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Estimation of productivity and quality of different origin Scots pine in Latvia
2008
Neimane, U., Latvia Univ. of Agriculture, Jelgava (Latvia)
The productivity and quality of different origin Scots pine (Pinus sylvestris L.) progenies at the age of 43 were estimated. The investigation was carried out in 1964. The seeds from six stands growing on mineral and peaty soils in different environmental conditions were sowed. The thinning was done in 2006. The following growth and quality characters were investigated: height of the trees, diameter at breast height, stem volume, standing volume, branch free tree length, branch thickness, branch angle, stem’s straightness. The growth and quality differences of the progenies depending on the seed origin were estimated. The environmental conditions of the Zvirgzde origin place and the test locality were similar. The progeny of the Zvirgzde stand showed superiority in the growth traits (height, diameter, stem volume) as well as good stem quality and high quality of the assortment outcome in thinning. The progeny of the swamp stand (Tireli) had low values in all investigated traits. A significant influence of the environmental conditions of the seeds origin place on the growth and quality of the progeny was found out. Environmental conditions of seeds origin locality and place of forest regeneration have to be similar to avoid decrease of progeny stand’s growth and quality.
显示更多 [+] 显示较少 [-]Genetic differences in needle cast damage of Scots pine (Pinus sylvestris L.)
2016
Polmanis, K., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Klavina, D., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Gaitnieks, T., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Baumanis, I., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Lazdins, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
The impact of climatic and genetic factors on needle cast damage, as well as relationship between the degree of damage and survival and growth of trees was evaluated in the study. The analysis was done in two series of experiments, both established in two locations in Latvia (central and eastern part). Needle cast damage (in 5 grade scale) as well as the height and height increment, diameter of root collar and survival of trees were assessed. Results suggest that the degree of needle cast damage was influenced by the genetic, as well as climatic factors, and also their interaction. The average degree of needle cast damage in experiment of open-pollinated families was 4.7 ± 0.01 in central and 4.6 ± 0.03 in eastern Latvia; in the experiment of control-crossed families it was 4.6 ± 0.02 in central and 3.4 ± 0.04 in eastern Latvia. The impact of genetics on the needle cast damage degree was statistically significant (p is less than 0.05), and this effect was observed when any of growth traits (diameter, height or height increment) was used as a covariate in analysis. Results suggest the potential to select more resistant families, since the genetic correlation of grade of the damage between locations was significant (r = 0.40 - 0.72) and therefore improve also the growth of trees, since the grade of the damage had a negative correlation with growth traits both at provenance and family mean level (r = -0.69 and r = -0.42; p is less than 0.01).
显示更多 [+] 显示较少 [-]Climate suitability effect on tree growth and survival for Scots pine provenances in Latvia
2014
Rieksts-Riekstins, J., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Jansons, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Smilga, J., Forest Sector Competence Centre, SIA, Riga (Latvia) - MNKC | Baumanis, I., Forest Sector Competence Centre, SIA, Riga (Latvia) - MNKC | Ray, D., Forest Research, Roslin, Midlothian, Scotland (United Kingdom). Northern Research Station | Connolly, T., Forest Research, Roslin, Midlothian, Scotland (United Kingdom). Northern Research Station
Climate in Latvia has been changing in last decades, and it is predicted to continue changing; therefore, it is important for forestry sector to understand how these climatic changes might affect tree growth and survival. In order to assess climate suitability effect on Scots pine (Pinus sylvestris L.) provenances in Latvia, height and survival data from a Scots pine provenance trial located in three geographically distant places in Latvia were analysed together with several climatic indices. Provenances in the corresponding trial originated from Latvia, Poland, Germany, Belarus, Russia and Ukraine. Thirty year average climate data values from 1961 – 1990 for the 64 origins of provenances were acquired from the WorldClim project. Correlation analysis between provenance average values for height and survival and climate index values for the origins of the provenances confirm that there is a relation between these amounts, and the relation differs between the three site locations, indicating that suitability of climate is an important factor affecting the results of provenance trials. Cluster analysis confirmed that provenances from distant origins might have a very similar growth and survival rates; therefore, geographical location of the provenance origins cannot be considered as the only influential factor on these rates and the results from provenance trials have to be analysed together with climate data in order to make conclusions about the suitability of the provenances.
显示更多 [+] 显示较少 [-]Impact of provenance on wood and fibres properties of lodgepole pine, grown in Latvia
2012
Sable, I., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvian State Inst. of Wood Chemistry, Riga (Latvia) | Grinfelds, U., Latvian State Inst. of Wood Chemistry, Riga (Latvia) | Sisenis, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Verovkins, A., Latvian State Inst. of Wood Chemistry, Riga (Latvia) | Treimanis, A., Latvian State Inst. of Wood Chemistry, Riga (Latvia)
Lodgepole pine (Pinus contorta) samples from three different provenances in Canada were investigated. All trees were the same age and had been grown in Latvia in similar conditions. Lodgepole pine of Summit Lake provenance had higher wood density (503 kg m-3) and a higher late wood content (46%) in comparison to Fort Nelson and Pink Mountain provenances. Investigation of chemical composition of wood indicated Summit Lake provenance wood as superior in cellulose content (49.7%), but no differences in lignin and extractives content were found between samples. Kraft pulp yield of Summit Lake samples (48%) was the highest, but the handsheet strength properties were relatively higher for pulp from Pink Mountain provenance pine wood.
显示更多 [+] 显示较少 [-]Influence of product attributes on milk consumer's choice in Lithuania
2014
Pileliene, L., Vytautas Magnus Univ., Kaunas (Lithuania) | Liesionis, V., Vytautas Magnus Univ., Kaunas (Lithuania)
Consumer decision making is one of the most relevant topics in marketing. Therefore, organizations endeavour to create products in a way that correspond to their customers’ needs and preferences. The emerging worldwide interest in healthy lifestyle and organic products could become the key success factor for food producing organizations. The article aims to determine the product attributes affecting consumer’s choice of a milk product in Lithuania. The method of Conjoint analysis was chosen for the research. The research was provided as a repetition of the same research, done in 2009. According to the principles of the Conjoint analysis, six attributes of milk were named: ‘Country of origin’, ‘Naturalness’, ‘Package size’, ‘Package type’, ‘Richness’, and ‘Price’. Each of the attributes was divided into several levels. While analyzing the structure of milk market in 2014, four market segments were distinguished: ‘Irrationally price concerned’, ‘Rationally price concerned’, ‘Ethnocentric ecologists’, and ‘Richness concerned’. Such segments like ‘Ethnocentric’, ‘Price-and-Richness concerned’ or ‘Ethnocentric price-concerned’ have disappeared from the market during the five-year period. According to research results, following suggestions were made for the companies dealing with the milk market in Lithuania: first of all, a company has to make a decision about the segment to work with; afterwards, based on the results of conjoint analysis (conditional utilities of attributes levels), optimal propositions for every particular segment have to be composed.
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