bluuebunny/crossref_metadata_2025 huggingface dataset:
ANALYSIS OF AGRONOMIC CHARACTERS FOR AN ELEVEN-PARENT DIALLEL OF EARLY-MATURING SOYBEAN GENOTYPES IN EASTERN CANADA
Authors: LOISELLE F. , ST-PIERRE C. A. , VOLDENG H. D. , TURCOTTE P.
Published: March 2010

Information on the genetic behavior of early-maturing soybeans (Glycine max (L.) Merr.) in northern latitudes is important for the formulation of appropriate selection schemes. The Gardner-Eberhart diallel model was used to study genetic effects and combining abilities of 11 early-maturing genotypes (maturity Groups 00 and 000) of soybean grown in Quebec and eastern Ontario. Agronomic characters were measured on spaced F1 plants at one site, and on F2 populations in replicated row plots at three sites. Cultivar (additive) effects were predominant for all characters. Three of eleven lines had positive but unstable varietal parameters for seed yield. Average heterosis was significant for seed yield and plant height at every location. Contrary to other reports, significant negative heterosis for oil content was observed at two locations. Varietal and specific heterosis were significant for most characters.Key words: Soybean, Glycine max (L.) Merr., diallel, Gardner-Eberhart, yield, oil, protein
EFFECT OF ROW SPACING AND SEEDING RATES ON SUMMER RAPE IN SOUTHERN MANITOBA
Authors: MORRISON M. J. , McVETTY P. B. E. , SCARTH R.
Published: March 2010

To determine the effects of varying plant densities on summer rape (Brassica napus L.), the cultivar Westar was seeded in 15- and 30-cm row spacings at seeding rates of 1.5, 3.0, 6.0, and 12.0 kg ha−1. Plants seeded in 15-cm rows yielded more per area, produced more pods per plant and lodged less than those in 30-cm rows. Higher yields were associated with a more even plant distribution and a lower degree of intra-row competition. There were no significant protein, oil and chlorophyll concentration differences between the row spacing treatments. The highest yields (kg ha−1) were achieved with the 1.5 and 3.0 kg ha−1 seeding rates. Summer rape compensated for lower plant densities with the production of more branch racemes. As seeding rate increased, competitive mortality increased, resulting in greater etiolation at bolting, and greater lodging at harvest. Seed oil and protein concentrations were not affected by seeding rate. However, seed chlorophyll concentration decreased with increased seeding rate.Key words: Brassica napus, plant density, seed quality, rape (summer)
EFFECT OF RATE, TIMING AND PLACEMENT OF N FERTILIZER ON STUBBLED-IN WINTER WHEAT GROWN ON A BROWN CHERNOZEM
Authors: CAMPBELL C. A. , McLEOD J. G. , SELLES F. , DYCK F. B. , VERA C. , FOWLER D. B.
Published: March 2010

Winter wheat (Triticum aestivum L.) production in Saskatchewan has increased in recent years due to the introduction of Norstar, a winter hardy variety, and due to the reduction in winter injury when the crop is seeded directly into standing stubble (stubbling-in). Large variations in the amount and distribution of seasonal precipitation in the Brown soil zone may prove detrimental to the adoption of this system. If implemented, fertilizer recommendations will need to be developed to fit this cropping system. A 4-yr study was conducted at Swift Current, Saskatchewan on an orthic Brown Chernozemic silt loam soil to determine the effect of rate, season of application, and placement of urea-N on grain yields and protein concentration of stubbled-in winter wheat. Plant density was unaffected by N. In 1984–1985 and 1986–1987 adequate weather conditions from seeding to early spring resulted in acceptable plant stands, but in 1985–1986 suboptimal winter temperatures and in 1987–1988 severe drought during fall and early spring reduced over-winter survival of wheat. Only 1 year provided better-than-average growing season weather conditions and thus good yields. Grain protein was < 11.5% (the critical lower level for milling) in two of the 4 years. In 1 year, a dry fall and winter coupled with a prolonged hot, dry early spring resulted in poor grain yields and very high protein concentrations (20–22%). Fertilizer-nitrogen, broadcast at 50 kg ha−1 at seeding, resulted in yields and grain protein concentrations similar to those when N was broadcast in April. Band placement of N was superior to broadcast application only in terms of grain protein concentration and N fertilizer recovery. There was no difference between banding N at 5 and 10 cm depth. In all years studied, application of N at 100 kg ha−1 was excessive for this system. It was concluded that producers should be cautious in attempting to grow stubbled-in winter wheat in the Brown soil zone.Key words: Yield, grain protein, N recovery, plant population, kernel weight
NITROGENASE ACTIVITY OF COWPEA (Vigna unguiculata (L.) Walp.) DURING AND AFTER DROUGHT STRESS
Authors: PARARAJASINGHAM S. , KNIEVEL D. P.
Published: March 2010

Greenhouse experiments were conducted with the objectives (1) to investigate the nitrogenase activity (NA) of cowpea (Vigna unguiculata (L.) Walp.) root nodules during the development of and subsequent recovery from drought stress and (2) to determine whether the changes in NA during and following drought stress are related to nodule water potential. Nitrogenase activity of root nodules decreased by more than 80% within 6–8 d of withholding water and recovered 1 or 2 d after watering. Nodule water potential declined significantly from approximately −0.2 MPa to −0.48 MPa with 8 d of stress and recovered to prestress levels within 24 h after watering. Midday abaxial stomatal conductance decreased significantly with stress but recovered within 24 h following watering. Midday leaf water potential did not change significantly during the experimental period. Nodule NA declined 2 d before that of nodule water potential in apparent response to declining soil water content. This response and the lag in the recovery of NA following drought stress after nodule water potential had returned to prestress levels support the hypothesis that nodule water potential per se is not the primary cause for the decline in NA of cowpea root nodules during drought stress.Key words: Vigna unguiculata (L.) Walp., nitrogenase activity, drought stress, recovery, cowpea
THE INFLUENCE OF VARIOUS CULTURAL FACTORS ON ANTHER CULTURE OF FOUR CULTIVARS OF SPRING WHEAT (Triticum aestivum L.)
Authors: McGREGOR LINDA J. , McHUGHEN ALAN
Published: March 2010

