Search

Published After
Published Before

Search Results

  • Micropropagation of Leuce-poplar clones and its role in selection breeding
    43-48
    Views:
    146
    Leuce-poplars (mostly white poplar and its natural hybrid grey poplar) are native tree species trough Hungary. They are covering more than 4.0 per cent of the Hungarian forested area (77 000 ha). The white (grey) poplars play a significant role in the forestation under sandy soil site conditions as well as they are of importance from nature conservation point of view as well.
    Long-term selection breeding work is going on at the National Agricultural Research and Innovation Centre Forest Research Institute (NARIC FRI), involving selection of fast-growing Leuce-poplar clones under dry site conditions.
    Micropropagation technology is relatively quickly spreading in forestry. In vitro multiplication of trees is applied mainly in fruit growing in Hungary, in case of forestry it is used mainly for selection breeding.
    This paper presents a short overview on the micropropagation trials with different Leuce-poplar clones and the early evaluation of the seedlings growing of the micropropagated clones/varieties.
  • Tending operation model for red oak stands
    133-136
    Views:
    156

    Red oak (Quercus rubra L.) is our most important exotic oak species, that possesses growing culture with almost one hundred years in our country. Plantation character of red oak growing predominates principally by applied regeneration method (mostly artificial), regular planting space, applying defined method and planting space regulation system. Forest tending model for red oak, that considered stopgap in the native literature is intended to serving the latter. Especially important equation in the viewpoint of stand growing, that describes relationship of stem number (N, in hectare) and diameter at breast height (D1.3 in cm) is: N=e9.80220-1.12607lnD1.3.

  • Improvement of black locust (Robinia pseudoacacia L.) growing under marginal site conditions in Hungary: case studies
    129-133
    Views:
    317

    In Hungary, black locust (Robinia pseudoacacia L.) is considered as an important exotic stand-forming tree species growing mostly under unfavourable ecological conditions for forest management. Due to climate change effects, its importance is increasing in many other countries, too. As a result of a selection programme, new black locust clones were tested in clone trials. Juvenile growth of 12 micropropagated black locust clones in two plots series established at different dates were evaluated in central Hungary under marginal site conditions. At age of 7 the clone R. p. ‘Bácska’ (‘KH 56A2/5’), at age of 10 the clones R.p. ‘Homoki’ (‘MB17D3/4’) and ‘PV201E2/4’ appeared to be especially promising for mass production. Based on the data obtained from the performed trials, it can also be concluded that tissue culture can be considered as a suitable tool for propagating superior individuals and offers new prospects for the rapid cloning of selected genotypes used for plantation forestry.

  • Promising Leuce poplar clones in sandy ridges between the rivers Danube and Tisza in Hungary: a case study
    111-113
    Views:
    214

    An intensive integrated research and development work has been carried out on the improvement of Leuce poplars including primarily the native white poplar (Populus alba L.) and its natural hybrid grey poplar (Populus × canescens). More than 70 percent of the Leuce poplar stands can be found on calcareous sandy sites in the Danube–Tisza region, so they play a significant role in the poplar management of this part of the country. The most important task ahead of Hungarian poplar growers is to improve the quality of poplar stands and plantations based on selecting new clones and cultivars. The growth and yield of four promising Leuce poplar clones was evaluated on a marginal site in central Hungary. The clones ‘H 425-4’ (Populus alba L. × Populus alba L.), and ‘H 758’ (Populus alba L. Mosonmagyaróvár 124) seem to be suitable for wood production, while the ‘H 427-3’ (Populus alba L. × Populus alba L. cv. Bolleana) and ‘H 422-9’ (Populus alba L. × Populus grandidentata (Michx)) clones (with decorative stem form) could be better used for tree lines and ornamental plantations.

  • Yield table for selected black locust (Robinia pseudoacacia L.) cultivars
    193-198
    Views:
    151

    In Hungary, the black locust (Robinia pseudoacacia L.) can be considered as the most important fast-growing, stand-forming introduced tree species. Due to its positive growing technological characteristics as well as wood utilization possibilities, at the present, black locust is the most widely planted tree species in Hungary, covering 25% of the country’s total forest area. One of the important tasks ahead of Hungarian black locust growers is to improve the quality of black locust stands with introducing selected cultivars. For the estimation of the growth rate and yield a numerical yield table has been constructed on the basis of surveys of the experimental plots established in pure,managed ’Nyirségi’ ,’Üllői’ and ’Jászkiséri’ black locust cultivars’ plantations which can be suitable for sawlogs production. In the course of 56 stand surveys the key stand characteristics were measured, and then, were reconsidered the average height, diameter (DBH), volume, basal area and stem number given separately for the main (remaining), secondary (removal) and total stands per hectare. The programmable editing procedure allows to extention and formal change of information content of the yield table according to different demands.

  • Angle-count sampling method for estimating forest stand volume – a practical approach
    99-102
    Views:
    140

    Point sampling, which is also known as angle-count sampling (ACS), can be considered an efficient way of estimating the basal area and volume of forest stands. It is possible to use it in forest management: providing more accurate estimates (precision <10%) of  site and stand characteristics needed for management planning. 20 black locust (Robinina pseudoacacia L.) stands were selected at final cutting age to determine the regeneration criteria based on their total volume. It was verified that at P=5% there was no difference between the main volume values of stands indicated in the relevant forest plans as well as calculated by the ACS method.

     

  • The effects of tending cuttings on yield and value changes in black locust (Robinia pseudoacacia L.) stands: a case study
    111-113
    Views:
    82

    Thinning experiments in black locust (Robinia pseudoacacia L.) stands have been carried out for many years in Hungary. This species has great economic importance in the timber supply of the country. This paper evaluates the effects of tending cuttings in two aspects: the effect on yield and stand value. The case study has proved that in black locust stands tending cuttings can not increase the periodic total production but the stem-quality index can be increased by 2%.