bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen mineralization under summer fallow and continuous wheat in the semiarid Canadian prairie
Authors: Campbell C A , Zentner R P , Basnyat P. , De Jong R. , Lemke R. , Desjardins R.
Published: April 2011

The ability of soils to provide a portion of the N required by crops via N mineralization of organic matter is of economic and environmental importance. Over a 40-yr period (1967–2006), soil NO3-N and plant-N measurements were made under summer fallow and in systems cropped to spring wheat (Triticum aestivum L.), on a medium-textured Orthic Brown Chernozem (Aridic Haploboroll), at Swift Current, Saskatchewan. These values were used to estimate net N mineralization (Nmin). Each year, above-ground plant N was measured at harvest and soil NO3-N was measured before seeding, soon after harvest, and just prior to freeze-up in October. Also, in the first 18 yr of this study NO3-N and above-ground plant N were measured eight times between spring and fall in selected treatments; these data were used to make a more detailed estimate of Nmin. In a third experiment, conducted on the same soil at a nearby site in 1975, many small lysimeters were sampled six times between spring and harvest of spring wheat. We used this lysimeter study to assess the effect of N fertilizer rate and soilwater on net Nmin. Results from the more frequent sampling were more plausible than those from sampling at three different times per year. On average, net Nmin in the 20-mo summer fallow period was about 118 kg ha-1 (15 kg ha-1 between harvest and the first spring, 93 kg ha-1 between the first spring and second fall, and 10 kg ha-1 between the second fall and seeding). The average net Nmin under a wheat crop between spring and fall was between 53 and 63kg ha-1. Net Nmin increased with water, but excessive water appeared to reduce apparent net Nmin, probably due to leaching and denitrification losses of N, which were not assessed in our estimation of Nmin. Regression analysis was used to show a positive association between net Nmin and precipitation, between spring and fall, for most of the systems examined. There was evidence that tillage promotes N mineralization. At normal rates of N fertilizer (i.e., < 100 kg ha-1), fertilizer had no effect on Nmin. Net Nmin was directly proportional to fallow frequency, averaging 68, 83, and 90 kg ha-1 yr-1 for continuous wheat, fallow-wheat-wheat, and fallow-wheat rotations, respectively. Although our results may only be applicable to medium-textured soils of similar organic matter content in the Brown and Dark Brown Chernozemic soil zone, they provide data and information against which process-based models can be tested. They also provide useful first approximations of Nmin measured under field conditions where few long-term data currently exist. Key words: N mineralization, plant-N, fertilizer-N, crop rotation, irrigation, tillage
A generally applicable pedotransfer function that estimates field capacity and permanent wilting point from soil texture and bulk density
Authors: Pollacco J. A. P.
Published: April 2011

Hydrological models require the determination of fitting parameters that are tedious and time consuming to acquire. A rapid alternative method of estimating the fitting parameters is to use pedotransfer functions. This paper proposes a reliable method to estimate soil moisture at -33 and -1500 kPa from soil texture and bulk density. This method reduces the saturated moisture content by multiplying it with two non-linear functions depending on sand and clay contents. The novel pedotransfer function has no restrictions on the range of the texture predictors and gives reasonable predictions for soils with bulk density that varies from 0.25 to 2.16 g cm-3. These pedotransfer functions require only five parameters for each pressure head. It is generally accepted that the introduction of organic matter as a predictor improves the outcomes; however it was found by using a porosity based pedotransfer model, using organic matter as a predictor only modestly improves the accuracy. The model was developed employing 18 559 samples from the IGBP-DIS soil data set for pedotransfer function development (Data and Information System of the International Geosphere Biosphere Programme) database that embodies all major soils across the United States of America. The function is reliable and performs well for a wide range of soils occurring in very dry to very wet climates. Climatical grouping of the IGBP-DIS soils was proposed (aquic, tropical, cryic, aridic), but the results show that only tropical soils require specific grouping. Among many other different non-climatical soil groups tested, only humic and vitric soils were found to require specific grouping. The reliability of the pedotransfer function was further demonstrated with an independent database from Northern Italy having heterogeneous soils, and was found to be comparable or better than the accuracy of other pedotransfer functions found in the literature. Key words: Pedotransfer functions, soil moisture, soil texture, bulk density, organic matter, grouping
Relationship of the Illinois soil nitrogen test to spring wheat yield and response to fertilizer nitrogen
Authors: Steckler S J , Pennock D J , Walley F L
Published: April 2011

The Illinois soil N test (ISNT) has been used to distinguish between soils that are responsive and non-responsive to fertilizer N in Illinois. We examined the suitability of this test, together with more traditional measures of soil fertility, including spring nitrate-N and soil organic carbon (SOC), for predicting yield and N fertilizer response of wheat (Triticum aestivum) on hummocky landscapes in Saskatchewan. The relationship between ISNT-N and wheat yield and fertilizer N response was assessed using data and soils previously collected for a variable-rate fertilizer study. Soils were re-analyzed for ISNT-N. Our goal was to determine if ISNT-N could be used to improve the prediction of crop yields. Although ISNT-N was correlated with both unfertilized wheat yield (r = 0.467, P = 0.01) and fertilizer N response (r = -0.671, P = 0.01) when data from all study sites were combined, correlations varied according to landscape position and site. Stronger correlations between nitrate-N and both unfertilized wheat yield (r = 0.721, P = 0.01) and fertilizer N response (r = -0.690, P = 0.01) indicated that ISNT-N offered no advantage over nitrate-N. Although both tests broadly discriminated between sites with high or low N fertility, few relationships were detected on a point-by-point basis within a field. Stepwise regression equations predicting yield and yield response did not include ISNT-N, due in part to the high degree of collinearity between ISNT-N and other variables such as SOC, suggesting that ISNT-N alone was not a key indicator of soil N supply. Key words: Illinois soil nitrogen test, potentially available N, soil N, fertilizer N recommendations
The long-term effects of silvicultural thinning and partial cutting on soil compaction in red pine (Pinus resinosa Ait.) and northern hardwood stands in the northern Great Lakes Region of the United States
Authors: Tarpey R A , Jurgensen M F , Palik B J , Kolka R K
Published: April 2011

