Stem Diameter Growth Research Articles

Application Techniques and Concentrations of Ascorbic Acid to Reduce Saline Stress in Passion Fruit

Salinity restricts the growth of irrigated fruit crops in semi-arid areas, making it crucial to find ways to reduce salt stress. One effective strategy is using eliciting substances like ascorbic acid. In this context, the objective of this study was to evaluate the effects of application methods and concentrations of ascorbic acid on the morphophysiology and production of sour passion fruit irrigated with saline water. The experiment was organized using a factorial randomized block design (3 × 3 × 2) with three application methods (soaking, spraying, and soaking and spraying), three concentrations of ascorbic acid (0, 0.8, and 1.6 mM) and two levels of electrical conductivity of irrigation water—ECw (0.8 and 3.8 dS m−1). Foliar spraying of ascorbic acid at a concentration of 0.8 mM mitigated the effects of salt stress on the relative water content of leaves, the synthesis of photosynthetic pigments, gas exchange, and total production of sour passion fruit when irrigated with ECw of 3.8 dS m−1. Plants grown with water of 0.8 dS m−1 and under foliar application of 0.8 mM of ascorbic acid achieved the maximum growth in stem diameter and the greatest volume of pulp in the fruits.

High nitrate and sulfate leaching in response to wetter winters in temperate beech forests

Climate models project moderate to large increases in air temperature for most temperate ecosystems with an overall increase in winter precipitation and a shift from snow towards rain. We investigated the effects of increased winter rainfall on the ecosystem functioning of European beech forests at their north-eastern distribution range. In a large-scale field experiment we manipulated winter climate at nine forest sites by increasing the amount of rainfall and excluding snow. Nutrient availability in the topsoil and leaching in 50 cm depth as well as litter decomposition and radial growth of mature European beech trees were analysed. It was hypothesized that (1) wetter winters lead to increased nutrient deposition as well as leaching, with an overall increase in net nutrient availability, (2) decomposition decreases in response to water addition containing also additional nutrients and (3) primary production during the subsequent growing season increases as presumably not all additionally available nutrients would be leached. We found an increase in topsoil nitrate and sulfate availability during winter in response to rain addition, likely as a consequence of collecting more atmospheric deposition, and surprisingly high leaching rates of the additionally available nutrients. During the subsequent early growing season, no difference in nutrient availability could be observed anymore. Enhanced nutrient availability in the topsoil and leaching do not seem to have a strong short-term influence on forest ecosystem processes in ecosystems which are close to their critical load of N deposition. Decomposition rates during winter and early growing season as well as stem diameter growth during the following growing season were not influenced. This indicates that additional nutrients in the topsoil in response to wetter winters are not available for plant growth but pollute ground- and surface waters.

Populus trichocarpa EXPA6 Facilitates Radial and Longitudinal Transport of Na+ under Salt Stress.

Expansins are cell wall (CW) proteins that mediate the CW loosening and regulate salt tolerance in a positive or negative way. However, the role of Populus trichocarpa expansin A6 (PtEXPA6) in salt tolerance and the relevance to cell wall loosening is still unclear in poplars. PtEXPA6 gene was transferred into the hybrid species, Populus alba × P. tremula var. glandulosa (84K) and Populus tremula × P. alba INRA '717-1B4' (717-1B4). Under salt stress, the stem growth, gas exchange, chlorophyll fluorescence, activity and transcription of antioxidant enzymes, Na+ content, and Na+ flux of root xylem and petiole vascular bundle were investigated in wild-type and transgenic poplars. The correlation analysis and principal component analysis (PCA) were used to analyze the correlations among the characteristics and principal components. Our results show that the transcription of PtEXPA6 was downregulated upon a prolonged duration of salt stress (48 h) after a transient increase induced by NaCl (100 mM). The PtEXPA6-transgenic poplars of 84K and 717-1B4 showed a greater reduction (42-65%) in stem height and diameter growth after 15 days of NaCl treatment compared with wild-type (WT) poplars (11-41%). The Na+ accumulation in roots, stems, and leaves was 14-83% higher in the transgenic lines than in the WT. The Na+ buildup in the transgenic poplars affects photosynthesis; the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); and the transcription of PODa2, SOD [Cu-Zn], and CAT1. Transient flux kinetics showed that the Na+ efflux of root xylem and leaf petiole vascular bundle were 1.9-3.5-fold greater in the PtEXPA6-transgenic poplars than in the WT poplars. PtEXPA6 overexpression increased root contractility and extensibility by 33% and 32%, indicating that PtEXPA6 increased the CW loosening in the transgenic poplars of 84K and 717-1B4. Noteworthily, the PtEXPA6-promoted CW loosening was shown to facilitate Na+ efflux of root xylem and petiole vascular bundle in the transgenic poplars. We conclude that the overexpression of PtEXPA6 leads to CW loosening that facilitates the radial translocation of Na+ into the root xylem and the subsequent Na+ translocation from roots to leaves, resulting in an excessive Na+ accumulation and consequently, reducing salt tolerance in transgenic poplars. Therefore, the downregulation of PtEXPA6 in NaCl-treated Populus trichocarpa favors the maintenance of ionic and reactive oxygen species (ROS) homeostasis under long-term salt stress.

