bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF SOIL MOISTURE ON THE EFFICACY OF FOLIAR-APPLIED WILD OAT HERBICIDES
Authors: WILCOX D. H. , MORRISON I. N. , MARSHALL G.
Published: March 2010

In controlled environment experiments, the efficacy of diclofop methyl applied to wild oat was reduced more than the efficacy of difenzoquat or flamprop methyl when the soil water content (SWC) was cycled between −0.24 and −2.18 MPa (low SWC) compared to when it was cycled between −0.03 and −0.06 MPa (high SWC). Similarly, at low SWC diclofop methyl was much less effective than either fluazifop-p-butyl or sethoxydim in reducing the post-treatment dry weight accumulation of the weed.Key words: Oat (wild), soil moisture, diclofop methyl, flamprop methyl, difenzoquat, fluazifop-p-butyl
CRYOPRESERVATION OF APPLE GENETIC RESOURCES
Authors: STUSHNOFF C.
Published: March 2010

Key words: Cold hardness, gene conservation, Malus cryopreservation
IMPACTS OF FREEZING TEMPERATURES ON CROP PRODUCTION IN CANADA
Authors: BROWN D. M. , BLACKBURN W. J.
Published: March 2010

Subzero temperatures are the most widespread hazard to crop production in Canada. This hazard ranges from temperature occurrences near 0 °C in spring and fall that damage many annual crops and some perennials to the winter occurrences of −30 °C and lower that damage or kill vegetative and/or reproductive tissues of some perennial species. Terminology, types of freeze damage, and the freeze risk are reviewed and discussed here along with some examples of the occurrence and adverse impact of freezing temperatures for the range of annual, winter annual and perennial crops grown in Canada. Spring grain losses from freeze damage occur about once every 3–4 yr in Saskatchewan, less frequently in Alberta (except the Peace River region), Manitoba and the northern clay belts in Ontario and Quebec, and seldom in the remainder of eastern Canada. Frequency of canola losses on the Prairies has been similar to cereals over the past 10–12 yr. The availability of short-season corn and soybean cultivars has expanded the production of these crops to areas with fewer than 2300 heat units over the last 20 yr. This has resulted in more frequent losses of these crops from fall freezes. Major losses of seed-corn occurred in southwestern Ontario on three occasions from 1965 to 1974, but very little freeze damage has occurred since 1974. Losses of vegetable crops from freezing occur less frequently than other crops because of the well-established cultural practices developed over the years that avoid or protect from frost. The high value per unit area of most vegetables makes freeze protection more affordable when needed. Forages and winter annuals are killed more frequently in central and eastern Canada by smothering and desiccation from formation of ice sheets than from low winter temperatures. Injury to young shoots and leaf buds of these crops occurs periodically from spring freezes. Losses of fruit trees occur periodically and apparently occurred more frequently 20–35 yr ago in British Columbia, whereas losses have been more severe in recent years in eastern Canada. Major declines in tender fruit production occur once or twice every 5–10 yr depending on location. Temperatures of −30 °C or lower may kill the tender fruit trees and −25 °C may damage the buds in winter, although late spring frosts during bloom reduce production more frequently.Key words: Frost hazard, crop losses, indemnities
EFFECT OF NITROGEN FERTILIZER ON THE AGRONOMIC PERFORMANCE AND SEED QUALITY OF ANNUAL CANARYGRASS
Authors: HOLT N. W.
Published: March 2010

Nitrogen (N) fertilizer was broadcast applied at rates of 0, 25, 50, 75 and 100 kg N ha−1 to annual canarygrass (Phalaris canariensis L.) in a field experiment at Indian Head, Saskatchewan each year from 1978 to 1983. Nitrogen fertilizer applied at seeding had no effect on days from seeding to emergence, heading or maturity or on 1000-seed weight. Nitrogen had a positive linear effect on seed N content and a negative linear effect on test weight in all years. There were positive linear and quadratic effects of applied N on seed yields, suggesting a maximum yield in the range of 50 – 75 kg ha−1 added N. Nitrogen content of the caryopsis was increased with N fertilizer applied at seeding, but total amino acid concentrations (per mg N) in the hydrolyzed proteins were not affected. The amino acid profile of the caryopsis was similar to that of other cereals and the N-to-protein factor was 5.5.Key words: Annual canarygrass, Phalaris canariensis, nitrogen fertilizer, agronomic performance
EFFECTS OF BARLEY INTRACOLEOPTILAR INTERNODE LENGTH AND EFFECTIVE XYLEM RADIUS ON WATER USE AND DRY MATTER PRODUCTION
Authors: IRVINE R. B. , THERRIEN M. C.
Published: March 2010

A series of experiments was conducted to determine if altering the length and effective xylem radius (EXR) of the intracoleoptilar internode (ICI) of barley (Hordeum vulgare L.) would alter water use and increase yields. Uniculm barley genotype F73-1 with long ICI conserved soil water from seeding to maturity, on a very restricted water supply. However, plants with long ICI did not produce significantly more (P > 0.1) dry matter or grain despite using less water per gram of dry matter produced. Plants of cultivar Abee, which have short ICI, used more water than plants with long ICI, under sample available soil moisture. Over a 3-h period, measured water loss for short ICI plants was, on average, 2.32 g vs. 1.37 g for long ICI plants. Progeny selected from the cross Abee/TR450 with genetically long ICI and small EXR, and those with short ICI and large EXR did not differ in water use or in amount of dry matter produced. When 16 barley cultivars were sown on a light-textured soil at 4 and 7 cm seeding depths, there was no cultivar by seeding depth interaction in any of four field experiments conducted. The cultivar Abee, with a long ICI and small EXR, did not produce higher yields. While increasing the length of the ICI of a given genotype and reducing its EXR may be of value under extreme conditions where plants are growing on stored subsoil moisture, this trait appears to be of little use in improving grain yields on drought-prone sandy soils in the eastern prairie region of western Canada.Key words: Barley, Hordeum vulgare, intracoleoptilar internode, effective xylem radius, drought tolerance
THE BIOLOGY OF CANADIAN WEEDS. 82. Holcus lanatus L.
Authors: THOMPSON JOHN D. , TURKINGTON ROY
Published: March 2010