Periodic silvicultural thinnings (23.0, 27.6, 32.1 m2 ha-1 residual basal area) in a red pine stand growing on a sandy soil in north-central Minnesota over a 57-yr period increased soil compaction as the intensity of the thinning treatment increased. Of the three different methods used to measure soil compaction (bulk density, penetration resistance, and saturated hydraulic conductivity), saturated hydraulic conductivity was the most sensitive, decreasing by 60% in the 23.0 m2 ha-1 basal area thinning treatment, as compared with the uncut control. Soil bulk density measurements were more variable, but generally increased with increased thinning intensity. Few differences in soil penetration resistance were found among the three thinning treatments. In contrast, no evidence of soil compaction was detected in a northern hardwoods stand growing on a rocky loam soil in north-central Wisconsin that had three thinning treatments (13.8, 17.2, 20.6 m2 ha-1 residual basal area), a two- stage shelterwood harvest, and a 20-cm-diameter limit cut over a 50-yr period. With the increased demand for forest products, fuel reduction operations in high fire-risk stands, and biomass removal for energy production, more information is needed on the impact of multiple stand entries on soil compaction, and if compaction occurs, whether it will affect long-term soil productivity. Key words: Soil physical properties, bulk density, soil penetration resistance, hydraulic conductivity
Extraction times and analysis methods influence soil test measurements of phosphorus and sulphur
Authors: Kowalenko C G
Published: April 2011

The influence of time of shaking (5, 30 and 60 min) on the extraction of phosphorus (P), sulphur (S), aluminum (Al), iron (Fe), manganese (Mn), potassium (K) and magnesium (Mg) by five soil test solutions (water, sodium acetate, sodium bicarbonate, Kelowna, and Mehlich-3) were examined on six diverse south coast British Columbia soil samples. Inorganic P and S were measured by ion chromatography (IC) and inductively coupled plasma spectrophotometry (ICP) to obtain total P and S and the other five elements. In most cases, increased amounts of the elements were extracted as shaking time increased and the amounts varied among the samples. The exceptions were P and Fe in Kelowna and Mehlich-3 extracts, where in many of the samples, amounts of these elements decreased. The solutions extracted substantial quantities of organic S (ICP minus IC measurements), and relatively small quantities of organic P. In Mehlich-3 extracts, IC values for P were often greater than ICP P measurements, suggesting analytical interference. The interference was assumed to be in the IC measurement, and concluded to be most likely due to the chelate (EDTA) in the solution. The increased S extracted as time of shaking time was increased was largely increased organic S. Increasing the shaking time from 1 to 24 h increased extraction of inorganic P from soils by water and the amount of P that was bound during a P equilibration treatment. The amounts of the changes were relatively small, making 1 h shaking acceptable for routinely using these measurements for current and potential pollution risk by P in soils. However, the extraction times must be precise to enhance reproducibility. The results of these studies show the importance of shaking time on these measurements, with short times being preferred for theoretical and operational considerations. The significant and variable amounts of organic P and S in extract solutions show the importance of the quantification method for interpreting results for soil testing and for fractionation studies. Since the two factors (time of extraction and method of element quantification) examined in this study changed the results dramatically both from individual (main) and compounded (interaction) effects, it is apparent that the practical implications for any changes to soil test analysis procedures need thorough and systematic re-examination. Key words: Soil testing, analysis methods, organic P, organic S, multiple element extraction, extraction shaking time
Soils, land use and sustainable agriculture: A review
Authors: Miller F. P. , Wali M. K.
Published: April 2011

Viewing soils in the full context of landscape ecology is imperative. Both land and its component soil resources are finite. The biological capability of the earth’s ecosystems is limited, even though agriculture productivity has been manipulated by genetic selection of plants, adjusting nutrient flows, managing water, and controlling pests. However, these interventions also have serious economic and environmental repercussions. Increasing populations require more space, more food, more fuels and more of other resources. For soil scientists, the challenge is to (a) understand soil processes, (b) characterize and map soil resources, and (c) predict soil behavior under a variety of potential uses in the interest of providing society and its governing institutions with options and trade-offs in land use decisions. Global and regional economic and agricultural productivity will depend solely on our ability to increase productivity by (a) making economic–agricultural development congruent with ecological and social–political realities, (b) proper use and conservation of indigenous genetic resources, and (c) rehabilitating disturbed and degraded ecosystems. In this review, we assess these considerations and suggest needed strategies. Key words: Productivity, sustainable agriculture, land use, food security, soil quality
Carbon sequestration in a Brown Chernozem as affected by tillage and rotation
Authors: Campbell C. A. , McConkey B. G. , Zentner R. P. , Dyck F. B. , Selles F. , Curtin D.
Published: April 2011