Four spring wheat cultivars (Katepwa, Columbus, Chris and Israel 676) were compared for androgenic ability. Temperature, medium, agar concentration and cold pretreatment were examined to find the optimal combinations for anther culture of Katepwa and Columbus in particular. At an incubation temperature of 30 °C, anthers of Chris were significantly more responsive than the other genotypes. In three temperature treatments (26, 28 and 30 °C) the potato extract medium (P1) was superior to the synthetic medium (N6) (Chu 1978) for callus induction and green plant regeneration. Over all genotypes, liquid media provided greater anther response than either 0.8% or 1.8% agar. At 28 °C, cultured anthers showed no significant increase in callus formation after being subjected to a cold pretreatment. A cold pretreatment prior to culture at 30 °C elicited a significant decrease in callus formation as compared with no cold pretreatment. However, maximum callus induction and regeneration frequencies for Katepwa and Columbus were obtained at 28 °C in the P1 liquid medium with cold pretreatment. An incubation temperature of 26 °C was inferior to 28° and 30 °C for callus induction and regeneration.Key words: Anther culture, wheat, genotype, incubation temperature, media, agar concentration
EFFECTS OF TEMPERATURE ON PHOTOSYNTHATE PARTITIONING IN ALFALFA
Authors: AL-HAMDANI SAFAA , TODD GLENN W.
Published: March 2010

This study was conducted to examine the effects of three temperature regimes (12/2 °C, 21/8 °C, and 34/25 °C day/night) on photosynthate partitioning in alfalfa (Medicago sativa L.). Plants were grown under greenhouse conditions for approximately 3 mo and then clipped back. When regrowth was at the bud stage, the plants were placed in growth chambers at the three temperatures, all having a photoperiod of 14 h. Two hours after the onset of the photoperiod of the second day, foliar application of 14C-labelled urea was used to provide a source of 14CO2 for tracing the movement of photosynthate from the source leaf to other parts of the alfalfa plant. Plants were harvested 24 h later and each plant was subdivided into six portions. The plant parts included the source leaf, treated upper shoot, treated lower shoot, untreated shoot, crown and roots. The percent of 14C exported of the total recovered radioactivity by the source leaf increased as temperature increased. As temperature increased, radioactivity recovery was increased in treated upper shoot, untreated shoots, and roots. The highest recovery of 14C by the crown was at 21/8 °C. followed by those in 12/2 °C and 34/25 °C, respectively. Total 14C recovered from the treated lower shoot was decreased as temperature increased.Key words: Relative specific activity (RSA), total plant radioactivity, translocation, 14C, Medicago sativa L., alfalfa
RELATIONSHIPS AMONG FREEZING, LOW TEMPERATURE FLOODING, AND ICE ENCASEMENT TOLERANCE IN ALFALFA
Authors: BOWLEY S. R. , McKERSIE B. D.
Published: March 2010

In order to select cultivars with improved tolerance to environmental stresses, the relationship among tolerance to environmental stresses needs to be determined. This study evaluated 16 populations of alfafla for their tolerance to freezing (−8 to −16 °C), low temperature flooding (21 and 28 d), and ice encasement (10 and 14 d). Stresses were applied on field-grown plants excavated in November. Dry matter yield of the regrowth was determined 40 d following application of the stress. Two stands differing in plant ages (seeding year and first production year) over 2 yr were assessed. Seeding year plants were smaller in size, had fewer crown buds, lower moisture contents, and greater regrowth yields in the absence of stress. Regrowth yield was linearly related to stress level. Seeding year plants had greater absolute reductions in yield when subjected to freezing and icing stress, but less relative (to control) yield reduction when subjected to freezing stress compared to first production year plants. Plant age did not affect yield reduction of plants exposed to icing stress. Superiority index (Pi) ranking of the populations varied with environmental stress and was not correlated with moisture content, number of buds, or fall growth habit. Differential rankings of Pi among the freezing, flooding, and ice encasement stresses indicated that tolerance to one environmental stress will not necessarily give tolerance to other stresses. Selection for improved stress tolerance in alfalfa should be based on assessment of all stresses.Key words: Alfalfa, stress tolerance, environmental stress, Medicago sativa L.
HERBICIDES FOR WEED CONTROL IN SAFFLOWER (Carthamus tinctorius)
Authors: BLACKSHAW R. E. , MUENDEL H.-H. , DERKSEN D. A.
Published: March 2010

Field studies were conducted in 1986, 1987 and 1988 at Lethbridge, Alberta and in 1987 and 1988 at Indian Head, Saskatchewan to determine herbicides suitable for selective control of weeds in safflower (Carthamus tinctorius L.). Safflower exhibited acceptable tolerance to trifluralin, ethalfluralin, sethoxydim, fluazifop-p-butyl, clethodim, diclofop methyl, difenzoquat, imazamethabenz, chlorsulfuron, thiameturon, metsulfuron and DPX-A7881 over all years and locations. These herbicides offer the grower the option of preplant incorporated or postemergent herbicide application or a combination of the two. A mixture of thiameturon plus DPX-L5300 caused severe injury to safflower, reducing yield, oil content, and seed weight. Desmedipham, phenmedipham, and mixtures of these herbicides injured safflower at Lethbridge but not at Indian Head. Weeds reduced safflower yield by 39–73% over the 3 yr of the study. Control of weeds in safflower is essential to obtain optimum yields.Key words: Crop tolerance, seed yield, oil content, seed weight, weed competition
EFFECTS OF DEFOLIATION OF WINTER RYE AT VARIOUS TIMES ON GRAIN PRODUCTION IN SOUTHWESTERN SASKATCHEWAN
Authors: McLEOD J. G.
Published: March 2010

