Control of heather (Calluna vulgaris (L.) Hull) by steam treatment: Effects on establishment and early growth of Scots pine

Following boreal forest ecosystem disturbance,such as fire and clear-cutting, the ericaceousspecies Calluna vulgaris often becomescompletely dominant and may convert forestlandinto heathland. Calluna is known toeffectively exclude other vegetation and causes``growth check' or stagnation of coniferseedlings to result in poor tree regeneration.In this study we investigated the use of steamtreatment as an alternative method forvegetation control of Calluna vulgaris.Scots pine (Pinus sylvestris L.)establishment and growth were recorded in botha planting and a seeding experiment. Steamtreatment was compared with mechanical soilscarification and intact vegetation in theplanting experiment and with intact vegetationin the seeding experiment. The results showthat the vegetation is still strongly reducedfive years after the treatment. The steamtreatment strongly favoured the establishmentand growth of both seeded and planted Scotspine. The planted seedlings grown in the steamtreated plots had a dry weight more than twiceas high when compared to scarified plots.Seedling height and basal diameter were alsohighest for seedlings grown in steamed plots.Seedlings planted in scarified plots did notgrow as well during the first years possiblydue to injuries caused by frost heaving. Theseeding experiment showed an increasedestablishment and growth of Scots pineseedlings in steam treated plots compared to inintact vegetation.     

Renewable cathode materials from biopolymer/conjugated polymer interpenetrating networks

Renewable and cheap materials in electrodes could meet the need for low-cost, intermittent electrical energy storage in a renewable energy system if sufficient charge density is obtained. Brown liquor, the waste product from paper processing, contains lignin derivatives. Polymer cathodes can be prepared by electrochemical oxidation of pyrrole to polypyrrole in solutions of lignin derivatives. The quinone group in lignin is used for electron and proton storage and exchange during redox cycling, thus combining charge storage in lignin and polypyrrole in an interpenetrating polypyrrole/lignin composite.     

The severity of field pea diseases depending on sowing rate and variety

ABSTRACT

Six varieties of field pea (Pisum sativum L.) were sown at two sowing rates over two years to assess the impact on disease occurrence in a Baltic climate. The varieties used were Bruno (Latvia), Capella (Sweden), Clara (Sweden), Kirke (Estonia), Onward (Greece), and Vitra (Latvia). The two sowing rates were 120 seeds per m² and 144 seeds per m². The increase in sowing rate by 20% did not influence field pea diseases. Variety influenced the incidence of disease in field pea. The varieties most damaged by pod spot (Ascochyta blight caused by Ascochyta spp.) were Vitra and Onward and least damaged were Bruno and Clara. The variety most damaged by downy mildew (caused by Peronospora viciae) was Vitra and least damaged was Bruno. The variety most damaged by white mould (or Sclerotinia rot caused by Sclerotinia sclerotiorum (Lib.) de Bary) was Onward. The varieties that had the most disease damage were Vitra and Onward, while least susceptible were Clara and Bruno. Therefore, Clara and Bruno are recommended for field pea production in a Baltic climate.     

Diabetes mellitus in a population of 180,000 insured dogs: incidence, survival, and breed distribution

BACKGROUND: Canine diabetes mellitus (DM) is a common endocrinopathy with an unclear etiology. For a better understanding of the underlying mechanisms, there is a need for comprehensive epidemiologic studies. Earlier studies have shown that the risk of disease is higher in certain dog breeds. HYPOTHESIS: Incidence, age of onset, survival and sex proportion of DM vary by breed. ANIMALS: Data from a cohort of 182,087 insured dogs aged 5-12 years accounting for 652,898 dog-years at risk were studied retrospectively. METHODS: Incidence rates by sex, breed, and geography were calculated with exact denominators. Age-specific incidence and survival after 1st DM claim were computed with Cox's regression and Kaplan-Meier survival function. Multivariable survival analysis was performed for the outcome diagnosis of DM with age, sex, and geography tested as fixed effects, previous endocrine or pancreatic diseases tested as time-dependent covariates, and breed tested as a random effect. RESULTS: The mean age at 1st insurance claim for the 860 DM dogs (72% females) was 8.6 years. The incidence of DM was 13 cases per 10,000 dog-years at risk. Australian Terriers, Samoyeds, Swedish Elkhounds, and Swedish Lapphunds were found to have the highest incidence. The proportion of females with DM varied significantly among breeds. Swedish Elkhounds, Beagles, Norwegian Elkhounds, and Border Collies that developed DM were almost exclusively females. The multivariable model showed that breed, previous hyperadrenocorticism, and female sex were risk factors for developing DM. Median survival time was 57 days after 1st claim. Excluding the 223 dogs that died within 1 day, the median survival time was 2 years after 1st claim of DM. CONCLUSION: The significant breed-specific sex and age differences shown in this study indicate that genetic variation could make breeds more or less susceptible to different types of DM.     