Soil organic matter is important because it influences the productivity and physical well-being of soils. Recently, increased attention has focussed on soil organic matter as a possible sink for C02-C. Despite this interest, there is a lack of data for quantifying the effect of tillage on soil organic matter. Between 1981 and 1994, two tillage experiments were conducted at Swift Current, Saskatchewan, on Swinton loam, an Orthic Brown Chernozemic soil. Organic C and N were monitored periodically to quantify the effects of crop rotation [continuous spring wheat (Cont W) (Triticum aestivum L.) vs. fallow–wheat (F-W)] and tillage management [no-tillage (NT) vs. conventional tillage (CT) involving primarily use of a cultivator and rodweeder]. The effect of snow management on soil organic matter was also evaluated in one experiment, but this factor was not significant. Organic matter changes were mainly observed in the 0- to 7.5-cm soil depth. Carbon and N were greater in both concentrations and amounts in Cont W than in F–W; the latter cropping system was employed on this land during the previous 70–80 yr. In the 0- to 7.5-cm depth, the amount of organic matter was only moderately greater in NT than CT in the Cont W systems while in the F-W systems tillage was not significant (P > 0.10). During the 12-yr period, Cont W (average of NT and CT) gained about 2 t ha−1 more C in the top 15 cm of soil than F-W (average of NT and CT), with most of the increase occurring in the first 5 yr. Further, Cont W (NT) gained about 1.5 t ha−1 more C than Cont W (CT), and F-W (NT) gained about 0.5 t ha−1 more than F-W (CT). When a system that was maintained as Cont W (NT) for 9 yr was changed to Cont W (CT) for 3 yr and then summerfallowed (CT) for 1 yr, soil organic matter declined (P < 0.05). Our observations, supported by calculations based on crop residue production, indicated that an increase in organic C, averaging about 0.4–0.5 t ha−1 yr−1, has occurred in the top 15 cm of soil in Cont W (NT) between 1982 and 1993. However, because of uncertainty in our estimated C levels at the start of the experiment, the nature of the rate of C increase (linear or curvilinear) is not known. Key words: Organic C, organic N, no-till, summerfallow
A computer program to express the properties of gypsiferous soils
Authors: Arslan Awadis
Published: April 2011

Data from gypsiferous soils on an oven-dry basis cannot be compared with similar data from nongypsiferous soils because gypsum loses most of its crystal water on drying at 105 °C. A short computer program that uses the successive-approximation technique was developed to convert percent gypsum values determined on an air-dry basis or on an oven-dry basis into percent gypsum values determined on an oven-dry basis plus crystal water of gypsum. Percent gypsum and percent moisture of the analyzed soil samples are the required input data. The program calculates the corrected percent moisture and the percent gypsum on an oven-dry basis plus crystal water of the gypsum. The output of the program allows a comparison of gypsum contents, and any other properties, of gypsiferous soils after obtaining the correct moisture contents of the gypsiferous soils and makes these properties comparable with those of nongypsiferous soils. Key words: Percent gypsum, computer program, water content, gypsiferous soils
SHORT COMMUNICATION: Variation in soil total organic matter content and total nitrogen associated with microrelief
Authors: Chang C.
Published: April 2011

In a 140 × 50-m plot area on a Dark Brown Chernozemic clay loam soil subdivided into two subplots by direction of slope, total nitrogen (TN) and total organic matter (TOM) were significantly correlated with elevation after accounting for direction of slope. This finding, in an area that is not a closed hydrological basin and appears relatively flat, suggests aspect deserves consideration in the layout and sampling of experiments which include characterization of TN and TOM. Key words: Elevation, organic matter, total nitrogen
Recovery of 15N-labelled fertilizers applied to bromegrass on a Thin Black Chernozem soil
Authors: Malhi S. S. , Nyborg M. , Harapiak J. T.
Published: April 2011

The availability of N fertilizers on established grass stands is a function of such processes as immobilization, gaseous loss, leaching and position of applied N. A field experiment was conducted on a Thin Black Chernozem soil at Crossfield, Alberta to determine the effect of source, time and method of application on the recovery of 15N-labelled fertilizers applied to smooth bromegrass (Bromus inermis Leyss.). The treatments included two sources of N [urea and ammonium nitrate (AN)], four application times (early autumn, late autumn, early spring and late spring) and two methods of placement (surface-broadcast and subsurface banding). In most cases the 15N recovery in soil did not differ much between urea and AN. However, when urea was surface-broadcast, there was, on average, 10.2% less 15N recovery in plants than AN. The N recovery for late spring > early spring > late autumn = early autumn. When urea was banded 4 cm deep into the soil, N recovery in plants increased significantly compared with its surface-broadcast application. However, this was not observed when the source of N was AN. Banding generally increased the amount of immobilized N present in the soil and N recovery. We concluded that the N recovery in plants and in plants plus soil was less for urea than for AN and was less with autumn broadcast N application than with spring broadcast application. Key words: Ammonium nitrate, band placement, bromegrass, recovery of N, surface-broadcast, time of application, urea
Impact of agronomic practices and environment on diseases of wheat and lentil in southeastern Saskatchewan
Authors: Bailey K. L. , Gossen B. D. , Derksen D. A. , Watson P. R.
Published: April 2011