The effects of fall, spring, and spring plus fall defoliation were studied in four winter rye (Secale cereale L.) cultivars for 2 yr. On average, the three treatments reduced grain yield by 8.7%, 16.6% and 23.2%, respectively, compared to the untreated check. The four cultivars responded similarly.Key words: Secale cereale L., rye (fall), simulated grazing, defoliation, cereals (winter)
OSLO RED SPRING WHEAT
Authors: GRAF R. J. , HUCL P. , SMITH J. , SONG L. S. P.
Published: March 2010

Oslo red spring wheat (Triticum aestivum L.) is a mid-season, semidwarf wheat with intermediate yield potential, eligible for grades of Canada Prairie Spring. Oslo performs best in the black soil zone; it is not well adapted to areas prone to pre-anthesis drought stress. Breeder seed of Oslo will be maintained by Saskatchewan Wheat Pool Product Development, Watrous, Saskatchewan.Key words: Triticum aestivum, wheat (spring), high yielding, cultivar description
LA FERTILISATION DU TABAC À CIGARETTE À L’AIDE D’ENGRAIS CONCENTRÉ
Authors: LAMARRE MICHEL , PAYETTE SUZANNE
Published: March 2010

During 5 yr, we studied the effect of ratio and concentration of N:P:K on flue-cured tobacco production. Each of the five ratios was studied at three different concentrations. The ratio 1:4:6 was superior to the ratios with a lower concentration of phosphorus such as 1:2:3 and 1:1:3. No significant differences within agronomic and chemical data resulted with the concentration of fertilizers within a ratio. The data showed the possibilities of increasing concentrated fertilizers in tobacco production.Key words: Flue-cured tobacco, nitrogen, phosphorus, potassium, ratio and concentrated fertilizer
INFLUENCE DE L’ENRICHISSEMENT CARBONÉ ET DE SON MODE DE DISTRIBUTION SUR L’ÉVOLUTION DES ÉCHANGES GAZEUX DE LA TOMATE DE SERRE
Authors: DUGAL A. , YELLE S. , GOSSELIN A.
Published: March 2010

Net photosynthesis, stomatal conductance, internal CO2 concentration and transpiration were measured on the fifth well-developed and excised leaf of tomato seedlings (Lycopersicon esculentum Mill. ’Vedettos’) 48–83 d old. These measurements were taken in order to monitor the evolution of the gas exchanges of seedlings exposed to concentrations of 330 or 1000 ppm, continuously, to 1000 ppm from 06: 00 h to 10: 00 h or to 1000 and 330 ppm alternately every 2 h. CO2 enrichment substantially increased the net photosynthesis rate of the seedlings, particularly at the beginning of the experiment. The long-term effects of CO2 enrichment subsided after a few weeks of treatment. Intermittent CO2 enrichment is partially helpful in remedying the loss of effectiveness of the CO2 after a long period of enrichment. High CO2 concentrations reduced the opening of the stomata. Our work shows that maintaining a high internal CO2 content in the leaves would indirectly reduce the stomatal conductance of the seedlings. However, our results show that the long-term loss of photosynthetic efficiency in the enriched seedlings cannot be attributed solely to an increase in the resistance of the stomata, since the internal CO2 concentration of the leaves remains very high regardless of which method of CO2 enrichment is used. Continuous CO2 enrichment improved the water uptake efficiency of the seedlings.Key words: Carbon dioxide, intermittent enrichment, gas exchanges, tomato, greenhouse, Lycopersicon esculentum Mill.
COPPER AND ZINC NUTRITION OF RUSSET BURBANK POTATOES GROWN ON PRINCE EDWARD ISLAND
Authors: SANDERSON J. B. , GUPTA UMESH C.
Published: March 2010

Field experiments were conducted on potatoes (Solanum tuberosum L.) at two locations in P.E.I. to determine the response to soil- and foliar-applied Cu and Zn on tuber yield and leaf tissue nutrient concentration over a period of 3 yr. Foliar applications of 0.5–2 kg Cu ha−1 applied 1–2 wk prebloom reduced total tuber yield, number of tubers over 55 mm in diameter, average tuber weight, and specific gravity. The mean potato yield of tubers over 55 mm from the foliar-applied Cu treatments was less than the soil applied Cu by 4.5, 0.74, and 7.5 t ha−1 for 1985, 1986, and 1987, respectively. The toxic concentrations of Cu in potato leaves ranged from 63 to 139 μg g−1. Soil-applied Cu increased tissue Cu in the first sampling but had no effect in the second sampling. Foliar applications of Zn at 1–2 kg ha−1 reduced total tuber yield, tuber yield and tuber count over 55 mm, and specific gravity. The toxic concentrations of Zn in potato leaves ranged from 97 to 224 μg g−1. For the first sampling, the leaf tissue Zn concentrations ranged from 21 to 30 μg g−1 for the control and 27 to 70 μg g−1 for soil-applied Zn treatment. There was no difference in the Zn concentration between these two treatments for the second sampling. Copper and Zn concentrations as low as 7 and 21 μg g−1, respectively, in potato leaves were not related to deficiency of these nutrients, based on tuber yields. Soil applications of Cu or Zn would appear preferable to foliar sprays, which may cause phytotoxicity, as a means of increasing plant Cu or Zn content where a deficiency is suspected.Key words: Solanum tuberosum L., tuber yield, leaf copper, leaf zinc, Podzolic soil, potato
INFLUENCE DE TRAITEMENTS PRÉALABLES AU FROID SUR LA CROISSANCE ET LE DÉVELOPPEMENT DU POINSETTIA
Authors: GAGNON SERGE , DANSEREAU BLANCHE
Published: March 2010