Фенотипическая оценка клонов плюсовых деревьев сосны обыкновенной (Pinus sylvestris L.) в лесостепной зоне Башкирского Предуралья

An assessment of the main morphometric features of the ramets of clones of Scots pine plus trees in a comparative aspect has been carried out. The vegetative progeny of plus trees of the species are represented as part of a clonal plantation created in 2005 in the Dyurtyulinskiy forestry of the forest-steppe zone of the Republic of Bashkortostan in an area with the С2 type of forest growing conditions. Compliance with the breeding and genetic principle of phenotypic assessment of intraand intergroup differences in Scots pine clones and ramets, as well as methodical and methodological requirements for conducting the field stage of the study, has been ensured. Taxation indicators (the height and diameter of the stem, the diameter and length of the crown, the increment of the central shoot in height) have been taken into account for 100 clones at a continuous count. A varying nature of the distribution of the average values of the analyzed stem indicators in the vegetative progeny of plus trees has been revealed. The best growth in stem diameter (25.5±0.73 cm) and height (11.2±0.16 m), as well as central shoot increment (0.45±0.02 m), are typical for the progeny of clones of the plus tree 29/17. Clones 263/40, 264/41, 262/39 with taxation indicators above the average for the entire set of trees in the clone archive are of high breeding value, which indicates the specificity of the genotypes of these specimens. The levels of significance of the differences and the intensity of selection of the best clones of plus trees based on morphometric features have been determined, which indicates the different nature of the individual non-identity of each of the plus trees relative to the rest of the trees studied. The valuable genotypes of the progeny of Scots pine plus trees identified in the clone archive can be recommended for further use in forest seed breeding when creating highly productive and sustainable artificial plantations of this valuable tree species in the region.

Kangkung microgreen growth analysis under T5 LED lighting using solar PV

Abstract The T5 LED lamp is one form of LED light that can be utilized for indoor microgreen growing. The T5 LED lamp has various advantages, such as great energy efficiency and a long lifespan, and they do not emit excessive heat. This research intends to analyze the growth rate of kangkung (Ipomoea reptans poir) utilizing a T5 LED lamp as the light source. The research was carried out through an experimental design. Kangkung microgreen plants were placed under a T5 LED lamp, positioned 50 cm below the lamp’s surface, and connected to the voltage output supply from solar PV. The results showed that the average value of root growth rate was 26% per day, stem length growth rate was 26% per day, leaf width growth rate was 3.74% per day, leaf length growth rate was 23% per day, petiole length growth rate was 29% per day, the stem diameter growth rate is 4% per day, and the wet weight growth rate is 1.42% per day.

