nap lines had significantly higher oil content than their corresponding pol lines, two nap lines had significantly higher protein content than their corresponding pol lines, and two nap lines produced significantly more seed energy than their corresponding pol lines. There are pleiotropic negative effects (biological costs) associated with the pol cytoplasm. These negative effects are affected by nuclear genotype and appear to be related to the depth of male sterility expressed in the derived pol A-line. Key words: Cytoplasm cost, Brassica napus L., cytoplasmic male sterility
Attempted transfer of leaf rust resistance from Triticum monococcum and durum wheat to hexaploid wheat
Authors: Dyck P. L. , Bartoš P.
Published: April 2011

An attempt was made to transfer leaf rust resistance from diploid Triticum monococcum, an autotetraploid of the T. monococcum accession, and durum cultivars Medora and Stewart to hexaploid wheat cultivars Thatcher and RL6058 (Lr34). A single gene for leaf rust resistance which was the same as Lr33 (RL6057) was transferred from the durum cultivars to hexaploid wheat. The gene transferred in crosses involving autotetraploid T. monococcum was also Lr33, but since Lr33 is on chromosome 1B, it was probably not from T. monococcum. This gene was not the same as the T. monococcum-derived gene in RL6137 (Tc*6/TMR5-J14-12-24). Using RL6058 (Lr34) as the recurrent parent appeared to facilitate the interspecific transfer of resistance since resistance was expressed in the first backcross generation involving RL6058 but not Thatcher. Key words: leaf rust resistance, wheat, Triticum aestivum
Inheritance of vernalization response in three populations of spring wheat
Authors: Jedel P. E.
Published: April 2011

Vernalization responses are known to differ among spring wheat (Triticum aestivum L.) genotypes. Three crosses were made to determine the inheritance of vernalization response in the spring wheat cultivars Cajeme 71, Yecora 70, Glenlea, Pitic 62 and Neepawa. Segregation analyses of days to anthesis were made of the F2 generation in a growth room (25/15 °C, 16/8 h). Segregation analysis of the F3 generation was made in a summer greenhouse. Reciprocal crosses between Neepawa and Pitic 62 indicated an early/late/transgressively late ratio of 12:3:1 in the F2 generation. The F3 generation results fitted an early/late/transgressively late/segregating ratio of 4:1:1:10. Based on the segregation of transgressively late types from both crosses, it was concluded that the genes for spring habit in Pitic 62 and Neepawa were different and not maternally inherited. The Glenlea/Pitic 62 cross produced one transgressively late segregant in an F2 population of 97 plants. The data fitted an early/late/transgressively late ratio of 60:3:1, indicating that Glenlea may differ from Pitic at three Vrn loci. Therefore, either Glenlea or Pitic 62 may carry two dominant Vrn alleles. The reciprocal crosses between Yecora 70 and Cajeme 71 did not segregate transgressively late types in the F2 generation. Therefore, those cultivars had a Vrn allele in common. Selection for vernalization response might be useful when introducing exotic germplasm into spring wheat breeding programs and in manipulating maturity responses. Key words: Vernalization, spring wheat, Vrn genes
Attractiveness of alfalfa (Medicago sativa L.) to wild pollinators in relation to wildflowers
Authors: Brookes B. , Small E. , Lefkovitch L. P. , Damman H. , Fairey D. T.
Published: April 2011

This study attempted to assess the effects of proximity to wildflowers on the relative number of pollinators foraging on alfalfa flowers, as this information may bear on alfalfa seed production, an important industry in Canada. Five hundred and forty-five collections were made of wild pollinating bees attracted to 20 alfalfa plantations in Canada. Of the 13 genera of bees collected, almost half belonged to Megachile, followed by Bombus with 20% of the collections. Analysis indicated that increased visitation to alfalfa was significantly related to distance of the alfalfa from wildflowers, but not to the size of the alfalfa plantation. Alfalfa growing less than 10 m from wildflowers seemed to benefit by spill-over ("facilitation") of pollinators from the wildflowers. Alfalfa isolated from wildflowers by other alfalfa plants for a distance of at least 200 m attracted very few pollinators, the wildflowers apparently providing more attractive sources of pollen and nectar. A single plantation highly isolated (by about 600 m) from wildflowers proved to be very attractive to pollinators, apparently because wild nesting bees in the vicinity had little alternative but the alfalfa. These observations may be useful in exploring crop layouts to maximize attraction of wild pollinators for seed production. Key words:Medicago sativa, alfalfa, pollinators, competition, facilitation, seed production
Oxygen limitation of N2 fixation in various legume symbioses
Authors: Kaiser B. N. , Shelp B. J. , Thumfort P. , Layzell D. B.
Published: April 2011