To achieve more rapid adaptation of plants grown under a constant cold night temperature regime, rooted poinsettia (Euphorbia pulcherrima Willd ex. Klotzsch ’Annette Hegg Dark Red’) cuttings were given one of several cold pretreatments (TPF): either 17/13 °C or 13 °C for 5, 10, or 15 d. The influence of these TPF treatments was compared with that of control plants where the night temperature was 17 °C. There was no significant difference for the number of days to the first visible flower buds and to anthesis, for the number of flowering stems and bracts formed, for leaf area and aerial dry weight. However, the TPF treatment of 17/13 °C given for 15 d caused a significant increase in bract area, and of average flower head diameter compared to those plants given a TPF treatment of 13 °C for the same length of time.Key words: Euphorbia pulcherrima, night temperature, split night temperature, pretreatment
EFFECT OF SEEDING DEPTH AND TEMPERATURE ON TILLERING CHARACTERISTICS OF FOUR SPRING WHEAT CULTIVARS
Authors: HUCL P. , BAKER R. J.
Published: March 2010

This study was conducted to investigate the effects of seeding depth and temperature on tillering patterns of cultivars of spring wheat (Triticum aestivum L.) with diverse tillering capacities. Four cultivars (Ingal, Neepawa, Pitic 62 and Potam) were grown at three seeding depths (3, 6 and 12 cm) and two temperature regimes (10/5 °C and 20/10 °C) in a controlled environment. Times to emergence of individual tillers were recorded as were their biomass, leaf area and leaf number at the time of main stem spike emergence. Increasing the seeding depth from 3 to 6 cm delayed seedling emergence, and reduced and delayed emergence particularly of the coleoptilar (TO) and first leaf (T1) tillers of all cultivars. Increased temperature resulted in reduced time to seedling and tiller emergence for all cultivars, increased (+13%) final tiller number in Pitic 62, little change in final tiller numbers of Neepawa and Ingal, and a significant reduction (−24%) in final tiller number for Potam. Pitic differed from other cultivars in having a vernalization requirement that affected its response to temperature. Potam differed from the other cultivars in showing an increase in main stem apical dominance with increased temperature. Tillers which had produced a minimum of three or four leaves, depending on the cultivar, had not senesced at the time of main stem spike emergence.Key words: Wheat (spring), tillering, seeding depth, temperature, cultivar-environmental interaction
THE INFLUENCE OF MINERAL NUTRITION ON THE EXPRESSION OF TRAITS ASSOCIATED WITH WINTERHARDINESS OF TWO WINTER WHEAT (Triticum aestivum L.) CULTIVARS
Authors: HETHERINGTON P. RICHARD , McKERSIE BRYAN D. , KEELER LISA C.
Published: March 2010

Two winter wheat (Triticum aestivum L.) cultivars, Fredrick and Norstar, which differ in their winterhardiness potential, were compared with regard to the effects of nitrogen (N), phosphorus (P) and potassium (K) application, during acclimation, on the expression of four traits associated with winterhardiness — freezing, ice-encasement, and low temperature flooding tolerances and crown moisture content. Modified Hoagland’s nutrient solutions containing five levels of each nutrient were applied to the seedlings during a 5-wk acclimation period at 2 °C, and subsequently the crowns were tested for their ability to survive varying intensities of the stress treatments. Increasing the level of applied N from 0, caused a reduction in the level of all stress tolerances. Increased P did not significantly alter the expression of freezing tolerance, but tended to increase tolerance of the anaerobic stresses, icing and low temperature flooding, to an optimum. Increased K had minimal effects on stress tolerance at the levels tested. Increased levels of each nutrient increased crown moisture content. The cultivar Norstar was consistently more tolerant of freezing and icing stress than Fredrick and this relative ranking was not influenced by mineral nutrition. However, the relative ranking for low temperature flooding tolerance varied depending on the nutrients provided to the seedlings. The results suggest that environmental and growth regulatory factors which influence the uptake of mineral nutrients would be expected to influence crown moisture content, and the expression of stress tolerance.Key words: Freezing, ice-encasement, flooding
DRY MATTER PRODUCTION AND NITROGEN ACCUMULATION IN NO-TILL WINTER WHEAT
Authors: DARROCH B. A. , FOWLER D. B.
Published: March 2010

Norstar winter wheat (Triticum aestivum L.) was examined in 11 trials with the objective of determining the pattern of dry matter and nitrogen (N) accumulation in dryland stubbled-in winter wheat grown in Saskatchewan. In all 4 yr of this study, replicated no-till field trials were supplemented with 0, 34, 67 and 100 kg N ha−1 applied as ammonium nitrate (34-0-0) in early spring. A fifth treatment of 200 kg N ha−1 was evaluated in the final year of trials. Plant samples were collected at 2-wk intervals. Early season N uptake was more rapid than dry matter accumulation and 89% of the total N, compared to 70% of the total dry matter, was present at anthesis (Zadoks growth stages 60–68). Poor soil moisture availability limited N uptake after anthesis. Consequently, N uptake during the growing season was best described by a quadratic equation, Nitrogen yield = −29.1 + 3.02 Z − 0.018 Z2, where Z represents the Zadoks growth stage. Nitrogen concentrations of the stems and leaves decreased during the growing season while the N concentration of spikes varied among trials. Nitrogen fertilization often produced large increases in tissue N concentration at the beginning of the growing season. These differences decreased with time and by the end of the season tissue N concentrations were usually similar for all N rates. In general, when residual soil N levels were low to intermediate and rainfall was adequate, N fertilization increased dry matter yield, plant N yield, grain yield and grain protein yield. Nitrogen fertilization increased plant N concentration, plant N yield, grain protein concentration and grain protein yield when soil N reserves were intermediate to high and rainfall was adequate.Key words: Nitrogen uptake, wheat (winter), nitrogen response, tissue nitrogen, grain protein, environment
THE BIOLOGY OF CANADIAN WEEDS. 94. Sonchus arvensis L.
Authors: LEMNA WANDA K. , MESSERSMITH CALVIN G.
Published: March 2010