To determine the effect of tillage and rotation on plant diseases, their severity and prevalence were monitored on spring wheat, lentil, and field pea grown in rotation with zero and conventional tillage at Indian Head, SK, from 1992 to 1995. Root disease severity of wheat was less under zero tillage than conventional tillage, but leaf spot severity was unchanged. Incidence of the causal agents from roots was variable, such that Fusarium spp. were higher under zero tillage than conventional and Bipolaris sorokiniana was lower. Pyrenophora triticirepentis was the only foliar pathogen more prevalent under zero tillage than conventional. Rotation did not affect the pathogens causing root disease. However, the rotation of canaryseed-sunola-wheat-lentil had higher disease severity and levels of Septoria tritci on wheat compared with wheat-canola-wheat-lentil or wheat-pea-wheat-lentil. Neither crop rotation nor tillage practice had a measurable impact on lentil diseases, but epidemics of Ascochyta lentis and Botrytis cinerea were most severe in treatments with the densest plant stands. Multivariate analyses explored trends of tillage, rotation, and environment over years demonstrating that regardless of tillage or crop rotation practices, the annual environment was the most important factor limiting the severity of disease and the prevalence of causal agents in the complex. Key words: Rotation, tillage, root rot, leaf spot, wheat, lentil
Alternative seeding dates (fall and April) affect Brassica napus canola yield and quality
Authors: Kirkland Ken J. , Johnson Eric N.
Published: April 2011

Brassica napus L. canola production on the Canadian prairies often is limited by hot, dry growing conditions in early July and a short growing season. Brassica napus canola seeded in the fall just prior to freeze-up or in the early spring as soon as fields are passable may allow canola to avoid these adverse conditions. Our objective was to determine if late October (fall), or mid- to late April (April) seeding dates improve canola yield and quality relative to a mid-May (15 to 20 May) seeding date. Plant density and height, phenological development, seed yield, seed weight and seed oil content were assessed in plots sown to herbicide-tolerant B. napus canola at three seeding dates on five fallow sites and three stubble sites at Scott, SK, from 1994 to 1998. A thinner plant stand occurred for the fall compared with spring seeding dates; however, this difference rarely corresponded with less canola yield. Fifty percent flowering occurred 20 d earlier (June rather than July), reproductive growth (50% flowering to maturity) was 10 d longer, plants were 23 (fall) or 8 (April) cm shorter, and maturity occurred 13 d earlier when canola was seeded in the fall and April compared with mid-May seeding. Canola seed yield was 38% greater when seeded on the alternative dates rather than the more traditional mid-May seeding date. The yield advantage for alternative seeding dates was greater and more consistent on stubble than on fallow likely because of lack of soil crusting and temperature and wind protection from stubble. The response of seed weight to seeding date was similar to that for seed yield, indicating that a portion of the positive yield response to alternative seeding dates was associated with larger seed size. Oil content also was greater for the fall and April compared with mid-May seeding dates, but the improvement was smaller (6%) than that for seed yield. Fall- and April-seed-ed canola tolerated spring frosts and avoided adversely hot, dry weather during the flowering period, thus improving canola seed yield and quality. Alternative seeding dates provide canola producers in semi-arid regions with a sustainable option to diversify their cropping systems. Key words: Seeding date, dormant, stubble, fallow, herbicide tolerant, alternative cropping practice
CG108 corn inbred line
Authors: Lee E. A. , Good B. , Chakravarty R. , Kannenberg L.
Published: April 2011

CG108 is a short seasoned corn (Zea mays L.) inbred line. CG108 is a large inbred developed from a total plant biomass selection program. Key words: Corn, Zea mays L., cultivar description
Physical sod suppression as an alternative to herbicide use in pasture renovation with clovers
Authors: Seguin P. , Peterson P. R. , Sheaffer C. C. , Smith D. L.
Published: April 2011

Using herbicides for sod suppression during pasture renovation by legume sod-seeding often results in the loss of potentially usable forage, weed encroachment, and inadequate legume:grass ratios. Physical sod suppression methods could alleviate some of the problems associated with suppression via herbicide. A study was conducted in Québec, Canada, to investigate, as an alternative to herbicide, sod suppression by sheep grazing or mowing before and after spring no-till seeding of red clover (Trifolium pratense L.) or white clover (T. repens L.). Sod-suppression treatments included six physical suppression methods: mowing or sheep grazing, to 5 or 10 cm, at seeding and when the grass sward reached 30 cm during the first 2 mo of clover establishment, or similarly managed mowing or sheep grazing to 5 cm with an additional defoliation the previous fall. Additional treatments included suppression by herbicide (glyphosate [N-(Phosphonomethyl) glycine] at 2.6 kg a.i. ha–1) and two controls: sod-seeding with no sod suppression and no seeding. Among the physical suppression treatments, grazing and mowing to 5 cm resulted in highest clover densities, similar to those achieved via herbicide suppression. Red and white clover had similar plant densities. Yield components and total forage yields varied with sites. Clover yields tended to be higher with herbicide than under physical suppression treatments. However, increasing the severity of physical suppression increased clover yields. Weed encroachment was observed only with herbicide sod suppression. Unlike suppression with herbicide, physical suppression did not decrease total forage yields in the renovation and post-renovation years when compared with controls. Forage quality was increased in the renovation year by both physical suppression methods and herbicide when compared with unrenovated controls; but the increase was greater with herbicide suppression. Only the most severe of the physical suppression methods sustained increased forage quality in the year after renovation. Timely mowing or grazing as methods for suppression of grass sod during renovation with legumes appear to have potential, but cannot yet be recommended as alternatives to herbicide. Key words: Clover, forage, grazing, pasture renovation, sod-seeding
The adaptation of seven broadleaf crops to the dry semiarid prairie
Authors: Miller P. R. , McDonald C. L. , Derksen D. A. , Waddington J.
Published: April 2011

