Resin Yield Research Articles

Comparative Chloroplast Genome Analysis in High-Yielding Pinus kesiya var. langbianensis

Pinus kesiya var. langbianensis, a species endemic to Yunnan, China, accounts for over 90% of Yunnan’s Pinus resin production. However, there is significant variation in resin yield among individuals, and molecular markers for identifying high-yielding individuals have yet to be developed. In this study, a comparative analysis of complete chloroplast genomes of P. kesiya var. langbianensis was conducted to perform a phylogenetic analysis and differentiate high-yielding individuals. Both high-yielding (HY) and low-yielding (LY) trees possess a typical quadripartite structure, with respective genome sizes of 119,812 bp and 119,780 bp. Each chloroplast genome contains 112 genes, including 72 protein-coding genes, 36 tRNAs, and 4 rRNAs. Furthermore, HY and LY trees contain 30 and 34 SSRs, respectively, with mononucleotide repeats being predominant; neither genome exhibited trinucleotide or pentanucleotide repeats. Six highly variable regions were identified: trnI-CAU-psbA, trnH-GUG-trnI-CAU, rpl16, rrn4.5-rrn5, petG-petL, and psaJ. Phylogenetic analysis based on 72 Pinus species revealed that HY and LY trees clustered separately, with the HY tree grouping with P. kesiya and the LY tree with P. yunnanensis. This study provides a theoretical foundation for the molecular identification of high-yield P. kesiya var. langbianensis individuals and enriches the understanding of its phylogenetic relationships.

Treatment of high-concentration semi-coke wastewater by phenolic condensation and persulfate oxidation

In this study, the combined process of phenolic condensation-persulfate(PS) advanced oxidation was adopted to treat semi-coking wastewater. Using the phenolic condensation method as a pretreatment unit to remove phenolic substances for the preparation of phenol-formaldehyde resins, and using an aerated/PS/pyrite oxidation system as a deep treatment unit to remove chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) from the wastewater. Analysis and characterization of phenol-formaldehyde resin, organic compounds in wastewater, and pyrite using FT-IR, TG-DTG, GC-MS, and XPS techniques. The results showed that under the conditions of adding 1.8vt % formaldehyde, pH 10.5, reaction temperature 95 ℃ and reaction time 3 h, the removal rates of volatile phenol, COD and NH3-N in semi-coke wastewater were 97.54 %, 41.14 % and 56.50 %, and the yield of phenolic resin was 6.62 g/L. Subsequently, treated with an aerated/PS/pyrite system, the PS concentration 0.4 mol/L, the pyrite dosage 15 g/L, the pH 3, the temperature 65 ℃, and the aeration 3 h, the removal rates of COD and NH3-N are 99.20 % and 86.80 %. In the phenolic condensation process, phenolic substances in semi-coke wastewater generate phenoxy anions under the influence of OH-, which undergo addition reactions with formaldehyde to produce hydroxymethyl phenol. Hydroxymethyl phenol further undergoes condensation reactions with other phenolic substances and itself to form phenolic resin, while amide compounds are generated through reactions between ammonia nitrogen and carboxylic acid substances. In the aeration/PS/pyrite system, Fe2+ released from pyrite oxidation activates PS to produce SO4•− and O2•−. The contribution of free radical oxidation and decomposition of pollutants such as phenols, amides, and NH3-N in wastewater is 84.60 %. Specifically, SO4•− oxidation contributes 61.54 %, while O2•− accounts for 22.21 %. Amide compounds and phenolic substances in the wastewater are oxidized, leading to ring opening and chain scission, resulting in the formation of alkane compounds.