Two O2 ramping techniques (linear versus exponential) were used to investigate the response of H2 evolution from intact nodules of soybean (Glycine max (L.) Merr. 'Maple Arrow'), stem-girdled soybean, pea (Pisum sativum L. 'Juneau'), and common bean (Phaseolus vulgaris L. 'Ex Rico 23') to increasing O2 concentrations from 20 to 100% over a 30-min period. The data indicate symbiosis-specific responses to the two ramps, and possible implications for determination of O2 limitation of N2 fixation. Key words: Hydrogen evolution, legume, nitrogen fixation
The Canadian Plant Germplasm System
Authors: Campbell K. W. , Fraleigh B.
Published: April 2011

The present system of formal plant germplasm conservation in Canada began in 1970 with the appointment of the first Plant Gene Resources Officer. Agriculture and Agri-Food Canada (AAFC), which has the main mandate for plant germplasm conservation, operates a seed genebank in Ottawa, which stores and documents accessions of value to Canada, and a clonal genebank in Smithfield, which concentrates on the preservation of tree and small fruits. A new multi-nodal system initiated under the Green Plan has added five new centres to the plant germplasm network. Located at AAFC research centres, plant breeders are responsible for rejuvenating and documenting important germplasm. Universities, companies and nongovernmental organizations contribute to germplasm conservation by increasing the genetic diversity available in the form of cultivars and operating plant and seed repositories. Key words: Germplasm conservation, genebank
Models for activation of plant genetic resources for crop breeding programs
Authors: Kannenberg L. W. , Falk D. E.
Published: April 2011

Although plant breeders recognize that their working germplasm is constricted, most make little use of the extensive genetic variability in gene banks and other collections. This is because breeders continue to make reasonable progress in most crop species and broadening the activated genetic base generally will dilute agronomic performance. Yet new germplasm can (1) raise the genetic ceiling on improvement, (2) decrease vulnerability to biotic and abiotic stresses, and (3) add new developmental pathways and ecological adaptations. Two breeding systems — HOPE for corn and RIPE for barley — are described which can significantly broaden the genetic base deployed in breeding programs while still producing lines and cultivars with commercial potential. The Hierarchical Open-ended Population Enrichment (HOPE) breeding system consists of two complementary sets, each of four gene pools arranged in a hierarchy based on agronomic performance. Introductions are added continually and desirable genes and gene complexes can routinely move upward in the hierarchy. Increasingly stringent selection procedures at each higher level of the hierarchy shape the extensive variability at the lower levels into the quality germplasm at the Elite level, which serves as the source of inbred lines. The Recurrent Introgressive Population Enrichment (RIPE) breeding system for barley employs male sterile facilitated recurrent selection to progressively introgress new genes and gene complexes into an Elite population which serves as the source of potential new cultivars. Key words: Broad-based breeding system, HOPE (maize), hierarchical open-ended system, RIPE (barley), recurrent introgressive selection, male sterile facilitated selection
Breeding durum wheat in western Canada: Historical trends in yield and related variables
Authors: McCaig T. N. , Clarke J. M.
Published: April 2011

Canadian durum wheat (Triticum turgidum L.) production is centred in the Brown and Dark Brown soil zones, areas of limited rainfall. For more than 50 yr, lines have been evaluated in the multi-location Durum Cooperative Test. Data from this test, over the period 1947–1992, were analyzed with the objectives of determining the advances that have been made within the Canada Western Amber Durum (CWAD) wheat class and comparing yield-related variables of recently registered cultivars with those of earlier cultivars. Canadian-developed cultivars have increased yields about 0.81% yr−1 relative to Hercules, or approximately 22.6 kg ha−1 yr−1. As kernel weight has remained unchanged, the genetic yield increases have resulted entirely from an increase in the number of kernels produced. Because kernel number is determined prior to, and during, anthesis, further yield increases may depend upon selection of genotypes that produce higher numbers of kernels, thereby increasing sink demand. While plant height and hectolitre weight have been decreasing over time, neither variable was significantly (P < 0.05) correlated with the yield increases that have taken place over the 29-yr period. The selection pressure toward shorter cultivars may have involved other agronomic advantages, such as decreased lodging. Days to maturity did not change significantly over time and was not correlated with yield. Key words:Triticum turgidum, kernel number, kernel weight, height, hectolitre weight
Effect of replications on measuring wheat plant height
Authors: Budak N. , Baenziger P. S. , Eskridge K. M.
Published: April 2011

Plant height is an important selection criterion in wheat (Triticum aestivum L.) breeding programs that are conducted in the ecogeographically diverse Great Plains. Despite this diversity, measuring plant height on only two replications provided a very accurate estimate of the cultivar mean in each trial and of the detectable difference between two wheat genotypes. Key words:Triticum aestivum, statistics
The effect of salinity on early seedling growth of seeds of three wheat (Triticum aestivum L.) cultivars
Authors: Reggiani R. , Bertani A. , Bozo S.
Published: April 2011

