No description available.

Faunistic composition and population dynamics of chrysopids were investigated in two old fields in Quebec. Nine species were collected; Chrysopa oculata Say and Chrysopa chi Fitch are dominant and resident. / Parasitism due to Chrysopophthorus americanus Mason has little effect on the reproductive potential of C. oculata and C. chi populations. However, embryonic mortality, resulting from autosomal translocations, is a major mortality factor in both species. Their karyotypes are described and developmental studies conducted on them and Chrysopa lineaticornis Fitch are reported. / Inheritance of wing and cephalic characters was investigated in C. oculata. A population genetics study revealed seasonal selection against the allelic gene B (black gradates) and superior fitness of its recessive counterpart b (green gradates). A meiotic drive mechanism also favors the b allele, and the allele A determining "facial band" expression. / Chrysopa chi exhibits obligatory and facultative prepupal diapause. The field population, however, is primarily univoltine. Voltinism is controlled by two independently segregating autosomal genes; the recessive alleles, in the homozygous state, determine obligatory diapause and, consequently, univoltinism. Diapause termination is reported.

The potential of grain amaranth production in southwestern Quebec was studied. Twenty-nine cultivars were evaluated in single row plots, and seven in mechanically managed plots. Yields averaged 27 g plant-1 in single row plots, and 649 kg ha-1 in mechanically managed plots. Another set of experiments evaluated different seeding dates, row spacings, seeding rates and nitrogen fertilization rates. Seeding date and nitrogen fertilization affected grain yield in one environment, and seeding rate and row spacing did not affect yield. Grains in all experiments required drying. These experiments suggest that grain amaranth could be cultivated in southwestern Quebec. Oxalate concentration and form were determined in seeds from the cultivar, seeding date and nitrogen fertilization trials, and the effects of cooking on oxalate were evaluated. Fertilization increased oxalate concentration, seeding date had no effects, and cooking increased soluble oxalate. Grain amaranth is high in oxalate, but its absorbability is probably low.

Carbon storage was compared between two perennial biomass energy systems, namely switchgrass (Panicum virgatum L.) and short-rotation willow Salix alba x glaffelteri L.) at 2 adjacent sites, and further compared with a corn cultivation, a 20-year-old abandoned field, and a mature hardwood forest, in southwestern Quebec. Aboveground carbon results indicated that switchgrass and corn had significantly greater carbon levels than willow at the less fertile site, but no significant differences were detected at the more fertile site. Root carbon results indicated that corn had significantly lower carbon levels than both perennial systems to a depth of 30 cm at both sites. However, switchgrass had significantly greater root carbon levels beyond 30 cm compared with willow and corn, and beyond 45 cm compared with the forest and abandoned field. These findings indicate that deep-rooted perennial grasses such as switchgrass have the potential to sequester carbon at deeper soil layers. Soil carbon results showed that at the more fertile site, willow was associated with significantly greater soil carbon levels than switchgrass. Moreover, both perennial crops had soil carbon levels that were greater than for corn, the abandoned field, and the forest. In contrast, at the less fertile site, no significant differences in soil carbon were detected between the various plant systems examined. The results of this study suggest that the perennial energy crops used, when grown on relatively fertile soils, have the potential to substantially increase soil carbon levels compared with conventional agricultural and/or forest systems. Consequently, when these crops are grown on less fertile soils, their added advantage of increasing carbon storage is lost.

The purpose of this descriptive study is to examine how some large organizations selected for the quality of their human resource management (HRM) practices evaluate their human resource (HR) function, and to investigate the purpose and usefulness of HRM evaluation within these organizations. Five questions are investigated: (1) Who decides whether or not to evaluate the HR function? (2) What are the objectives of HRM evaluation? (3) What is the focus of HRM evaluation? (4) What are the means used to evaluate HRM? (5) What is the impact of HRM evaluation on the direction of human resource management within the organization? / Despite the growing strategic importance of human resource management, there is still little research evaluating its effectiveness. Most participants consider that their organization does not systematically evaluate HRM. Most use indirect or informal methods. This confirms that systematic HRM evaluation is not a priority for most organizations. Some Vice-Presidents, Human Resources (VPHR) expressed disappointment with this situation and indicated that the necessary resources were not available. / Within the limited sample of 10 organizations, the HRM evaluation practices are diversified. The extent of HRM evaluation is surprising given the reservations and modesty expressed by the participants. Most organizations have evaluated multiple HRM policies, programs or services representative of multiple sub-systems within the HRM system. / The high-impact HR function uses performance measures to support its business plans and to convincingly communicate the benefits of its contribution to the stakeholders, especially senior management. Despite a strong continuous improvement culture and the participation of the VPHR in strategic decision making, measuring HRM effectiveness and benchmarking against the best HRM practices is not a systematic process in most organizations.

