Prunus Cerasifera Ehrh Research Articles

Morphological Evaluation and Phenolic Content of Wild Prunus cerasifera Ehrh. Fruits from Slovenia

Wild fruit species offer significant nutritional, environmental, and economic benefits. Among them, Prunus cerasifera Ehrh. (myrobalan) stands out for its resilience and nutrient-rich fruits, traditionally consumed fresh or dried. This study aimed to assess the morphological and biochemical diversity of 21 wild P. cerasifera accessions from Slovenia, focusing on 18 fruit and stone traits, including size, shape, color, and phenolic compounds such as total monomeric anthocyanins and total phenolic content (TPC). The objective was to identify genotypes with potential for cultivation and food production or as parental components in breeding programs. The results showed variability in fruit length (2.19–2.82 cm), width (2.18–2.99 cm), weight (67.98–150.30 g), firmness, and juiciness, with notable differences in stone characteristics. Phytochemical analysis revealed a wide range of TPC (277–1756 mg/100 g) and anthocyanin levels (0–710 mg/100 g), with higher concentrations in darker fruits. Statistical analysis compared PAM and AGNES clustering methods, finding that PAM with five clusters and AGNES with two clusters provided similar insights. The study emphasized variability in morphological and chemical traits among clusters, with specific accessions showing particularly valuable traits, such as accession RK13, which had high TPC and anthocyanins and a non-adherent stone.

Enhancing drought, heat shock, and combined stress tolerance inMyrobalan29C rootstocks with foliar application of potassium nitrate.

Drought and heat stress are significant concerns to food security in arid and semi-arid regions, where global warming is predicted to increase both frequency and severity. To cope with these challenges, the use of drought-tolerant plants or technological interventions are essential. In this study, the effects of foliar potassium nitrate (KNO3) application on the stress tolerance and recovery of Myrobalan 29C rootstocks (Prunus cerasifera Ehrh.) were evaluated. These rootstocks are widely recognized for their adaptability and are extensively used in fruit production. To assess their response, the rootstocks were subjected to drought, heat shock, or a combination of both stressors. Additionally, they were treated with 1.0% KNO3 via foliar application. Throughout the stress and recovery periods, various morphological, physiological, and bio-chemical parameters were measured. Based on our results, KNO3 treatment improved LRWC, Chl stability, SC, and key stress markers like proline, MDA, H2O2, along with antioxidant enzymes CAT, SOD, POD during both stress and recovery phases. Moreover, our results emphasized KNO3's critical role in hormone regulation under stress. KNO3 application significantly altered hormone levels, notably increasing ABA during drought and heat shock stress, essential for stress response and adaptation. In contrast, IAA, GA, and cytokinin's significantly increased during the recovery phase in KNO3-treated plants, indicating improved growth regulation and stress recovery. In addition, KNO3 application improved the recovery process of the rootstocks by restoring their physiological and biochemical functions. This study suggests that the application of foliar KNO3 is an effective technique for enhancing the drought and heat tolerance as well as the recovery of Myrobalan 29C rootstocks. These results hold significant value for farmers, policymakers, and researchers, as they offer crucial insights into the development of drought-tolerant crops and the management of climate change's adverse effects on agriculture.

Polymorphism in cherry plum (<i>Prunus cerasifera</i>) and its significance for stone crop breeding

