Chemical composition of crops before winter is important for successful overwintering of plants. The aim of the research, carried out from 2007/2008 till 2009/2010 at the Research and Study farm ‘Vecauce’, was to investigate the influence of agricultural practices (sowing date, sowing rate, and fungicide application) and meteorological conditions during winter on the content of sugar in apical bud and root of two types of winter oilseed rape (Brassica napus L.) cultivars. The content of sugars (monosaccharides) in apical bud and root in autumn and following spring was analysed using the Luff–Schoorl method. Sugar content in apical bud and root of winter oilseed rape in autumn and spring differed depending on the trial year, because of different, even contrary (in season 2009/2010), meteorological conditions. Sugar content was higher in plant parts developed when rape was sowed on earlier sowing dates, but it was substantially influenced by the sowing date only on some occasions. Sowing rate had no impact on sugar content in apical bud and root. Application of a fungicide as a growth regulator had no significant impact on the result, but sugar content decrease during winter 2009/2010 in the root of winter oilseed rape was smaller when fungicide as growth regulator was applied.

Norway spruce (Picea abies (L.) H.Karst.) is amongst the most important tree species for forestry in Latvia. It has been suggested that due to the foreseen climate change the productivity of Norway spruce in Latvia may decrease. Continuous observations of radial increment allow to identify periods with different growth intensity and to study the effect of environmental conditions on radial increment during them. The aim of this study was to analyse stem radial variation of Norway spruce in mixed-species stand in response to meteorological conditions over one growing season. Stem radial variation of one Norway spruce tree was monitored by band dendrometer throughout the growing season of 2013. Cumulative radial increment was divided into contraction, recovery and increment phases by the stem cycle approach. Four periods with distinct apportionment of these phases were identified – winter/spring dormancy, spring/ summer growth, growth termination and autumn hydration fluctuations. Radial increment began in the second part of May and the most active increment was observed during period of spring/summer growth. This period lasted for 42 days with the mean amplitude of stem radial variations reaching 0.06 mm while the length of increment phase reached up to two days. Throughout the growing season increment was facilitated by an increase in the temperature. Meanwhile, the effect of precipitation was insignificant, presumably due to sufficient water availability and low interspecies competition for it, characteristic in mixed species stands due to differences in depth and distribution of root systems between the species.

The normal wood colour changes due to the biochemical reactions as well as under the fungal exposure. Some of these fungi during all the exposure time cause only a discoloration (staining fungi); others change not only colour, but also the structure of the wood in its further development (wood destructing fungi). The development of blue stain in sapwood of pine roundwood and its influencing factors were studied in the spring summer period of 2016 (April, May and June) in the districts of Nica, Jelgava and Daugavpils. 650 discs from pine log end planes were prepared in order to evaluate the influence of harvesting type, spreading type of fungi spores, placement in pile, storage duration, diameter, distance from the end plane, daily average temperatures, precipitation amount and relative humidity on blue stain of sapwood and rot development. The most important factors influencing the blue stain development on pine roundwood during the storage are the harvesting type of roundwood, spreading type of fungal spores, placement in pile, storage duration, diameter, and distance from the end plane, daily average temperature and amount of precipitation. By evaluating the daily average temperatures, it was concluded that blue stain of sapwood begins to develop when the average daily temperature reaches +5...+6 °С. But when the average daily temperatures reach +10 °С, depending on the harvesting type (chainsaw or harvester) and spreading type of the fungal spores (via air or bark beetle assistance) the first signs of blue stain may occur from 10 to 42 days of storage.

The greatest interest in the cultivation of spring wheat is in regions with an increased intensity of late fallow. However, there are also stronger tendencies to limit the area of its cultivation (similarly to other spring cereals), which is mainly due to a lower level of yielding. Farmers decide on the sowing date of varieties mainly after plants that leave the field late, e.g., potatoes, beets and maize. That is why these varieties are usually called „alternative wheat”. The aim of the research was to determine the effect of autumn sowing date on the yield and the technological value of the grains of selected spring wheat varieties. A two-factor field experiment was established using a split-plot design at the Experimental Station of Cultivar Testing (ESCT) in Bezek (51°12′06″N 23°16′06″E), the Lubelskie Voivodeship, Poland (2008/2009, 2009/2010, 2010/2011). Experimental factors were as follows: A) sowing date – I – October, II – November, III – spring, B) spring wheat variety: ‘Tybalt’, ‘Cytra’, ‘Bombona’, ‘Monsun’, ‘Parabola’. It was found that grain yields of spring wheat sown in the autumn were higher than those sown in the spring term. Without regard to the sowing term, the highest grain yields were obtained from ‘Tybalt’ cultivar.

Morphological parameters and their changes common for artificially reared one year old sea trout were examined from January to May the year 2013 to determine whether these parameters indicated the smoltification in one year old sea trout and whether these fish achieved smolts stage. Fish were reared in flow-through and recirculation systems in hatcheries based on three different rivers (Brasla, Daugava, Venta basin). Sea trout were examined in the Latvia University of Agriculture, Faculty of Veterinary Medicine, Institute of Food and Environmental Hygiene and in the Institute of Food Safety, Animal Health and Environment BIOR, Laboratory of Aquaculture and Fish Pathology. To appreciate fish growth stage condition index, hepatosomatic index, spleen index was calculated and silvering level was evaluated. The fish condition index decreased in all hatcheries and flow-through and recirculation rearing systems from January to April and increased in May. Spleen index was the most stable parameter and did not change a lot showing that fish did not have migratory stress in April and May. Silvering level increased from January to April but suddenly the increase became slower in May without reaching the top level. These results made us to consider that one year old sea trout parrs released in May 2013 probably did not become smolts before release and they had to stay in river for one additional year until reaching pronounced smolt stage.