Dispersal and spatiotemporal distribution of Protapion fulvipes in white clover fields: implications for pest management

Journal of Pest Science - Yield loss caused by insect pests remains a substantial problem in agriculture. Chemical control, with potential negative effects on non-target organisms, is still the...     

Increase of leaf tipburn in chervil and lettuce by restricting volume of growing medium

Abstract

The objective of this investigation was to examine the effect of restriction of growing medium volume on the level of tipburn in chervil and leaf lettuce. Chervil: The plants were grown in different sizes of rock wool cubes: a. 31 cm³, b. 64 cm³, c. 135 cm³. The incidence of tipburned leaves decreased by increasing the size of cubes. Leaf lettuce: Plants were grown in different sizes of pots: 12 cm pots with capacity of 0.6 L and 8 cm pots with capacity of 0.25 L. The incidence of tipburned leaves increased by decreasing pot size.     

Impact of variety and farming practices on growth,yield, weed flora and symbiotic nitrogen fixation in faba bean cultivated for fresh seed production

The main objective of this study was to investigate the performance of faba bean landraces originating from different regions of Greece under both organic and conventional farming systems focusing mainly on yield, biological nitrogen fixation (BNF), and competitiveness to weeds. Faba bean exhibited a high ability to fix nitrogen from the atmosphere, as indicated by the percentage of N₂ derived from the atmosphere which exceeded 75% in all evaluated varieties, and the total amount of biologically fixed N up to full anthesis, which fluctuated from 118.5 to 193.9?kg?ha^?1 in the various cropping systems and cultivars. The weed density was appreciably higher in the organic plots, without significant differences among the faba bean cultivars, while wild mustard and corn poppy were the most competitive weeds. The application of inorganic starter fertiliser in the conventionally-treated plots had no negative effect on biologically-fixed nitrogen by faba bean plants, while the herbicide pendimethalin had no negative impact on the nodulation process. Protein concentrations in faba bean cultivars fluctuated from 27.3% to 31.4%. The evaluated landraces could be utilised in breeding programmes due to their earliness, and their high performance in terms of protein content, BNF ability, and productivity.     

Prediction of protein content in malting barley using proximal and remote sensing

This paper examines the prediction of within-field differences in protein in malting barley at a late growth stage using the Yara N-Sensor and prediction of its regional variation with medium resolution satellite images. Field predictions of protein in the crop at a late growth stage could be useful for harvest planning, whereas regional prediction of barley quality before harvest would be useful for the grain industry. The project was carried out in central Sweden where the variation in protein content of malting barley has been documented both within fields and regionally. Scanning with an N-sensor and crop sampling were carried out in 2007 and 2008 at several fields. The regional data used consisted of weather data, quality analyses of the malting barley delivered to the major farmers’ co-operative, crops grown and field boundaries. Satellite scenes (SPOT 5 and IRS-P6 LISS-III) were acquired from a date as close as possible to the N-sensor scans. Reasonable partial least squares (PLS) models could be constructed based on weather and reflectance data from either the N-sensor or satellite. The models used mainly reflectance data, but the weather data improved them. Better field models could be created with data from the N-sensor than from the satellite image, but a local satellite-based model based on a simple ratio (middle infrared/green) in combination with weather was useful in regional prediction of malting barley protein. A regional prediction model based only on the weather variables explained about half the variation in recorded protein.     

A Regional Perspective on Present and Future Soil Chemistry at 16 Swedish Forest Sites

Assessing the timescales of recovery, by the use of dynamic models, will be used as input to the policy process to abate acidification. In this study the multilayer dynamic soil chemistry model SAFE was applied to 16 forest sites in Sweden, covering a sulfur deposition gradient of 1.2–11 kg S/ha/yr. Soil samples were collected at all sites and the pH and sulfate concentration dependent isotherm, used for modeling sulfate adsorption in SAFE, was parameterized for every site. A new way of implementing the nutrient uptake distribution in SAFE was developed, which allows the uptake distribution between layers in the rooting zone to vary with time, depending on the availability of base cations in the individual layers. Model output was compared to measurements of base cation concentration, total inorganic Al, pH and Bc/Al both site-by-site and cumulatively for all sites, and the usefulness of these comparisons is discussed from a policy viewpoint. Future projections of recovery show that the overall recovery, expressed as minimum Bc/Al ratio > 1 in the rooting zone, is slow. Assuming full implementation of the UNECE LRTAP Gothenburg Protocol and no further emission reductions thereafter, 44% of the modeled sites still have a Bc/Al ratio below 1 in 2100 in some soil layer within the rooting zone.     

Macrophyte succession in Swedish lakes caused by deposition of airborne acid substances

Water, Air, & Soil Pollution - Recurrent biological investigations have been made in six lakes in two areas in western Sweden. It has been found that the supply of acid substances induces...