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Wyszukujesz frazę "thinning" wg kryterium: Wszystkie pola


Tytuł:
Efektywność pozyskiwania drewna harwesterem w młodszych trzebieżowych drzewostanach sosnowych w zależności od technologii pracy
Efficiency of timber harvesting using harvester in thinned young pine stands as a function of working technique
Autorzy:
Stańczykiewicz, Arkadiusz
Szewczyk, Grzegorz
Brzoza, Bartosz
Powiązania:
https://bibliotekanauki.pl/articles/18055686.pdf
Data publikacji:
2023
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
metoda drewna krótkiego z międzypolem
trzebieże wczesne
pozyskanie ręczno-maszynowe
pozyskanie maszynowe częściowo zautomatyzowane
wydajność pracy
czasochłonność pracy
CTL method with midfield
early thinning
motor-manual logging
semi-automated logging
work efficiency
worktime consumption
Opis:
In Poland, more and more timber is harvested with the use of harvesters of different types. These machines can also be used in cooperation with chainsaw operators, e.g. in stands damaged by violent winds, in the removal of windthrows, or in stands of younger age classes in the technological variant with the so-called „midfield”. The aim of the study was to characterise the working time structure and to estimate the efficiency of timber harvesting with a harvester in two technological variants. In the first variant, the felling of trees was carried out by a chainsaw operator and the processing was performed by a harvester operator. In the second variant all operations were carried out by a harvester operator. In both variants, the machine worked on the skid trails, but in the second variant, the operator descended from the skid trails a short distance into the stand. Harvesting was conducted in two pine stands that were approximately the same age and differed in site conditions. The structure of the harvester operator's work time was clearly dominated by the moving of felled trees to the skid trails in both variants. Of all the activities studied, the observed differences between their durations in both variants were insignificant only in the case of delimbing and bucking (processing). In the case of cooperation between harvester operator and chainsaw operator, a higher work efficiency was achieved than in the case of timber harvesting with a harvester alone. At the same time, significantly lower work time consumption was observed. However, when considering the efficiency of the entire technologies, thinning with two workers was 30-60% more time consuming. Significant relationships were found between the amount of merchantable timber of harvested trees and the efficiency of the harvester operator.
Źródło:
Leśne Prace Badawcze; 2023, 83; 16-24
1732-9442
2082-8926
Pojawia się w:
Leśne Prace Badawcze
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical and experimental substantiation of the extraction process with thinning bimetallic tubular elements of dissimilar metals and alloys
Teoretyczne i eksperymentalne uzasadnienie procesu ciągnienia z przerzedzaniem bimetalicznych elementów rurowych z różnych metali i stopów
Autorzy:
Titov, Viacheslav
Mozghovyi, Oleksandr
Borys, Ruslan
Bogomolov, Mykola
Amirgaliyev, Yedilhan
Aitkulov, Zhalau
Powiązania:
https://bibliotekanauki.pl/articles/27315425.pdf
Data publikacji:
2023
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
deformation
bimetal tubular elements
stretching with thawing
dispersing of mechanical energy
odkształcenie
bimetaliczne elementy rurowe
ciągnienie z przerzedzaniem
rozpraszanie energii mechanicznej
Opis:
The article proposes a scheme of the process of manufacturing bimetallic tubular elements by extraction a cylindrical cup of two dissimilar metals without thinning and extraction with thinning cup. At the same time, in the process of extraction in the heated state, the layers of dissimilar metals and alloys are connected and the desired shape of the product is obtained. A mathematical model of deformation of the process of joint extraction with thinning of two dissimilar metals with heating in a flat deformed state is developed. The influence of the deformation value on the dispersion of mechanical energy by bimetal was revealed.