To develop diversified cropping systems for the dry semiarid prairie, the adaptation of alternative crops must be known. This experiment compared the adaptation of seven pulse and oilseed crops—desi chickpea (Cicer arietinum L.), dry bean (Phaseolus vulgaris L.), dry pea (Pisum sativum L.), lentil (Lens culinaris L.), mustard (Brassica juncea L.), safflower (Carthamus tinctorius L.), and sunflower (Helianthus annuus L.) — with spring wheat (Triticum aestivum L.), using two tillage practices — no-till and minimum tillage, including both fallow and wheat stubble-field phases. It was conducted near Swift Current, SK 1992–1996, and on a commercial farm near Congress, SK 1994–1995. Tillage system had no consistent effect on plant densities, which were generally adequate. Mustard, desi chickpea, dry pea and lentil required fewer degree days (5°C base) to reach anthesis, compared with wheat, while safflower and sunflower required more than wheat. Dry pea generally matured sooner than wheat, while lentil and mustard matured earlier than wheat only in years when near normal climatic conditions occurred. All other crops generally matured later than wheat. Safflower required an additional 400 degree-days and as a result presents considerable production risk in the semi arid prairies. Dry pea grain yields averaged 103% of wheat when grown on fallow and 135% of wheat when grown on stubble. Chickpea, lentil and dry pea yielded 76%, 77% and 90%, respectively, of their fallow-field yields when grown on stubble, indicating that the pulse crops have excellent potential for intensifying cropping systems in the dry semiarid prairie by replacing summerfallow in crop rotations. In contrast, wheat and mustard grown on stubble yielded only 66 and 61%, respectively, of fallow-field yields, suggesting they are not as well suited for stubble-cropping as the pulse crops. Low and highly variable yields were observed for safflower, dry bean and sunflower in both field-phases, although the yields from dwarf hybrid sunflower in the latter 2 yr of the study appeared promising. Low seed N concentration in wheat indicated yields were limited by soil-available N in most years, due to the generally wetter than normal growing seasons encountered during this study. The mean N yield (seed N concentrat ion × grain yield) of dry pea was double that for chickpea and lentil, indicating that dry pea fixed the greatest amount of atmospheric N2. Water-use efficiency for dry pea averaged 9.4 kg ha–1 mm–1 compared with 7.4 kg ha–1 mm–1 for wheat. Dry pea, chickpea, lentil, mustard and sunflower have good potential for diversifying cropping systems in the dry semiarid prairie. Key words: Oilseeds, pulses, adaptation, semiarid prairie, tillage systems, water-use efficiency
Selected physiological responses of kudzu to different chromium concentrations
Authors: Connell Shounda L. , Al-Hamdani Safaa H.
Published: April 2011

This study was designed to evaluate the potential use of kudzu (Pueraria montana var. lobata) as a phytoremediator to reduce Cr (VI) contamination. In addition, the effect of Cr concentrations of 4, 8, and 12 mg L–1 on kudzu growth, gas exchange, pigment concentration, and carbohydrate accumulation were evaluated. In general, Cr uptake by kudzu was increased as Cr concentration increased in the growing media. Most of the Cr taken up by kudzu was accumulated in the root as indicated by the significantly higher ratio of root/shoot Cr concentrations at increasing Cr levels in the root environment. Kudzu growth, photosynthetic rate, and chlorophyll a and b concentrations declined as the Cr concentration increased. The decrease in photosynthesis was independent of the internal carbon dioxide. Anthocyanin was found to increase as Cr concentration gradually increased from 4 to 12 mg L–1. Kudzu clearly demonstrated its ability to survive at Cr concentrations up to 8 mg L–1 in the root environment. Kudzu, therefore, can be considered as a replacement crop in areas of Cr contamination falling within the concentration range of this study. Key words: Carbohydrate, chromium uptake, photosynthesis, phytoremediation
AC Sampson winter wheat
Authors: Nass H. G. , Atlin G. N. , Walker D. F.
Published: April 2011

AC Sampson, a hard red winter wheat (Triticum aestivum L. em. Thell.) is adapted to eastern Canada, particularly the Atlantic Region. It expresses high grain yield, milling quality, lodging resistance, and good winter survival. It has moderate resistance to powdery mildew, leaf and glume blotch, and fusarium head blight. Key words: Triticum aestivum, wheat (winter), winter survival, cultivar description
CO427 and CO428 corn inbred lines
Authors: Reid L. M. , McDiarmid G. , Parker A. J. , Hamilton R. I.
Published: April 2011

CO427 and CO428 are short-season corn inbred lines with excellent combining ability, average to superior lodging resistance in hybrids and excellent emergence and early season vigour. Key words: Corn, maize, Zea mays, cultivar description
AC Ultima spring triticale
Authors: McLeod J. G. , Pfeiffer W. H. , DePauw R. M. , Clarke J. M.
Published: April 2011