Holcus lanatus L. (velvetgrass, Yorkshire fog) is a grass of European origin, distributed widely throughout the temperate regions of the world, and is naturalized in Canada. It is a minor weed in Canada, but it is common in Nova Scotia and British Columbia. It is noticeably absent from the prairies, probably because of low summer rainfall and long cold winters. Holcus lanatus occurs as a weedy invader of pastures and rough grassland where it may suppress the growth of seeded species, and on roadsides, waste ground and woodland margins, particularly on moist sites. It is a vigorously growing species that displays a wide tolerance of edaphic factors and can be controlled by several herbicides. Its abundance is influenced by a variety of management practices.Key words: Holcus lanatus, velvetgrass, Yorkshire fog, weed biology
A SUPERIORITY MEASURE OF CULTIVAR PERFORMANCE FOR CULTIVAR × LOCATION DATA
Authors: LIN C. S. , BINNS M. R.
Published: March 2010

A measure of cultivar general superiority for cultivar × location data is defined as the distance mean square between the cultivar’s response and the maximum response averaged over all locations. Since the maximum response is the upper boundary in each location, a small mean square indicates general superiority of the test cultivar. The method requires that all test cultivars be balanced over locations but not necessarily the checks. The advantage of the proposed method are: (i) The checks provide only a plausible maximum response for each location and are not required for assessing the test cultivars. Thus checks do not have to be present in all locations. This allows a greater flexibility for a breeder to choose locally adapted cultivars as checks without unduly increasing the size of a regional trial. (ii) The measure of general superiority consists of only one parameter, thus simplifying the screening process considerably. A subsidiary parameter for interaction can be used to indicate lack of general adaptability. (iii) The difference between the mean of the maximum response averaged over all locations and the mean of the best cultivar provides useful information as to how many cultivars are needed to achieve optimum productivity for the entire region, (iv) The specific adaptability of a cultivar can be identified by plotting the maximum and the test cultivar responses on the location means.Key words: Genotype × environment interaction, cultivar assessment, regional trial
KG 20 SOYBEAN
Authors: PARK S. J. , BRADNER N. R. , SCOTT-PEARSE F.
Published: March 2010

KG 20 is an early-maturing, high-yielding soybean (Glycine max (L.) Merr.) cultivar with similar maturity and higher yield than Maple Amber and Baron in the western, central and maritime regions in Canada. It is about 8 d later than Maple Presto and outyields it by 33% in western Canada and by 27% in Ontario. The main advantage of KG 20 is its yield performance as an early-maturing cultivar.Key words: Glycine max (L.) Merr., soybean, cultivar description
KG 30 SOYBEAN
Authors: PARK S. J. , BRADNER N. R.
Published: March 2010

KG 30 is an early-maturing, high-yielding soybean (Glycine max (L.) Merr.) cultivar which has similar maturity and is 4–5% higher in seed yield than its two parents Maple Arrow and McCall. Its main advantage is its yield performance as an early-maturing cultivar.Key words: Glycine max (L.) Merr., soybean, cultivar description
RATES OF INFECTION AND EFFECTS OF FIVE VESICULAR-ARBUSCULAR MYCORRHIZAL FUNGI ON APPLE
Authors: REICH LEE
Published: March 2010

Apple plants, cultivar Novole, were either uninoculated (control) or inoculated with one of the following mycorrhizal fungi: Glomus macrocarpum Tul. and Tul., Glomus intraradices Schenk and Smith, Glomus fasciculatum (Thaxter sensu Gerd.) Gerd. and Trappe, Glomus mosseae (Nicol. and Gerd.) Ger. and Trappe, or Glomus epigaeum Daniels and Trappe. Groups of plants were harvested of three successive intervals. Glomus intraradices and G. epigaeum caused most rapid and highest levels of root infection, and increased P uptake compared with plants which were inoculated with the other fungi, or were uninoculated. Plants inoculated with G. intraradices and G. epigaeum had greatest dry weights.Key words: Glomus macrocarpum, Glomus intraradices, Glomus fasciculatum, Glomus mosseae, Glomus epigaeum, phosphorus
INFLUENCE OF FOLIAR-APPLIED N-P-K FERTILIZERS ON PRODUCTIVITY AND NUTRITION OF JUNE-BEARING STRAWBERRIES
Authors: ROSEN C. J. , HOOVER E. E. , LUBY J. J.
Published: March 2010

A 2-yr field experiment was conducted to determine the influence of supplemental N-P-K foliar fertilizers (9-8-7 or 16-2-3) applied during flowering, fruit enlargement and/or flower initiation on yield, quality, and nutrition of Earliglow strawberries (Fragaria × ananassa Duch.). All plots received soil applied fertilizer at planting and at renovation according to soil test recommendations. Foliar fertilizers did not significantly increase total yield at any of the rates or times of application employed. Average yields the first year were 1.5 times greater than those the second year, regardless of whether foliar fertilizers were applied. Treatments did not significantly affect mean berry weight or percent soluble solids. Concentrations of N and P in recently matured leaves sampled during harvest were not significantly affected by foliar treatments, but K level was increased in the second year of the study by some foliar treatments.Key words: Fragaria spp., foliar nutrient sprays, nitrogen, phosphorus, potassium, strawberry
VULNERABILITY OF COMMON WHEAT CULTIVARS TO MAJOR STORED-PRODUCT BEETLES
Authors: SINHA R. N. , DEMIANYK C. J. , McKENZIE R. I. H.
Published: March 2010

