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  • The role of black locust (Robinia pseudoacacia L.) in establishment of short-rotation energy plantations in Hungary
    41-44.
    Views:
    261

    Establishment of short-rotation energy plantations for fuel production has been of international interest for many years. Energy plantation experiments in Hungary have been conducted for a longer time. In the country black locust ( Robinia ps eudoacacia L.) is one of the most important stand-forming tree species, covering approximately 23% of the forested land (410 000 ha) and providing about 19% of the annual timber output of the country. This fast growing species seems to be suitable for energy plantations as well. So, in Helvecia (Central­ Hungary, sand-soil region) two energy plantation s were established u sing common black locust and its cultivars improved in Hungary. The spacing variations of the common black locust were: l.5x0.3 m, I .5x0.5 m and l.5x 1.0 m. At the age of 5 the closest spacing ( 1.5x0.3m) produced the greatest annual increment in oven-dry weight (6.5 t ha·1 yr- 1). In the trial with black locust cultivars planted in spacing of 1.5xl.0m, at the age of 7 the highest annual increment in oven-dry mass was produced by the cultivar ' Ulloi' (9.7 t ha-1 yr- 1) followed by the common black locust (8.4 t ha-1 yr- 1) and the cultivar 'J tiszkiseri (1.6 t ha·1 yr- 1). The trials have verified that in temperate climate the increment in oven­ dry dendromass of black locust energy plantation s has ranged from 6 to 12 t ha·1 yr·1. On the basis of the trials' evaluation the quantity of dendromass mostly depends on site quality, species and cultivars, as well as on the initial spacing (plants per hectare).

  • Tending operation models for black locust (Robinia pseudoacacia L.) stands growing on sandy soils in Hungary
    55-57.
    Views:
    197

    A more intensive integrated research and development approach to the work carried out on the growth on sandy soils of stands of black locust (Robinia pseudoacacia L.) has been adopted in recent years, revealing several factors influencing stand growth. The fact that certain ecological factors influencing fundamentally the growth of trees have become unfavourable in Hungary in recent years has led to the more extensive use of black locust in the course of afforestation and forest regeneration schemes. The study presents a new,  simplified tending operation model for black locust stands and age, growing space and target diameter models suitable for qualitaty log production and for mass assortments. The simplicity of these practice-oriented
    models may foster the qualitative development of black locust management in Hungary and in some other countries where this tree species may gain greater acceptance by landowners and the forest industry.

  • Effects of initial spacing on the stand structure and yield of young black locust (Robinia pseudoacacia L.) stands
    37-39.
    Views:
    155

    The choice of the right initial spacing of stands is one of the most decisive operations of a successful afforestation. It is even more important in the case of fast growing tree species grown in plantations; it is expressed in their early phase of development and in wood quality. The results of a 5-year long experiment with four treatments will be presented in this paper. They proved the priority of an initial spacing of 1.61.0 m in the majority of quality This treatment has been proved optimal exploitation of growing space by the young trees.

  • Improved clonal approaches to growing black locust (Robinia pseudoacacia L.) in Hungary: a case study
    53-56.
    Views:
    230

    In Hungary black locust (Robinia pseudoacacia L.) is considered as an important exotic stand-forming tree species and due to climate change effects its importance is increasing in many other countries. It has some desirable characteristics from both the practical and research standpoints. As a result of a partly new black locust selection programme new black locust clones were improved and a technology was developed for mass clonal micropropagation of juvenile trees. Clone trials with micropropagated plants were established in the country for evaluating the juvenile growth and the stem form of promising black locust clones under marginal site conditions. Significant differences (P<5%) were found for stem form value which partly verified the genetic gain of the selected clones against the common black locust. It was also proved that tissue culture could offer partly new prospects for the rapid mass cloning of selected genotypes.

  • Promising white poplar (Populus alba L.) clones in sandy ridges between the rivers Danube and Tisza in Hungary
    113-116.
    Views:
    170

    White poplar is a native stand-forming tree species in Hungary, covering 3.1 per cent of the forested area. More than 70 per cent of the white 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 white poplar clones was evaluated on a marginal site in central Hungary. The clones `1-1 425-4' (Populus alba x Populus alba), and 11 758' (Populus alba Mosonmagyaróvár 124) seem to be suitable for wood production, while the 427-3' (Populus alba x Populus alba cv. Bolleana) and 422-9' (Populus alba x Populus grandidentata) clones (with decorative stem form) could be better used for tree lines and ornamental plantations.

  • Black locust (Robinia pseudoacacia L.) selection programmes in Hungary: a short review
    31-34.
    Views:
    265

    Black locust (Robinia pseudoacacia L.) was the first forest tree species introduced from North America to Europe, at the beginning of the 17th century. Its unprecedented fast spread is due to its high-grade adaptability, drought-tolerance, abundant and frequent seed crop, excellent sprouting ability, fast growth and relatively high timber yield. Other advantages are, that it has scarcely any fungi or insect pests. This review is a short summary on black locust improvement in Hungary, giving guidance for specialists who are interested in black locust management.