A gene pool of cherry plum (Prunus cerasifera Ehrh.) numbering over 1000 accessions including wild forms and released cultivars of various origins has been gathered at the Krymsk Experiment Breeding Station, a branch of VIR. The study of the morphological diversity of cherry plum, or myrobalan plum, made it possible to clarify its position within the system of the genus Prunus L., and to propose an intraspecific system composed of three subspecies: Prunus cerasifera subsp. cerasifera – the typical cherry plum, P. cerasifera subsp. orientalis (M. Pop.) Erem. et Garcov. – the oriental cherry plum, and P. cerasifera subsp. macrocarpa Erem. et Garcov. – the large-fruited cherry plum with the following several varieties: Armenian (P. cerasifera subsp. macrocarpa var. nairica (Koval.) Erem. et Garkov.), Georgian (var. georgica (Erem.) Erem. et Garcov.), Iranian (subsp. macrocarpa var. iranica (Koval.) Erem. et Garcov), Pontic (subsp. macrocarpa var. pontica (Koval.) Erem. et Garcov.), Tauric (subsp. macrocarpa var. taurica (Kost.) Erem. et Garcov.), and the red-leaved cherry plum (Pissard plum) (subsp. macrocarpa var. pissardii (Carriere) Koehne).The most important role of interspecific hybridization involving the species P. cerasifera is in the origin of a number of Prunus L. species, including domestic plum P. domestica L., Fenzl’s almond P. fenzliana Fritsch, and black apricot P. dasycarpa Ehrh., has been established.The cherry plum gene pool had been found to contain donors of a number of traits of importance for breeding, which were used to create an assortment of Russian plum (Prunus × rossica Erem., hybrid myrobalan plum) cultivars and clonal rootstocks of stone fruit crops. Among them, the Russian plum ‘Globus’, ‘Kubanskaya Kometa’, ‘Gek’, ‘Kolonnovidnaya’, ‘Iyulskaya Roza’, and clonal rootstocks ‘Kuban 86’, ‘VVA 1’, ‘Evrika 99’, ‘Best’, ‘Zarevo’ have been regionally adapted and got a wide distribution.An outstanding general combining ability was demonstrated by cherry plum cvs. ‘Pionerka’, ‘Purpurovaya’, ‘Otlichtnitsa’, ‘Ashtarakskaya 2’ and ‘Tsiteli Drosha’, which were used in breeding a number of cherry plum cultivars at the Krymsk EBS, e.g. cherry plums ‘Neberdzhaevskaya Rannyaya’, ‘Kremen’, Russian plum ‘Kubanskaya Kometa’, ‘Iyulskaya Roza’, ‘Naydena’, ‘Gek’, ‘Podarok Sad-Gigantu’, etc.Most effective was the hybridization of Crimean, Armenian and Georgian cherry plum cultivars with the Chinese plum (Prunus salicina Lindl.) ‘Burbank’, ‘Gigant’, and ‘Skoroplodnaya’. As clonal rootstocks, the hybrids of myrobalan plum with peach (‘Kuban 86’ and ‘Fortuna’ rootstocks), with cherry plum ‘Sapa’ (‘Evrika 99’ and ‘Spiker’ rootstocks), as well as with low micro-cherry (rootstock ‘Best’) and Louiseania ulmifolia (Franch.) Pachom. (rootstock ‘Upriamets’) turned out to be very valuable.

Dye stability of black cherry plum anthocyanins in the interaction with co-pigments and sucrose sweetener.

In this research, the co-pigmentation reactions between black cherry plum (Prunus cerasifera Ehrh. cv. Pissardii Nigra) anthocyanins and caffeic, gallic, 4-hydroxybenzoic, malic, and tannic acids with different concentrations (0, 120, 240, 480, and 960 mg L-1) at various temperatures (20, 40, 60, 80, and 100°C) were investigated at pH 3.5. The strongest immediate co-pigmentations resulted at 960 mg L-1, being significantly highest using tannic acid at all temperatures. In addition, the anthocyanin stability and the brown polymeric color formation were investigated in the presence of different concentrations of sucrose sweetener (0, 30, and 60%) and different pHs (2 and 3) in the range of 0-60 h. Also, the amount of furfural was measured in the presence of 0% and 30% sucrose concentrations at pH 2 after 20 h at 90°C by HPLC (high-performance liquid chromatography), and the most polymeric color formation was observed in the concentration of 60% sucrose at pH 2 after 60 h.

Patterns of Prunus cerasifera early invasion stages into a temperate primeval forest

AbstractThe cherry plum (Prunus cerasifera Ehrh.) is considered an invasive plant species in numerous areas of the temperate climate zones around the world. Although this exotic tree can naturalize in a wide spectrum of forest ecosystems, its invasion mechanisms remain totally unknown. This study is the first approach aiming to investigate potential drivers shaping the ecological success of P. cerasifera invasion, with an example of the temperate primeval forest as a model recipient ecosystem. Using generalized linear models, we suggest that the distance to the propagule source may shape considerably this exotic species occurrence in primeval forest’s understory, expressed by the presumably high role of birds and small mammals in short-, and large ungulates in long-distance seed dispersion. The probability of this invader occurrence decreased with decreasing functional and phylogenetic diversity of understory vegetation. This suggests the importance of habitat filtering generated in small tree-fall gaps in shaping the P. cerasifera success. Thus, interactions between natural disturbances, characteristics of recipient vegetation, as well as traits of various animal dispersers, may be identified as key drivers promoting the occurrence of P. cerasifera in the primeval forest ecosystem. However, further studies on the patterns of P. cerasifera invasion are needed to identify drivers promoting invasion, as well as the effects of this exotic plant on biodiversity and the functioning of ecosystems.

