Resin Yield Research Articles

Growth-defence trade-offs in tapped pines on anatomical and resin production

Resin harvesting is a traditional forestry activity that provides economic revenue along with crucial ecosystem services (i.e., fire protection and employment) thus contributing to the socio-economic development of rural areas. In the Iberian Peninsula, Pinus pinaster Aiton has traditionally been exploited for resin to complement the profitability of timber harvesting. Trade-offs between resin yield and radial growth are not fully understood, however. Resin ducts, the anatomical structures that produce and transport resin within the tree, have been used as a proxy for resin yield or resistance to pathogens as they represent the tree’s investment on resin defences throughout its lifespan. It is not yet clear if these structures can be linked to growth or how well the resin duct network correlates with resin yield in tapped trees. To answer these questions, we investigate annual tree-ring width, resin duct traits (absolute and standardized), and resin yield of two maritime pine stands tapped for resin extraction in the North of Portugal (VPA and PCO). Resin duct features are assessed before and during tapping periods as may show the constitutive investment, as well as the combination of constitutive and induced ones. Before resin tapping, average tree-ring width in PCO and VPA was ~2.25 and ~1.13 mm year−1, respectively. During tapping, standardized growth rates increased by ca. 40% in VPA, the population living under lower water availability and shorter growing seasons, while growth rates were almost unaffected in PCO. Median resin production in 2016 was 2.9 kg (PCO) and 1.8 kg (VPA), but inter-tree variance was high in both sites. Resin duct production increased exponentially with tree-ring width similarly in the different sites and for the same periods, but wider rings and ducts in PCO resulted in greater areas occupied by resin ducts. Within the population, constitutive anatomical resin-based defences did not trade-off with radial growth, although, lower growth rates were related to higher resin duct investments in response to tapping. Despite this, annual resin production did not correlate with resin duct density or relative area. Conversely, resin yield was positively associated with trunk perimeter, average growth, and absolute resin duct traits. These variables will thus be the most valuable when trying to identify the best resin producers in a stand. Differences in growth sensitivity to resin tapping between sites suggested that the impact of resin harvesting on radial growth is site-dependent and may not be as negative as previously thought.

Enhancing CF/PEEK interfacial adhesion by modified PEEK grafted with carbon nanotubes

The weak interfacial adhesion caused by the low wettability of carbon fiber (CF) and inert polyetheretherketone (PEEK) hinders the great application potential of CF/PEEK composites. In this study, the interface between CF and PEEK was modified by coating hydroxylated PEEK grafted onto multi-walled carbon nanotubes (M-HPEEK). Modified CFs by M-HPEEK sizing had rougher surfaces with more polar groups, showing decreased contact angle and increased surface energy. The wettability of these CFs was enhanced, beneficial to PEEK infiltration and physical adhesion improvement. As a result, the interlaminar shear strength, flexural strength, and flexural modulus of modified CF/PEEK composites were increased by 73.0% (84.7 MPa), 163.2% (906.2 MPa), and 84.8% (58.4 GPa), respectively. An improved interface with stress transferring was proved by the interface debonding failure changed to fiber crack and resin yield. M-HPEEK sizing is considered as a promising modification method to optimize the interface performance of composites.

Characterization of the Cannabis sativa glandular trichome proteome.

Cannabis sativa has been cultivated since antiquity as a source of fibre, food and medicine. The recent resurgence of C. sativa as a cash crop is mainly driven by the medicinal and therapeutic properties of its resin, which contains compounds that interact with the human endocannabinoid system. Compared to other medicinal crops of similar value, however, little is known about the biology of C. sativa. Glandular trichomes are small hair-like projections made up of stalk and head tissue and are responsible for the production of the resin in C. sativa. Trichome productivity, as determined by C. sativa resin yield and composition, is only beginning to be understood at the molecular level. In this study the proteomes of glandular trichome stalks and heads, were investigated and compared to the proteome of the whole flower tissue, to help further elucidate C. sativa glandular trichome biochemistry. The data suggested that the floral tissue acts as a major source of carbon and energy to the glandular trichome head sink tissue, supplying sugars which drive secondary metabolite biosynthesis. The trichome stalk seems to play only a limited role in secondary metabolism and acts as both source and sink.