Alnus glutinosa (Alder) sapling as a phytoremediator for cadmium in contaminated soil of industrial park

Heavy metals can contaminate soil through human activities such as mining, waste disposal, excessive use of chemical fertilizers, and fossil fuels. In Iran, uncontrolled urban growth and lack of waste collection systems have led agricultural lands to become receptors of urban and industrial waste, resulting in the contamination of soil with cadmium, which has negative consequences for the environment and health. Alder sapling may have considerable potential for phytoremediation. The soil was placed in plastic pots of 40 cm in diameter with 7 kg air-dried weight soil per pot, spiked with solutions of cadmium chloride [Cd Cl2.H2O] at rates of 0 (control), 50, 100, 150, and 200 mg/kg in a solution. The analyzed data revealed a significant reduction in vegetative growth (plant height, leaf area, chlorophyll, stem diameter growth, stem dry weight, root dry weight, and leaves dry weight). The means were compared to assess the impact of cadmium accumulation on certain biochemical and physiological characteristics. The mean separation was performed using Duncan's Multiple Range test with a p-value ≤0.05. However, there was a simultaneous significant increase in enzymatic activities (peroxidase and catalase) and an increase in proline compared to control plants. The bioconcentration factor of stem, leaves, and roots was under one. The translocation factor (TF) of cadmium was more than 1, and cadmium contents were more localized in roots compared to leaves and stems, minimizing the risk of contamination through leaves. Alnus glutinosa has defense mechanisms against cadmium up to 19.5 mg/kg soil, as the tolerance index for roots and biomass is more than 0.8. Finally, it is a good candidate for research on phytoremediation and phytoextraction.

Brazil nut tree increases photosynthetic activity and stem diameter growth after thinning

Brazil nut tree increases photosynthetic activity and stem diameter growth after thinning

Appropriate Water and Nitrogen Regulation Improves the Production of Wolfberry (Lycium barbarum L.)

Wolfberry (Lycium barbarum L.) production in arid and semi-arid areas is drastically affected by the low utilization rate of soil and water resources and the irrational application of water and nitrogen fertilizers. Thus, this study explored a high-yielding, high-quality, and efficient irrigation and nitrogen regulation model to promote the production efficiency of wolfberry and rational utilization of water and land resources in arid and semi-arid areas. We compared and analyzed the effects of different soil water treatments (the upper and lower limits of soil water were estimated as the percentage of soil water content to field water capacity (θf), with the following irrigation regimen: adequate irrigation (W0, 75–85% θf), mild water deficit (W1, 65–75% θf), moderate water deficit (W2, 55–65% θf), and severe water deficit (W3, 45–55% θf)) and nitrogen levels (no nitrogen (N0, 0 kg·ha−1), low nitrogen (N1, 150 kg·ha−1), moderate nitrogen (N2, 300 kg·ha−1), and high nitrogen (N3, 450 kg·ha−1)) on the growth, physiology, and production of wolfberry. The results showed that water regulation, nitrogen application level, and their interaction significantly affected plant height and stem diameter growth amount (p < 0.05). Additionally, the relative chlorophyll content of wolfberry leaves first increased and then decreased with increasing nitrogen levels and water deficit. The average net photosynthetic rate (Pn), stomatal conductance (gs), intercellular carbon dioxide concentration, and transpiration rate (Tr) reached the highest values in plants exposed to W0N2 (19.86 μmmol·m−2·s−1), W1N1 (182.65 mmol·m−2·s−1), W2N2 (218.86 μmol·mol−1), and W0N2 (6.44 mmol·m−2·s−1) treatments, respectively. Pn, gs, and Tr were highly correlated with photosynthetically active radiation and water vapor pressure difference (goodness-of-fit: 0.366–0.828). Furthermore, water regulation and nitrogen levels exhibited significant effects on the yield and water- (WUE), and nitrogen-use efficiency (NUE) (p < 0.01), and their interactions exhibited significant effects on the yield, WUE, and nitrogen partial productivity of wolfberry plants (p < 0.05). Moreover, the contents of total sugar, polysaccharides, fats, amino acids, and proteins were the highest in W1N2, W1N2, W1N2, W2N3, and W0N2 treatments, respectively, which were increased by 3.32–16.93%, 7.49–54.72%, 6.5–45.89%, 11.12–86.16%, and 7.15–71.67%, respectively. Under different water regulations (except for the W3 condition) and nitrogen level treatments, the net income and input–output ratio of wolfberry were in the order W1 > W0 > W2 > W3 and N2 > N3 > N1 > N0. The TOPSIS method also revealed that the yield, quality, WUE, NUE, and economic benefits of wolfberry improved under the W1N2 treatment, suggesting that WIN2 might be the most suitable irrigation and nitrogen regulation model for wolfberry production in regions with scarce land and water resources such as the Gansu Province and areas with similar climate.