Selection and Molecular Characterization of Promising Plum Rootstocks (Prunus cerasifera L.) among Seedling-Origin Trees.

The plum (Prunus cerasifera Ehrh) has been used worldwide both as a genetic source for breeding new rootstocks and as clonal rootstock for many Prunus species. Considering situations where wild relatives of plums are endangered, in-depth characterization of rootstock traits of genetic diversity of plum germplasm of Turkey with many ecogeographical locations is crucial. In the present study, therefore, three steps were followed for the selection of rootstock candidates among the plum germplasm grown in the Middle Euphrates. This region is characterized by an extremely hot climate with extremely warm summers and very low precipitation in summers. Initially, 79 rootstock candidates were selected based on rootstocks traits, and Myrobalan 29C was also used for the control rootstock in all steps. Hardwood cuttings were taken from each rootstock candidate, and after the rooting process in rootstock candidates, 39 rootstock candidates outperforming other candidates were selected according to root characteristics. Based on rooting ability, forty rootstock candidates with the longest root length below 33.50 mm, root number below 3.00, and rooting cutting number below 30.00% were eliminated. The second step of the study focused on the dwarfing characteristics of 39 rootstock candidates, and 13 and Myrobalan 29C out of 39 rootstock candidates' dwarfing traits showed value higher compared to the other 26 rootstock candidates. Results indicated that the vigor of rootstock candidates was usually found to be strong (26), intermediate (4), and weak (9). Moreover, 13 out of 39 rootstock candidates' dwarfism trait was better than the other 26 rootstock candidates. In Step 3, some morphological, physiological, and molecular evaluations were conducted in 13 rootstock candidates and the Myrobalan 29C clone, and there were significant differences between both rootstock candidates and the parameters evaluated. PCA has also been indicated that the reference rootstock Myrobalan 29C was grouped with 63B62, 63B69, and 63B14. The highest genetic similarity was found between 63B11 and 63B16, as well as between 63B76 and 63B66, while the lowest genetic similarity was observed between 63B72 and 63B61 candidates. Overall, the findings presented here provide valuable information about the level of rootstock candidates that could potentially be superior among previously uncharacterized plum cultivars in this plum-growing region of Turkey.

Susceptibility of the plum cultivars ‘Jojo’ and ‘Togigant Plus’ to some postharvest diseases

Postharvest diseases cause significant losses in orchards before and after fruit harvest. The study aimes to compare the susceptibility of the plum cultivars ‘Topgigant Plus’ and ‘Jojo’ each grafted on the plum seedling rootstock Prunus cerasifera Ehrh. and the clonal rootstock ‘Docera 6’ (Prunus domestica L. x Prunus cerasifera Ehrh.) to infection with fungal pathogens. Three fungal pathogens Botrytis cinerea (Pers), Penicillium sp (Link) and Monilinia sp. (Aderh and Ruhl.) Honey were used for artificial inoculation. From each scion/rootstock combination, 30 fruits were infected by injecting 25 μl of conidial suspension. From the spread in the experimental orchard pathogens at the most significant frequency were isolated and used. All scion/rootstock combinations had the highest percentage of infected fruits after the inoculation with Monilinia sp. However, the results for the other two pathogens vary - the ‘Topgiant Plus’ cv. is more susceptible to the pathogen Penicillium sp, compared to ‘Jojo’ cv. On the other hand, the fruits of ‘Jojo’ cv. are more susceptible to the pathogen Botrytis cinerea.

Silicon and Nitric Oxide Applications Allow Mitigation of Water Stress in Myrobalan 29C Rootstocks (Prunus cerasifera Ehrh.)