Heritability and characteristics of resin ducts in Pinus oocarpa stems in Michoacán, Mexico

Abstract Despite the extensive distribution and use of Pinus oocarpa in Mexico, knowledge on the range of genetic variation and magnitude of quantitative parameters of the defensive structures of the species is rare. Our study attempts to fill this gap by providing a comprehensive assessment of resin duct traits in mother trees and their offsprings in an open-pollinated trial of P. oocarpa. Resin ducts are fundamental structures of the defense mechanisms of the coniferous trees. They vary depending on the age of the tree, the genotype, the species, and may be influenced by environmental factors. We investigated intraspecific variation among families of the resin duct system in secondary vascular tissues (wood and inner bark) of P. oocarpa trees. Our study attempts to explore the variance and the possible genetic control of these defensive structures. We hypothesized that the resin duct features analyzed would vary with the tree’s genetic make-up. We analyzed samples from two groups of trees. First, from mature mother trees selected as superior in resin yield. Second, from their six-year-old off-springs established in a progeny trial. Axial and radial ducts showed differences in their size and quantity, between wood and bark and between ages. The axial duct density showed differences among families, and the heritability estimates were moderate. In P. oocarpa trees selected as phenotypically superior in resin yield, the size of its constitutive resin ducts is a less variable trait, and the differences in axial duct density can be attributed to genetic factors.

Salicylic and citric acid as promising new stimulants for resin tapping in maritime pine (Pinus pinaster Ait.)

Aim of the study: We tested alternative active principles to the most widely used resin tapping stimulant which contains sulphuric acid. We also studied the effect of wounding in five-year-old Pinus pinaster seedlings with a microtapping method.Area of study: The experiment was carried out at the Universidad Politécnica de Madrid in Spain.Material and Methods: The experiment consisted of six treatments: control (no stimulant no wounding), wound (no stimulant), and pines stimulated with sulphuric acid, ethrel, salicylic acid and citric acid. We evaluated the resin yield differentiating between released resin and internal resin (resin retained within the xylem), and the physiological status of the tree.Main Results: Wounded plants produced on average three times more resin than control plants. Plants stimulated with salicylic and citric acids showed the highest resin yield and produced on average 15% more resin than those stimulated with sulphuric acid, mainly because the released resin was higher. Tree diameter affected resin yield and thicker trees produced more resin. We did not observe any significant effect of the treatments on stomatal conductance and only a marginal significant effect (p<0.10) on water potential.Research highlights: Salicylic acid and citric acid seem to be promising stimulants for the resin tapping activity to be further tested in field experiments with adult trees.Keywords: sulphuric acid; ethrel; pine resin; microtapping; wounding; water potential; stomatal conductance.Abbreviations used: TR: total resin content; RR: released resin; IR: internal resin; gs: stomatal conductance; Ψleaf: midday leaf water potential.

Tapping into nature’s benefits: values, effort and the struggle to co-produce pine resin

ABSTRACT The concept of ecosystem services (ES) and related conceptual frameworks like the cascade model, can be relevant to explore the ways through which people and nature are connected and how the benefits of nature, upon which people depend, are realised. An integrated cascade framework was used to study the ES pathway of pine resin, a traded forest product, in a rural mountain community in Mexico. We conducted mixed-methods research, combining participatory tools with measures of service capacity, resin yield, and key farmer endowments. Resin was co-produced by an intricate interaction between the human and natural components of the social-ecological system. Substantial human inputs and coordinated efforts were required to realise resin benefits, and people’s appreciation and plural values emerged along the whole service pathway. Though there were stark differences in natural resource endowments, working farmers gained a high share of resin’s income through labour, labour relations and social networks. But most social conflicts and struggles also occurred over labour relations and organisation, revealing power dynamics. Furthermore, external actors controlled different mechanisms of access, and exerted power over the community’s ability to derive benefits from resin. In resin co-production, values connect people to the landscape, while labour and power mediate the access to nature’s benefits.