  • Clonal selection of black locust (Robinia pseudoacacia L.) in Hungary: a review
    153-56.
    Views:
    179

    Black locust (Robinia pseudoacacia L.) is the most important fast growing stand-forming tree species in Hungary. Its importance is increasing in many other countries, too. As a result of a new selection programme 13 black locust clones have been improved for setting up clones trials and seed orchard. In 2003 five of them (R.p. `Bácska', `Homoki', 'Szálas', `Oszlopos' and `Vacsi') were registered as cultivar­candidates. Tissue culture method has proved as a suitable mean of propagating superior individuals. The micropropagated plants have been growing successfully in the clone trials.

  • The antioxidant capacity of sea buckthorn (Hippophae rhamnoides L.) berries depends on the genotype and harvest time
    27-29.
    Views:
    237

    Berries of sea buckthorn (Hippophae rhamnoides L.) are characterized by increasing popularity due to their presumable healtheffects. The aim of this study was to compare the antioxidant capacity and total polyphenolic content in the berries of six Hungarian grown sea buckthorn genotypes and characterize the genetic variability in this trait. The harvest time of sea buckthorn berries affects the antioxidant capacity and total phenolic contents in berries of three popular cultivars of German origin. Berries harvested in October had higher antioxidant capacity compared with those harvested one month later. The extent of the difference was genotype-specific. Our analysis revealed a nearly 3-fold difference between the lowest and highest antioxidant capacities of the 6 tested genotypes with ‘Leikora’ showing the highest ferric reducing antioxidant power and total phenolic content. The TEAC values ranged between 1.76 and 3.13 mmol Trolox/100g fresh weight with Pető 1 and ‘Frugana’ having the highest values. The results presented in this study demonstrated that Hippophae rhamnoides berries possess in vitro antioxidant activity strongly determined by genotype but also influenced by harvest time.

  • Above-ground dendromass of sprouted black locust energy plantations: a case study
    19-21.
    Views:
    234

    Black locust (Robinia pseudoacacia L.) can be considered as one of the most suitable tree species for establishing energy plantations due to its favourable growing characteristics such as vigorous growing potential in the juvenile phase, excellent coppicing ability, a relatively high resistance to pests. Based on national and international test results the mean annual increment of oven-dry weight of energy plantations regenerated by coppicing generally exceeds the first cycle plantations established by seedlings.

  • Tending operation models for white poplar (Populus alba L.) stands growing under sandy soil conditions
    125-127.
    Views:
    150

    Integrated research aimed to intensify the practices of afforestation especially of white poplar and grey poplar woods. A new, simplified tending procedure has been developed to substitute earlier models considering the target diameter by right spacing as a tool to achieve adequat quality of logs. The practice-oriented model may help the qualitative improvement of white poplar growing technology in Hungary as well as in Serbia.

  • Promising black locust (Robinia pseudoacacia L.) cultivars in Hungary
    18-20.
    Views:
    320

    In Hungary, black locust (Robinia pseudoacacia L.) is one of the most important exotic stand-forming tree species, growing mostly under unfavourable ecological conditions. Considering the climate change effects its importance is increasing in many other countries. As a result of a selection programme, several black locust cultivars have been improved for setting up cultivar trials. In the paper four black locust cultivars were evaluated in Central Hungary under arid hydrological and brown forest soil conditions. Significant differences (P<5%) were found in height, DBH, mean tree volume and average stem form value (SFV).  At the age of 35 the cultivar ‘R.p. Jászkiséri’ appeared to be the most promising one for yield production and ‘R.p. Zalai’ for SFV.

  • Generative propagation of Robinia x ambigua POIR. – Pink locust
    41-42.
    Views:
    236

    The genus Robinia is a small group of about 10 species of trees and shrubs indigenous only to NorthAmerica. Two species are endemic to Mexico, one being confined to south-western part of the country, while the rest are endemic to the south-eastern part of USA. Of the most important species and varieties of genus Robinia, Robinia x ambigua Poir.(Robinia viscosa x R. pseudo-acacia)-pink locust can be considered as the most significant one for bee-forage and decorative planting. In this paper a generative propagation method is presented for pink locust.

  • Increment analysis in black locust (Robinia pseudoacacia L.) stand – a case study
    106-109
    Views:
    222

    The study on the diameter and volume increment of black locust (Robinia pseudoacacia L.) stand (age 10-27 years, yield class II) have shown that in comparison to the periodic annual increment of the breast height diameter of tree in height class I, trees in height class II have reached 83.3%, while in class III only 43.9. The same relations for volume were found 59.0% and 24.5%, respectively. The mean values of the whole stand were close to those of height class II. According to the distribution of the periodic annual increment of volume between 10 and 27 years of age, 50% of the values were between 2.00 and13.88 dm3, 73% were between 2.00 and19.82 dm3, and 96% were between 2.00 and 37.64 dm3. The range of 13.88–19.82 dm3 had the highest occurrence (24.5%).

  • Propagation from root cuttings for black locust (Robinia pseudoacacia L.) improvement in Hungary: a review
    39-41.
    Views:
    247

    Black locust (Robinia pseudoacacia L.) is a valuable stand-forming tree species introduced to Europe approximately 400 years ago from North America. Today it is widely planted throughout the world, first of all for wood production. In Hungary, where black locust has great importance in the forest management, it is mainly propagated by seeds. But since the seed-raised plants present a great genetic variation, this type of propagation can not be used for Robinia’s improved cultivars. In the Hungarian black locust clonal forestry, propagation from root cuttings can be used for reproduction of superior individuals or cultivars in large quantities. However, this method demands more care than raising seedlings from seeds and can be applied with success in well-equipped nurseries.