Perennial sow-thistle (Sonchus arvensis L.) was introduced into North America from Europe and Asia and is distributed widely throughout the Canadian provinces. Two varieties are common; var. arvensis and var. glabrescens differ morphologically in the presence or absence of glandular hairs on peduncles and involucral bracts, respectively. Both varieties are common along roadsides and river and lake shores and in waste areas and cultivated fields throughout their introduced and native ranges. The perennial nature and ability to spread both by spreading roots and by seed make these weeds difficult to control. Details on the morphology, cytology, distribution, reproductive and population biology, and control methods are reviewed.Key words: Distribution, perennial sow-thistle, smooth perennial sow-thistle, weed biology
HERITABILITY OF IN VITRO REGENERATION IN WHEAT (Triticum aestivum L.)
Authors: CHEVRIER N. , QURESHI J. A. , KARTHA K. K. , HUCL P.
Published: March 2010

This study measured the heritability of in vitro regeneration in wheat (Triticum aestivum L.). Immature embryos of 28 F2-derived families of the spring wheat cross HY912 × HY320 were cultured in the F3, F4, and F5 generations. Highly significant (P < 0.01) genotypic differences were observed for embryo germination, callus induction, embryogenic callus formation, and plantlet regeneration. Comparisons of generation means and mid-parent values suggest that additive variance is an important factor in the inheritance of in vitro regeneration.Key words: Regeneration, in vitro, heritability, Triticum aestivum, wheat
EFFECT OF ROW SPACING ON BIOMASS PRODUCTION AND ABOVEGROUND HARVESTABILITY OF RUSSIAN WILDRYE
Authors: LEYSHON A.J. , CUTFORTH H. , WADOINGTON J. , RYMES P. C.
Published: March 2010

Russian wildrye (Psathyrostachys juncea [Fischer] Nevski) was grown in 15- and 60-cm row spacings at Swift Current, Saskatchewan. Beginning in the third year after establishment and continuing for 4 yr, dry matter yields taken by machine were compared to yields taken by hand in a two-cut system. The machine harvested 54% of the available dry matter in the 60-cm rows but only 27% in the 15-cm rows. Apart from one cut in 1 yr, there were no significant yield differences due to row spacing when the forage was harvested by hand. The results indicate the need for more research on the effects of row spacing, especially with regard to the grazing animal.Key words: Psathyrostachys juncea (Fischer) Nevski in Komarov, hand sampling, machine harvesting, plant morphology, forage yield
EFFETS DE LA COMPOSITION DU SUBSTRAT TOURBEUX ET DU VOLUME DES SACS DE CULTURE SUR LA PRODUCTIVITÉ DE LA TOMATE DE SERRE
Authors: OUIMET ROCK , CHARBONNEAU JOSÉE , GOSSELIN ANDRÉ , PARENT LÉON-ÉTIENNE , BLAIN JACQUES , JOYAL PIERRE
Published: March 2010

A large-fruited greenhouse tomato cultivar (Lycopersicon esculentum Mill. ’Dombello’) was grown in 12-, 24- and 36-L bags containing three types of peat:perlite substrates (85:15, 70:30 and 55:45, vol:vol). The control consisted of 36-L bags containing peat only. Plant density was three plants per bag, i.e. 3.22 plants m−2. Early and total yields of marketable and nonmarketable fruits were measured. Early yields were higher for plants grown in 12- or 24-L bags as compared to those grown in 36-L bags, although blossom-end rot followed the same trend. Seasonal cumulative yields were not influenced significantly by bag size and substrate composition. Reduced perlite content and bag size increased the incidence of blossom-end rot. The incidence of blossom-end rot and average fruit weight indicate that reduction of root-zone volume and air porosity increased water stress. Greenhouse tomatoes can be grown successfully in smaller bag sizes containing peat substrate amended with more than 15% perlite.Key words: Tomato, peat-lite substrates, root-zone restriction, blossom-end rot, fruit weight, grow bag
EFFECT OF TIME OF APPLICATION OF HERBICIDES ON YIELD OF THREE WINTER WHEAT CULTIVARS
Authors: IVANY J. A. , NASS H. G. , SANDERSON J. B.
Published: March 2010

In field experiments at Charlottetown, Prince Edward Island, herbicides were applied in the fall or spring on winter wheat (Triticum aestivum L.) to determine effect on yield. Application of 2,4-D or the mixture 2,4-D/mecoprop/dicamba in the fall gave significantly lower yields than when spring-applied on the cultivar Lennox. The herbicides MCPA, bromoxynil, dicamba, mecoprop, chlorsulfuron, MCPA/dicamba, and MCPA/bromoxynil had no adverse effect on yield of Lennox at either time of application. A further study on the cultivars Lennox, F29-76, and Borden using the herbicides MCPA, bromoxynil, MCPA/dicamba, chlorsulfuron, and dicamba showed no detrimental effects on 1000 kernel weight, or percent winter survival from fall or spring application. Yield losses were noted for spring application of dicamba but not for MCPA/dicamba and all cultivars responded similarly to all herbicide treatments.Key words: Wheat (winter) cultivars, fall versus spring application, 2,4-D, MCPA, dicamba, bromoxynil, chlorsulfuron
END-USE QUALITY OF MONTANA-GROWN HARD RED SPRING COMPARED TO HARD RED WINTER WHEATS
Authors: McGUIRE CHARLES F. , BLACKWOOD LARRY G.
Published: March 2010