Dynamics of resin yield in Pinus brutia: A quantitative analysis using bark streak tapping

The sustainable harvesting of resin yield from forests plays a crucial role in providing valuable renewable resources. Specifically, Pinus brutia forests in Türkiye are significant for their oleoresin, utilized in various industries. Yet, understanding how dendrometric and meteorological factors influence resin yield is essential for optimizing production while ensuring forest sustainability. This study aimed to estimate oleoresin yield in Pinus brutia plantations using dendrometric parameters (such as diameter at breast height and tree height, basal area, volume and canopy closure) and meteorological parameters (including monthly; minimum, maximum, and average temperature, precipitation, humidity, vapor pressure, and wind speed), to identify the key factors affecting resin production. Resin was collected from 389 Pinus brutia trees of varying diameters across 27 different plots using the bark streak tapping method, with data recorded every 15 days over a year. Weighted Leased Square regression analysis was conducted to explore the relationship between resin yield and the aforementioned dendrometric and meteorological parameters. The analysis revealed that diameter at breast height, monthly average temperature, wind speed, and precipitation significantly influence resin yield. The study underscores the intricate interplay between these factors and resin production, indicating that larger diameters and specific meteorological conditions—especially average temperature, wind speed, and precipitation—are positively correlated with increased resin output. The findings suggest that sustainable resin extraction practices in Pinus brutia forests should account for not only the physical characteristics of the trees but also the local meteorological conditions to maximize yield without compromising forest health. This research contributes to the development of more effective guidelines for oleoresin harvesting, ensuring both economic viability and ecological preservation.

Thermal stability and decomposition kinetics of polybenzoxazine and oligomeric polyhedral octaphenyl silsesquioxane nanocomposites

AbstractIn this study, the impact of octaphenyl polyhedral oligomeric silsesquioxane (POSS) on the thermal stability of polybenzoxazine resin at 1, 3, and 5 wt% POSS loading through dynamic thermogravimetric analysis (TGA) at heating rates of 10, 20, 30 and 40°C min−1 was investigated. Besides, the decomposition kinetics of polybenzoxazine resin (PBZ) and various nanocomposites were studied using Kissinger, Friedman, Flynn‐Wall‐Ozawa (FWO) and Coats‐Redfern (CR) models and also, the activation energies of samples were calculated. At first, benzoxazine monomer was synthesized and then nanocomposites were prepared via solution mixing method. The qualitative dispersion of nanoparticles in benzoxazine resin was examined through the utilization of scanning electron microscopy and x‐ray diffraction experiments. The results showed that the addition of nanoparticles improved the thermal stability of PBZ resin specially at 1 wt% POSS loading and at higher POSS content the thermal stability of the resin decreased. As determined by TGA, the char yield of resin was enhanced by 2.6% upon the addition of 1 wt% nanoparticles. In addition, in 1 weight percent of nanoparticles, as the heating rate rose from 10 to 40°C min−1, the Integral Program Decomposition Temperature (IPDT) has increased by about 260°C, and this increase is about 183°C compared to the resin, and also elevating the heating rate, Td (5%) and Td (10%) weight loss of samples shifted to higher temperatures. The degradation mechanism of the resin and nanocomposites was evaluated through Kissinger, Friedman, FWO and CR models. The results displayed that the addition of 1 wt% nanoparticles increased the activation energy (Ea) values of the nanocomposites compared to that of neat resin and above this filler content, the Ea values decreased. The findings derived from the FWO model indicated that the inclusion of a 1 wt% filler raised the Ea values of the first and second stages of PBZ resin decomposition from 136–200 and 151–214 kJ mol−1 to 148–210 and 180–228 kJ mol−1, respectively.

Application and study on preparation of bio-asphalt by modified phenolic resin from corn straw tar

XPS, GPC, FT-IR, and GC–MS analyses were conducted on corn straw tar and 70# petroleum asphalt. The results indicate that the sulfur content in corn straw tar is lower than that in petroleum asphalt, potentially mitigating the volatilization of harmful substances upon substituting petroleum asphalt. This finding serves as evidence for the substantial presence of phenolic substances in corn straw tar. Upon employing the BOX-Behnken response surface analysis and utilizing resin yield as the evaluation index, the significance of three factors was established as follows: reaction time > phenol molar ratio > straw tar content. Based on the secondary multiple regression model, the optimal conditions for synthetic resin production are a phenolic mole ratio of 0.8, a reaction time of 125 min, and a straw tar dosage of 10 %. An assessment of resin viscosity at different VI temperatures reveals that corn stover tar can partially replace phenol and formaldehyde in the condensation reaction. Additionally, viscosity improvement is observed at elevated temperatures. Thermal gravimetric(TG) spectroscopy indicates lower mass loss in B-PF resin at high temperatures compared to PF resin or corn stover tar. In the evaluation of biological bitumen performance, it is discerned that the mixing amount of the prepared biological bitumen should be controlled at approximately 10 % of its performance. This ensures optimal efficacy without adversely affecting the performance of petroleum bitumen.