Study of the chemical and technological properties of long-flame, long-flame-gas and gas coals of the Kuznetsk Basin

The results of a study of the chemical and technological properties of low-metamorphosed coals of the Kuznetsk basin of long-flame (L), long-flame-gas (LG) and gas (G) technological grades. Coal samples are low-sulfur, medium-ash with a low ash basicity index, are characterized by a rather significant yield of semi-coking resin, gaseous and volatile substances. According to the established technological indicators, these coals can be recommended for energy and technological use, for example, in the process of semi-coking.

Study of the influence of technological parameters of the cooking process on the quality of coal tar produced in com ovens “ArcelorMittal Temirtau” JSC

In the article there are presented results of a research that was carried out to determine a reason for the increase of more than 1,22 g/cm3 coal-tar oil density at the coke production of “ArcelorMittal Temirtau” joint-stock company. There have been studied samples of coal concentrates from nine layers of eight mines in Karaganda coal basin and GZh coal concentrate which are supplied to the coke chemical production of “ArcelorMittal Temirtau” joint-stock company from “Kunetskaya” Enrichment plant (Russia). During the work there has been determined dependence of the gas composition on the temperature affecting gas that was released during coal carbonizing process. It is experimentally established that with an increase in the temperature of the released coke gas above 750 ° C to 1000 ° C, light fractions evaporate from the resin and are removed into the gas discharge path, which is accompanied by a weighting, an increase in the density captured for processing coal tar into pitch. The results of the resin studies that is isolated in the same temperature ranges show the indicators of the resin yield and its density during the tests of concentrates also follow a certain pattern – with an increase in the coal carbonizing temperature and with overheating of the released gas, the resin density increases and its yield decreases. The researches in the plant has found that the technological reason for the weighting of the coke gas resin is a low level of coal charge stockline, which makes possible to linger the coke gas in the underroof space and to overheat with increasing the access of light fractions of the resin with the gas.

Genetic variation in resin yield and covariation with tree growth in maritime pine

The potential of pine resin as a renewable non-timber product is furthering the socioeconomic relevance of the resin industry in Europe, where maritime pine (Pinus pinaster Ait.) is the main tapped species. Characterizing maritime pine genetic resources in terms of resin yield potential and its covariation with tree growth is crucial to implement efficient tree breeding programs aiming to maximize resin yield without negatively impact tree growth. We explored genetic variation in resin yield and tree growth among provenance regions, populations within regions, and families of maritime pine. We used a progeny trial located at Central Spain to estimate additive genetic variation and heritability of resin yield, and a common garden located at Northwest Spain to explore variation among provenance regions and populations within regions. Resin yield was assessed in both trials with and without sulphuric-based stimulant paste. Association between growth and resin yield at different levels (phenotypes, families, populations and provenance regions) was also explored. Growth and resin yield were highly variable within populations, with narrow-sense heritability estimates being particularly high for resin yield (hi2 = 0.49). Growth varied significantly across provenance regions and populations within regions, while resin yield was only variable among provenance regions. Genetic variation in resin yield was similar in trees with and without stimulant paste. We did not find evidence of genetic correlations between growth and resin yield. However, at the phenotype level resin yield and growth were significantly correlated, although the sign of such association switched between trials. Across provenance regions, growth and resin yield where negatively correlated. Altogether, the high narrow-sense heritability estimate, the highly consistent genetic variation and the lack of negative genetic correlation with growth evidence the opportunity for implementing breeding programs to increase resin yield in maritime pine forests.