(1) Background: Silicon (Si) and nitric oxide (NO) have been proven to protect against cellular injury caused by stress conditions, mostly by salinity and water stress in agriculture. (2) Methods: The goal was to study the effect of soil applications of NO, Si, and their combination (Si+NO) on the response of Myrobalan 29C rootstocks (Prunus cerasifera Ehrh.) subjected to water stress and well-watered conditions. (3) Results: The results showed that water stress decreased growth parameters (i.e., leaf area, shoot dry weight, root fresh weight, shoot fresh weight, root dry weight, and relative shoot diameter), physio-biochemical parameters (i.e., chlorophyll and relative water content in leaves), and leaf and root minerals (i.e., P, Ca, Fe, and Zn in leaves and N, K, Ca, and Zn in roots), compared to well-watered plants. Under these conditions, all treatments mitigated the detrimental effects of water stress on Myrobalan 29C rootstocks, being the most effective the Si+NO treatment. (4) Conclusions: These findings briefly highlight that the combination of silicon and nitric oxide may provide greater tolerance to water stress in Myrobalan 29C rootstocks.

Developing New Cultivars of Prunus × Rossica Erem. And Clonal Rootstocks at the Krymsk Experiment Breeding Station

Abstract The paper considers the possibilities of expanding the assortment of plum cultivars in world production by hybridising large-fruited myrobalan plum (Prunus cerasifera Ehrh.) cultivars with those of Japanese plum (Prunus salicina Lindl.) and other diploid stone fruit species. Because of many years of breeding work in Russia, cultivars of a new hybridogenous species Prunus × rossica Erem. (Russian plum) have been created, which can ensure a stable supply of fresh fruit from late June to September and complement the assortment of common plum cultivars. A description is given for the best adaptive, high-yielding cultivars with good taste and high canning qualities — ‘Kubanskaya Kometa’, ‘Globus’, ‘Gek’, ‘Iyulskaya Roza’, ‘Dynnaya’, ‘Kolonnovidnaya’, and ‘Podarok Sad-Gigantu’. The efficiency of their cultivation using intensive technologies and own-rooted plants, as well as clonal rootstocks bred at the Krymsk Station, has been shown. It is recommended to carry out intensive cultivation of Russian plum using medium vigorous rootstocks like Kuban 86, Evrika 99, Zarevo, Fortuna and dwarf rootstocks VVA 1, Best, Upryamets and VSV 1.

INVASIVE CYCLE AND ASSESSMENT OF THE DEPTH OF INVASION OF REPRESENTATIVES OF DENDROFLORA OF UKRAINE IN THE SOME ECOSYSTEMS BY EUROPEAN MISTLETOE (VÍSCUM ÁLBUM L.)

Research is related to the biology and ecology of white mistletoe (Víscum álbum L.), with an analysis of its impact on the dendroflora of natural and artificial ecosystems. The sequence of stages of the invasive cycle of mistletoe, starting from the stage of infection, the intensity of the invasion (the degree of its spread in the crown), the suppression of host trees, their death and biodegradation, as well as the mechanism of these processes. These stages have different durations in different species. A comparison of the full cycle of mistletoe infection for those species that are most often infected in Polissya, Eastern Podillya and in the coastal areas of the right bank of the Dnieper. The most sensitive species to the invasion were the following: Populus nigra L., Populus balsamifera L., Tilia cordata Mill, Salix babylonica L., Salix fragilis L., Juglans nigra L. and Juglans cinerea L., Sorbus aucuparia L., Betula pendula Roth , Acer saccharum Marshall, Acer saccharinum L., Fraxinus excelsior L. The intensity of the invasion by mistletoe also takes into account the degree of suppression aforementioned and some other species, have become particularly threatening today, so it requires finding ways to solve this biological and environmental problem. However, a number of tree species can resist to the spreading of mistletoe even under invasion due to mechanisms that ensure their high resistance, among them Populus pyramidalis Rozier, hybrids of poplars, Quércus rúbra L, some others. A number of species are able to resist to mistletoe spreading even under their conditions of infection due to the presence inner mechanisms that ensure their relatively high resistance to this parasite, among them: Populus pyramidalis Rozier, its hybrids, Quércus rúbra L., Prunus avium L., Prunus cerasifera Ehrh. A significant number of dendroflora species are outside of the influence of mistletoe. It is indicates on existing specific biological barriers which block following spreading and adaptation among Víscum album L. populations. The concept of resistance and sensitivity to mistletoe of representatives of dendroflora is offered. The algorithm for determining the tention of invasion by Víscum album, the processes of suppression, death and subsequent biodegradation of affected trees is optimized. The classification of the nature of the interaction of mistletoe and host trees is carried out. Strong invasion of mistletoe white require mutuals special efforts of scientists and state for restriction its spreading.