Labdanum Resin from Cistus ladanifer L. as a Source of Compounds with Anti-Diabetic, Neuroprotective and Anti-Proliferative Activity.

Labdanum resin or "gum" can be obtained from Cistus ladanifer L. by two different extraction methods: the Zamorean and the Andalusian processes. Although its main use is in the fragrance and perfumery sectors, ethnobotanical reports describe its use for medicinal purposes in managing hyperglycemia and mental illnesses. However, data concerning the bioactivities and pharmacological applications are scarce. In this work, it was found that the yield of labdanum resin extracted by the Andalusian process was 25-fold higher than the Zamorean one. Both resins were purified as absolutes, and the Andalusian absolute was purified into diterpenoid and flavonoid fractions. GC-EI-MS analysis confirmed the presence of phenylpropanoids, labdane-type diterpenoids, and methylated flavonoids, which are already described in the literature, but revealed other compounds, and showed that the different extracts presented distinct chemical profile. The potential antidiabetic activity, by inhibition of α-amylase and α-glucosidase, and the potential neuroprotective activity, by inhibition of acetylcholinesterase, were investigated. Diterpenoid fraction produced the higher α-amylase inhibitory effect (~30% and ~40% at 0.5 and 1 mg/mL, respectively). Zamorean absolute showed the highest α-glucosidase inhibitory effect (~14% and ~24%, at 0.5 and 1 mg/mL, respectively). Andalusian absolute showed the highest acetylcholinesterase inhibitory effect (~70% and ~75%, at 0.5 and 1 mg/mL, respectively). Using Caco-2 and HepG2 cell lines, Andalusian absolute and its purified fractions showed moderate cytotoxic/anti-proliferative activity at 24 h exposure (IC50 = 45-70 µg/mL, for Caco-2; IC50 = 60-80 µg/mL, for HepG2), whereas Zamorean absolute did not produce cytotoxicity (IC50 ≥ 200.00 µg/mL). Here we show, for the first time, that labdanum resin obtained by the Andalusian process, and its fractions, are composed of phytochemicals with anti-diabetic, neuroprotective and anti-proliferative potential, which are worth investigating for the pharmaceutical industry. However, toxic side-effects must also be addressed when using these products by ingestion, as done traditionally.

A Study of the Effects of Stimulants on Resin Yield, Resin Duct and Turpentine Chemical Composition in Pinus kesiya var. langbianensis

This study presents a comprehensive examination of Pinus kesiya var. langbianensis (Pinus kesiya var. langbianensis), the primary resin-extraction tree species in Yunnan Province, China. In this study, we formulated different concentration gradients of 0.25%, 0.5%, 1%, and 2% of diquat solution as tapping stimulant to test the effect of different concentrations on the resin gain rate of Pinus kesiya, and analyzed the relationship between anatomical structure, major chemical composition of turpentine and resin yield by methods such as wood anatomy and chemical composition analysis of turpentine. The primary focus of the investigation was on exploring the interrelationships among resin-tapping stimulants, anatomical structures, turpentine components, and resin yield. Research findings demonstrate a significant enhancement in resin production due to the application of stimulants, with the highest increase rate reaching 55% in a specific group, while others achieved approximately 30% increments. Moreover, measurement data about resin duct dimensions indicate a noteworthy increase in resin duct area for the stimulant-treated group compared to the control group. However, it should be noted that the impact on resin duct area by varying stimulant concentrations was relatively minor. Furthermore, continuous observation of resin extraction from different resin-yield classes of P. kesiya revealed insignificant variation in resin yield over time for the low and moderate resin-yield groups. In contrast, the high resin-yield group exhibited a gradual increase in resin production. Interestingly, the high resin-yield group exhibited the smallest resin duct area, but the highest resin duct density, indicating an interconnectedness of resin duct-related data that influences resin yield. Additionally, correlative investigations between anatomical structures and resin yield demonstrate a positive correlation between resin duct area and resin yield, total resin production, and average resin yield. This underscores the importance of resin duct area as a significant factor in resin production. On the other hand, the influence of stimulant concentrations on the turpentine components was found to be negligible. Overall, the correlation results suggest that turpentine components cannot reliably predict or differentiate between high and low resin-yield trees. This study provides a comprehensive analysis of the interrelationships among stimulants, anatomical structures, and turpentine components, offering a theoretical foundation for the resin extraction and resin processing industries in Yunnan Province.

