Volumeproduktie van de unalklonen op 20-jarige leeftijd
Onderzoeksoutput: Boek/rapport › Mededelingen van het Instituut voor Natuur- en Bosonderzoek › Onderzoek
- Instituut voor Bosbouw- en Wildbeheer
|Uitgeverij||Instituut voor Bosbouw en Wildbeheer|
|Status||Gepubliceerd - 1994|
|Naam ||Mededelingen van het Instituut voor Bosbouw en Wildbeheer|
|Uitgeverij||Instituut voor Bosbouw en Wildbeheer: Geraardsbergen|
The growth data of some former commercial clones and relict clones have been studied in seven
populeta of the Belgian National Poplar Commission, in comparison with the euramericana Unalclones.
The clone 'Robusta' was used as reference.
A soil survey was made in each plot, based on a profile pit or by augering.
Concerning the former commercial clones and relict clones, 'Tardif de Champagne' and 'Gelrica' equal the volume of 'Robusta'. However 'Gelrica' is too often liable to "flooting" symptoms at their stembase,which makes this clone not suitable.
'Lommel 421' and 'Bocholt 3-3' even surpass the growth of the reference clone.
The clones 'Harff' and 'Neeroeteren' are among the least interesting clones due to their poor growth.
The yield level of 'I 214' can reach twice that of 'Robusta' provided a high soil fertility. The production of 'I 214' doesn't even equal that of 'Robusta' on less favourable sites.
Among the euramericana Unal-clones'Ghoy' and 'Gaver' certainly belong to the most promising clones
, because of their high adaptability to the site.
'Ghoy', with its rather dominant nature, can reach a volume of 185 % as compared with that of 'Robusta'.
If 'Gaver' can grow without suppression, it surpasses the volume of 'Robusta' with 25 %.
The clones 'Primo', 'Ogy' and 'Isières' can give satisfactory yields (35 à 55 % in comparison with 'Robusta') on sufficient fertile soil. However their growth may disappoint when they are planted on less adapted sites.
As for 'Gibecq', the combination of a moderate girth growth and a lower height growth results in a volume that never reaches that of the reference cloneThe site-index or S-value (asymptotic value of height) is a good measure of the yield possibilities of a site.
'Robusta' and the euramericana Unal-clones can be divided into two groups.
The first group consists of 'Robusta', 'Primo', 'Ghoy' and 'Isières', with a site-index between 40 and 50.
The other group contains 'Gaver' and 'Gibecq', whose site-index is situated between 35 and 43.
The violent storms in spring 1990 and 1991 have damaged many plantations of poplar, including the populeta here mentioned. They gave us the opportunity to examine the sensitivity of these clones to wind.
Among the former commercial clones and relict clones, 'Tardif de Champagne' and 'Harff' seem ratherresistent to windthrow. On the other side 'Neeroeteren', 'Robusta', 'I 214' and 'Lommel', but especially 'Gelrica' and 'Bocholt' are very suspectible to storm.
Moreover 'Gelrica' shows a high fall out after planting.
Roughly, all euramericana Unal-clones show a higher wind resistance in comparison with the clones mentioned above.
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