Assessment of drought resistance of some hybrid forms of cherry plum (Prunus cerasifera Ehrh.) in the steppe zone of Crimea

Assessment of drought resistance of some hybrid forms of cherry plum (Prunus cerasifera Ehrh.) in the steppe zone of Crimea

Productivity of cherry plum (Prunus cerasifera Ehrh.) in connection with abiotic environmental factors

Productivity of cherry plum (Prunus cerasifera Ehrh.) in connection with abiotic environmental factors

MACROELEMENTS CONCENTRATION IN PLUM TREE LEAVES AND SOIL IN RESPONSE TO ORCHARD FLOOR MANAGEMENT

The aim of the study was to determine the influence of various methods of orchard floor management on extractable mactronutrients concentration in plum leaves and orchard soil. Study carried out between 2013 and 2015. Standard mineral fertilization on experimental plots was applied. Trees of ‘Valjevka’ plum (Prunus domestica L.), grafted onto Myrobalan seedlings (Prunus cerasifera Ehrh. var. divaricata Ledeb.), were planted in the spring of 2008. From 2009 to 2015, the following methods of soil cultivation under tree canopies were introduced: control with limited weeding around tree trunks; spraying with foliar herbicides; mulching with organic waste, i.e. straw with compost; mechanical soil cultivation with the use of rotary cultivators and hoe; weed mowing. The method of soil cultivation had influence on leaf concentration of phosphorus, potassium, magnesium and calcium, as well as soil concentration content of phosphorus, potassium, and magnesium in particular years of the study or as three-year mean. Orchard floor management did not affect leaf nitrogen concentration in any way. The results showed that regular weed control in the evaluated type of orchard is not necessary for properly supplying plum trees with macronutrients.

Prunus Hexokinase 3 genes alter primary C-metabolism and promote drought and salt stress tolerance in Arabidopsis transgenic plants

Hexokinases (HXKs) and fructokinases (FRKs) are the only two families of enzymes in plants that have been identified as able to phosphorylate Glucose (Glc) and Fructose (Fru). Glc can only be phosphorylated in plants by HXKs, while Fru can be phosphorylated by either HXKs or FRKs. The various subcellular localizations of HXKs in plants indicate that they are involved in diverse functions, including anther dehiscence and pollen germination, stomatal closure in response to sugar levels, stomatal aperture and reducing transpiration. Its association with modulating programmed cell death, and responses to oxidative stress and pathogen infection (abiotic and biotic stresses) also have been reported. To extend our understanding about the function of HXK-like genes in the response of Prunus rootstocks to abiotic stress, we performed a detailed bioinformatic and functional analysis of hexokinase 3-like genes (HXK3s) from two Prunus rootstock genotypes, ‘M.2624’ (Prunus cerasifera Ehrh × P. munsoniana W.Wight & Hedrick) and ‘M.F12/1’ (P. avium L.), which are tolerant and sensitive to hypoxia stress, respectively. A previous large-scale transcriptome sequencing of roots of these rootstocks, showed that this HXK3-like gene that was highly induced in the tolerant genotype under hypoxia conditions. In silico analysis of gene promoters from M.2624 and M.F12/1 genotypes revealed regulatory elements that could explain differential transcriptional profiles of HXK3 genes. Subcellular localization was determinates by both bioinformatic prediction and expression of their protein fused to the green fluorescent protein (GFP) in protoplasts and transgenic plants of Arabidopsis. Both approaches showed that they are expressed in plastids. Metabolomics analysis of Arabidopsis plants ectopically expressing Prunus HXK3 genes revealed that content of several metabolites including phosphorylated sugars (G6P), starch and some metabolites associated with the TCA cycle were affected. These transgenic Arabidopsis plants showed improved tolerance to salt and drought stress under growth chamber conditions. Our results suggest that Prunus HXK3 is a potential candidate for enhancing tolerance to salt and drought stresses in stone fruit trees and other plants.