Resin tapping of Atlantic pine forests: towards an optimized use of stimulant pastes over the season

Pine resin is a valuable non-wood forest product with an increasing interest in multiple industrial sectors. Resin-tapping activities also provide valuable ecosystem services in timber-oriented and highly productive pine forest of Atlantic regions, where little previous experience in resin-tapping is available. The objectives of this study were to determine the efficiency of different stimulant pastes and its variation with pine species, site conditions, seasonality and frequency of tapping interventions. We conducted parallel experiments using both conventional and micro-tapping techniques in mature pine stands in NW Spain. We tested four stimulants (control and Zeta, Cunningham and Salicylic pastes) and two groove frequencies (every 2 or 3 weeks). All stimulant pastes significantly increased resin yield compared to the control, being resin stimulation highly consistent across years, sites and species. In conventional resin tapping, resin yield was maximized with the Cunningham and Salicylic pastes while in micro-tapping Salicylic was the most outstanding stimulant treatment. According to the rapid decay of resin flow after wounding, total resin yield decreased with more spaced grooves. However, the reduction was low, and the global efficiency of the tapping operations are likely maximized with grooves applied every three weeks, which would allow increasing the number of tapped trees. Micro-tapping techniques were valuable for screening stimulant pastes and anticipating variation among sites in resin production. Altogether, the Salicylic paste is recommended, especially at the beginning of the resin campaign, when the effect of the pastes was maximized, and if tapping is conducted using closed atmospheres and containers.

Effect of collection period on oleoresin yield of Pinus merkusii

Pinus merkusii is one of the most important timber species in Indonesia, the main product of which is its oleoresin. The objective of this study was to examine the effects of collection period (three periods, with 6-day observation each) on oleoresin yield in relation to two factors: growth sites of Pinus merkusii, which in the case of this study were East Banyumas, West Banyumas, and West Pekalongan Forest Management Units, and use of stimulants (sulfuric acid and ethephon mixtures, ETRAT, SR4, and no treatment). The average total oleoresin yield from a single tree or wound during the 18-day observation period was 110-185 g/tree for untreated trees and 159-442 g/tree for stimulant-treated trees. By analysis of variance, the interaction between each collection period (6-day observation period) and tree growing sites showed that the maximum average oleoresin yield for one hole was 109.32 g/tree measured in East Banyumas in the first collection period. Furthermore, the East Banyumas site consistently showed significantly the highest yield in each period. The interaction between the factors of stimulant and collection period (6-day observation) resulted in the highest average oleoresin yield (121.86 g/tree) measured for trees treated with sulfuric acid (20%) and Ethephon (2%) mixtures in aqueous solution (v/v) treatment in the first collecting period. In West Pekalongan, the resin yield from trees treated with different treatments tended to be positively related to tree diameter. In addition, a positive correlation was found between resin yield and tree height or crown closure, while a negative correlation was found between resin yield and site elevation in trees treated with certain stimulants.