The United States Department of Agriculture (USDA) grading standards for wheat places hard red spring and hard red winter (Triticum aestivum L. em. Thell) wheat into separate classes. One important criterion for this designation is kernel type. Because of genotypes being released by plant breeders in recent years, distinction between these two classes is difficult for grain graders. As a consequence some people in the grain industry favor placing both of these wheat types into one class. One hazard of this action is that end use properties of these two wheats, according to some industrial firms, is class dependent. We studied quality characteristics of five hard red spring and seven hard red winter wheat cultivars grown at the same three Montana locations in 5 different years to evaluate this concept. Analysis of variance indicated quality differences between classes for all traits except flour yields, which were similar for the two classes. Flour ash content, farinograph absorption, peak time, stability time, valorimeter, grain protein content, bake absorption, mix time, and loaf volume were all significantly higher for spring than winter wheats. These values were still higher for spring than winter wheats except for test weight when wheat protein content was the co-variate. Both statistical treatments show that hard red spring wheat flour has higher water absorption percent, longer dough mixing requirements, longer dough stability times, and higher loaf volumes than hard red winter wheat flour.Key words: Bread wheat quality, loaf volume, grain protein content, protein quality
SUPERIOR PERFORMANCE OF THE HUP−Bradyrhizobium japonicum STRAIN 532C in ONTARIO SOYBEAN FIELD TRIALS
Authors: HUME D. J. , SHELP B. J.
Published: March 2010

Field trials were conducted at different sites close to Guelph, Ontario, from 1981 to 1985, to evaluate the effects of Hup+ and Hup− strains on the performance of soybean (Glycine max L. Merrill) and to identify strains that could support high soybean yields under Ontario conditions. Each year six individual strains, Nitragin Soil Implant granular inoculant and an uninoculated control were compared for their effect on soybean yield. Soil at each experimental site was relatively free of indigenous B. japonicum as exhibited by an average of less than one nodule per plant from the uninoculated control plots. Inoculation with Hup+ or Hup− strains of B. japonicum caused similar average soybean seed yield. Of the inoculants tested (strains as well as commercial inoculant), the Hup− strain, 532C, also known as strain 61A152, supported the highest yields in 4 of the 5 yr. Omitting 1982 data, when soil available N was high and the uninoculated control had yields equivalent to inoculated plots, 532C treatments averaged 3.08 t ha−1 compared to 2.70 for 61A89, 2.84 for 61A133, 2.83 for the commercial inoculant and 1.96 for the uninoculated control. The consistent performance of 532C across years and locations suggested major advantages for this strain. Strain 532C is now being used as a single strain in five of the seven inoculants sold in Ontario.Key words: Soybean, inoculation, Hup+, seed yield
HERITABILITY OF PHYSICAL PROPERTIES AND OTHER QUALITY TRAITS IN TIMOTHY
Authors: SURPRENANT J. , MICHAUD R. , ALLARD G. , ST-PIERRE C. A.
Published: March 2010

An important aspect in breeding for improved quality is to identify and evaluate new selection criteria. The purposes of this work were (1) to evaluate genetic variability for three physical properties in timothy (Phleum pratense L.): packed volume (PV), water retention (WR) and water solubility (WS); these traits being potential indicators of voluntary intake, (2) to estimate their heritability, and (3) to determine the genetic relationship between these physical properties and some other quality traits. In this study, 25 clones and their half-sib families were evaluated over a 3-yr period for dry matter yield (DMY), crude protein (CP), digestibility (IVDMD), neutral detergent fiber (NDF), acid detergent fiber (ADF) and three physical properties. The genetic analysis revealed that most genetic variability was additive for these traits. Narrow sense heritability estimates for PV (0.77–0.93), WR (0.70–0.96) and WS (0.33–0.67) suggest that genetic gains could be expected from selection. The phenotypic correlations indicated that PV, WR and WS were positively correlated with CP and IVDMD but negatively correlated with NDF and ADF. The exception was WS, which was not correlated with CP. According to these results, selection for either lower PV or lower WR would have a detrimental effect on CP, IVDMD, NDF and ADF while selection for WS would have little if any effect on these traits.Key words: Digestibility, packed volume, water retention, water solubility, fiber
STABILITY OF SELF-INCOMPATIBILITY AND CROSS-COMPATIBILITY IN PARTIALLY SELF-INCOMPATIBLE ALFALFA CLONES
Authors: CAMPBELL T. A. , BAUCHAN G. R.
Published: March 2010

The stability of self-incompatibility and cross-compatibility in 10 partially self-incompatible clones selected as potential parents for hybrid seed production was evaluated in the growth chamber. Clones (nulliplex for a completely dominant "red root" (RR) trait) were cultured in four regimes (allowed to develop at a constant 22 °C or 27 °C or allowed to develop at 22 °C then acclimated at 27 or 35 °C for 72 h) then self-pollinated or crossed with one of two clones that were quadraplex or triplex for the RR trait. Clones transferred to 27 or 35 °C were returned to 22 °C after 1 wk. Seeds/flower tripped (S/FT) were computed and data derived from cross-pollination were adjusted using the formula S/FT × (% RR seedlings/100) before analysis. Mean S/FT were 0.81, 0.88, 0.66, and 0.36 for the 22 °C, 27 °C, 22 °C/27 °C and 22 °C/35 °C regimes, respectively. Temperature regimes had no significant effect on self-incompatibility but did affect cross-compatibility significantly in some clones. There was more autogamy at 27 °C and in the 22 °C/27 °C regime than in the other regimes. Mean percent RR seedlings was 78.3 and clones did not differ significantly in percent hybrid seed production. Variation in autogamy observed in these clones was not correlated significantly with variation in hybridity. Stability analyses revealed considerable variation among the clones in terms of potential for hybrid seed production.Key words: Medicago sativa L., autogamy, allogamy, red root, stability, hybrid, heterosis, heat shock
EFFECT OF ONE CYCLE OF DIVERGENT PHENOTYPIC SELECTION FOR CRUDE PROTEIN, DIGESTIBILITY AND DIGESTIBLE YIELD IN TIMOTHY
Authors: SURPRENANT J. , MICHAUD R. , ALLARD G.
Published: March 2010

