Revista Árvore

Implications of using shading meshes and plant density on the leaf anatomy of Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson seedlings

Claiton Nardini — 2025-02-06

Shading meshes are important techniques used during seedling cultivation. However, improper use can lead to excessive shading, which may be intensified by the distribution of seedlings in the tray, directly affecting their growth and development. This study aimed to assess the effect of using colored shading meshes combined with different plant densities on the leaf anatomy and seedling quality of Corymbia citriodora (Hook.) K.D. Hill and L.A.S. Johnson. The experiment was conducted in a protected environment at the Federal University of Santa Maria/Frederico Westphalen campus, from May to September 2018. A completely randomized experimental design was used, in a 2 x 3 factorial scheme with two seedling densities, two shading meshes, and no mesh. The assessed densities consisted of 736 seedlings per m² (high density) and 528 seedlings per m² (medium density). The shading meshes used were in the red and blue colors, and there was a meshless (full sun) treatment as well. Assessments were conducted when seedlings reached 25 cm in height, with the following variables being analyzed: stomatal count, cuticle thickness, adaxial and abaxial epidermis thickness, spongy and palisade parenchyma thickness, as well as seedling quality through the Dickson Quality Index. The use of meshes in different colors and the plant densities altered the anatomical characteristics of Corymbia citriodora, such as cuticle and adaxial epidermis thickness, abaxial epidermis, palisade parenchyma, and leaf thickness. However, these anatomical changes observed in seedlings under different meshes do not necessarily indicate better seedling quality.

Keywords: Seedling quality, Stomata, Solar radiation

Survival and initial growth of seedlings produced in different containers and the use of mulching in anthropized area

Thairini Claudino Zavistanovicz — 2024-12-24

The demand for seedlings of native tree species for the restoration of altered areas has increased considerably. Therefore, knowing the strategies that favor quality seedling production in the nursery, in addition to survival, growth, and development in the field, is important. This study was to evaluate the survival and initial growth of Inga vera Will and Schinus terebinthifolius Raddi, after 24 months of planting, seedlings in an anthropized area. The experiment was conducted using a factorial scheme (2 × 2), considering the types of containers used in the production of seedlings and the presence or absence of mulching in the surroundings. The survival of the seedlings, as well as their morphophysiological attributes, was verified 24 months after planting. I. vera presented a higher average survival for seedlings grown in plastic bags (86.7%), whereas S. terebinthifolius did not show any difference between treatments. The morphological attributes of increased height (IncH), diameter of the stem (IncSD), crown area (AC), and shoot dry mass (SDM) were favored by the use of plastic bags in seedlings of I. vera. For S. terebinthifolius, the plastic bag favored only IncH, equaling the seedlings produced in containers for the other variables. Using mulching was ineffective in helping the growth of either species, and the physiological attributes were similar for all the treatments tested. Aiming at the high survival and rapid growth of seedlings in the field, it is recommended to produce I. vera in 1.5 L plastic bags, while S. terebinthifolius seedlings can be produced in 180 cm³ containers. Therefore, using mulching as a culture treatment for both species should be investigated in future studies.

Keywords: Inga vera; Schinus terebinthifolius; Morphophysiological attributes; Extreme south of the Atlantic Forest biome

Effect of wastewater and phosphate fertilization on photosynthetic pigments and macronutrients of Moringa oleifera Lam.

Armando Rodrigues de Melo — 2025-02-06

The use of unconventional resources, such as treated domestic wastewater, has proven to be a promising alternative for agricultural irrigation in semi-arid regions, contributing to water sustainability. This study evaluated the effects of fertigation with wastewater and phosphate fertilization on photosynthetic pigments (chlorophyll A, chlorophyll B and carotenoids) and the concentration of macronutrients (N, P and K) in leaves of Moringa oleifera Lam. The experiment was conducted in a greenhouse at the Professor Ignácio Salcedo Experimental Station of the National Institute of Semiarid (INSA), in Campina Grande-PB, in a haplic PLANOSOL soil. The experimental design was in randomized blocks, with a 5 x 2 factorial scheme (five concentrations of wastewater and two levels of phosphate fertilization), totaling 10 treatments. Irrigation was performed manually, and the drained volume was collected to calculate evapotranspiration. At 90 days, the levels of chlorophyll A, B and carotenoids did not differ significantly between the treatments with wastewater, but phosphate fertilization increased the levels of N and P in the plant. Wastewater, applied at up to 75%, increased the N level and, at 100%, increased P and K. It is concluded that wastewater, with adequate management, is viable for Moringa cultivation, but caution is required due to possible chemical interactions and content proportions in the soil.