W artykule zaproponowano schemat procesu wytwarzania bimetalicznych elementów rurowych poprzez ciągnienie cylindrycznego kielicha z dwóch różnych metali bez przerzedzania i ciągnienie z przerzedzaniem kielicha. W procesie ciągnienia w stanie nagrzanym warstwy różnych metali i stopów są łączone i uzyskuje się pożądany kształt produktu. Opracowano matematyczny model odkształcenia procesu wspólnego ciągnienia z przerzedzaniem dwóch różnych metali z ogrzewaniem w płaskim stanie odkształconym. Ujawniono wpływ wartości odkształcenia na rozpraszanie energii mechanicznej przez bimetal.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2023, 13, 2; 44--49
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wykonania szlaków operacyjnych na wartość hodowlaną jednowiekowych drzewostanów sosnowych przy różnych metodach trzebieży
The influence of the establishment of skid trails on the silvicultural quality of even-aged Scots pine stands in different thinning treatments
Autorzy:
Zachara, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/29519606.pdf
Data publikacji:
2023-11-23
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
silviculture
Scots pine
future crop trees
tending cuts
skid trails
hodowla lasu
sosna zwyczajna
drzewa dorodne
cięcia pielęgnacyjne
szlaki operacyjne
Opis:
The study was conducted on a permanent experimental plot established in 1965 in the Kozienice Forest District to investigate the effects of spacing on the growth of Scots pine. Since 1999, the plot has also been used to study the effects of thinning - using a randomized block design. In this study, seven treatments (four blocks) out of a total of nine treatments present on the plot were included. The following treatments were tested: (1) moderate selective thinning TU1 and TU2 (focusing on 500 future crop trees per hectare evenly distributed on the plot), (2) group thinning TG1 and TG2 (focusing on the same number of future crop trees not evenly distributed on the plot), (3) heavy thinning TS1 and TS2 (focusing on 350 future crop trees per hectare), and (4) control plot (K, without thinning). During the last thinning, a network of skid trail s (each 17-18 m) was established in the study plot to enable the use of a harvester. The aim of the study was to evaluate the influence of the establishment of skid trails on the loss of future crop trees in different treatments. All trees removed in the period 2015-2020 (including natural mortality and mortality caused by the establishment of skid trails) were counted and their basal area calculated. ANOVA was performed to investigate the influence of thinning treatments on natural and artificial loss of trees between successive thinnings. The largest total number and basal area of trees removed was found in control plot K. The greatest loss of future crop trees was observed in the plots treated with group thinning TG1. In plots with a lower number of future crop trees (TS1), the loss was zero. In summary, the establishment of skid trails in heavily thinned Scots pine stands with wide spacing is acceptable. The skid trails should be established before the selection of future crop trees.
Źródło:
Leśne Prace Badawcze; 2023, 83; 51-56
1732-9442
2082-8926
Pojawia się w:
Leśne Prace Badawcze
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A simulation of thinning of microphone array in near-field broadband beamformers
Autorzy:
Wielgus, Agnieszka
Szlachetko, Bogusław
Powiązania:
https://bibliotekanauki.pl/articles/2146656.pdf
Data publikacji:
2021
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
acoustics
beamforming systems
microphone array
thinning technique
akustyka
beamforming
macierz mikrofonów
technika przerzedzania
Opis:
This paper is devoted to the problem of designing an optimal microphone matrix. We define a criterion function where the performance of our matrix should be as close as possible to the desired one based on L2 norm. In the classical approach, increasing a size of the matrix is used to improve the system performance. However, in many cases it is not a good solution. In this paper we propose a solution based on thinning technique. We work with rectangular, equispaced microphone matrix and using metaheuristic approach called simulated annealing we optimise the set of active microphones (we switch off some of the microphones from the regular matrix). For illustrations, few numerical examples are solved. Comparing to the classical approach we show that thinning microphone matrix can significantly improve system performance.
Źródło:
Vibrations in Physical Systems; 2021, 32, 2; art. no. 2021204
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection of thinning of homogeneous material using active thermography and classification trees
Autorzy:
Dudzik, Sebastian
Dudek, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/1848987.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active thermography
classification tree
defect detection and characterization
material thinning detection
Opis:
Active thermography is an efficient tool for defect detection and characterization as it does not change the properties of tested materials. The detection and characterization process involves heating a sample and then analysing the thermal response. In this paper, a long heating pulse was used on samples with a low thermal diffusivity and artificially created holes of various depths. As a result of the experiments, heating and cooling curves were obtained. These curves, which describe local characteristics of the material, are recognized using a classification tree and divided into categories depending on the material thickness (hole depths). Two advantages of the proposed use of classification trees are: an in-built mechanism for feature selection and a strong reduction in the dimensions of the pattern. Based on the experimental study, it can be concluded that classification trees are a useful tool for the thinning detection of homogeneous material.