Vulnerability of seven common wheat cultivars to nine major species of stored-product beetles was determined in two experiments by measuring multiplication rates on whole and crushed seeds at 30 °C and 70% relative humidity for 12 wk. Susceptibility of a cultivar to an insect was assumed to be proportional to the multiplication of that insect. Vulnerability of cultivars varied considerably depending on the insect species infesting the seed. Whole seeds generally were less susceptible to insects than crushed seeds, except for Sitophilus spp. and Rhyzopertha dominica. In the first exploratory experiment using three cultivars and nine insect species, whole seeds of Norstar, HY320 and Neepawa were least susceptible to Tribolium audax and Oryzaephilus mercator, and most susceptible to Sitophilus oryzae and R. dominica. In the second experiment using six cultivars and six insect species, susceptibility of whole seeds appeared to be related to the kernel hardness of a cultivar with Glenlea and Neepawa being least susceptible to infestation by Cryptolestes ferrugineus, O. surinamensis, T. castaneum and T. confusum. Kernel hardness either did not affect or slightly affected the multiplication rates of Sitophilus spp. and R. dominica. Generally, soft wheat cultivars grown in western Canada are at a greater risk of postharvest insect damage than are the hard red spring cultivars; HY320 which is intermediate in kernel hardness may be prone to greater insect infestation.Key words: Wheat, Norstar, HY320, stored-product beetles
GENOTYPE × ENVIRONMENT INTERACTION AND STABILITY ANALYSIS OF SEED YIELD OF OILSEED RAPE GROWN IN MANITOBA
Authors: BRANDLE J. E. , McVETTY P. B. E.
Published: March 2010

Genotype × environment interactions, cultivar response to environments and cultivar stability for yield of oilseed rape (Brassica napus L.) were studied using five cultivars grown for 3 yr at nine locations in Manitoba. The objectives were: (1) to estimate the components of variance associated with the first- and second-order interactions and to determine their effects on the standard error of a cultivar mean so that optimum test combinations of replications, locations and years for cultivar testing in Manitoba could be determined; (2) to measure cultivar response to varying environments; and (3) to measure cultivar stability. The genotype × year and the genotype × year × location interactions were significant. The genotype × location interaction was not significant, indicating the cultivars tested performed similarly relative to each other across locations over years. Increasing years, locations and replications in that order had the greatest effects on the standard error of a cultivar mean. Calculation of the contribution of each variety to the G × E sums of squares indicated that Westar made the largest contribution and Altex the smallest.Key words: Rape (oilseed), Brassica napus L., stability, cultivar testing
TOTAL CELL WALL AND FIBER CONCENTRATIONS OF PERENNIAL GLANDULAR-HAIRED AND EGLANDULAR Medicago POPULATIONS
Authors: LENSSEN A. W. , SORENSEN E. L. , POSLER G. L. , HARBERS L. H.
Published: March 2010

Host-plant resistance in alfalfa (Medicago sativa L.) is insufficient for control of the alfalfa weevil (Hypera postica) or the potato leafhopper (Empoasca fabae), two of the most important insect pests of alfalfa. Some wild Medicago species, which have erect glandular hairs, possess adequate host-plant resistance for control of both pests. We established a field trial (Wymore silty clay loam) in 1985 to determine the effects of erect glandular hairs on forage quality of several perennial Medicago species. Glandular and eglandular (without erect glandular hairs) plant populations were selected from the diploids, M. prostrata Jacq. and M. glandulosa David, and the tetraploids, M. glutinosa Bieb., M. sativa × M. glutinosa, and M. sativa × M. prostrata. Eglandular M. sativa ’Riley’ and M. sativa subsp. caerulea (Less, ex Ledeb.) Schmalh. were included as controls. Foliar diseases and insects were controlled. Leaves and stems were separated for three harvests in 1985 and one in 1986. The presence of erect glandular hairs did not significantly affect concentrations of neutral or acid detergent fibers, hemicellulose, lignin, or cellulose of leaves or stems within the species or hybrids tested. Neutral and acid detergent fibers and cellulose concentrations were generally lower in stems and higher in leaves of diploids than in corresponding parts of the tetraploid alfalfa cultivar Riley.Key words: Alfalfa, Medicago sp., glandular hairs, forage quality
DIFFERENTIAL RESPONSE OF MAIZE INBREDS TO BENTAZON AND OTHER HERBICIDES
Authors: FLEMING A. A. , BANKS P. A. , LEGG J. G.
Published: March 2010

One field and two greenhouse experiments were conducted to determine the reaction of various maize (Zea mays L.) inbreds and single crosses to four herbicide treatments (atrazine, atrazine plus tridiphane, bentazon, metolachlor) relative to a nontreated control. All herbicides except metolachlor, which was used preemergence, were applied early postemergence with a nonphytotoxic crop oil at 1% carrier volume. Of significant importance is the discovery of maize susceptibility to bentazon and its inheritance. We suggest that the symbol, ben, be assigned to the recessive gene that causes this susceptibility. In the greenhouse, inbreds were more tolerant to atrazine and bentazon than other herbicide treatments. Tridiphane increased atrazine activity and reduced dry plant weight of inbreds on the average by 19%. None of the single crosses was significantly susceptible to atrazine. All inbreds and single crosses were sensitive to metolachlor in the greenhouse, as shown by the 49 and 35% reduction in dry weight, respectively. Information from these experiments can be useful in identifying sources of tolerance and susceptibility to the tested herbicides for programs in conventional maize breeding, weed control, and molecular engineering.Key words: Maize, bentazon, atrazine, tridiphane, metolachlor, inheritance
THE CYANIDE POTENTIAL IN TWO VARIETIES OF Amelanchier alnifolia
Authors: BROOKE B. M. , McDIARMID R. E. , MAJAK W.
Published: March 2010