Keywords: Irrigation efficiency; Water reuse; Fertigation; Chlorophylls; Sustainability

Effect of free and nanoencapsulated nitric oxide donor on the response of tree plants during the hardening off process

Hugo Roldi Guariz — 2024-12-24

Nitric oxide (NO) plays a crucial role as a signaling molecule in several biological processes in plants, participating in the response to different types of environmental stresses. The technique of nanoencapsulation of NO donors appears as a promising approach to expand and enable the exogenous application of NO nitric oxide in environmental restoration programs. Therefore, this study aimed to verify the effect of using a NO donor, in free and encapsulated form, on the hardening off of seedlings of three tree species: Hymenaea courbaril L., Amburana cearensis (Allemão) A.C. Smith, and Hymenaea stigonocarpa Mart. ex Hayne. The seedlings were grown for 3 months under moderate shade and translocated to the hardening off sector, where they remained for 3 months under the treatments: chitosan nanoparticles containing S-nitrosoglutathione (NP-CS-GSNO) at concentrations of 0.025, 0.5, 0.1, and 0.2 mM, free S-nitrosoglutathione, at concentrations of 0.1 and 0.2 mM, or the Control. For H. stigonocarpa, treatments with free or nanoencapsulated GSNO did not differ from each other, differing only from the Control. H. courbaril presented similar behavior in relation to growth variables, however, in the analysis of physiological variables, only the NP-CS-GSNO 0.1 and 0.2 mM treatments differed from the other treatments. A. cearensis maintained similar behavior to H. courbaril, with only a difference in the Control treatment in relation to the other treatments. These results indicate that GSNO presents beneficial physiological effects when made available to native forest species, such as H. stigonocarpa, H. courbaril, and A. cearensis, triggering protective and incremental activities regarding photosynthesis, stomatal conductance, and biomass formation.

Keywords: Nanotechnology; Environmental stress; Acclimation

Anatomy as a tool to understand the causes of seed failure: a study of crosses Eucalyptus species

Genaina Aparecida de Souza — 2025-04-14

Seminal propagation of eucalypt plays a crucial role in breeding programs, serving internal consumption and commercial applications. This study aimed to develop a method for examining anatomical changes in seeds obtained from Eucalyptus crosses to elucidate the causes of seed viability loss and low seed production observed in certain mating pairs. Flower buds/fruits were collected from four different genetic materials (E. grandis, E. urophylla, E. urophylla × E. grandis, and self- pollinated E. urophylla). Crosses classified as good or poor seed producers were sampled at 15-day intervals from anthesis to maturity. After collection, samples were fixed in FAA₅₀ solution (1:1:18 v/v formaldehyde, acetic acid, and 50% ethanol) and stored in 70% ethanol. Subsequently, the samples were subjected to six different preparation methods, involving standard procedures, combinations of high and/or low temperatures, seed softening substances, and vacuum treatment. Flower buds producing unformed seeds exhibited a functional ovary with reduced locules and increased lignification. Aditionally, unformed seeds were covered by thick integuments and displayed abnormal endosperm cells. In cases where the developing ovary was visible, highly lignified tissues with numerous sclereids were observed. By contrast, flower buds with lower lignification had ovaries with well-developed locules, containing seeds with a normal appearance, characterized by a single-layered integument and well-delimited nucleated endosperm cells. Also, self-pollinated materials produced a few seeds, some of which were unformed. Thus, we conclude that anatomical alterations, likely influenced by genetic factors, lead to incompatibility, resulting in limited seed production or the production of unformed seeds in certain Eucalyptus crosses.

Keywords: Seed viability; Anatomical analysis; Controlled crosses

Adsorption of 2,4- dichlorophenoxyacetic acid (2,4-d) herbicide on activated carbon of Brazil nut shell