B-COPNA resin formation from ethylene tar light fractions: Process development and mechanical exploration by molecular simulation

Efficient utilization strategy of ethylene tar (ET), the main by-product of ethylene cracking unit, is urgently required to meet demands for modern petrochemical industry. On the other hand, condensed polynuclear aromatic resin of moderate condensation degree (B-COPNA) is a widely used carbon material due to its superb processability, the production of which is however seriously limited by high cost of raw materials. Under such context, an interesting strategy was proposed in this study for producing B-COPNA resin using crosslinked light fractions of ethylene tar (ETLF, boiling point < 260 °C) facilitated by molecular simulation. 1,4-Benzenedimethanol (PXG) was first selected as the crosslinking agent according to the findings of molecular simulation. The effects of operating conditions, including reaction temperature, crosslinking agent and catalyst content, on the softening point and yield of B-COPNA resin products were then investigated to optimize the process. The reaction mechanism of resin production was studied by analyzing the molecular structure and transition state of ETLF and crosslinking agent. It was shown that PXG exhibited a superior capacity of withdrawing electrons and higher electrophilic reactivity than other crosslinking agents. In addition to the highest yield and greatest heat properties, PXG-prepared resin contained most condensed aromatics. The corresponding optimized conditions of resin preparation were 180 °C, 1:1.9 (PXG:ETLF) and 3% (mass) of catalyst content with a resin yield of 78.57%. It was the electrophilic substitution reaction occurred between the ETLF and crosslinking agent molecules that was responsible for the resin formation according to the experimental characterization and molecular simulation. Hence, it was confirmed that the proposed strategy and demonstrated process can achieve a clean and high value-added utilization of ETLF via B-COPNA resin preparation, bringing huge economic value to the current petrochemical industry.

Non-Destructive Assessment of Agarwood Resin Formation Status in Aquilaria crassna using Near-Infrared Spectroscopy

Agarwood is a unique and valuable resin synthesized within a few tree species of the tree family Thymelaeaceae primarily as a self-defence mechanism against stress causes such as fungal invasions. Instead, artificial inoculation leads to short-time harvesting practiced in intensive commercial-level cultivations. The extraction of this resin can be done only after the harvesting where accurate estimation of resin yield is crucial for avoiding immature or underdeveloped harvesting. However, the amount of resin accumulated in the trunk cannot be estimated by the outside inspection. As a result, trees are being cut down before they have reached their maximum harvest potential. Therefore, precise detection of fragrant resin formation status inside the tree has become one of the primary challenges in the agarwood production industry. Currently, the methods available are either destructive, inefficient, or inaccurate. As such, this study evaluates the possibility of the use of NIR spectroscopy as a non-destructive and quick detection method for agarwood formations status inside trees in the in-situ mode. Near-infrared (NIR) range (588–1,025 nm) spectra were acquired from resin-formed and non-formed areas from twenty tree trunks of agarwood with five different formation levels. The best agarwood formation areas of logs were assigned as class level 1 and the least was assigned as the class level 5. The spectra were acquired near the opening made for the artificial inoculation process of considered Aquilaria crassna tree trunks. The results of Soft Independent Modelling of Class Analogies showed consistent evidence of differences in the NIR spectral profiles of all levels of agarwood formations. The SIMCA discrimination between the resin developed versus not was achieved with 86% accuracy. The accuracy rates of the degree of the presence of agarwood were obtained as 80%, 100%, 85%, 90%, and 85% respectively, as assigned levels 1 to 5 in the SIMCA models. This research revealed the potential possibility of using NIR technology for the prediction of agarwood resin status inside the agarwood tree in A. crassna before harvesting the tree as a non-destructive and rapid method.&#x0D; &#x0D; Keywords: NIR spectroscopy, Agarwood, Aquilaria crassna, Non-destructive, Agarwood formation&#x0D;

Enhanced Estimation of Axial Compressive Strength for CFRP Based on Microscale Numerical Simulation and the Response Surface Method.