A major goal in the breeding of timothy (Phleum pratense L.) is to improve its nutritive value. The objective of this study was to evaluate the effects of one cycle of divergent phenotypic selection for crude protein, digestibility and digestible yield. The progeny of genotypes selected either for high or low crude protein, high or low digestibility, and high or low digestible yield along with a subpopulation representing the unselected original parents were evaluated for dry matter yield and several forage quality characteristics under spaced plant and sward conditions. Under spaced plant conditions significant variation was observed for digestibility (IVDMD), crude protein (CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF). Under sward conditions, significant variation was observed for water retention (WR), ADF and NDF. Under spaced plant conditions, a priori contrasts indicated that one cycle of selection was sufficient to create distinct populations for CP in selecting for CP, for IVDMD and ADF with the IVDMD selection and in 2 out of 3 yr for digestible yield with selection for digestible yield. Evaluation under sward conditions indicated that selection for digestible yield modified CP, WS, ADF, NDF, PV and WR. The results from the evaluation under sward conditions were used to compute different parameters related to potential animal production such as dry matter intake, lactation net energy, energy intake, and different estimates of potential milk production that could be obtained from feeding this hay.Key words: Phleum pratense, timothy, quality, dry matter intake
FACTORS INFLUENCING THE TOLERANCE OF BARLEY TO FALL-APPLIED TRIFLURALIN
Authors: DARWENT A. L. , O’SULLIVAN P. A. , LEFKOVITCH L. P.
Published: March 2010

The effects of cultivar × date of seeding and of depth of seeding × date of seeding on the tolerance of barley (Hordeum vulgare L.) to a granular formulation of trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl) benzenamine] applied the fall prior to seeding were studied in field experiments from 1982 to 1985 at Beaverlodge, Alberta and from 1983 to 1985 at Lacombe, Alberta. At Beaverlodge, barley yields were generally unaffected by trifluralin at 1.1 kg (active ingredient) ha−1, while at Lacombe they were not affected by the herbicide at rates to 1.4 kg ha−1. In the single incidence where barley yields were reduced by the 1.1 kg ha−1 rate at Beaverlodge (i.e. yields were 30% lower from plots sprayed with trifluralin at this rate than from unsprayed plots) moisture stress following crop emergence appeared to increase stress from the herbicide. Injury occurred from trifluralin at rates above 1.1 kg ha−1 at Beaverlodge and 1.4 kg ha−1 at Lacombe. No differences in tolerance to the herbicide were observed among 10 cultivars seeded at Beaverlodge or 4 cultivars seeded at Lacombe. Similarly, no consistent trends in the tolerance of barley to trifluralin were observed as a result of depth of seeding or its interaction with date of seeding. Losses in yield caused by the herbicide were no greater when the barley was seeded as early as possible in the spring into cool soils (mean weekly soil temperatures as low as 5.2 °C) than when it was seeded later in the spring when soil temperatures were above 10 °C. Also, yield losses due to herbicide injury were no greater for barley seeded at a depth of 10 cm than for barley seeded at a depth of 5 cm. Keywords: Trifluralin, barley, cultivar, seeding depth, seeding date
SYMKO BARLEY
Authors: HO K. M.
Published: March 2010

Symko is a two-rowed spring feed barley (Hordeum vulgare L.) suitable for growing in Eastern Canada. It has high yield, high test weight, large kernels, good lodging resistance and is resistant to powdery mildew. Breeder seed of Symko is being maintained by the Plant Research Centre, Agriculture Canada.Key words: Hordeum vulgare L., barley (two-rowed spring feed)Symko is a high-yielding, two-rowed spring barley (Hordeum vulgare L.) developed at the Plant Research Centre, Agriculture Canada and tested under number OB751-27 by the Ontario Cereal Crops Committee. It has short rachilla hair and does not meet the quality standards required in a malting type. Registration no. 3135 was issued for Symko on 4 July 1989 by the Food Production and Inspection Branch of Agriculture Canada. This cultivar is named in recognition of Mr. S. Symko’s significant contribution to the cereal breeding program as a former cereal cytogeneticist at the Ottawa Research Station, Agriculture Canada.
RCAT ALLIANCE SOYBEAN
Authors: ABLETT G. R. , BEVERSDORF W. D.
Published: March 2010

RCAT Alliance is a late Maturity Group I soybean [Glycine max L. (Merr.)] cultivar which carries the Rps1-c gene for resistance to the major races of Phytophthora megasperma f. sp. glycinea in Ontario.Key words: Soybean, cultivar description
MANAGEMENT PROGRAMS FOR THE LOWBUSH BLUEBERRY: NATIVE STAND VS. CULTIVATED CLONES AND SEEDLINGS
Authors: BLATT C. R. , O’REGAN R. J.
Published: March 2010