The cyanide potential of Saskatoon foliage was re-examined to further elucidate its toxicity to ruminants. Average prunasin concentrations in newly initiated leaves of Amelanchier alnifolia var. cusickii were threefold greater than in A. alnifolia var. alnifolia. This was determined with an extraction procedure that simplified sample preparation for cyanide determination. Improved conditions are also described for determining cyanide colorimetrically and for detecting prunasin by liquid chromatography.Key words: Amelanchier alnifolia, Saskatoon, serviceberry, HCN potential, cyanogenic glycoside, prunasin
A DIGITAL IMAGE ANALYSIS METHOD FOR SELECTING OZONE-INSENSITIVE WHITE BEANS
Authors: MICHAELS T. E.
Published: March 2010

Rating ozone damage in common bean (Phaseolus vulgaris L.) requires visual estimation by experienced evaluators. The objective of this study was to determine whether an alternative digital method based on the mean and standard deviation of pixel brightness values from the video image of a leaf could rapidly and reliably measure ozone sensitivity of white bean breeding lines. Fourteen-day-old seedlings of 35 breeding lines and six parental cultivars were exposed to controlled fumigation with 0.20 μL L−1 ozone for 6 h during each of 4 d in growth chambers. On day 5, injury of the two unifoliolate leaves was evaluated using the digital method and visual estimates of damaged leaf area. The standard deviation of pixel brightness values was significantly correlated with the percentage damaged leaf area estimates (r = 0.68). The digital and visual methods identified most of the same breeding lines as ozone-insensitive, but disagreed on the ranking of the ozone-sensitive lines.Key words: Bean (common), Phaseolus vulgaris L., ozone, video image analysis, selection
GENOTYPIC DIFFERENCES IN DARK RESPIRATION OF MATURE LEAVES IN WINTER WHEAT (Triticum aestivum L.)
Authors: WINZELER M. , McCULLOUGH D. E. , HUNT L. A.
Published: March 2010

Oxygen uptake of mature leaves was measured on a range of winter wheat (Triticum aestivum L.) genotypes both indoors (four genotypes) and in the field (six genotypes). The relationship among mature leaf respiration, leaf size, specific leaf weight and leaf nutrient status was investigated. Correlations between leaf respiration and total plant dry weight as well as tiller number were calculated in the indoor study. Significant differences of 6–25% in mature leaf respiration rates were evident among winter wheat genotypes in the indoor as well as in the field study. Leaf position as well as environment had a marked influence on the order and magnitude of genotype effects on mature leaf respiration rates. Leaf respiration was not related to specific leaf weight, leaf nitrogen, or phosphorus content, but was negatively related to leaf size. Leaf respiration was not related to total dry weight and tiller number of single plants grown indoors.Key words: Respiration, genotypic differences, wheat (winter), Triticum aestivum L.
RESPONSE OF BROMEGRASS TO N, P AND S FERTILIZER ON A GRAY LUVISOLIC SOIL IN NORTHWESTERN SASKATCHEWAN
Authors: UKRAINETZ H. , CAMPBELL C. A. , ZENTNER R. P. , MONREAL M.
Published: March 2010

A 9-yr study was conducted on a Gray Luvisolic loam at Loon Lake, Saskatchewan to determine the effect of ammonium nitrate-N (34–0–0) and urea-N (46–0–0) on bromegrass (Bromus inermis Leyss.) production and nutrient quality, N recovery, and N use efficiency when the N was applied either annually or as a single application at the start of the experiment. The effects of phosphorus (P) and sulphur (S) were also assessed. Each N source was applied at single rates of 0, 100, 200, 400 and 800 kg ha−1 N and annual rates of 0, 50, 100 and 200 kg ha−1 N. The ammonium nitrate was also applied as a single dose at rates of 600 and 1000 kg ha−1 N. Phosphorus and S were applied every second year at 224 kg ha−1 P2O5 and 45 kg ha−1 S. Forage dry matter yields were positively related to precipitation received in May and July, and April–May, but negatively related to June precipitation. Forage dry matter production was greater over the first 8-yr period for annual N applications than for a single application receiving an equivalent amount of N; but fertilizer N recovered in forage over the same period was similar (about 30%) for the two methods of application. Dry matter yields were 19% greater after 4 yr and 26% greater after 8 yr when ammonium nitrate was used compared to urea. Recovery of fertilizer N in forage also favored the ammonium nitrate source. The application of low to moderate N rates depressed forage N and P concentrations when yield response was high but concentrations were increased by the highest rates of N fertilizer and by repeated annual applications of N. Toxic concentrations of NO3-N occurred in bromegrass in the first year when N was applied at or above 400 kg ha−1 as one application and also in the second year when N was applied at 800 kg ha−1. When N was applied annually at 200 kg ha−1, NO3-toxicity became a potential problem in later years as soil mineral N accumulated. Phosphorus and S fertilizers increased dry matter yields of forage; P fertilizer increased and S decreased forage P concentration. Annual N applications resulted in more uniform year-to-year yields and N uptake response compared to a single application and provided greater dry matter production without loss of nutritive quality. It was concluded that, in contrast to reports in the literature, the response of forage grasses to N is not site specific.Key words: N source, N recovery, N application method, N use efficiency, phosphorus, sulfur
SELECTION IN ALFALFA FOR TOLERANCE TO TOXIC LEVELS OF ALUMINUM
Authors: CAMPBELL T. A. , ELGIN JR. J. H. , FOY C. D. , McMURTREY III J. E.
Published: March 2010