Compressive strength is one of the most important properties of carbon fiber reinforced plastics (CFRP). In this study, a new method for predicting the axial compressive strength of CFRP using the response surface method is developed. We focused on a microbuckling model to predict the compressive strength of unidirectional fiber composites. For the microbuckling model, axial shear properties are required. To obtain the compressive strength for various material properties, we perform individual shear tests and numerical simulations, but these require enormous computational costs and extended time. To address the issue of computational cost, in this study, we propose a new method to predict compressive strength using the response surface method. First, we perform shear simulation in a microscale fracture model for unidirectional CFRP with various parameters of the fiber and resin properties. Based on the results of the shear simulation, the response surface method is used to evaluate and develop prediction equations for the shear properties. This method allows for the study of the objective values of the parameters, without significant computational effort. By comparing both the results predicted from the response surface method (RSM) and the simulation results, we verify the reliability of the prediction equation. As a result, the coefficient of determination was higher than 94%, and the validity of the prediction method for the compressive strength of CFRP using the response surface method (RSM) developed in this study was confirmed. Additionally, we discuss the material properties that affect the compressive strength of composites comprised of fibers and resin. As a result, we rank the parameters as follows: fiber content, elastic modulus after resin yield, yield stress, and initial elastic modulus.

Experimental investigation of yield and hysteresis behaviour of an epoxy resin under cyclic compression in the large deformation regime

Experimental investigation of yield and hysteresis behaviour of an epoxy resin under cyclic compression in the large deformation regime

Polyarylacetylene as a novel graphitizable precursor for fabricating high-density C/C composite via ultra-high pressure impregnation and carbonization

High-density carbon/carbon (C/C) composite plays a critical role in the aerospace industry owing to excellent mechanical properties and resistance to ablation. However, traditional manufacturing relies on pitch precursor and hot isostatic pressure impregnation and carbonization (HIPIC) technology, which is time-consuming and expensive. In this study, we report an innovative method utilizing polyarylacetylene (PAA) resin and ultra-high pressure impregnation and carbonization (UHPIC) technology. The extremely high char yield of PAA resin (85 wt.%) and high isotropic pressure of UHPIC (over 200 MPa) promote the densification of the composite. As a result, we achieve a high-density (1.90 g/cm3) C/C composite with a high degree of graphitization (81%). This composite exhibits impressive properties, including flexural strength of 146 MPa, compressive strength of 187 MPa, and thermal conductivity of 147 W/(m K). When exposed to oxyacetylene flame at 3000 K for 100 s, it displays minimal linear ablation, with a rate of 1.27 × 10−2 mm/s. This study demonstrates the exceptional graphitizable characteristic of PAA resin, setting it apart from conventional resins. Our time-saving and cost-effective approach holds significant promise for aerospace applications, particularly in harsh aerodynamic heating environments.

Base-age invariant models for predicting individual tree accumulated annual resin yield using two tapping methods in maritime pine (Pinus pinaster Ait.) forests in north-western Spain

In southern Europe, especially in Spain and Portugal, maritime pine resin is one of the main non-timber forest products. After suffering a crisis at the end of the 20th century, it is currently a growing sector. In Spain, depending on the area, the management of pine forests is one of the pillars of the national bioeconomy. In addition to timber production, these forests may be oriented towards resin production only, or resin production as a complementary activity to timber production. In both cases, as in any sector, it is essential to have tools to manage and anticipate production, especially in the new context of the bioeconomy. For this reason, the aim of this study is to develop a dynamic model to estimate the accumulated resin yield during the resin production season. For this study, 180 trees from three plots located in the northwest of the Iberian Peninsula were resin tapped using two extraction methods (non-mechanized and mechanized circular notching) and stimulant pastes. Four base models were used from which eight equations were derived using ADA and GADA techniques. The most efficient equations, both for modelling with the train data and for prediction with the test data, were those derived from the Bertalanffy-Richards model. The RRMSE was 23% for the non-mechanised method and 29% for the mechanised circular method. The results of this study make it possible to add the cumulative annual resin yield of maritime pine to the processes that the Bertalanffy-Richards equation is capable of modelling. Furthermore, the great versatility of these models will be of great use to the forest manager in optimising the annual harvesting season as well as for the scientific community.