Pengaruh Pemupukan Nano Zinc dan Vitamin B1 terhadap Pertumbuhan Tanaman Alpukat YM (Persea americana) Menggunakan Sistem Irigasi Tetes

The avocado plants had various types and were favored by the Indonesian community. This was one of the reasons for the increased production. One type of avocado in Indonesia is the YM avocado from Lebak. The research aimed to enhance the growth of YM avocado plants by applying nano zinc fertilizer and vitamin B1. This research was carried out in May-August. It was an experimental study with a randomized block design with two factors. It employed Analysis of Variance (ANOVA) and post hoc tests using the Duncan Multiple Range Test (DMRT) at 5%. The first factor was Vitamin B1 (V) (15 mg/l, 30 mg/l, and 45 mg/l), the second factor was nano zinc fertilizer (Z) (2 ml/l, four ml/l, and six ml/l) and repeated three times, so there were 27 plants. Growth parameters observed included plant height, stem diameter, leaf length, leaf width, length-to-width ratio, leaf count, and leaf greenness index. The 45 mg/l dosages of vitamin B1 showed the best influence on planted growth, resulting in a height increase of 54.83 cm, a leaf length of 11.53 cm, a leaf length-to-width ratio of 2.57 cm, and a leaf greenness index of 50.11 units. The broadest leaf expansion occurred at the 15 mg/l dosage, reaching 5.44 cm. On the other hand, nano zinc fertilizer positively impacted stem diameter growth, especially with the optimal dosage of 6 ml/l, increasing from 8.50 mm. Combining nanozinc fertilizer and vitamin B1 supports plant growth by providing essential micronutrients and accelerating vegetative growth. However, vitamin B1 and nano zinc fertilizer do not exhibit a positive interaction in promoting the development of YM avocado plants.

Potential of Albizia zygia and Albizia lebbeck leafy biomasses as organic soil amendments on the growth and yield of okra, Abelmoschus esculentus (L.) Moench

In the array to assess the suitability of using amendments from nitrogen fixing trees in agroforestry, the response of okra to Albizia lebbeck and Albizia zygia leafy biomasses as soil amendments were investigated at the Faculty of Renewable Natural Resources Demonstration Farm in the Kwame Nkrumah University of Science and Technology, Kumasi-Ghana. The objective of this study was to assess the effect of different levels of A. lebbeck and A. zygia leafy biomasses on the growth and yield of okra in a randomized complete block design. Four treatments were used and allocated as T1 (Control, no biomass), T2 (0.2454 kg of A. lebbeck leafy biomass per 2.7 m2), T3 (0.2932 kg of A. zygia leafy biomass per 2.7 m2), T4 (0.2127 kg of A. lebbeck leafy biomass + 0.1466 kg of A. zygia leafy biomass per 2.7 m2. The treatments were replicated four times. Growth in height, stem diameter, fruit yield and fruit dry weight were the parameters investigated on. The application of A. lebbeck and A. zygia leafy biomasses as soil amendment significantly improve the growth (height and stem diameter) and yield (fruit yield and fruit dry weight) of okra compared to the control treatment during the twelve weeks period of the experiment (p˂0.05). Therefore, A. lebbeck and A. zygia leafy biomass amendments are recommended for use by okra farmers, as it has great prospects for use in soil fertility improvement.

Variability and correlationship of agronomic characteristics of unproducing arabica coffee of Sumatra Island

Indonesia is the main producer of robusta coffee, while the coffee world wants Arabica coffee. The study was conducted in the lowlands at an altitude of 10 meters above sea level using a randomized block design. The treatment was 9 varieties of Sumatran Arabica coffee with three replications. The results showed that the growth of plant height and stem diameter of Arabica coffee in the lowlands was normal. The characteristics of internode length and primary branch length have narrow variability, the characteristics of plant height, stem diameter and length of stem segments have moderate variability, and characteristics of the number of pairs of leaves and canopy area have wide variability. Arabica coffee from Sumatra Island shows a close relationship to coffee from Nangroe Aceh Darusalam and North Sumatra and quite far from coffee from South Sumatra. The growth of Arabica coffee is normal. The number of pairs of leaves and canopy area can be used as selection criteria. The relationship between arabica coffee from Nangroe Aceh Darussalam and North Sumatra is quite close, whereas the coffee from South Sumatra it is quite distant. Germplasm from Sumatra under study needs to be added from other coffee-producing regions.