The alfalfa (Medicago sativa L.) population ’B13’ was screened through four cycles of recurrent phenotypic selection for tolerance to toxic levels of Al in growth chambers; germplasm from cycles 1 through 4 was designated B13-A11, B13-A12, B13-A13, and B13-A14, respectively. Cycles 1 and 2 were screened in Tatum clay-loam subsoil (36% Al saturation for cycle 1 and 61% Al saturation for cycle 2), and cycles 3 and 4 were screened in a modified Steinberg solution (111 μmol Al, pH 4.5). Selection was based on root growth in the first two cycles and shoot growth in the latter two cycles. Selections were intercrossed with honey bees (Apis mellifera L.) at the end of each cycle. Efficacy of the selection procedure was evaluated in pH 4.5 Steinberg solutions (Al concentration of 0 or 111 μmol), and in Tatum soil (0 or 68% Al saturation). Regression analysis indicated that significant but minimal progress was made in developing synthetics with improved vigor under Al toxic conditions. B13-A14 was among the least impaired of the entries in the ability to take up nutrients whereas AS-4 and Williamsburg (susceptible checks) were among the most impaired. It was concluded that tolerance to Al in nutrient solutions and soil could involve different mechanisms and that the screening procedure used here was much more effective in selecting for vigor than for Al tolerance. Alternative breeding approaches were proposed.Key words: Alfalfa, plant breeding, germplasm, recurrent selection, hydroponic, nutrient solution
EFFECT OF FREEZING TEMPERATURE ON THE EFFICACY OF WILD OAT HERBICIDES
Authors: WILCOX D. H. , MORRISON I. N. , MARSHALL G.
Published: March 2010

In controlled environment experiments diclofop methyl, difenzoquat, flamprop methyl, fluazifop-P and seythoxydim were applied to wild oat at the three-leaf stage at recommended rates 10 h before or after a single night of freezing (−4 °C) temperature. Herbicide efficacy, as determined by the change in post-treatment dry weight accumulation of treated wild oats during the ensuing 3 wk period, was unaffected by the freezing temperature. The dry matter accumulation of wild oat exposed to the −4 °C temperature was reduced by 10–20% compared to plants which were grown under a constant 15/5 °C day/night regime.Key words: Oat (wild), frost, diclofop methyl, flamprop methyl, difenzoquat, fluazifop-P, sethoxydim
G. S. SWAIN RHODODENDRON
Authors: CRAIG D. L. , HICKLENTON P. R.
Published: March 2010

G. S. Swain, an ivory-yellow flowering rhododendron, forms a quality plant that is attractive, semi-compact and floriferous. It can be readily propagated from softwood cuttings or by tissue culture.Key words: Ericareae, cultivar, G. S. Swain rhododendron
WATER IMBIBITION RATE OF WHEAT KERNELS AS AFFECTED BY KERNEL COLOR, WEATHER DAMAGE, AND METHOD OF THRESHING
Authors: CLARKE J. M. , DePAUW R. M.
Published: March 2010

The rate of water imbibition by wheat kernels may be related to preharvest sprouting damage and tempering times during milling. The effects of kernel color and exposure to weather damage on water imbibition rate of wheat (Triticum aestivum L.) kernels, and the effects of field vs. oven drying and hand vs. mechanial threshing on water uptake rate of HY320 wheat and Welsh triticale (X-Triticosecale Wittmack) were investigated. Rates of imbibition were determined by sequential weighings over a 32-h period of 50-kernel samples imbibing water from agar media. In HY320 wheat, the rate was faster for mechanically threshed (0.0117 g g−1 h−1) than for hand-threshed (0.0115 g g−1 h−1) samples. Threshing method did not affect imbibition rate of Welsh triticale kernels (average 0.0141 g g−1 h−1). Rate of germination was significantly greater for mechanically threshed than for hand-threshed Welsh, but there was no significant difference for HY320. Method of drying did not affect kernel water imbibition rate. Rate of imbibition was faster in nonweathered than in weathered wheat (0.0136 vs. 0.0130 g g−1 h−1). In five wheat crosses involving white and red kernel color, rate of water imbibition was not associated with the allele for kernel color. Rate was negatively correlated with kernel weight (r = 0.49**, n = 49) and kernel hardness (r = −0.29*) in the five crosses, and positively correlated with protein content (r = 0.44**). Other undetermined factors accounted for the major part of the genotypic differences in rate of imbibition.Key words: Triticum aestivum L., X-Triticosecale Wittmack, windrowing, kernel water imbibition rate, germination rate
RESPONSE OF SOYBEAN TO LOWER-CANOPY DEFOLIATION DURING SEEDFILL
Authors: VASILAS B. L. , FUHRMANN J. , GRAY L. E.
Published: March 2010

One of the effects of Septoria brown spot on soybean is accelerated lower-canopy defoliation. Field experiments were conducted in 1986 and 1987 to determine the response of soybean yield and yield components to progressive lower-canopy defoliation during seedfill. Soybean cultivar Williams 82 was machine planted in rows 76 cm wide and hand thinned to a uniform stand of 23 plants m−1. Three treatments were used: controls; defoliated, starting at R5 (beginning seed stage; DEF1), and defoliated, starting 7 d past R5 (DEF2). Defoliation treatments were applied by removing the leaflets and petioles from the lowest three or four leaf-bearing nodes four times at 4-d intervals so that only three or four nodes at the top of the plant remained leaf-bearing when defoliation ceased. Yield and yield components were determined for upper, lower and total nodes. Although the two growing seasons were very different, yield responses to defoliation were similar in both years. On the average, DEF1 reduced seed yield by 18% which is similar to losses that occur when brown spot is induced by inoculation; DEF2 reduced yields by 9% which is similar to yield losses reported for naturally occurring brown spot. Yields of DEF2 exceeded yields of DEF1 because of differences in pod number in 1986 and seeds/pod in 1987. Controls out-yielded DEF2 because of differences in seeds/pod in 1986 and seed size in 1987. The proportion of the total yield contributed by pods found on the upper nodes averaged 76% and was not affected by defoliation.Key words: Glycine max, Septoria glycines, brown spot, leaf loss
EFFECT OF SOIL Pseudomonas ISOLATES APPLIED TO CORN, SORGHUM AND WHEAT SEEDS ON SEEDLING GROWTH AND CORN YIELD
Authors: EL-MELEIGI MOHAMED A.
Published: March 2010