An economic analysis was carried out using costs and returns for the establishment of a 3-ha planting of a mixture of cultivated lowbush blueberry clones and seedlings and the establishment of a similar sized native stand of wild blueberries. Two management programs were applied to two 3-ha cultivated stands and these were compared with the traditional crop-burn-crop program used in the native stand. Capital and startup costs were higher for the cultivated blueberry stand, but crop productivity and returns were also higher. Over a 20-yr lifetime, internal rates of return (IRR) averaged 10% higher for cultivated stands. A 20% market price drop would result in a 6–7% IRR decrease for the cultivated stand; however, the resultant 15% IRR is still an acceptable return. In contrast, a similar price drop for the native stand product caused the IRR to drop from 11% to zero. However, should market price be equivalent for native and cultivated stands, the IRR for the native stand is higher at all prices. With the native stand IRR at 11%, there has to be a 40–45c kg−1 price differential against the cultivated stand in order for all IRR values to be similar.Key words: Economics, internal rate of return (IRR), sensitivity analysis, Vaccinium angustifolium Ait.
HUMIDITY AND SOIL WATER INFLUENCE THE TRANSPIRATION RESPONSE OF MAIZE TO CO2 ENRICHMENT
Authors: BARR ALAN G. , KING K. M. , THURTELL G. W. , GRAHAM M. E. D.
Published: March 2010

The impact of increasing atmospheric CO2 on the productivity of C4 crops may vary with soil water availability. This study investigates the hypothesis that elevating CO2 in Zea mays L. reduces the degree to which transpiration is limited by soil water at high vapor pressure deficits or low soil water contents. Plants growing in controlled environments at 300 and 600 μmol mol−1 CO2 were exposed daily to five levels of vapor pressure deficit as water was withheld and the soil dried over an 8-d period. Doubling CO2 caused an overall reduction of 23% in the transpiration rate and 34% in the leaf conductance, but the effect of CO2 on transpiration and leaf conductance was greatest at high soil water content and low vapor pressure deficit, when soil water least limited transpiration. Implications for the productivity of C4 crops in the field are discussed.Key words: Maize, transpiration, carbon dioxide, soil water, vapor pressure deficit, controlled environment
DYNAMICS OF DRY MATTER, N AND P ACCUMULATION IN THE DEVELOPING KERNELS OF FOUR SPRING WHEAT CULTIVARS FOR IRRIGATION AND DRYLAND
Authors: CAMPBELL C. A. , CUTFORTH H. W. , SELLES F. , DEPAUW R. M. , CLARKE J. M.
Published: March 2010

The effect of moisture and cultivar on the dynamics of N and P concentration and on dry matter, N and P accumulation of the developing central kernels on the main spike of four wheat (Triticum spp.) cultivars were determined. Two common wheat (T. aestivum L.) cultivars, Neepawa and HY320, and two durum (T. turgidum L. var. durum) cultivars, DT367 and Wakooma, were grown on an Orthic Brown Chernozem in southwestern Saskatchewan in 1985. HY320 and DT367 have higher grain yield potentials and lower protein concentrations than Neepawa and Wakooma. Logistic equations satisfactorily decribed the accumulation patterns of dry matter, N, and P contents in the kernels from anthesis to maturity, while linear and second degree polynomials adequately described the variations in N and P concentrations. Response of N and P concentration to moisture and cultivar was variable but could be explained in terms of rate and amount of dry matter accumulation in kernels and the greater mobility and availability of N compared to P in soil. N and P accumulation was mainly dependent on kernel dry matter response, although N and P concentration did influence accumulation patterns under irrigation. Duration of accumulation of dry matter, N and P in kernels were equal under dryland, but under irrigation the period was several days longer for N than for dry matter and P. Cultivar had no effect on duration of N accumulation under irrigation, but on dryland duration was shortest for Neepawa. For P accumulation, duration was longest for HY320. The mean rates of accumulation of kernel dry matter, N, and P were directly related (R2 = 0.98**) to kernel dry matter, N, and P content, respectively.Key words: Wheat, Triticum aestivum L., Triticum turgidum L. var. durum, filling rate, filling duration
Fusarium SPECIES ISOLATED FROM WHEAT SAMPLES CONTAINING TOMBSTONE (SCAB) KERNELS FROM ONTARIO, MANITOBA, AND SASKATCHEWAN
Authors: CLEAR R. M. , PATRICK S. K.
Published: March 2010

The Fusarium spp. associated with samples of wheat seed containing tombstone kernels were identified for 454 samples collected in 1986 and 1987, representing six wheat classes from three provinces. The results indicate that the frequencies and distribution of the 13 species isolated were influenced by geographic location, growing conditions and wheat class. In 1986 and 1987, F. graminearum infected the most seeds and samples of Ontario-grown wheats. It was also the most frequently recovered species from Manitoba wheats in 1986, but was absent from the Saskatchewan wheats. In 1987, F. avenaceum was isolated from the greatest percentage of seeds from Manitoba and Saskatchewan. The greatest percentage of Manitoba samples in 1986 and 1987 were infected by F. sporotrichioides whereas F. acuminatum infected the most Saskatchewan samples. Only F. graminearum infected more than 7% of the seeds of any sample of Canada Western Red Spring, Canada Prairie Spring, Canada Eastern White Winter, Canada Eastern Red Winter, or Canada Eastern Red Spring class of wheat (to a maximum of 52%), whereas five species (F. acuminatum, F. avenaceum, F. equiseti, F. poae, and F. sporotrichioides) exceeded that level in one or more samples of the Canada Western Amber Durum class. The other seven Fusarium spp. (F. compactum, F. crookwellense, F. culmorum, F. proliferatum, F. oxysporum, F. pallidoroseum, and F. subglutinans) combined accounted for <5% of isolates. Overall, the lowest frequency of Fusarium spp. was found in the Canada Western Red Spring class of wheats, and the highest in the Canada Western Amber Durum class.Key words: Fusarium, wheat, disease, graminearum, avenaceum, scab