We studied the effects of three salinity levels (50, 100 and 150 mM NaCl) on the early seedling growth of three wheat (Triticum aestivum L.) cultivars of Albanian origin characterized by different sensitivities to salt. Sodium accumulation was similar in seedlings of different cultivars and, in general, Na+ was confined to the root. Chloride accumulated at high levels in both the root and the shoot but least so in Daity. No appreciable differences were observed in K+ content. The most salt-tolerant cultivar showed a higher capacity for osmoregulation than the other two cultivars. Key words: Ion regulation, ion toxicity, osmoregulation, salinity, Triticum aestivum
Transient changes in wheat endosperm polymeric proteins during the later stages of grain development
Authors: Hussain A. , Lukow O. M.
Published: April 2011

End-use quality of wheat depends mainly on the composition of the storage proteins. These proteins undergo changes during grain development. This study was carried out to examine modifications in the polymeric protein fraction at different days post anthesis (DPA) and to determine whether these changes are cultivar dependent. Endosperm proteins of three hexaploid wheat cultivars harvested at different stages of maturity and extracted sequentially from distal half kernels showed quantitative and qualitative changes when separated in a 7.5–9.0% gradient polyacrylamide gel system. Sudden qualitative changes were observed at a later stage of seed development (35 DPA) in all tested cultivars. Most qualitative changes occurred in proteins of molecular weight 60–90 kDa and least in proteins above 90 kDa. An intense 60-kDa band appeared in the 35-DPA sample of Columbus; this band faded as the grain approached full maturity (40 DPA). Key words: Developmental changes, electrophoresis, gluten proteins, seed ripening
LOTIL high-yielding spring wheat
Authors: Hucl P. , Baker R. J.
Published: April 2011

LOTIL spring wheat germplasm was selected on the basis of reduced tillering capacity and high grain yield from three crosses involving an oligoculm parent. This germplasm yielded up to 42% more than the free-tillering cultivar Neepawa but was later maturing. This germplasm is available to spring wheat breeders who wish to use it in their breeding programs. Key words: Low-tillering, spring wheat, high yield
Reducing herbicide use for weed control in soybean (Glycine max) grown in two soil types in southwestern Ontario
Authors: Hamill Allan S. , Zhang Jianhua , Swanton Clarence J.
Published: April 2011

The rate, application method and (or) combination of herbicides, with or without cultivation for soybean production, were studied during several years at Ridgetown and Woodslee, Ontario. One cultivation combined with a herbicide application at reduced rates of metribuzin (e.g., 0.42 kg a.i. ha−1) not only provided effective weed control but also maintained reliable economic return over the years. When used alone, however, neither of them provided satisfactory results. The success of a given weed management system appeared to depend on temporal and spatial environmental variations. In years of adequate rainfall, neither cultivation nor herbicide treatment significantly enhanced the soybean yield or economic return at Woodslee, despite greater weed control than with plots receiving no herbicide or cultivation. Thus, weed control is probably more critical in years of sub-favourable growth conditions than in years of favourable growth conditions. Key words: Cultivation, efficacy, economy, herbicide, reliability, soybean, Glycine max
An appraisal of cereal crop phenology modelling
Authors: Shaykewich C. F.
Published: April 2011

A review of responses of phenological development of cereal crops, primarily corn (Zea mays L.), wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), to environmental conditions was conducted. Examples of how these studies have been used to model phenological development on the basis of weather data were given.It was concluded that the development rate of most species is a sigmoidal rather than a linear function of temperature. Consequently, phenological models assuming a linear relationship (e.g., degree–days) are inappropriate. Another consequence of the way plants respond to temperature is that the most precise phenological models will require use of temperature data over relatively short periods (e.g., 3 h), rather than just a daily mean temperature. Several suggestions regarding the ways standard climatological station data may be used in such phenological modelling are made.Phenological response to photoperiod was also reviewed, and methods of modelling this response were proposed. Key words: Phenology, temperature, photoperiod, modelling
Association of sunflower achene color with other achene characters and bird preference
Authors: Dedio Walter
Published: April 2011

The association of achene color with other achene characters and bird preference was investigated in segregates of a striped Yugoslavian line NS 39 and in 12 crosses of various genotypes. In the NS 39 segregates, the strongest association of achene color was with kernel content (r = 0.606), bird preference (r = 0.610) and achene oil (r = 0.445). Birds preferred lines with darker achene color which in turn was linked with higher oil and nutmeat content. In the crosses of various genotypes, achene color was strongly associated with achene oil content in segregates of two grey × black achene color crosses (r = 0.436 and 0.292) and in segregates of anthocyanin-containing × black achene color cross (r = 0.419). Key words: Sunflower, color association, achene characters, bird preference, achene oil, nutmeat anthocyanin
Mineral composition of flax (Linum usitatissimum L.) and safflower (Carthamus tinctorius L.) on a saline soil high in sulfate salts
Authors: Beke G. J. , Volkmar K. M.
Published: April 2011