The purpose of this study was to determine the effect of several Pseudomonas isolates obtained from the rhizosphere of corn (Zea mays L.), sorghum (Sorghum bicolor Moench L.) and wheat (Triticum aestivum L.) on the seedling growth of these cereals and on stalk rot and grain yield of corn. Seeds of BoJac 56 and NC 5288 corn hybrids. Asgrow and Pioneer 8272 sorghum hybrids and Parker 76 and Scout wheat cultivars were coated with rhizobacteria (176 isolates) and germinated in nonautoclaved or autoclaved field soils in the greenhouse. The dry weights of cereals seedlings (3 wk old) were not significantly affected by bacterial treatments in the autoclaved soils regardless of plant species. Eight cereal Pseudomonas rhizobacteria increased seedling growth significantly in one or more of corn, sorghum or wheat cultivars in nonautoclaved soils in the greenhouse. The stand density, stalk and root rot incidence and grain yield of two corn hybrids were not improved by coating their seeds with growth-promoting rhizobacteria during 2 yr of field testing. Some isolates actually reduced the stand and grain yield of certain corn hybrids in the field. The effect of each rhizobacterium varied considerably between plant species and between cultivars within the same species. The growth-promoting rhizobacteria differed significantly in their ability to inhibit growth of 14 plant pathogenic bacteria and fungi on agar media.Key words: Biological control, antagonism, Pseudomonas, corn, sorghum, wheat, stalk rot
EFFECTS OF TIME OF EMERGENCE, POPULATION DENSITY AND INTERSPECIFIC COMPETITION ON HEMP-NETTLE (Galeopsis tetrahit) SEED PRODUCTION
Authors: LÉGÈRE ANNE , DESCHÊNES JEAN-MARC
Published: March 2010

Various conditions of intra- and interspecific competition may influence weed seed production thus affecting the extent of seed return to the soil. The objective of this study was to measure the effects of time of emergence, population density, and weed crop interaction on seed production of hemp-nettle (Galeopsis tetrahit) in natural field populations. Hemp-nettle seed production was studied in pure hemp-nettle stands, mixed hemp-nettle-stinkweed (Thlaspi arvense) stands, hemp-nettle-crop stands, and hemp-nettle-stinkweed-crop stands. Crop species used were alfalfa (Medicago sativa) and oats (Avena sativa). In pure hemp-nettle stands, delayed emergence and high population density reduced seed production of individual hemp-nettle plants. Hemp-nettle seed production per unit area was comparable for all but the lowest population density. Stink-weed population densities up to 200 plants m−2 had no consistent effect on average seed production of individual hemp-nettle plants. Seed production of individual plants was scarcely affected by the presence of alfalfa whereas it was largely reduced in the presence of the oat crop. Oats were usually more competitive than alfalfa, the latter crop being disadvantaged by slow initial growth. Hemp-nettle was not as prolific as other weed species but still produced enough seeds to reinfest the soil, even under highly competitive conditions.Key words: Hemp-nettle, Galeopsis tetrahit, seed production, weed reproduction
RESIDUES OF 2,4-D AND PICLORAM IN ASPEN POPLAR AND SOIL AFTER APPLICATION WITH A ROLLER
Authors: CESSNA ALLAN J. , WADDINGTON JOHN , BITTMAN SHABTAI
Published: March 2010

The use of wipers to apply herbicides to brush regrowth in pastures has been suggested as a way of reducing damage to the forage understory. Estimates of picloram in the soil around the base of Aspen poplar (Populus tremuloides Michx.) regrowth and of picloram and 2,4-D in poplar tissues were made 84 and 39 d, respectively, after using a roller to apply these herbicides in a 7.3:1 2,4-D:picloram (acid equivalent) mixture to the brush. Bioassay revealed that between 11 and 16% of the picloram applied reached the soil and that, when the herbicide mixture was applied at a high enough concentration to kill the trees, sufficient picloram reached the soil around them to affect legume establishment. Chemical assay revealed that only about 2% or less of the picloram and 2,4-D applied remained in the poplar tissue and that greater than 80% of this was in the leaves — the primary application surface. These residues are unlikely to cause problems in the environment because of the small quantities and the slow release from poplar tissue by leaching and decay. The remainder of the applied picloram and 2,4-D was unaccounted for and was assumed lost through metabolism and photochemical degradation.Key words: 2,4-D, picloram, aspen poplar, soil, roller applicator
IMPACT OF PRUNING STRATEGY, CLUSTER THINNING, AND SHOOT REMOVAL ON GROWTH, YIELD, AND FRUIT COMPOSITION OF LOW-VIGOR DE CHAUNAC VINES
Authors: REYNOLDS ANDREW G.
Published: March 2010

To explore alternative means of crop control on vineyard attributes, 10-yr-old, low-vigor De Chaunac vines were subjected over a 3-yr period to eight crop regulation treatments, which involved combinations of pruning strategy (15 + 10 balanced pruning; 40 nodes per vine), cluster thinning, shoot thinning to one shoot per node, and removal of base shoots. Treatments involving cluster thinning maximized vine size, periderm development, yield components, °Brix, and anthocyanins. Yield per vine was not affected by any treatment. Cane periderm, yield components, and °Brix of cluster thinned, balance pruned vines exceeded those in cluster thinned vines pruned to 40 nodes. Shoot thinning of balance pruned vines did not improve cane periderm formation or yield components over un-thinned vines, but reduced °Brix. Combining cluster and shoot thinning with balanced pruning and base shoot removal proved to be superior to all treatments in every aspect of growth, yield, and fruit composition. Vines pruned to 40 nodes and subjected to base shoot removal and shoot thinning had improved yield components and °Brix over vines shoot thinned only, but were inferior to cluster thinned vines in terms of all vineyard parameters. Crop loads below 7 kg kg−1 cane prunings appear necessary to maintain vine size, yield, and acceptable fruit composition of low-vigor De Chaunac vines.Key words: Vitis, De Chaunac, pruning, cluster thinning, vine
EFFECTS OF POPULATION, ENVIRONMENT AND THEIR INTERACTION ON SASKATOON BERRY (Amelanchier alnifolia Nutt.) SEED GERMINATION
Authors: ACHARYA S. N. , CHU C. B. , HERMESH R.
Published: March 2010