Warm season grasses are increasingly being cultivated in North America for summer forage, soil conservation, and biomass production. In more northern environments, temperature and length of growing season have an overriding effect on the productivity of warm season grasses. There is limited information on the adaptability and production potential of warm season grasses in these short season areas. A study was conducted in south-western Quebec from 1993 to 1996 to evaluate the productivity of five species of warm season grasses. Phenological development, canopy leaf area development and architecture, radiation-use efficiency (RUE), yield and chemical composition were determined. In terms of phenology, there was a diversity of developmental patterns and the genotypes of greatest potential were characterised by early spring growth and late onset of dormancy in fall. Most of the genotypes that were early in spring growth were also early maturing and low yielding. Late maturing genotypes were generally late in spring growth, high yielding and generally of southern origin. Differences in developmental patterns were partly explained by differences in base temperatures for germination and growth, and growth rates. Seed osmoconditioning and/or matriconditioning alleviated effects of low temperatures on switchgrass seed germination and potential establishment. Maximum leaf area index ranged from 6.1 to 8 and the vertical leaf area distributions and light interception levels varied among genotypes. Average end of season biomass yields ranged from 8.5 to 14.4 Mg ha-1. Switchgrass rates of DM accumulation ranged from 175 to 191 kg ha-1 day-1 and RUE 0.89 to 1.1 g MJ-1 of incoming solar radiation. Moderate amounts of N fertilisation increased yield and quality of switchgrass, which could be harvested in a 2-cut system. NDF and ADF ranged from 77--88 and 46--57% respectively, and showed a rapid increase to a mid season plateau. Nitrogen concentrations declined curvilinearly wit

Soil structure and crop response under annual compactive loads of 10 and 18 t/axle and compaction alleviation treatments were assessed in a continuous corn production system. The alleviation treatments consisted of chemical conditioning with a non-ionic surfactant, and subsoiling with narrow-tined and winged implements. Parameters utilized for determining effects on soil structure were bulk density, water retention characteristics and soil profile characteristics. Significant topsoil and subsoil compaction resulted from both loading levels. Crop yield reductions due to compactive loading ranged from 18 to 27% under optimal weather conditions and were as high as 55 to 86% under adverse weather conditions. Soil amendments by chemical conditioning had no beneficial effect on soil structure or crop yields. Inter-row subsoiling with narrow-tined and winged subsoilers was effective in reducing soil compaction and increasing crop yields. / Soil bulk density measurements gave good indication of overall compaction to a depth of 0.4 m and correlated well with crop yields, but were unable to locate differences between compactive treatments. Water retention characteristics indicated significant differences between compactive treatments to a depth of 0.6 m. Soil profile characteristics were useful for determining ped type and size as well as rooting depth and gave the best overall assessment of compaction alleviation effects. / Studies were also conducted to develop a method for predicting soil compactibility that would serve to manage soil compaction at the farm level. Preliminary studies focused on the determination of soil material properties for predicting bulk density changes under applied loads. Further investigations were conducted on the variations in constrained modulus, cone index and soil bulk density values under uniaxial loading. A model relating constrained modulus as a function of cone index, bulk density and soil moisture content was developed. Subsequent studies conducted yielded significant relationships between penetration resistance and soil compactibility as indicated by constrained modulus and coefficient of compressibility. Relationships obtained between penetration resistance and parameters of compactive work and bulk density change indicated the feasibility of assessing soil compactibility at the farm level.

No description available.

No description available.

No description available.