Trocas gasosas e crescimento de algodoeiro colorido sob estresse salino e aplicação de ácido salicilico

ABSTRACT The occurrence of water sources with high salt content stands out as a limiting factor for the expansion of irrigated agriculture in the semi-arid region. In this context, it is essential to look for strategies to mitigate the effects of salt stress, and the application of salicylic acid stands out. The objective of this study was to evaluate gas exchange and growth of the naturally colored cotton cv. BRS Jade under saline water irrigation and foliar application of salicylic acid under semi-arid conditions. The experiment was carried out in containers adapted as drainage lysimeters, under open air conditions at the Center of Science and Agri-Food Technology of the Federal University of Campina Grande in Pombal, Paraíba, Brazil. A randomized block design was adopted, in a 5 × 5 factorial scheme, with treatments resulting from the combination of five levels of electrical conductivity of irrigation water - ECw (0.3, 1.8, 3.3, 4.8, and 6.3 dS m-1) associated with five concentrations of salicylic acid - SA (0, 1.5, 3.0, 4.5, and 6.0 mM), with three replicates. Water salinity from 0.3 dS m-1 limited the photosynthetic efficiency and therefore the growth of cotton cv. BRS Jade. Foliar application of SA at concentration of 6.0 mM mitigated the effects of salt stress on the stomatal conductance and leaf transpiration of these plants. However, SA concentrations ranging from 0 to 6.0 mM reduce the internal CO2 concentration, growth in stem diameter and plant height, and root and stem dry mass accumulation of cotton plants cv. BRS Jade.

Effect of planting time and seedling feeding area on the yield and biochemical composition of leek (Allium porrum L.)

In the article, the results of the research carried out in order to study the effect of planting time and feeding area on the biochemical composition of leek (Allium porrum L.) are presented with an in-depth scientific analysis. Planting was done by hand in 4x1 cm rows in 7x40x60 cm boxes in the greenhouse on February 20, March 10, and April 1. Seedlings appeared after 10-12 days, on May 1 they were transplanted to open ground. This ensured that the seedlings were 70, 50, and 30 days old. Planting in open ground was carried out in a scheme of 50x10 cm. Harvesting took place on September 1-5. At the end of the research, the data analysis shows that by evaluating the nature of growth of false stem diameter in leek onion plants at different planting periods during the growing season, it can be noted that the feeding area for seedlings is larger and the seedlings when planted early, standard products had earlier maturity and higher product quality.

Effects of Rubber Factory Wastewater Sludge Compost on the Growth Parameters of Rubber Seedlings: A Nursery Study and Environmental Perspective

Conducted at the University of Jambi's Teaching and Research Farm in Mendalo Indah Village, this three-month study from September to November 2022 utilized a Completely Randomized Design (CRD) with a single variable: rubber factory wastewater sludge compost application. Five treatment levels were tested: a0 = 25 g NPKMg dose, a1 = 100 g rubber factory wastewater sludge compost + 20 g NPKMg dose, a2 = 200 g rubber factory wastewater sludge compost + 15 g NPKMg dose, a3 = 300 g rubber factory wastewater sludge compost + 10 g NPKMg dose, and a4 = 400 g rubber factory wastewater sludge compost + 5 g NPKMg dose. Statistical analysis, employing ANOVA and the Honestly Significant Difference (HSD) test, determined treatment effects at a 5% significance level. The study assessed various rubber plant growth parameters, such as live seedling percentage, shoot emergence, budded shoot height, leaf count, stem diameter, root count, shoot and root dry weight. Notably, the application of 400 g of rubber factory wastewater sludge compost significantly influenced plant growth, specifically enhancing shoot emergence, stem diameter growth, and budded shoot height.