To determine the effects of population, environment and their interaction on the variability of seed germination, seeds of 27 random native Alberta populations of Saskatoon berry (Amelanchier alnifolia Nutt.) were collected over 3 yr. Each year the seeds were stratified at 3 °C for 84 d and then germinated at 25/10 °C light(16 h)/dark. Among the populations, mean seed germination after 4 wk ranged between 7 and 67%. Ecoregion and moisture condition at the site of origin did not significantly influence germinability. Of the total variance, 56% was contributed by population while the year and the population-year interaction contributed 0.3% and 17.5%, respectively. Over years the rank order of the populations was maintained. Three populations of diverse origin, grown in a common nursery, produced seeds with significantly different germination. Therefore, germination in A. alnifolia can largely be considered a genetically controlled character which is influenced to a limited extent by yearly environmental fluctuation.Key words: Saskatoon berry, Amelanchier alnifolia Nutt., germination, population-environment interaction
RATING CLIMATE IN SOUTHWESTERN ONTARIO FOR HORTICULTURAL CROPS
Authors: BROWN D. MURRAY , PLACE ROBERT E.
Published: March 2010

A climatic rating scheme was developed for qualitative assessment of land areas in southwestern Ontario for all commercial edible horticultural crops grown in the region. The general approach was to place the crops into three main groups — frost susceptible, frost tolerant, and winter temperature susceptible perennials. A four-point rating system was used to place areas into "very good", "good", "fair," or "poor" categories based on restrictions produced by the critical climatic factors appropriate for each group of crops. The Corn Heat Unit (CHU) map was used as the primary criterion to subdivide the area for the four-point rating. Secondary climatic features appropriate for each crop group were used to further subdivide the crops into subgroups. The climatic features used for the secondary subdivision were spring and fall frost dates, spring and summer maximum temperatures, and winter minimum temperatures. This scheme is the first step in developing a system that can be used to rate areas for their ability to produce edible commercial horticultural crops in this region of Ontario. It should prove useful when combined with soil ratings for these crops.Key words: Vegetable, fruit crop, growing season, winter/spring conditions, land rating
CHIP COLOR, SUGAR CONTENT AND YIELD OF SUMMER POTATOES DURING GROWTH IN SOUTHERN ONTARIO
Authors: LESZKOWIAT M. J. , YADA R. Y. , STANLEY D. W. , COFFIN R. H. , McKEOWN A. W.
Published: March 2010

Tubers of five summer potato cultivars were monitored weekly for chip color, reducing sugars, sucrose, and marketable yield for 4 wk commencing 3 July, about 80 d after planting, in 1985 and 1986 at Harrow and Simcoe, Ontario. Atlantic and Conestoga tubers generally contained the lowest sugar levels, were the only cultivars to produce acceptable colored chips by 3 July, and had lighter chip color than all cultivars, even lighter than the standard cultivar, Superior. Conestoga yields by 3 July (about 13 t ha−1) exceeded those of Superior (about 10 t ha−1), but Atlantic required 7–10 d more growth to produce comparable yields. Atlantic and especially Conestoga may be more suitable than Superior for use as main summer chipping cultivars in southern Ontario.Key words: Solanum tuberosum L., cultivar, chip color, sugar content, marketable yield, maturity
FERTILIZATION AND NIGHT TEMPERATURE EFFECTS ON GROWTH AND CARBOHYDRATE STATUS OF POINSETTIA
Authors: SENÉCAL M. , DANSEREAU B. , PAQUIN R.
Published: March 2010

Poinsettia (Euphorbia pulcherrima Willd ’Annette Hegg Dark Red’) were fertilized with 3.0, 4.5 or 6.0 g per 15-cm pot of Osmocote (14N-6.1P-11.6K) and were grown in greenhouses at 9, 13, or 17 °C night temperature. As the night temperature increased, the number of days to anthesis, bract number and carbohydrate levels decreased. Maximum bract mean area and minimum root dry weight were achieved at 13 °C. High fertilizer rates increased the number of days to anthesis while bract number, root and shoot dry weights, reducing and total sugar content decreased.Key words: Euphorbia pulcherrima, fertilization, night temperature, carbohydrate
MAIZE (Zea mays L.) HYBRID USE OF 15N-NITRATE ABSORBED VEGETATIVELY BY ROOTS
Authors: WEILAND R. T.
Published: March 2010

The use and mobilization of N absorbed at various vegetative growth stages by maize (Zea mays L.) roots have not been investigated by pulsing/chasing N. During this study two maize hybrids, B73 × LH39 (B×LH) and H93 × L10 (H×L), were evaluated in a greenhouse experiment for vegetative 15N absorption and subsequent utilization and mobilization. At 35 (EI) and 43 (EII) days after seed was planted (DAP), separate plants were given 99 atom % 15N as [Formula: see text] for 48 h. The experimental design was a randomized complete block with three replications. Plants were harvested at 38 DAP, 43 DAP, silking and physiological maturity (PM) for EI and at 46 DAP, 51 DAP, silking and PM for EII. Neither hybrid nor treatment differences were observed for uptake of 15N. Genotype B×LH remobilized more of the vegetatively absorbed N to the kernels than H×L (P ≤ 0.10). Initial deposition of 15N was in the leaves (60%), stalk (30%), and roots (10%) for EI and in the leaves (50%), stalk (40%) and roots (10%) for EII for both genotypes. Forty percent of the 15N in the plant (80, 12 and 8% from the leaves, roots and stalk) during EI was mobilized to reproductive tissue by PM, while 50% (60, 30 and 10% from the leaves, stalk and roots) was mobilized during EII. Thus, the later N is vegetatively absorbed by the maize plant, the more likely it will be translocated to the kernels.Key words: Nitrate, nitrogen, uptake, translocation, Zea mays L., maize
EFFECT OF LONG-TERM CONTINUOUS CROPPING OF SPRING WHEAT ON AGGRESSIVENESS OF Cochliobolus sativus
Authors: EL-NASHAAR H. M. , STACK R. W.
Published: March 2010