Needle functional features in contrasting yield phenotypes of slash pine at three locations in southern China

Pine resin, a valuable secondary metabolite, is derived from the products of photosynthesis. Pine needles, serving as the primary organ for photosynthesis and nutrient absorption, facilitate the continuous transport of nutrients to all plant organs through photosynthesis. The functional traits of pine needles exhibit a close association with the photosynthetic efficiency of pine trees, thereby affecting resin yield. The selection of superior trees with high-resin yield (RY) for slash pine (Pinus elliottii Engelm.) faces difficulties due to low selection efficiency and a high false selection rate caused by the absence of reliable indirect selection traits. The objective of this study was to systematically investigate the relationships between slash pine needle functional traits and RY in different regions. Understanding the relationship between functional traits of pine needles and RY is essential for addressing the challenges mentioned above. There were positive correlations between RY and most morphological traits, except for leaf dry matter content (LDMC), which showed a negative correlation. Moreover, low-resin yield trees exhibited lower values for most morphological variables, except for LDMC. High-yield trees exhibited higher stomata number per mm2 (STN), larger stomata diameter (STD) and size (STS), and stomata area per mm2 (STA) across all periods and sites when compared with low-yield individuals. Chloroplast pigment component analysis revealed that high yielders exhibited higher levels of chloroplast a (CHL a) and chloroplast a+b (CHL a+b) compared to low yielders, and positive correlations were found between resin yield and CHL a, chloroplast b (CHL b), and CHL a+b. Higher nutrient contents were observed in high resin yield individuals, and positive correlations were found between resin yield and most nutrients, except for potassium (K). Different needle functional traits exhibited varying periodic patterns of resin production. Most needle functional traits could be useful criteria for evaluating resin production in slash pine breeding programs, which could improve the efficiency of breeding, shorten the breeding cycle, and accelerate the breeding process.

Water Use, Growth, and Yield of Ratooned Guayule under Subsurface Drip and Furrow Irrigation in the US Southwest Desert

Guayule (Parthenium argentatum, A. Gray) is a perennial desert shrub with ratoon-cropping potential for multiple harvests of its natural rubber, resin, and bagasse byproducts. However, yield expectations, water use requirements, and irrigation scheduling information for ratooned guayule are extremely limited. The objectives of this study were to evaluate dry biomass (DB), contents of rubber (R) and resin (Re) and yields of rubber (RY) and resin (ReY) responses to irrigation treatments, and develop irrigation management criteria for ratooned guayule. The water productivity (WP) of the yield components were also evaluated. Guayule plants that were direct-seeded in April 2018 were ratooned and regrown starting in April 2020, after an initial 2-year harvest at two locations in Arizona: Maricopa and Eloy on sandy loam and clay soils, respectively. Plots were irrigated with subsurface drip irrigation (SDI) at 50, 75, and 100% replacement of crop evapotranspiration (ETc), respectively, and furrow irrigation at 100% ETc replacement, as determined by soil water balance measurements. The Eloy location did not include the 100% irrigation treatment under SDI due to unsuccessful regrowth for this specific treatment. The irrigation treatments at the locations were replicated three times in a randomized complete block design. After 21–22 months of regrowth, the guayule plants were harvested in plots. The results showed that DB increased with the amount of total water applied (TWA, irrigation plus precipitation), while R and Re were reduced at the highest TWA received at both locations. Ultimately, the SDI treatments with 75% ETc replacement resulted in the best irrigation management in terms of maximizing RY and ReY, and WP for both locations and soil types. Compared to the initial 2-year direct-seeded guayule crop, ratooned guayule required less TWA and attained higher DB, RY, and ReY, as well as higher WP, with average increases of 25% in dry biomass, 33% in rubber yield, and 32% in resin yield. A grower’s costs for planting the initial direct-seeded guayule crop would be offset by the additional yield revenue of the ratooned crop, which would have comparatively small startup costs.

Physiological, Proteomic, and Resin Yield-Related Genes Expression Analysis Provides Insights into the Mechanisms Regulating Resin Yield in Masson Pine.