Parámetros genéticos de caracteres de crecimiento en un ensayo de progenies de Pinus oocarpa

Pinus oocarpa Schiede ex Schltdl. es una de las especies forestales en México de mayor importancia ecológica (por su amplia distribución geográfica) y económica (por la extracción de su resina en poblaciones naturales). Una resinación más intensiva requerirá de plantaciones comerciales, que podrían ser multipropósito: resina y madera. El objetivo del presente trabajo fue conocer el control genético (heredabilidad) de caracteres de crecimiento (altura total, ALT), diámetro a la base del tallo (DIAM) y diámetro a la altura del pecho (DAP), de progenies de medios hermanos de árboles originalmente seleccionados para producción de resina. Esto con la finalidad de valorar la factibilidad de un programa de mejoramiento genético multipropósito. Se estableció un ensayo de progenies en el año 2011 en Michoacán, México con 27 familias de medios hermanos en un diseño de 10 bloques completos al azar. A los cinco años después de la plantación, los promedios fueron ALT = 5.5 m, DIAM = 13.4 cm y DAP = 10.4 cm. Hubo diferencias significativas entre familias para todos los caracteres. La heredabilidad a nivel individual (h2i) fue: ALT = 0.15, DIAM = 0.22 y DAP = 0.17; a nivel media de familias (h2f) fue de 0.44, 0.54 y 0.47, respectivamente. A una intensidad de selección de mejores individuos de i=1.4, las ganancias genéticas para ALT, DIAM y DAP fueron de 3.9%, 5.2% y 5.0%, respectivamente. De demostrarse posteriormente asociación entre diámetro y producción de resina, sería factible incrementar ambos, mediante selección de individuos con mayores diámetros.

Resin yield in Pinus elliottii Engelm. is related to the resin flow rate, resin components and resin duct characteristics at three locations in southern China

In pine species, resin ducts are the specialized secretory structures to synthesize and store resin. Resin terpenes finds broad applications in pharmaceutical, chemical, biofuel, and food fields. Previous slash pine (Pinus elliottii Engelm.) breeding programs mainly focused on improvements in growth and wood properties in China. The incorporation of resin production into selective slash pine tree breeding occurred rarely, as standard tapping method to identify high-resin yield (RY) individuals is time-consuming, laborious, and expensive. The objective of this study was to identify high-RY slash pine trees with the method of resin flow rate (RFR) in a short timeframe in three plantations of southern China. The comparison of chemical profile between high- and low-yield individuals was also conducted. Moreover, the structural basis referred to resin secretion was studied by investigating the relationship between resin duct characteristics and RY. The phenotypic and genetic correlation coefficients between RY and RFR at all three sites were 0.44−0.85 and 0.58−0.71 respectively, which indicated that RFR measuring technology was reliable for tree breeders to select slash pine trees with high RY for breeding purpose. Resin component analysis revealed that the relative contents of β-pinene were higher in more productive trees; however, for α-pinene, the relative contents were significantly lower. Seasonal variation was low for most resin components and highly consistent across resin yielding classes and test sites. There were strong relations between RY and resin duct size and area at all three sites. High-yield individuals were always characterized by larger duct sizes and larger total areas when compared with low-yield trees. The RFR, certain resin components such as β-pinene, and most resin duct characteristics could be useful criteria for evaluating resin production in slash pine and could be applied to improve tapping management and breeding programs.

