Volume 34 (2015): Issue 329 (December 2015)
Rural Sustainability Research

Apple fruit rot can be caused by several fungi. In Northern Europe, the most common storage rot, Bull’s eye rot, is caused by Neofabraea spp., bitter rot by Colletotrichum spp., brown rot by Monilinia fructigena, grey mould is caused by Botrytis cinerea and Fusarium rot by several Fusarium species. Blue mold decay caused by Penicillium expansum is an important disease in several European countries. Incidence of different causal agents may vary depending on cultivar, climate during growing season and agricultural practices. The main objective of the study was to obtain baseline information about apple rot-causing fungi, their incidence during fruit storage and to evaluate the fungicide sensitivity of most of isolated fungal species. The study was performed during the storage period of apples after the growth season of 2013. Rotten apples were sorted in the storage and part of them was brought to the laboratory in order to obtain fungal isolates. Fungi were identified according to the morphological characteristics and sequencing of the ITS1-5.8S-ITS2 region. During storage in February and March the total percentage of rotten apples in various cultivars varied from 3.6 to 58.9%. All post-harvest diseases described in Northern Europe were detected. In part of the storehouses apple rot caused by Cadophora luteo-olivacea was observed. Alternaria spp. and Cladosporium spp. were detected on few apples as secondary infection agents. Using the most often isolated fungal species, sensitivity tests were performed against five commonly used fungicides. In general, the sensitivity of tested fungi to the fungicides was high with exception of several Neofabraea and Alternaria isolates.

Artificial weathering is a widely used method for predicting wood behaviour during its service life. A study was carried out to compare the colour change of thermally modified aspen (Populus tremula L.) and grey alder (Alnus incana (L.) Moench) wood during natural solar and artificial ultra violet (UV) irradiation. Thermally modified wood specimens were exposed for 30 h to artificial UV irradiation at two different intensities, i.e.1.36 W m⁻² at 340 nm and 0.68 W m⁻² at 340 nm, as well as to solar irradiation outdoors and indoors. After 2.5, 5 and 10 h exposure, colour parameters and reflectance spectra (360–740 nm) were determined. Colour was expressed in accordance with the CIELAB colour model as colour parameters L*, a*, b*. The total colour change ΔEab was calculated from colour parameter differences ΔL*, Δa*, Δb*. The colour changes caused by solar and artificial UV irradiation had a similar pattern for both thermally modified hardwood species under study. Changes in the individual colour parameters in the course of the experiment altered their direction, which implies that discolouration of thermally modified wood is a complicated and dynamic process with various and different chemical transformations in wood chromophores. Colour and reflectance changes had similar trends for different intensities of the same type of irradiation, but they differed for various irradiation types – natural solar or artificial UV irradiation. Greater discolouration was detected for the specimens exposed to both solar irradiations - outdoors and indoors. The results suggest that the fluorescent lamps of the UVA-340 type, which only imitate well the sunlight UV spectrum from 290 nm to 365 nm, do not fully simulate the changes in thermally modified wood induced by solar radiation.

The aim of the study was to investigate the beef and dairy cow parasitosis epizootic situation in Vidzeme region. Research was done throughout Vidzeme territory during the period of the years 2013-2014. The total number of animals examined was: 273 dairy and 90 young beef cattle aged from 6 months to two years and 248 dairy and 29 beef cows older than two years. For the diagnosis of helminthes standardized ovoscopic and larvoscopic methods were used. For the diagnosis of protozoa flotation and modified Ziehl-Neelsen methods were used. The main species in the samples were Cryptosporidium spp., Eimeria spp. and Strongylus spp. In the young dairy and beef cattle aged from 6 months to two years and cattle older than two years Cryptosporidium spp. invasion accordingly was 32.6% and 19% (dairy cattle) and 62.2% and 65.5% (beef cattle); the invasion of Eimeria spp. 30% and 7.3% (dairy cattle) and 55.6% and 10.3% (beef cattle); and the invasion of Strongylus spp. was 17.6% and 13.7% (dairy cattle) and 43.3% and 27.6% (beef cattle). Both dairy and beef cattle were infected with Moniezia spp., Paramphistomum spp., Strongyloides spp. Dairy cows aged from 6 months to two years had Trichuris spp., Dictyocaulus spp. and Neoscaris spp. invasion.

During the last decades, thermally modified wood has become an object of interest among the wood scientists as an environmentally friendly material, because nowadays environmental aspects of materials have become more and more significant. Leaching is one of the processes that occurs in outdoor use. The aim of this study was to evaluate concentration of potentially hazardous substances in leachates of thermally modified pine wood. Scots pine (Pinus sylvestris L.) wood was thermally modified using Wood Treatment Technology (WTT) company device at 170 °C for 1 hour (TMP170/1) and at 160 °C for 3 hours (TMP160/3) and the mass loss was calculated. Material preparation and leaching procedure was made according to standard LVS EN 84:2000. In obtained leachates, the content of sugars, acetic acid, furfural and tannic acid were determined. Results showed that the total wood mass loss was 7.1 ± 1.4% (n=20) for TMP170/1 and 4.0 ± 1.6% (n=20) for TMP160/3. The initial leaching velocity differs between both modes and is higher for TMP160/3. The velocity decreases exponentially with immersion time and reaches plateau after 7^th (5 days) immersion, but leaching still continues after the 9^th immersion (14 days). The main components in leachates were tannic acid and pentoses. Among all studied compounds furfural is the hardest leachable one. Thermally modified wood treated at TMP170/1 is more environmentally friendly due to less water leachable substances. It is worth looking forward by investigating volatile organic compounds emissions in the air as it also could give high impact on human health.

Wood-based ash landfilling is increasing issue not only in Latvia but in the whole world as more biomass is used for energy production. Utilization of wood burning waste as fertilizer is already used worldwide, but there is lack of information about chemical composition of wood ash obtained from Latvia plants, so the aim of this study was to determine chemical composition and analyse possible utilization options of wood-based ash from Latvia plants. Therefore wood ash samples from 53 companies were collected, sieved and chemical composition of samples was determined. It was concluded that within higher capacity of furnace more coarse fraction of wood ash was observed which is less valuable as fertilizer. Wood ash is good liming material consisting alkali compounds and other biogenic elements but also heavy metals, which are pollutants and could cause environmental problems.