KONSENTRASI DAN FREKUENSI PEMBERIAN PUPUK MAJEMUK BERTEKNOLOGI NANO UNTUK MENINGKATKAN PERTUMBUHAN DAN HASIL PANEN TANAMAN OKRA (Abelmoschus esculentus)

Okra (Abelmoschus esculentus) is a tropical vegetable with numerous benefits that can adapt to tropical climates. Meeting the demand for okra requires a technological package to enhance its crop yield. One approach to improving okra yield involves the use of economically efficient nano-technology compound fertilizers, which enhance nutrient absorption by plants through direct nutrient release absorbed by the plant roots. This research aims to investigate the interaction between the concentration and frequency of nano-technology compound fertilizer application on the growth and yield of red okra (Abelmoschus esculentus). The study employs a two-factor randomized block design. The first factor involves different concentrations of nano-technology compound fertilizer with four treatments: P1: 2 ml/L, P2: 4 ml/L, P3: 6 ml/L, and P4: 8 ml/L. The second factor pertains to the frequency of nano-technology compound fertilizer application with three treatments: S1: Irrigation once a week, S2: Irrigation twice a week, and S3: Irrigation thrice a week. Each treatment consists of three replications. Observational variables include plant height, leaf count, stem diameter, flower count, fruit count, fruit diameter, fruit length, and fruit weight. The results of this research: application of nano-technology compound fertilizer at a concentration of 2 ml/L with a frequency of thrice a week significantly promotes the growth in plant height and stem diameter of okra. Furthermore, the application of nano-technology compound fertilizer at a concentration of 6 ml/L with a frequency of thrice a week significantly influences fruit diameter, fruit length, and fruit weight in okra plants.

Tree height and stem growth dynamics in a Scots pine dominated boreal forest

Tree growth is a key forest ecosystem service and essential for carbon sequestration and biomass production. However, the intra-seasonal dynamics of tree height and stem diameter growth have been difficult to measure hampering the understanding of the interplay between these processes. Here, we investigated the feasibility of a laser scanning system in monitoring tree height development, aiming to study how tree height and stem diameter growth dynamics vary and interact, and how environmental variables explain the tree growth dynamics within a growing season. The experimental design consisted of 40 boreal trees equipped with dendrometers measuring changes in the stem diameter at 15-minutes intervals while a laser scanner fixed to a 35-meter tower was used to measure tree height near-daily during the monitoring period from May to mid-August 2021. We found that vertical changes in the tree-segmented point clouds enabled monitoring of tree height increment and investigation of the temporal dynamics of changes in tree height and stem diameter, when coupled with dendrometer measurements. The experiments revealed that, on average, height increment occurred ahead of diameter increment and deviated more towards the late season. Norway spruce showed more delayed diameter increment than Scots pine during the late season. Silver birch experienced diameter increment ahead of height increment. Based on the dendrometer measurements, we computed a radial change response function that aimed at characterizing the current state of stem diameter development, whether it was increasing or decreasing from its past state. When these radial change responses were compared against environmental variables, we found that the radial change response was mostly controlled by balance between precipitation and evapotranspiration, soil water content, minimum daily temperature, and vapor pressure deficit. Our findings support the utilization of laser scanning time series for measuring intra-seasonal changes in tree height and increase our understanding of the interactions between tree height and stem diameter growth processes.

Сибсовое потомство карельской березы на Заонежской лесосеменной плантации

The article reports the results of studies on the growth and development of curly birch sibs progeny (produced through controlled pollination) aged 35 and 15 years growing in the Zaonezhye forest seed orchard (sites 1 and 2, respectively) in south-eastern Karelia, Medvezhyegorsky District. The number of trees with signs of wood figure in the seed progeny of curly birch in site 1 was 67 % by the age of 20 years, and by the age of 35 years – almost 80 %. This can probably be attributed to the genetic characteristics of the parent (plus) trees on one hand and to the favorable conditions in the forest seed orchard during the first years of the sibs progeny development on the other. Four of the 36 hybrid families (selected to include forward- and backcrossing products) were used for the case study of the growth and development patterns in stands of different age. The sibs progeny of these hybrid families was dominated by high-stemmed plants, but the main trunk shape in the 15-year-old stand was one with necks and muffs, while in the 35-year-old stand – with small protuberances. The rate of height growth in the trees decreased notably with age, whereas radial (stem diameter) growth, on the contrary, accelerated. As the bark grew thicker, however, the formerly bulgy surface “smoothed down”. We have also identified specific features of the ground vegetation formed under the effect of curly birch plantations of different age (15- and 35 years old). A conclusion drawn from the study is that good results from targeted cultivation of curly birch with figured grain (e.g., for sliced veneer) can be achieved already by the age of 20–35 years. Furthermore, considering the number of trees and their origin, this forest seed orchard constitutes an essential part of the valuable gene pool of curly birch, which may turn into a source for expanded reproduction of the resources of this unique member of the European forest tree flora. For citation: Vetchinnikova L.V., Titov A.F., Kostina E.E., Zhigunov A.V. Sibs Progeny of Curly Birch at the Zaonezhye Forest Seed Orchard. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 5, pp. 9–26. (In Russ.). https://doi.org/10.37482/0536-1036-2023-5-9-26