Źródło:
Metrology and Measurement Systems; 2021, 28, 1; 89-105
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostics of the strength and stiffness of the loader carrier system structural elements in terms of thinning of walls by numerical methods
Autorzy:
Orobey, Viktor
Nemchuk, Oleksii
Lymarenko, Oleksandr
Piterska, Varvara
Sherstiuk, Olha
Romanov, Oleksandr
Tkachuk, Kateryna
Powiązania:
https://bibliotekanauki.pl/articles/1840856.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
gantry cranes
boundary element methods
finite element methods
stress state
strain state
Matlab
Ansys
suwnica
metoda elementów brzegowych
metoda elementów skończonych
naprężenia
odkształcenia
Opis:
Modern gantry cranes are an indispensable element of large industrial and transport enterprises. Port handling equipment is operated under conditions of complex spatial loading of varying intensity, as well as under conditions when the walls of structural elements are thinned in the crane carrier system. During the operation of handling equipment in ports, at construction sites, in machine-building industries, in addition to the external load, aggressive media act on the carrier system elements, which leads to various types of wear: corrosive, abrasive and mechanical. Monitoring of the state of handling equipment structures is a very important task of diagnosing the state of the material of elements of the carrier system of cranes and transporting machines. An important and urgent scientific and technical problem of taking into account the influence of aggressive environment on the stress-strain state of the metal structures of gantry cranes is considered. It is noted that during corrosion, a significant thinning of the walls of structural elements occurs. The safety of crane operation requires this factor to be taken into account. It is proposed to use modern numerical methods for this, i.e. the boundary element method (BEM) and the finite element method (FEM). The implementation of these methods is performed in the Matlab programming and modeling environment (BEM), and the FEM is used in the Ansys package. In accordance with the technologies of these methods, the design diagrams of the lower girders and the crane structure as a whole were formed. Exact models of strain of crane elements during transverse bending and constrained torsion are given. Calculations of the stressstrain state of the crane metal structures have been performed. On the basis of a preliminary field study, a numerical model is proposed for diagnosing the strength and stiffness characteristics of the carrier system of handling equipment using the BEM and FEM, which has never been used in the world. Conclusions are drawn about the influence of the thinning of the walls of metal structures on the values of normal and tangential stresses.
Źródło:
Diagnostyka; 2021, 22, 3; 73-81
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostics of the strength and stiffness of the loader carrier system structural elements in terms of thinning of walls by numerical methods
Autorzy:
Orobey, Viktor
Nemchuk, Oleksii
Lymarenko, Oleksandr
Piterska, Varvara
Sherstiuk, Olha
Romanov, Oleksandr
Tkachuk, Kateryna
Powiązania:
https://bibliotekanauki.pl/articles/1840862.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
gantry cranes
boundary element methods
finite element methods
stress state
strain state
Matlab
Ansys
suwnica
metoda elementów brzegowych
metoda elementów skończonych
naprężenia
odkształcenia
Opis:
Modern gantry cranes are an indispensable element of large industrial and transport enterprises. Port handling equipment is operated under conditions of complex spatial loading of varying intensity, as well as under conditions when the walls of structural elements are thinned in the crane carrier system. During the operation of handling equipment in ports, at construction sites, in machine-building industries, in addition to the external load, aggressive media act on the carrier system elements, which leads to various types of wear: corrosive, abrasive and mechanical. Monitoring of the state of handling equipment structures is a very important task of diagnosing the state of the material of elements of the carrier system of cranes and transporting machines. An important and urgent scientific and technical problem of taking into account the influence of aggressive environment on the stress-strain state of the metal structures of gantry cranes is considered. It is noted that during corrosion, a significant thinning of the walls of structural elements occurs. The safety of crane operation requires this factor to be taken into account. It is proposed to use modern numerical methods for this, i.e. the boundary element method (BEM) and the finite element method (FEM). The implementation of these methods is performed in the Matlab programming and modeling environment (BEM), and the FEM is used in the Ansys package. In accordance with the technologies of these methods, the design diagrams of the lower girders and the crane structure as a whole were formed. Exact models of strain of crane elements during transverse bending and constrained torsion are given. Calculations of the stressstrain state of the crane metal structures have been performed. On the basis of a preliminary field study, a numerical model is proposed for diagnosing the strength and stiffness characteristics of the carrier system of handling equipment using the BEM and FEM, which has never been used in the world. Conclusions are drawn about the influence of the thinning of the walls of metal structures on the values of normal and tangential stresses.