The effect of stimulants and environmental factors on resin yield of Pinus merkusii tapping

Oleoresin from Pinus merkusii is one of the most important forest products in Indonesia. The objective of this study was to examine the effects of various stimulants and environmental factors on oleoresin yield. The first factor was the stimulant treatment, i.e., SAEt1 (20% sulfuric acid + 1% Ethephon); SAEt2 (20% sulfuric acid + 2% Ethephon); SR4 (mainly composed by sulfuric acid); ETRAT (mainly composed by ethylene and citric acid); and without stimulant spraying. The second factor was the site with different altitudes, i.e., West Banyumas (326 m asl), East Banyumas (797 m asl), and West Pekalongan (1150 m asl). Through analysis of variance, the relation between stimulant and site was highly significant in regards to the average daily oleoresin yield. The results indicated that the combination of sulfuric acid and Ethephon increased oleoresin production 1.69- to 2.85-fold compared with untreated trees, depending on the sites. The trees with SAEt1 and SAEt2 treatments yielded an equivalent amount of oleoresin compared to that of trees exposed to the SR4. The ETRAT showed the lowest resin yields compared to the other stimulants. The values of daily relative humidity and temperature did not show similar responses in all sites when correlated with daily oleoresin yield.

Resin tapping potential of Atlantic maritime pine forests depends on tree age and timing of tapping

Pine resin is a highly valuable and sought-after non-timber forest product with multiple uses in many industrial sectors. Maritime pine (Pinus pinaster Ait.) is the main tapped species in Europe, where resin tapping activities are concentrated in only a few specific Mediterranean regions. Although maritime pine also occupies vast extensions under Atlantic climates, the resin tapping potential of these forests remains unexplored. The objectives of this study were to determine the main factors driving resin yield under Atlantic conditions and to adapt extraction practices to these regions. Resin yield was assessed in two naturally regenerated maritime pine forests in NW Spain. The effects of tree age, inter-tree competition, dendrometry, seasonality and wounding time on resin production were tested. The feasibility of a simple and rapid microtapping procedure to predict resin yield was also assessed. Tree age was identified as the main factor driving resin production, which increased considerably with tree age. Tree slenderness, tree size and inter-tree competition also significantly influenced resin production, although the effects were lower and likely mediated by age variation. Resin yield followed marked seasonal patterns, with maximum production in late summer and minimum production in winter. Resin flow decreased rapidly with time after wounding. More than 95 % of resin yield flowed in the first week after trees were wounded. The proposed microtapping procedure, which estimates resin flow from small wounds in just a few days, was shown to be a useful and reliable tool both for phenotyping and to predict resin yield in new stands. The results confirm the high potential for resin tapping in Atlantic maritime pine forests, although tapping should be restricted to stands older than 30 years and a season should be delimited for this activity in the region studied. Additionally, the periodicity of grooves (typically fortnightly) may need to be increased.

Jasmonate induced terpene-based defense in Pinus massoniana depresses Monochamus alternatus adult feeding.

Symptoms of pine wilt disease (PWD) are caused when pathogenic pine wood nematodes (PWN) invade healthy host trees via wounds created by adult Monochamus alternatus. Exogenous methyl jasmonate (MeJA) can trigger terpene-based induced defense in conifers, which is a core part of the conifer defense system. Herein, we hypothesized that the terpene-based plant defense induced by MeJA could negatively affect the feeding behavior of M. alternatus adults, and may contribute to a new strategy in the control of PWD. The feeding area for M. alternatus adults feeding on MeJA-treated seedlings was significantly smaller compared with control seedlings. However, no significant difference was detected in the enzyme activities in the midgut of beetles that had fed on these seedlings. Terpenoids were mainly accumulated in traumatic resin duct, whereas the constitutive resin duct accumulated only diterpenoids. Correspondingly, large-scaled responses at the transcriptional level mainly focused on terpenoid and phenolic biosynthesis in the defending trees. Breeding tree species with a high resin yield may contribute to control of the spread of PWD by suppressing the feeding of M. alternatus adults. Transcriptome sequencing results provided abundant information for further breeding of highly resistant trees. Based on these findings, a potential push-pull strategy for the control of M. alternatus was discussed.