Cochliobolus sativus cultures were collected from symptomatic wheat plants from a plot planted continuously to wheat for over 90 yr and from symptomatic wheat plants in commercial grain fields cropped rotationally in the surrounding area. Pathogenicity of these isolates was tested in replicated greenhouse trials using wheat plants scored for disease 6 wk after inoculation. Isolates from the continuous-cropped wheat plot were more aggressive on average than were isolates from commercial fields. Long-term continuous cropping to wheat appears to shift the population of C. sativus toward more aggressive types, although many less aggressive types also remain.Key words: Aggressiveness, Drechslera sorkiniana, Helminthosporium sativum, wheat root rot
SIMULATION OF GROWTH AND MORPHOLOGICAL DEVELOPMENT OF MAIZE UNDER CONTRASTING WATER REGIMES
Authors: GRANT R. F. , FREDERICK J. R. , HESKETH J. D. , HUCK M. G.
Published: March 2010

The use of crop growth models for resource management decisions such as weed control will require the detailed simulation of plant structures and functions in order to determine crop response to resources. A crop growth model was constructed on the computing facility at the National Center for Supercomputing Applications which was intended to simulate the effect of changing water status on plant growth processes. The model was tested against field data collected during an experiment in which the morphology of a maize crop growing under an imposed water deficit over a shallow water table was compared to that of an irrigated control treatment. The effects of this deficit on soil and canopy water status, leaf tip appearance, and on the distribution of growth with node number were compared for the simulated and recorded data. The use of simple equations describing the partitioning of growth to successive nodes enabled reasonably accurate estimates to be made of the distribution of leaf, sheath and internode mass with node number during both deficit and irrigated treatments. Consequently, realistic estimates of the vertical distribution of leaf area could be made for use in subsequent studies of inter-specific competition for irradiance interception.Key words: Simulation modelling, water stress, leaf area, canopy, maize growth
RESPONSES OF FIELD BEAN (Phaseolus vulgaris L.) TO LEVELS OF Rhizobium leguminosarum bv. phaseoli INOCULATION IN SOILS CONTAINING EFFECTIVE R. leguminosarum bv. phaseoli POPULATIONS
Authors: KUCEY R. M. N.
Published: March 2010

Greenhouse studies were conducted to determine the effect of adding Rhizobium leguminosarum bv. phaseoli inocula to field beans (Phaseolus vulgaris L.) growing in soils already containing R. leguminosarum bv. phaseoli. Indigenous R. leguminosarum bv. phaseoli populations in the 12 soils used ranged from 1.1 × 101 to 4 × 105 rhizobia g−1 of soil. Antibiotic-resistant isolates of R. leguminosarum bv. phaseoli strain 3644 were used as inocula and inoculum levels ranged from 104 to 108 bacteria per seed. N-15 isotope dilution methods with barley as a nonfixing control plant were used to determine N2 fixation levels. Bean plants grown in soils containing greater than 8 × 10 R. leguminosarum bv. phaseoli did not show positive responses to added rhizobia, except in one soil where the inoculum formed a significant proportion of nodules on inoculated plants. Plants growing in soils with less than 8 × 103R. leguminosarum bv. phaseoli did show increased levels of plant N accumulation and dry matter production in response to rhizobium addition if the level of soil mineral N was less than 25 μg N g−1 soil. Nodule occupancy by the marked R. leguminosarum bv. phaseoli isolate increased only in soils containing 8 × 103R. leguminosarum bv. phaseoli or less. The resident population of rhizobia in many of the soils was determined to be effective in N2 fixation since the proportion of N derived from N2 fixation did not increase in response to inoculation. Increasing the number of R. leguminosarum bv. phaseoli added per seed from 104 to 108 did not generally increase the effectiveness of the added inocula. Responses of beans to R. leguminosarum bv. phaseoli inoculation can only be expected in soils with low levels of resident R. leguminosarum bv. phaseoli and mineral N.Key words: Field bean, nodule occupancy, N-15 dilution, competition, N2 fixation
FALL GROWTH AND WINTER SURVIVAL OF ALFALFA IN INTERIOR BRITISH COLUMBIA
Authors: STOUT DARRYL G. , HALL JOHN W.
Published: March 2010

Extensive winter injury, likely caused by cold damage, occurred in alfalfa (Medicago sativa L.) cultivar yield tests underway at Kamloops, British Columbia during the 1985–1986 winter. Fall yield of cultivars during the year of seeding was negatively correlated with their winter survival (r = − 0.92 in one trial with 20 cultivars or strains, and r = − 0.74 in a second study with 34 cultivars or strains). Use of fall yield to predict winter survival has the advantage over the usual procedure of measuring plant height in space-planted plots, in that both total annual yield and fall growth can be evaluated in a single study. This results in a major saving of costs. Six cultivar studies all revealed that in the interior of British Columbia spring-summer yield is positively correlated to fall yield (r = 0.24 to 0.72). For this reason, selection of a cultivar with low fall growth to obtain high winter survival is likely to result in selection of a cultivar with reduced spring-summer yield.Key words: Medicago sativa, alfalfa, low temperature growth, winter injury, cold hardiness