Masson pine (Pinus massoniana Lamb.) is an important resin-producing conifer species in China. Resin yield is a highly heritable trait and varies greatly among different genotypes. However, the mechanisms regulating the resin yield of masson pine remain largely unknown. In this study, physiological, proteomic, and gene expression analysis was performed on xylem tissues of masson pine with high and low resin yield. Physiological investigation showed that the activity of terpene synthase, as well as the contents of soluble sugar, jasmonic acid (JA), methyl jasmonate (MeJA), gibberellins (GA1, GA4, GA9, GA19, and GA20), indole-3-acetic acid (IAA), and abscisic acid (ABA) were significantly increased in the high yielder, whereas sucrose and salicylic acid (SA) were significantly decreased compared with the low one. A total of 2984 differentially expressed proteins (DEPs) were identified in four groups, which were mainly enriched in the biosynthesis of secondary metabolites, protein processing in the endoplasmic reticulum, carbohydrate metabolism, phytohormone biosynthesis, glutathione metabolism, and plant-pathogen interaction. Integrated physiological and proteomic analysis revealed that carbohydrate metabolism, terpenoid biosynthesis, resistance to stress, as well as JA and GA biosynthesis and signaling, play key roles in regulating resin yield. A series of proteins associated with resin yield, e.g., terpene synthase proteins (TPSs), ATP-binding cassette transporters (ABCs), glutathione S-transferase proteins (GSTs), and heat shock proteins (HSPs), were identified. Resin yield-related gene expression was also associated with resin yield. Our study unveils the implicated molecular mechanisms regulating resin yield and is of pivotal significance to breeding strategies of high resin-yielding masson pine cultivars.

Influence of a novel resin tapping method on the resin yield and turpentine chemical composition of Masson pine (Pinus massoniana)

Pine resin is a potential renewable non-wood product with a wide range of industrial applications and economic value. Masson pine (Pinus massoniana), the main tree species of pine resin in the world, is widely planted in Southern China. However, the resin tapping by traditional methods is performed in an open environment under the sun and rain, resulting in the continuous volatilization of turpentine components such as α-pinene and β-pinene and a loss of the turpentine. This reduced not only the yield of pine resin but also the quality of turpentine and rosin. In this study, a novel resin tapping method was explored by introducing film mulching to pine wounds. The experimental results showed that the mulching treatment was indeed beneficial for pine resin yield. The growth rate of resin yield was up to 55.46 % by transparent film treatment (TFM) when re-wounding was carried out every two days, and the collection was carried out every eight days. The relationship between turpentine content and pine resin yield was analyzed, and a positive relationship was observed. The increase in turpentine content after the film mulching treatment proved that the film mulching treatment could reduce the turpentine loss and thus increase pine resin yield. The turpentine composition and its content variation were analyzed by Gas chromatography (GC) and Gas chromatography-Mass spectrometry (GC-MS) and correlated with turpentine content and pine resin yield. It was confirmed that the key components in turpentine indeed affect pine resin yield. This study can provide a simple and cost-effective method for effectively increasing the turpentine content and pine resin yield, which is economical for both the tapping industry and the pine resin processing industry.

Forecasting of Resin Yield and Number of Blazes of Naturally Regenerated Chir Pine (Pinus roxburghii Sargent) in Himachal Pradesh by Using Single Exponential Smoothing Method

The present investigation entitled “Forecasting of resin yield and number of blazes of naturally regenerated chir pine (Pinus roxburghii Sargent) in Himachal Pradesh by using single exponential smoothing method” was carried out during the year 2020-2022. The secondary information was collected regarding the resin yield and number of resin blazes w.e.f. 2005 to 2022 from Himachal Pradesh State Forest Department. Exponential smoothing is a particular moving average technique applied to time series data and to produce smoothed data to make forecast. In exponential smoothing, one or more smoothing parameters are to be determined explicitly and those choices determine the weights assigned to the observations. Forecasting with the help of various linear and non-linear models is on the assumption that the series is stationary. Often time series is found to be non-stationary which means they are integrated and can be made stationary by differencing the time series. To check the stationarity of the number of blazes and resin yield, Augmented Dickey Fuller test was used. The results indicated that data was not approaching stationarity even after taking third difference. So, the prerequisite condition of ARIMA model is that the data should be stationary and if the time series data does not contain trend and seasonal components, Single Exponential Smoothing model was used. The Single Exponential Smoothing model was found to be best fit for the prediction of number of blazes and resin yield as per the high value of , low value of MAPE and Normalized BIC.