Diversified roles of mineral transformation in controlling hydrocarbon generation process, mechanism, and pattern

Organic matter (OM) is intimately associated with minerals in clay-rich mudstones, leading to widespread organic-mineral interaction during hydrocarbon generation in argillaceous source rocks. What we are concerned is the effects of the different mineral properties on hydrocarbon generation process and mechanism during mineral transformation. In this way, pyrolysis experiments with smectite-octadecanoic acid complexes (Sm-OA and Ex-Sm-OA) were conducted to analyze correlation of mineralogy and pyrolysis behaviors. Based on organic-mineral interaction, hydrocarbon generation process was divided into three phases. At 200–300 ​°C, collapse of smectite led to desorption of OM, resulting in high yield of resin and slight increase in saturates. Subsequently, enhanced smectite illitization at 350–450 ​°C was accompanied with large amounts of saturates and a mere gaseous hydrocarbon. Featured by neoformed plagioclase, ankerite, and illite, 500 ​°C saw plenty of asphaltene and methane-rich gaseous hydrocarbons, revealing cracking reactions of OM. Noteworthy is that saturated and gaseous hydrocarbons in Ex-Sm-OA were considerably more than that in Sm-OA during second and third phases. Quantitative calculation of hydrogen revealed organic hydrogen provided by cross-linking of OM could not balance hydrogen consumed by cracking reactions, but supply of inorganic hydrogen ensured cracking could readily occur and consequently greatly promoted hydrocarbon generation. Further investigating characteristics of mineralogy and pyrolytic products, as well as effects of solid acidity on hydrocarbon generation, we concluded desorption of OM and decarboxylation promoted by Lewis acid were dominated at 200–300 ​°C, resulting in low-degree hydrocarbon generation. While high yield of saturated and gaseous hydrocarbons in second and third phases, together with occurrence of ankerite, indicated predominance of decarboxylation and hydrogenation promoted by Lewis and Brønsted acid, respectively. Variations in organic-mineral interactions indicated (1) the controls of mineral transformation on hydrocarbon generation process and mechanism include desorption, decarboxylation, and hydrogenation reactions; (2) clay minerals acted as reactants evolving together with OM rather than catalysts. These findings are profoundly significant for understanding the hydrocarbon generation mechanisms, organic-inorganic interactions, and carbon cycle.

Effect of Different Chemical Formulation on Agarwood (Aquilaria malaccensis) Resin Weight

Agarwood is described as fragrance, smelling wood that is usually derived from the trunk of genus Aquilaria The objective of this study was to develop and evaluate four chemical-based inoculants to induce karas tree to form agarwood resin. Four chemical inoculants were applied into 6 years old karas tree (Aquilaria malaccensis) plantations in Slim River, Perak, Malaysia using dripping techniques. The inoculant used were labelled as A, B, C and D. Commercial inoculant was also used for comparison purposes and labelled as K while a healthy tree, act as control was labelled as N. After four months of inoculation, these samples were cut down and discoloured tissue samples were collected. Solvent extraction method using dichloromethane (DCM) was carried out to obtain the resin crude extract from plant tissues of the samples. All chemical formulation used were succesfully stimulated sample trees to produce resin. Inoculant B produced the highest crude extract recovery (5.49%) compared to inoculant C (4.78%) followed by A (4.32%), D (2.98%), K (1.07%) and N (0.13%). From this study, inoculant B showed the highest yield of resin. Hence, result from current study has the potential to contribute in enhancing new types of inoculant production for the agarwood industries in Malaysia.