Źródło:
Diagnostyka; 2021, 22, 3; 73-81
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porównanie efektywności mechanicznego przerzedzania kwiatów do chemicznego i ręcznego przerzedzania zawiązków owocowych jabłoni odmian ‘Gala Must’ i ‘Red Jonaprince’
Comparison of the effectiveness of mechanical thinning of flowers to chemical and manual thinning of fruitlets of apple trees ‘Gala Must’ and ‘Red Jonaprince’
Autorzy:
Buler, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2118897.pdf
Data publikacji:
2021
Wydawca:
Instytut Ogrodnictwa
Tematy:
apple tree
thinning
yielding
fruit quality
Opis:
Eight-year-old abundantly blooming apple trees ‘Gala Must’ and ‘Red Jonaprince’ grafted on a dwarf rootstock M.9, spaced 3.5 × 1.5 m and 3.5 × 1.8 m, were subjected to bloom and fruit thinning. This included 7 types of treatments: 1. (M) mechanical flower thinning in the full bloom stage with the German produced BAUM appliance; 2. (C) chemical thinning of fruitlets with cytokinins (Globaryll product); 3. (R) hand fruit thinning in June; 4. (M+C) mechanical thinning of flowersin full bloom, followed by chemical thinning of fruitlets in June as in point 3; 5. (M+R) mechanical thinning of flowers in full bloom stage, followed by hand fruit thinning in June; 6. (C+R) chemical thinning of fruitlets, followed by hand fruit thinning in June; 7. (K) control – no thinning. All thinning treatments decreased yield but increased the size of the fruit, the mean fruit weight, and the growth of the shoots. Among the treatments applied to ‘Gala Must’ trees, the best results were obtained with the M and M+R treatments. Most of the fruit had a favorable marketing size, in the range of 7.5–8.5 cm. The M+C and C+R treatments resulted in too many overgrown apples, which are prone to physiological disorders during storage. Among the treatments applied to ‘Red Jonaprince’, the best results were obtained with M and M+R. The other treatments resulted in an excessively large drop in yield and a very high share of overgrown fruit over 9.0 cm in diameter, unacceptable on the market. The thinning treatments increased the solubility of the solids in the fruit of both cultivars with no clear effect on their firmness.
Źródło:
Zeszyty Naukowe Instytutu Ogrodnictwa; 2021, 29; 1-14
2300-5882
2391-8969
Pojawia się w:
Zeszyty Naukowe Instytutu Ogrodnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The damage caused by wind in middle-aged Scots pine stands on permanent thinning experimental plots
Autorzy:
Zachara, Tadeusz
Gil, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/2040918.pdf
Data publikacji:
2021
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
Pinus sylvestris
silviculture
windbreak
Opis:
In July 2002, the very strong hurricane appeared in northern Poland, which caused destruction of forest cover of area more than 10,000 ha. The permanent thinning research plot in a 53-year-old pine stand located in Myszyniec forest district (150 km north of Warsaw) was lying on the edge of damaged area. The following treatments were tested on this plot: 1) control plot (without thinning); 2) schematic cut in 20-year-old stand, selective thinning to 40 years, then thinning from below; 3) schematic cut in 20-year-old stand, then selective thinning; 4) selective thinning in young stand (20–40 years), then thinning from below and 5) selective thinning all the time. A significant part of this plot was completely destroyed and in the other part of the plot, some trees survived. A small part of the plot resisted the wind attack. An analysis of the amount of destroyed trees (measured by basal area) showed no differences between particular silvicultural treatments. The level of damage differed between particular parts of the plot. Another plot located in Ostrów Mazowiecka forest district (100 km NE of Warsaw) with the same thinning treatments was touched by heavy wind in July 2011 when the stand was 62 years old. Unlike the hurricane of 2002, this storm did not destroy the experimental plot which was located outside the zone of heaviest calamity. Therefore, damage on this plot had point and group character. Although on particular measurement units, share of broken or fallen trees did not exceed 10% of total basal area, it can be observed that the lowest level of damage was noticed on plots with selective thinning in young age and thinning from below in older stand.