The role of Prunus cerasifera Ehrh. in the origin, evolution and improvement of stone fruit cultivars

At Krymsk Experiment Breeding Station of VIR, as a result of collecting, studying, and selective use of myrobalan plum genetic diversity, the intraspecific taxonomy of the species Prunus cerasifera Ehrh. was clarified. Donors of traits significant for breeding were identified and, with their use, adaptable cultivars of myrobalan plum, Russian plum and clonal rootstocks of stone fruit plants were developed.Intraspecific classification of P. cerasifera is proposed, with the identified subspecies:subsp. cerasifera (typical myrobalan plum);subsp. orientalis (M. Pop.) Erem. et Garcov. (Oriental myrobalan plum);and subsp. macrocarpa Erem. et Garcov. (large-fruited myrobalan plum).Within subsp. P. cerasifera subsp. macrocarpa, varieties were identified:var. macrocarpa (typical, or Krymsk);var. georgica Erem. et Garcov. (Georgian);var. iranica (Koval.) Erem. et Garcov. (Iranian);var. nairica (Koval.) Erem. et Garcov. (Armenian);var. pissardii Carr. (Pissard);and var. taurica (Kost.) Erem. et Garcov. (Taurida).The participation of myrobalan plum in the origin of spp. P. brigantiaca Vill., P. cocomilia Tem., and P. spinosa L. was traced. Involvement of large-fruited myrobalan plum in hybridization with blackthorn contributed to the manifestation of an exceptional polymorphism among the varieties of the hybridogenic species P. domestica L. (P. cerasifera × P. spinosa). As a result of hybridization between myrobalan plum and Chinese plum varieties, a new cultigen species emerged – Russian plum (× P. rossica Erem.). By now, 127 cultivars of this species and 7 clonal rootstocks for stone fruit crops have been developed. These cultivars and clonal rootstocks are zoned for Russia and a number of other countries.

Prunus cerasifera Ehrh. fruits are a source of biologically active substances and high-quality feedstock for Food for Specific Health Use

From the Southern Coast collection of Prunus cerasifera Ehrh. the fruits cultivars of the Nikitsky Gardens’ breeding Medovaya, Olenka, Rumyanaya Zorka and Idilliya were distinguished by their high taste qualities and the content of BAS. According to the norms of the Russian Federation, the fruits of these cultivars belong to the group of products with a high content of potassium and cuprum; satisfactory content of magnesium and ferrum, pastilles and jams from them belong to the group of products with a satisfactory content of potassium and cuprum. Cherry plum fruits, especially dark-colored ones, are a natural complex source of antioxidants, characterized by a high content of phenolic compounds and cuprum, and a satisfactory content of ascorbic acid and zinc. The content of pectin substances in the studied cultivars is comparable to that in apples. The fruits of the Idyllia cultivar with dark-colored pulp are distinguished by the maximum accumulation of pectins - 1.14%, ascorbic acid - 9.3, phenolic compounds – 441 mg/100 g, potassium – 11239, magnesium - 464, ferrum -10.81, zinc - 10.23, cuprum - 4.17, manganese - 0.228 mg/kg. Cherry plum fruits are characterized by a high content of BAS and are suitable for use in health nutrition both in fresh form and as raw materials for Food for Specific Health Use.

Impact of Compressed Natural Gas (CNG) Fuel Systems in Small Engine Wood Chippers on Exhaust Emissions and Fuel Consumption