Pengaruh Aplikasi Kompos Tandan Kosong Kelapa Sawit (Elaeis guineensis Jacq) Terhadap Pertumbuhan Vegetatif Bibit di Main Nursery

This research was carried out in the practice garden and Laboratory of the Indonesian Palm Oil Institute (ITSI) Medan. It will be carried out from March to June 2022 to get the growth and development of oil palm seedlings by applying empty palm fruit bunch compost as the use of organic fertilizer during the nursery period. This study used a Non-Factorial Randomized Block Design (RBD) with one factor studied, namely variations in the application of compost to oil palm seedlings. Parameters observed were plant height, stem diameter, number of leaves, root length, root volume, root fresh weight, shoot wet weight, root dry weight, shoot dry weight. The data obtained was analyzed statistically by Analysis Of Variance (ANOVA). Based on the results of observations and analysis of variance, it was shown that the application of empty palm fruit bunch compost had a significant effect on shoot wet weight and had a significant effect on shoot dry weight and had a significant effect on stem diameter growth at 16 WAP observations, and had no significant effect on plant height, number leaves, root length, root volume, root wet weight, root dry weight.

Thinning on the Growth of Red Jabon Trees (Anthocephallus Macrophyllus) in the Industrial Plantation Forest Area

This study aims to observe the growth of red jabon (Anthocephalus macrophyllus) plants at various thinning intensities. Red jabon is a native Indonesian plant species that have the potential to develop forest plantations and reforestation ex-mining land. The research measured stem diameter and plant height at each thinning intensity. The study results are expected to provide information on the potential of red jabon cultivation and become a recommendation for red jabon wood farmers to improve the quality of company and farmer income. This research is expected to contribute to the development of thinning activities in improving the quality of red jabon tree stands, as well as providing a better understanding of this plant's cultivation and potential benefits. The thinning intensity applied 6 months the growth of Red Jabon trees in the Industrial Plantation Forest Area of PT. Global Citra Lestari showed a significant effect on stem diameter increment, 40% intensity treatment has a promising potential to enhance both stem diameter and height growth.

Wood density and leaf traits independently relate to growth rate of naturally regenerated tree species in Araucaria angustifolia plantations in the Atlantic Forest, Argentina

Tree plantations can facilitate the establishment of native trees, thus providing opportunities for the ecological restoration or rehabilitation of degraded forest lands. Stand variables can influence the establishment of native tree species, but few studies have been carried out to determine how sapling growth response to stand variables varies among functionally different species. We evaluated the effect of stand age, stand basal area, tree density, and time since last logging on stem diameter growth rates, as well as the dependence of such effect on whole plant, stem, and leaf functional traits. We measured the stem diameter increment on 280 individuals of 22 species in permanent plots for a period of 2 years in araucaria ( Araucaria angustifolia (Bertol.) Kuntze) plantations in the Atlantic Forest, NE Argentina. Increasing all-species basal area and plantation age negatively affected the growth rates, and such effect tended to be higher in species with low wood density. Two functional axes independently explained growth rate differences between species in growth rate. Growth rates increase with decreasing wood density, increasing leaf phosphorus and potassium content, and decreasing specific leaf area. Among species that are similar in the traits associated with the first functional axis, plant growth increases with increasing leaf nitrogen content.