Źródło:
Folia Forestalia Polonica. Series A . Forestry; 2021, 63, 4; 300-307
0071-6677
Pojawia się w:
Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variation Between Voivodships in Terms of Forest Area and Silviculture Activities in Polish Forests in 2015-2019
Autorzy:
Grużewska, Agata
Rymuza, Katarzyna
Niewęgłowski, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2069934.pdf
Data publikacji:
2021
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
forest area
forest regeneration
afforestation
thinning
voivodship
Opis:
The objective of the study reported here was to compare voivodships in terms of forest area, forest regeneration area, afforested area, thinned forest area and natural forest regeneration area Main Statistical Office data for Polish voivodships was analysed. It included forest area, natural forest regeneration and silviculture activities (forest regeneration, afforestations and thinning) in all forests, state-owned forests and privately-owned forests. Voivodships were compared using the arithmetic mean, the indicator of structure, the average rate of change, principal component analysis and cluster analysis. Principal Component Analysis, revealed that state-owned forest area, forest regeneration in state forests, total forest regeneration, and thinning in state-owned forests had the greatest share in the multivariate variation among voivodships analysed in terms of forestry. Cluster analysis yielded two groups of voivodships. The voivodships in the first group had a higher average total forest area, area of state-owned forests, total area of forest regeneration and forest regeneration in state-owned forests, area of natural forest regeneration and thinning in state-owned forests. On average, forests of voivodships which formed group 2 included less privately-owned forests in which fewer forest regeneration and afforestation activities had been conducted. Opolskie and Śląskie Voivodships as well as Łódzkie and Świętokrzyskie Voivodships were the most similar in terms of all the analysed characteristics.
Źródło:
Rocznik Ochrona Środowiska; 2021, 23; 524--538
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ mechanicznego przerzedzania kwiatów urządzeniem BAUM na plonowanie i jakość owoców czereśni odmiany ‘Summit’
Effect of mechanical thinning of flowers by BAUM device on yielding and fruit quality of sweet cherry ‘Summit’
Autorzy:
Filipczak, J.
Powiązania:
https://bibliotekanauki.pl/articles/2118941.pdf
Data publikacji:
2021
Wydawca:
Instytut Ogrodnictwa
Tematy:
sweet cherry
mechanical flower thinning
BAUM
Opis:
Thinning of flowers or fruitlets is currently one of the most important agrotechnical treatments in the cultivation of some fruit trees. This paper presents the results of the research on the effect of mechanical thinning of flowers on the yield and fruit quality of ‘Summit’sweet cherries. The experiment was carried out in 2018 at the Pomological Orchard of the National Institute of Horticultural Research in Skierniewice. Mechanical thinning of flowers was carried out with a BAUM machine at two rotor speeds: 300 rpm and 420 rpm. Compared with the control, the obtained results showed that mechanical flower thinning at the rotor speed of 420 rpm resulted in the greatest reduction in the fruit yield (21,5%) and the greatest increase in the weight of a single fruit (26,9%).
Źródło:
Zeszyty Naukowe Instytutu Ogrodnictwa; 2021, 29
2300-5882
2391-8969
Pojawia się w:
Zeszyty Naukowe Instytutu Ogrodnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extraction of Ziziphus lotus fruit syrups: effect of enzymatic extraction and temperature on their rheological and chemical properties
Autorzy:
Letaief, T.
Mejri, J.
Ressureicao, S.
Abderrabba, M.
Costa, R.
Powiązania:
https://bibliotekanauki.pl/articles/2083051.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
Ziziphus lotus L.
syrup
shear-thinning
rheology
enzymatic extraction
Opis:
Fruit syrups are attracting increasing interest in the food industry. Ziziphus lotus fruit syrups were elaborated through the traditional and enzymatic methods with 30, 50 and 70° Brix. A chemical analysis revealed that Ziziphus lotus fruit powder and syrups present a potential source of energy through their relatively higher content of carbohydrates. Rheological oscillatory tests showed that syrups of 30°Brix demonstrate a viscous type of behaviour, the 70°Brix syrups possess an elastic behaviour, while the 50°Brix syrups present a mixed behaviour over the temperature range of 20 to 80°C. These syrups did not demonstrate any thixotropy or time dependence of viscosity. The complex viscosity was described successfully with a mathematical model that incorporates both independent variables, with an Arrhenius-type dependence on temperature, with an activation energy of 21.94 kJ mol-1 for the whole Brix range. The flow behaviour evaluation of the 30 and 50°Brix showed that these are shear-thinning fluids, tending to Newtonian fluids at higher temperatures. The dynamic viscosity was well described by the power law and the dependence of its parameters on temperature was adequately described by a Turian approach. The syrups of Ziziphus lotus fruit demonstrated a potential for further beneficial research with a view to obtaining a commercial food product.