The projected increase in the availability of gaseous fuels by growing popularity of household natural gas (NG) filling stations and the increase in the production of gaseous biogas-derived fuels is conducive to an increase in the use of NG fuel. Currently, natural gas in various forms (compressed natural gas (CNG), liquefied natural gas (LNG)) is popular in maritime, rail and road transport. A new direction of natural gas application may be non-road mobile machines powered by a small spark-ignition engine (SI). The use of these engines in the wood chippers can cause the reduction of machine costs and emissions of harmful exhaust gases. In addition, plant material chippers intended for composting in bio-gas plants can be driven by the gas they are used to produce. The biogas can be purified to bio-methane to meet natural gas quality standards. The article presents the design of the natural gas supply system, which is an upgrade of the Lifan GX 390 combustion engine spark ignition engine (Four-stroke, OHV (over head valve) with a maximum power of 9.56 kW), which is a common representative of small gasoline engines. The engine is mounted in a cylindrical chipper designed for shredding branches with a maximum diameter of up to 100 mm, which is a typical machine used for cleaning work in urban areas. The engine powered by CNG and traditionally gasoline has been tested in real working conditions, when shredding cherry plum (Prunus cerasifera Ehrh. Beitr. Naturk. 4:17. 1789 (Gartenkalender4:189–204. 1784)). Their diameter was ca. 80 mm, 3-metere-long, and humidity content ca. 25%. The systems were tested under the same actual operating conditions, the average power generated by the drives during shredding is about 0.69 kW. Based on the recorded results, it was found that the CNG-fuelled engine was characterized by nitrogen oxides (NOx) emissions higher by 45%. The other effects of CNG were a reduction in carbon dioxide (CO2), carbon monoxide (CO) and hydrocarbon (HC) emissions of about 81%, 26% and 57%, respectively. Additionally, the use of CNG reduced fuel consumption by 31% and hourly estimated machine operating costs resulting from fuel costs by 53% (for average fuel price in Poland: gasoline: 0.99 EUR/L and CNG: 0.71 EUR/m3 on 08 November 2020). The modernization performed by the authors ensured the work of the drive unit during shredding, closer to the value of stoichiometric mixtures. The average (AVG) value of the air fuel ratio (AFR) for CNG was enriched by 1.2% (AVG AFR was 17), while for the gasoline engine the mixture was more enriched by 4.8% (AVG AFR was 14). The operation of spark-ignition (SI) combustion engines is most advantageous when burning stoichiometric mixtures due to the cooperation with exhaust aftertreatment systems (e.g., three-function catalytic converter). A system powered by CNG may be beneficial in systems adapting to operating conditions, used in low-power shredding machines, whose problem is increased HC emissions, and CNG combustion may reduce them. The developed system does not exceed the emission standards applicable in the European Union. For CO emissions expressed in g/kWh, it was about 95% lower than the permissible value, and HC + NOx emissions were 85% lower. This suggests that the use of the fuel in question may contribute to tightening up the permissible emission regulations for non-road machinery.

Computer Aided Modeling of Wood Chips Transport by Means of a Belt Conveyor with Use of Discrete Element Method

The effectiveness and precision of transporting wood chips on the transport trailer or hopper depends on an inclination angle, a conveyor belt speed, and length. In order to devise a methodology aiding designing and the selection of technical and performance parameters (aiding the settings of conveyor belt sub-assemblies), the authors carried out the simulation tests concerning wood chips transport on the belt conveyor and their outlet. For the purposes of these tests, a simulation model was performed in the Rocky DEM (discrete element method) software in the numerical analysis environment and compared to analytical tests. The tested wood chips were taken from cherry plum branches chipping processes (Prunus cerasifera Ehrh. Beitr. Naturk. 4:17. 1789 (Gartenkalender 4:189-204. 1784)), out of which seven basic fractions were separated, which differed mainly in terms of their diameter from 5 mm to 50 mm and the length of 150 mm. The article presents the results of wood chips ejection distance in the form of the 3D functions of wood chips ejection distance depending on the conveyor belt inclination angle and belt speed. The results are presented for five conveyor belt lengths (1 m, 2 m, 3 m, 4 m, 5 m). The tests also involved the conveyor belt inclination angle in the range from 10° to 50° and the belt velocity in the range from 1 m/s2 to 5 m/s2. The numerical test results demonstrate higher average values of wood chips ejection distance than designated in the analytical model. The average arithmetical difference in the results between the numerical and analytical model is at the level of 13%.

Development of Root Architecture in Thirty-seven Tree Species of Field Grown Nursery Stock1