AC Ultima, a spring triticale cultivar (X Triticosecale Wittmack), is widely adapted to the Canadian Prairies. AC Ultima represents an improvement in Hagberg Falling Number, which is usually associated with improved harvest-time sprouting resistance. AC Ultima expressed high grain yield, early maturity, heavy kernels and excellent lodging resistance compared to the check cultivars. AC Ultima is very resistant to the prevalent races of leaf rust, stem rust, and common bunt and resistant to common root rot. AC Ultima is eligible for the grades of Canada Triticale. Key words: Cultivar description, triticale (spring, X Triticosecale Wittmack), Hagberg Falling Number, yield, maturity, disease resistance, seed size
Influence of source, timing and placement of nitrogen on grain yield and nitrogen removal of durum wheat under reduced- and conventional-tillage management
Authors: Grant C. A. , Brown K. R. , Racz G. J. , Bailey L. D.
Published: April 2011

Effective fertilizer management is critical to maintain economic production and protect long-term environmental quality. Field studies were conducted over 4 yr at two locations in southwestern Manitoba to determine the effect of source, timing and placement of N on grain yield and N recovery of durum wheat (Triticum durum L. ‘Sceptre’) under reduced-tillage (RT) and conventional-tillage (CT) management. The effect of N management on durum grain yield and N recovery differed with soil type and tillage system. On the clay loam (CL) soil, lower yields with fall- as compared with spring-banded N were more frequent under RT than CT. Lower yields occurred more frequently with fall-applied as compared with spring-applied urea ammonium nitrate (UAN) than when urea or NH3 was the N source. On the drier fine sandy loam (FSL) soil, fall applications of N generally produced similar to higher grain yield than did spring applications. Differences among fertilizer sources and tillage systems were much less frequent with spring than fall applications of N. Where differences occurred, durum grain yields were higher with in-soil than surface applications of urea or UAN. In-soil applications of urea and UAN increased durum grain yield as compared with surface applications more frequently under RT than CT on the CL soil where yield potential was high, whereas increases on the FSL were as common under CT as under RT. On soils with a high yield potential, enhanced immobilisation and/or volatilisation of surface-applied N may reduce grain yield by reducing available N, particularly under RT. Selection of a suitable source-timing and placement combination to optimise crop yield may be more important under RT than CT. Key words: Conservation tillage, direct seeding, placement
AC Advantage field pea
Authors: Warkentin Tom , Xue Allen , Sloan Al , Rashid Khalid , Ali-Khan S. T. , Vera Cecil , Orr Denise , Turkington Kelly , Clayton George , Loeppky Gerald
Published: April 2011

AC Advantage, a green cotyledon field pea (Pisum sativum L.) cultivar was released in 1999 by Agriculture and Agri-Food Canada, Morden Research Centre, Morden, Manitoba. AC Advantage has a semileafless leaf type, powdery mildew resistance, medium-large round seeds, and good yielding ability. Key words: Field pea, Pisum sativum L., cultivar description, powdery mildew resistance
Weed survey of lowbush blueberry fields in Saguenay–Lac-Saint-Jean, Québec, following eight years of herbicide application
Authors: Lapointe Line , Rochefort Line
Published: April 2011

A weed survey was conducted in 1995 and 1996 in eight lowbush blueberry (Vaccinium angustifolium Ait.) producer sites of the Saguenay–Lac-Saint-Jean region to measure the impact of repeated herbicide applications on weed frequency and percent cover. A previous survey (1981–1983), done in the same area before the widespread use of herbicides by the producers, had shown an impact of weed abundance on blueberry productivity. Weed frequency decreased from 1981–1983 to 1995–1996. Some species have apparently disappeared and all showed a reduction in abundance, suggesting that tolerance to herbicides or shifts to herbicide tolerant species has not occurred in this region. Weed cover decreased from over 65% to 10% in surveyed blueberry producer sites, and their presence no longer affects blueberry productivity. However, herbicide use is associated with an increase in percent bare ground, which now accounts for an average of 38% of lot surfaces. Blueberry plants do not seem to be able to quickly colonise bare weeded sites. In plots weeded manually, blueberry shoots did not increase in cover after 2 yr. Herbicide applications are still needed to maintain the weed populations at low levels, but we now have to stimulate the colonisation of bare patches by blueberry plants. Key words: Vaccinium angustifolium, glyphosate, hexazinone, weed control, weed frequency, blueberry productivity
Effect of ozone on qualities of fruits and vegetables in cold storage
Authors: Skog, and C. L. Chu L. J.
Published: April 2011

Ozone at the concentration of 0.04 mL L–1 appears to have potential for extending the storage life of broccoli and seedless cucumbers stored at 3°C. Response to ozone was minimal for mushrooms stored at 4°C and cucumbers stored at 10°C. Ozone generators producing 0.04 mL L–1 ozone reduced the ethylene level in vegetable storage rooms from 1.5–2 mL L–1 (as produced by apples placed in the room) to a non-detectable level. At concentrations of 0.4 mL L–1, ozone was effective in removing ethylene from the atmosphere in an apple and pear storage room. The ozonized and non-ozonized apples and pears showed no difference in fruit quality. This study explored a potential use of ozone application in wholesale storage rooms where ethylene-producing and ethylene-sensitive fruits and vegetables may be stored together. Key words: Ozone, ethylene, fruit, vegetable, apple, pear, broccoli, cucumber, mushroom, storage
Certain chemical thinning treatments advance maturity of Paulared apple
Authors: Embree Charles G. , Nichols Douglas S. , DeLong John M. , Prange Robert K.
Published: April 2011