Źródło:
International Agrophysics; 2021, 35, 1; 31-40
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of partial spur leaves removal on fruitlet shedding, fruit quality and shoot growth in apple trees as a basis for mechanical thinning
Autorzy:
Jakopic, J.
Veberic, R.
Powiązania:
https://bibliotekanauki.pl/articles/12704909.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Opis:
Knowledge of the physiology of natural fruitlet shedding is especially important to insure thinning efficiency in apple production. The effect of partial spur leaf removal on shedding, as well as on fruit quality and bourse shoot growth, was investigated. Removing spur leaves increased shedding, while there was no effect of partial leaf removal on mature fruit quality in terms of weight, firmness and sum of sugars, detected by HPLC-RI and resulted in lower contents of citric, fumaric and shikimic acids, detected by HPLC-UV. Growth of bourse shoots was poorer in treatments with leaf removal. To summarize, a decreased number of spur leaves caused more intensive fruitlet abscission and poorer bourse shoot growth but had no negative influence on fruit size. These results show the potential use of decreasing spur leaf area to stimulate more intensive natural shedding to support fruitlet thinning, which could be used in combination with prospective mechanical thinning.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2020, 19, 1; 53-59
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rozmiar uszkodzeń drzew pozostających podczas nasiębiernej zrywki w drzewostanie sosnowym przy wykorzystaniu posztucznej metody szacowania
Size of the damage to the trees remaining during the digging skidding in Scots pine stand using the original method of estimation
Autorzy:
Wójcik, K.
Powiązania:
https://bibliotekanauki.pl/articles/978984.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
drzewostany sosnowe
zrywka drewna
zrywka nasiebierna
forwardery
uszkodzenia drzew
leśnictwo
oddziaływanie na las
metody szacowania szkód
damaged trees
frequency of injuries
selective thinning
skidding
forwarder
Opis:
The purpose of the research was to present problems related to the damage to the stand resulting from the scraping works performed on its surface, mainly with the use of forwarder skidding. The research was conducted in thinned Scots pine stands in the IV and V age class in the Wipsowo Forest District (northern Poland). In the selected stands we carried out the inventory of the stand layers. Based on the obtained data, the level of damage to trees after thinning operations was calculated. Damage resulting from the skidding with forwarder in the individual manipulation plots was at a level of 18.2−18.7% in the method used by the Wipsowo Forest District, while in the method proposed by the author damage level equaled 3.9−9.8%. It was found out that the highest number of damage occurred in the belt up to 5 m from the skidding trail, especially at the width of the trails below 4 m. The damage is most affected by the stand density – the higher it is, the more trees are damaged.
Źródło:
Sylwan; 2020, 164, 03; 216-225
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ pory roku na uszkodzenia drzewostanów olchowych podczas trzebieży wczesnej
Influence of the season on damage in black alder stands during early thinning
Autorzy:
Grzywiński, W.
Turowski, R.
Naskrent, B.
Powiązania:
https://bibliotekanauki.pl/articles/978921.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
logging
tree damage
stand damage rates
Alnus glutinosa
Opis:
The paper presents the comparison of the influence of the season (winter and summer) on the level of damage to trees remaining after the timber harvest during early thinning in young alder stands. The study was carried out in black alder stands aged 38 and 40 years located in north−eastern Poland (Płaska Forest District). Chainsaw logging was performed in the cut−to−length harvest system, while timber was extracted using an agricultural tractor with a trailer with manual timber loading and unloading. The number and share of damaged trees and stand damage rates were estimated in a particular season of the year. Logging resulted in the damage of 8.3% to residual trees. Almost twice as many trees were damaged in summer as in winter (p=0.001). Significantly higher share of trees in 3rd, 4th, and 5th damage classes was found. Only the damage of timber fibers (6th class) did not differ significantly between analyzed seasons. The stand weighted damage rate (W) ranged in winter from 0.12 to 0.38, and in summer between 0.12 and 0.80. In turn, the value of weighted coefficient of damaged trees in the remaining stand amounted to 10.24−60.15 in winter, and 19.07−119.64 in summer. Both W (p<0.01) and WDI (p<0.05) indices were twice higher in the summer than in the winter period.
Źródło:
Sylwan; 2020, 164, 05; 365-372
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł

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