AbstractThe number and size of lateral roots of a tree seedling can be evaluated visually, and could potentially be used to select plants with better root systems early in nursery production. To evaluate how root architecture develops in young trees, root architecture of 37 species of trees was compared at two stages of development: as harvested seedlings, and then one year after replanting. The total number of lateral roots and the number of roots >2mm (0.08 in) diameter that were present on the portion of the taproot remaining on seedlings after standard root pruning were recorded. Neither could consistently predict the number of lateral roots on the root system one year after replanting. Development of roots (sum of diameters) regenerated from the cut end of the seedling taproot was equal or greater than lateral root development in 84 percent of evaluated species. Even when regenerated root development was significantly less than lateral root development, the regenerated roots still comprised up to 44 percent of the root system. Regenerated roots from the cut end of the taproot can become a major component of the architecture of the structural root system in nursery stock.Index words: structural roots, nursery production, root regeneration.Species used in this study: European black alder (Alnus glutinosa Gaertn.), green ash (Fraxinus pennsylvanica Marshall), quaking aspen (Populus tremuloides Michx.), European white birch. (Betula pendula Roth), river birch (Betula nigra L.), black locust (Robinia pseudoacacia L.), northern catalpa (Catalpa speciosa (Warder) Warder ex Engelm.), Mazzard cherry [Prunus avium [L.) L.], chokecherry (Prunus virginiana L.), American elm (Ulmus americana L.), Siberian elm (Ulmus pumilia L.), goldenchain tree (Laburnum anagyroides Medik.), northern hackberry (Celtis occidentalis L.), Cockspur hawthorn (Crateagus crus-galli L.), single seed hawthorn (Crateagus monogyna Jacq.), honeylocust (Gleditsia tricanthos L.), Japanese pagodatree [Sophora japonica (L.) Schott], Katsura tree (Cercidiphyllum japonicum Siebold & Zucc.), Kentucky coffee tree [Gymnocladus dioicus (L.) K. Koch], littleleaf linden (Tilia cordata Mill.), boxelder (Acer negundo L.), hedge maple (Acer campestre L.), Norway maple (Acer platanoides L.), red maple (Acer rubrum L.), silver maple (Acer saccharinum L.), sugar maple (Acer saccharum Marshall), sycamore maple (Acer pseudoplatanus L.), English Oak (Quercus robur L.), northern red oak (Quercus rubra L.), Siberian peashrub (Caragana arborescens Lam.), American plum (Prunus Americana Marshall ), Myrobalan plum (Prunus cerasifera Ehrh.), redbud (Cercis Canadensis L.), Russian olive (Elaeagnus angustifoliaI L.), tuliptree (Liriodendron tulipifera L.), black walnut (Juglans nigra L.), Japanese zelkova (Zelkova serrata (Thunb.) Makino).

Influence of the Use of Liquefied Petroleum Gas (LPG) Systems in Woodchippers Powered by Small Engines on Exhaust Emissions and Operating Costs

The use of alternative fuels is a contemporary trend in science aimed at the protection of non-renewable resources, reducing the negative impact on people and reducing the negative impact on the natural environment. Liquefied petroleum gas (LPG) is an alternative fuel within the meaning of the European Union Directive (2014/94/UE), as it is an alternative for energy sources derived from crude oil. The use of LPG fuel in low-power internal combustion engines is one of the currently developed scientific research directions. It results from the possibility of limiting air pollutant emissions compared to the commonly used gasoline and the lower cost of this fuel in many countries. By “gasoline 95” the Authors mean non-lead petrol as a flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines, whereas 95 is an octane rating (octane number). This article presents the results of research on fuel consumption, toxic exhaust gas emission, and operating costs of a woodchipper used for shredding branches with a diameter of up to 100 mm in real working conditions. The woodchipper, powered by a 9.5 kW internal combustion engine, fueled by gasoline and LPG was tested. Liberal regulations of the European Union (Regulation 2016/1628/EU) on the emission of harmful exhaust compounds from small spark-ignition engines (up to 19 kW) and non-road applications contribute to the low technical advancement level of these engines. The authors researched a relatively simple and cheap LPG fueling system, as in their opinion, such a system has the best chance of being implemented for use. In the study, the branches of cherry plum were shredded (Prunus cerasiferaEhrh. Beitr. Naturk. 4:17. 1789 (Gartenkalender4:189-204. 1784)). Their diameter was ca. 80 mm, length 3 m, and moisture content ca. 25%. The system was tested during the shredding of the branches in real working conditions (the frequency of supplying the branches about 4 min−1 and the mass productivity of about 0.73 t/h). Based on the recorded results, it was found that the LPG fueled engine was characterized by higher carbon monoxide (CO) and nitrogen oxides (NOx) emissions by 22% and 27%, respectively. A positive effect of using LPG was the reduction of fuel consumption by 28% and carbon dioxide (CO2) and hydrocarbons (HC) emissions by 37% and 83%, respectively. The results of the research show that the use of alternative fuels can bring benefits in terms of CO2 and HC emissions, but at the same time be characterized by an increase in CO and NOx emissions. Further research should be conducted on innovative alternative fuel supply systems, such as in the automotive industry. At the same time, legislators should limit the use of low-quality fuel supply systems with the limits of pollutant emissions in exhaust gases, contributing to the development and economic competitiveness of new fuel injection systems.