Variation in resin flow among Maritime pine populations: Relationship with growth potential and climatic responses

Pine trees produce large amounts of oleoresin to defend against biotic threats. Resin is highly costly to produce and investment in its production must be accurately optimized in relation to allocation to other life functions such growth. As a result of these costs, resin production is highly variable both genetically (among and within species) and plastically (across temporal and spatial environmental heterogeneity). The relative contribution of these sources of variation is, however, far from being completely understood. Besides being a main defensive mechanism, pine resin is also a valuable non-timber forest product that is regaining attention as a renewable resource for different industrial sectors. Improving our knowledge on the main drivers of resin production is vital to fine-tune resin-tapping management, especially in regions with little tradition in resin-tapping such are the Atlantic areas of the Iberian Peninsula. Here, we assessed resin flow and growth in a network of seven Maritime pine (Pinus pinaster) provenance tests established in North West Spain to explore the within species variation in resin flow, the plasticity of resin flow across sites and across the season and the (phenotypic and genotypic) relationships between resin flow and tree growth. Resin flow was assessed in three contrasting Maritime pine populations at three times within the season using a micro-tapping procedure that predicts well the resin yield potential for exploitation purposes. Results supported the theoretical predictions as resin flow significantly varied among populations, with populations from more favorable environmental conditions producing less resin than those from harsher conditions. Resin flow was positively correlated with tree size at the phenotypic level. However, the genetically-based relationship between growth potential and resin flow was markedly negative. Fast growing populations produced less resin than slow growing origins. Resin flow was also highly plastic across sites and across seasons, with resin flow consistently increasing towards the end of the growing season. Temperature and water deficit immediately before sampling emerged as main drivers of the observed variation in resin flow across sites and seasons. Results are valuable to understand the extremely large variation in defensive investment on resin-based defenses in conifer species, to model the potential of Atlantic Maritime pine forest for resin tapping, and to fine-tune the resin-tapping management of these forests.

Sulfur Distribution in Gasification Products of Car Tires

The gasification of used tires in the filtration combustion mode is studied using calcium-containing additives, both chemically inert and those capable of absorbing sulfur. It is found that during the gasification of compositions with an inert additive, 28, 29, and 43% of the sulfur contained in the initial material passes into the ash, resin and gaseous products, respectively. The introduction of marble crumb as an additive increases the proportion of sulfur passing into ash by a factor of 1.5 and reduces the yield of pyrolysis resins in comparison with an inert additive. In this case, the distribution of sulfur between the solid, liquid, and gaseous products of gasification is 40, 26, and 34%, respectively.

Experimental investigation on characteristics of resole based phenolic resin

In this study, characteristics of two different resole based phenolic resin being used in aerospace application were investigated. Phenolic resins were advanced by conditioning to bring down its point of trouble. At this stage both resins were separately impregnated with PAN based carbon fabric as reinforcement and evaluated their rheologyproperties. Residues of free phenol, free formaldehyde and sodium content in resins were estimated for both the resins and compared. Also other properties such as neat resin cure characteristics, resin characteristic frequencies, molecular weight distributions, char yield of resins were evaluated and compared. A conclusion is drawn from the test results that char yield is affected by purity of phenolic resin viz presence of unreacted free phenol and free formaldehyde. Also viscosity plays a vital role in wetting of the reinforcement resulting in better interlaminar shear properties.

Application of a vermicomposter containing biostimulant for pine tapping

The issues of biotechnological development of economics have become rather topical in recent years. Scientific papers in the field of environmental economics, namely in the field of the forest sector, are of particular interest. The main component of the forest industry bioeconomics development is the increase in the volume of forest resources management. Rubber tapping (tapping) is the main form of natural resource management of pine plantations. During the analysis of the resources, it was found that the development of an alternative biological stimulant of animal origin for tapping is needed to be developed for its further application, and its efficiency of the maximum pine resin yield should be assessed. A 1% aqueous extract of the vermicomposter of Black Soldier Fly (Hermetia illucens L.) was used as the main active component of the experimental biostimulant. At the test area, where the studies were conducted, trees involved in tapping procedure included ones, on which the stimulant was tested, and those trees, where ordinary tapping was carried out without the use of the stimulant; the latter ones were considered to be a control group. In the course of studies, it was found that the biostimulant based on the vermicomposter of Black Soldier Fly led to the excess of the resin yield per centimetre of face in comparison with the control group. Also, no negative effect of the biostimulant on the pine forest condition was revealed.