Little information is available on the ion control mechanisms of safflower and flax under the sulfate-salinity conditions typical of the Canadian prairies region. Chemical constituents of Saffire safflower and Andro flax were investigated in the field to evaluate their response to soil salinity. Mean Ca:Mg and K:Na ratios of plant tops, yield, and seed oil-content were lower on saline soil than on nonsaline soil. On saline soil, the total cation content of flax tops decreased less rapidly with age than that of safflower, mainly due to high uptake of Na+ by flax. The pattern of ion regulation in safflower (high K:Na ratio) typifies a more "tolerant" response to salinity than that in flax. Key words: Mineral composition, oilseed crops, saline field soil, Na2SO4 salinity, Na+ uptake, K:Na ratio
AC Stacey barley
Authors: Wolfe R. I. , Faris D. G. , Davidson J. G. N. , Clarke P. J.
Published: April 2011

AC Stacey is an early maturing, six-row feed barley (Hordeum vulgare L.) with excellent barley leaf scald resistance. It was developed at the Northern Agriculture Research Centre, Beaverlodge, Alberta from the cross Otal/Melvin. It is moderately strong strawed, and adapted to barley leaf scald prone areas in Alberta, and the Peace River region of British Columbia. Key words:Hordeum vulgare, barley, early maturity, cultivar description, Rhynchosporium secalis, scald
AC Sunshine summer turnip rape
Authors: Woods D. L.
Published: April 2011

AC Sunshine summer turnip rape (Brassica rapa L.) is a canola-quality cultivar that is well adapted to the short and mid-season growing areas of western Canada. It has higher oil and protein content than Tobin. Key words: Rape, canola, Brassica rapa, cultivar description
AC Blue J alfalfa
Authors: Acharya S. N. , Huang H. C. , Hanna M. R.
Published: April 2011

AC Blue J alfalfa (Medicago saliva L.) was developed by the Agriculture and Agri-Food Canada Research Centre, Lethbridge, Alberta. This verticillium wilt and bacterial wilt resistant cultivar outyielded Beaver by about 8% in 4-yr trials and 15% in 7-yr trials in western Canada. It is well suited for hay production, dehydration, and silage in areas where verticillium wilt reduces alfalfa yield and stand life. Key words: Cultivar description, alfalfa, Medicago sativa
Rootstock, severity of dormant pruning, and summer pruning influences on peach tree size, yield, and fruit quality
Authors: Kappel Frank , Bouthillier Michel
Published: April 2011

Peach trees in British Columbia are pruned heavily during the dormant season with some potentially detrimental effects. Summer pruning has been used to control fruit tree vigor and improve fruit quality. The objective of this study was to reduce tree size, increase yield, and improve fruit color by using a less severe dormant pruning system and summer pruning prior to harvest. Over 4 yr, mature, self-rooted (micropropagated) Fairhaven peach trees and Fairhaven on Siberian C rootstock were subjected to two different dormant pruning regimes, with or without summer pruning. Yield, tree growth, pruning weights (dormant and summer) and fruit quality (size and color) measurements were recorded annually. There were no differences in yields per tree for the two rootstocks or for the summer pruning treatments. The lighter ("long") dormant pruning increased yields but average fruit weight was higher in the heavier ("short") dormant pruning treatment. Summer pruning increased the amount of red color on the fruit but only slightly. Own-rooted trees were larger (tree height and ground area covered) than trees budded on Siberian C. Tree height was also increased by the lighter dormant pruning treatment. The partitioning index was higher for trees on Siberian C rootstock, "long" dormant pruned, or non- summer pruned trees. Key words:Prunus persica, fruit color, fruit size, partitioning index
Une étude du rôle des gluténines de haut poids moléculaire chez les blés hybrides: effet sur la qualité en situation d'hétérozygotie
Authors: Oury F-X. , Rousset M. , Bérard P. , Pluchard P. , Doussinault G.
Published: April 2011

Thirty-three winter wheat hybrids produced using a chemical hybridizing agent and their 27 parents were compared for bread-making quality. The F1 was intermediate between the two parents for grain hardness, Pelshenke test and W of alveograph. Correspondence analyses and tree-based models showed strong associations between high molecular weight glutenin composition and Pelshenke or alveograph. For the Pelshenke test, the Glu-D1 encoded subunits were preponderant, and the effect of the alleles appeared additive between loci, as well as within locus. For the alveograph, Glu-B1 was the most important locus. Dominance effects appeared, involving the 7 + 8 allele associated with high values for tenacity and extensibility. Key words: Hybrid wheat, bread-making quality, high molecular weight glutenin, Pelshenke, alveograph, grain hardness