Mature Paulared (Malus ×domestica Borkh L.)/MM106 apple trees with a heavy bloom were sprayed with carbaryl [Sevin® XLR 1.25 mL L–1 (600 mg L–1 a.i.)], benzyladenine (BA)/gibberellic acids (GA4 + 7) [Accel® 1.22 mL L–1 (23.1 mg L–1/2.31 mg L–1 a.i.)], carbaryl [Sevin® XLR 1.25 mL L–1 (600 mg L–1 a.i.)] + BA/GA4 + 7 [Accel® 1.22 mL L–1 (15.6 mg L–1/1.56 mg L–1 a.i.)] and napthaleneacetic acid (NAA) [FruitoneN® 0.32 g·L–1 (1.13 mg L–1 a.i.)] when fruitlet diameter was 7 mm. Ethephon [Ethrel® 2.29 mL L–1 (549.6 mg L–1 a.i.)] was applied at the 13.5 mm fruitlet diameter stage. Carbaryl alone, NAA and ethephon all resulted in improved fruit size at harvest, whereas BA/GA4 + 7 was ineffective as a thinner and did not alter fruit size at harvest. Of these treatments, only ethephon significantly reduced crop load. Both NAA and ethephon, and especially ethephon, advanced fruit maturity at harvest as indicated by a lower Streif index. Only ethephon increased commercial levels of fruit colour and following-year blossom density. Thus, while ethephon appears promising as a fruitlet thinner and a promoter of maturity for this cultivar, these effects will have to be balanced against possible adverse effects on storage and shelf life. Key words: Crop load, carbaryl, ethephon, apple maturity, Streif index
Food and feed potential breeding value of green, dry and vegetable pea germplasm
Authors: Santalla M. , Amurrio J. M. , De Ron A. M.
Published: April 2011

Pea is an important grain legume and vegetable in the South of Europe where it is grown on small farms and gardens using traditional varieties and methods during the winter. Variability in old, unimproved varieties needs to be determined in order to create useful genetic variation for broadening the narrow genetic base of commercial cultivars and for making efficient use of available resources. One hundred and four unimproved pea varieties and ten elite cultivars were evaluated in 1991 and 1992 at two locations for seed and vegetable quality, canopy and agronomic traits. Significant genotype by environment (G × E) interactions were found for protein concentration, fresh seed size and weight, canopy traits, pod length and weight, days to flowering, and days to fresh seed and pod maturity. There were significant differences between unimproved pea varieties for all traits studied except for seed soluble sugars and seed tenderness. Most of the significant differences for seed and vegetable quality traits were observed in the unimproved germplasm from the South of Europe when compared with differences within the elite germplasm. Data from the evaluation of available pea germplasm provide information needed by breeders to develop varieties efficiently for the different needs of growers, processors and feed manufacturers. The relevance of these results in devising breeding strategies is discussed. Key words: Pisum sativum, seed and vegetable quality, field performance, genotype by environment interaction
AC Alberte hulless barley
Authors: Choo T. M. , Martin R. A. , ter Beek S. , Ho K. M. , Caldwell C. D. , Walker D. , Rodd V.
Published: April 2011

AC Alberte is a two-row, spring hulless barley (Hordeum vulgare L.) cultivar developed by the Eastern Canada Barley Breeding Group, Agriculture and Agri-Food Canada. It has high yield, good test weight, good seed weight, and lodging resistance. AC Alberte performs well in the Maritime Region of Canada. Key words: Barley, Hordeum vulgare L., cultivar description, high yield, high seed weight
AC Klinck barley
Authors: Choo T. M. , Ho K. M. , Martin R. A. , ter Beek S.
Published: April 2011

AC Klinck is a six-row, spring feed barley (Hordeum vulgare L.) cultivar developed by the Eastern Canada Barley Breeding Group, Agriculture and Agri-Food Canada. It has high yield, high seed weight, and a moderate level of resistance to powdery mildew and barley yellow dwarf virus. AC Klinck performs well in Ontario, Canada. Key words: Barley, Hordeum vulgare L., cultivar description, high yield, powdery mildew, barley yellow dwarf virus
Effect of post-harvest management on seed production of creeping red fescue, tall fescue, and Kentucky bluegrass in the Peace River region of north-western Canada
Authors: Fairey N. A. , Lefkovitch L. P.
Published: April 2011

