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Bernava A.,Riga Technical University | Reihmane S.,Riga Technical University | Strazds G.,Forest Industry Competence Center
Proceedings of the Estonian Academy of Sciences | Year: 2015

The analysis of hemp cultivation and usage trends in the world and Europe shows that hemp cultivation and processing in Latvia has good perspectives. This paper presents the results of a first study about the usage of pectinase enzyme Beisol PRO (4% water solution) for Latvian hemp sort “Purini” retting at different time and temperatures conditions and treatment influence on obtained fibres quality. Gravimetrical examination of the quantity of fibres and sheaves after retting, physical-mechanical tests and TG analysis, colour properties, and selected samples microscopy evaluation show that enzyme treatment is not significant for fibre separation from stem as well as TG characteristics at investigated time and temperature conditions. Use of pectinase enzyme for hemp retting in some cases increases tensile strength of fibres and causes changes of colour characteristics. © 2015, Estonian Academy Publishers. All rights reserved.

Rieksts-Riekstins J.,Latvian State Forest Research Institute Silava | Jansons A.,Latvian State Forest Research Institute Silava | Smilga J.,Forest Industry Competence Center | Baumanis I.,Forest Industry Competence Center
Research for Rural Development | Year: 2014

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.

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