A field study in the Peace River region of northwestern Canada evaluated five post-harvest management (PHM) treatments on the seed yield and quality of four grasses, viz. Boreal creeping red fescue (Festuca rubra L. var. rubra), Safari and Tomahawk tall fescue (F. arundinacea Schreber), and Midnight Kentucky bluegrass (Poa pratensis L.). The PHM treatments were: straw removal after seed harvest plus trimming prior to winter; a single propane burn; a double propane burn; power cultivation; and diuron applied in spring. The study was conducted for 3 consecutive harvest years. The grass × harvest year × PHM interaction was not statistically significant (P ≤ 0.05) for any of 10 characteristics, viz. panicle density, time of seed maturity, seed yield (per unit land area and per individual panicle), whole-plant yield, harvest index, seed dockage, 1000-seed weight, specific seed weight, and germination capacity. The grass × harvest year interaction was statistically significant (P ≤ 0.05) for each of the 10 characteristics, primarily because of the differential response of the bluegrass as compared to the fescue grasses. The grass × PHM interaction was statistically significant (P ≤ 0.05) for seed yield of individual panicles, harvest index, seed dockage and 1000-seed weight. The PHM × harvest year interaction was statistically significant (P ≤ 0.05) for specific seed weight only. The main effect of PHM was statistically significant (P ≤ 0.05) for specific seed weight and germination capacity only. The average annual seed yield of the two tall fescue cultivars (1002 and 1171 kg ha–1 for Safari and Tomahawk) was approximately twice that of Boreal creeping red fescue (554 kg ha–1) and four times that of Midnight Kentucky bluegrass (284 kg ha–1). At this northerly latitude (55°N), the effects of any PHM treatment on the seed productivity of these grasses may be limited by the short period of environmental conditions between seed harvest and the onset of winter that are conducive to vegetative and reproductive tiller development. Key words: Post-harvest management, propane burning, mechanical and chemical rejuvenation, grass seed yield, grass seed quality
RCAT Staples soybean
Authors: Ablett G. R. , Stirling B. T. , Fischer J. D.
Published: April 2011

RCAT Staples is a mid-Maturity Group II soybean [Glycine max (L.) Merrill] cultivar with excellent yield potential and good lodging resistance. It was developed by Ridgetown College, University of Guelph and is adapted to the 3000 –3500 heat unit areas of Southwestern Ontario. RCAT Staples was issued the registration number 4942 on 2 June 1999 by the Variety Registration Office, Plant Health & Production Division of the Canadian Food Inspection Agency. Key words: Soybean, cultivar description
Corn Inbred Line CG102
Authors: Lee E. A. , Good B. , Chakravarty R. , Kannenberg L.
Published: April 2011

CG102 is short seasoned corn (Zea mays L.) inbred line. Key words: Corn, Zea mays L., cultivar description
AEC Mountaineer broadglumed wheatgrass
Authors: Darroch B. A. , Acharya S. N. , Woosaree J.
Published: April 2011

AEC Mountaineer broadglumed wheatgrass, Elymus trachycaulus subsp. violaceus (Horneman) A. & D. Love, is a cultivar developed for reclaiming and revegetating disturbed sites at high elevations. It is the first cultivar of broadglumed wheatgrass available in Canada. Its primary advantage over other subspecies of slender wheatgrass is its ability to grow rapidly and produce mature seed at elevations as high as 2300 m. Production of mature seed enables plants to propagate, thus increasing plant density and stand longevity in high stress, high elevation environments. Key words: Broadglumed wheatgrass, slender wheatgrass, Elymus trachycaulus, reclamation, cultivar description
AEC Glacier alpine bluegrass
Authors: Darroch B. A. , Acharya S. N. , Woosaree J.
Published: April 2011

AEC Glacier alpine bluegrass, Poa alpina L., is a reclamation cultivar developed for use in reclaiming and revegetating disturbed sites at high elevations. It is the second alpine bluegrass cultivar released by the Alberta Environmental Centre, Vegreville, AB. This cultivar is expected to complement a prior release, AEC Blueridge alpine bluegrass. AEC Glacier is adapted to high elevations where it is capable of rapid growth and seed production. Key words: Alpine bluegrass, Poa alpina, cultivar description, reclamation
AC Corinne hard red spring wheat
Authors: Humphreys D. G. , Townley-Smith T. F. , H. McKenzie R. I. , Czarnecki. E.
Published: April 2011

AC Corinne is a hard red spring wheat belonging to the Canada Western Extra Strong (CWES) class. It has superior preharvest sprouting resistance and improved leaf rust resistance compared to Glenlea and Wildcat, and is higher yielding than Wildcat. AC Corinne has extra strong wheat quality similar to Glenlea combined with higher grain protein content. It is adapted to the wheat growing areas of the prairie provinces. Key words: Triticum aestivum L., Canada Western Extra Strong, hard red spring wheat, cultivar description, yield, disease resistance
A naked oat mutant with very short rachillas
Authors: Burrows V. D. , Konzak C. F. , McDiarmid G. , Deyl J.
Published: April 2011

Groats of the naked seeded oat variety Tibor were treated with mutagenic agents sodium azide and ethylmethane sulfonate. A floral mutant with very short rachillas was selected from a M4 population of the mutagen treated seed. This very unusual trait was found to be controlled by a single recessive gene named sr-1. Key words: Mutant, Avena sativa L., naked oat, very short rachilla, gene sr-1
Gene controlling reduced trichomes on oat groats
Authors: Burrows V. D. , McDiarmid G. , Marder T.
Published: April 2011

The groats of naked oat varieties are commonly covered with an abundance of surface borne trichomes. The trichomes are liberated into the air during threshing and handling and act as skin, eye, and respiratory irritants to operators. A bald strain (CN 18943) with a greatly reduced number of trichomes was bred and the bald trait was found to be conditioned by a single recessive gene, designated Gt-1. Key words: Avena sativa L., naked oat, reduced groat trichomes, gene Gt-1