Pryscila Machado de Castro — 2024-12-24

Activated carbon is a material with a high fixed carbon content and large surface area, whose capacity for adsorbing organic compounds depends on the precursor material and the process it undergoes. 2,4-D is a molecule associated with numerous health hazards and is widely used in Brazil for weed control. In rural areas, its use can lead to contamination of surface and groundwater. This study aimed to evaluate the adsorption potential of 2,4-dichlorophenoxyacetic acid (2,4-D) using carbon derived from Brazil nut shell activated at 800 °C, comparing activation atmospheres of water steam and CO₂. Activated carbons, both with water steam and CO₂, were characterized in terms of pore diameter distribution using the Brunauer–Emmett–Teller (BET) theory, morphology by scanning electron microscopy (SEM), and thermal stability by thermogravimetric analysis (TGA). The activated carbons with steam and CO₂ presented high surface areas (397 ± 8 m²/g and 325 ± 7 m²/g, respectively). The micrographs showed high porosity in the activated carbons, and the loss of only 20% of their mass in the thermogravimetric test confirmed the material’s thermal stability. The adsorption kinetics assay was performed by High-Performance Liquid Chromatography (HPLC) over time ranging from 0 to 120 minutes. The equilibrium time was 45 minutes for water steam-activated carbon, achieving 92.51% removal, and 120 minutes for CO₂-activated carbon with 84.81% of 2,4-D removed. The pseudo-second-order kinetic model best fit the data.

Keywords: Adsorption, Herbicide, Potability

A Correlation between the kappa number and the Ventorim index in the bleaching process

Vitor Hideyoshi Hayashida Ribeiro — 2025-02-06

The determination of the kappa number in the bleaching process is typically conducted with a pulp quantity between 3 and 4 grams, allowing for the calculation of values above four. However, after the oxidative extraction stage with hydrogen peroxide, the pulp presents a kappa number lower than this value. Therefore, the present study proposes a new method for determining the kappa number by creating the Ventorim bleaching index, which avoids the inconveniences associated with traditional kappa number analysis. For this study, industrial oxygen-delignified pulp was used. Four different ECF bleaching sequences were performed: OD(E+P)DD, OAD(E+P)DP, OADEDP, and OAEDP, along with the determination of the kappa number and the Ventorim bleaching index. The Ventorim index was based on the four chlorine-free bleaching sequences (ECF), all of which achieved a final brightness of 90% ISO, with very similar R² values and linear regressions. Consequently, a single equation was generated using all the data: Y=0.7202x+0.1464. This unified approach simplifies the analysis and broadens the applicability of the Ventorim bleaching index in the pulp and paper industry.

Keywords: Bleaching; Kappa number; Ventorim bleaching index

Fiber quality indices of Corymbia spp. and Eucalyptus spp. wood for the selection of genetic materials for pulp production

Wagner Patrício de Sousa Júnior — 2024-12-26

The selection of genetic materials for obtaining cellulosic pulp and paper production necessitates evidence of efficiency in terms of silvicultural performance and industrial processing. In this context, this study aimed to select genetic materials from Eucalyptus spp. and Corymbia spp. for pulp production. The selection was achieved through cluster analysis, based on the morphological traits of the main anatomical elements of the wood, the screened brown pulp yield, and fiber quality indices (Runkel ratio, slenderness ratio, Mulsteph coefficient, and flexibility coefficient). Sixteen genetic materials were evaluated, each represented by three trees of average diameter, collected at 81 months of age with a planting spacing of 6x1.5 m, from plantations located in the municipality of Itamarandiba - MG, Brazil. Axiovision 4.8 software was used to measure the dimensions of fibers and vessels under an optical microscope. Information regarding the screened pulping yield for these genetic materials was obtained from literature. Three distinct groups of genetic materials emerged from cluster analysis. In group I, hybrids with longer and less flexible fibers (Runkel ratio >1, wall fraction >50%, and flexibility coefficient <50%) predominated, making them more suitable for manufacturing absorbent papers. In contrast, groups II and III comprised genetic materials with higher screened yields (>52.0%), lower wall fractions (<50%), and other fiber quality indices indicating a predominance of more flexible fibers (flexibility coefficient >50% and slenderness ratio >51%). These fibers are primarily more suitable for producing tear- and burst-resistant papers, intended for packaging and bags.

Keywords: Runkel ratio; Mechanical resistance of cellulose pulp; Fiber flexibility

Federal protected areas in Brazil and Italy: A comparative analysis

Ana Carolina da Silva — 2025-03-21

Protected areas (PA) play a crucial role in preserving global biodiversity and ecosystem services. They ensure the protection of endemic species, preserve sensitive environments, and, in some cases, contribute to the livelihoods of local communities. Currently, there are 265,908 protected areas across 245 countries and territories, covering 16.64% of the planet's land and 7.74% of its marine areas. This article compares national legislation on PA in Brazil and Italy, evaluating their alignment with IUCN standards. In Brazil, Law No. 9,985/00, which establishes the National System of Conservation Units (SNUC), regulates protected areas, while in Italy, Law 394/91 guides the classification and management of these areas. The classifications of both countries were analyzed based on the framework established by the International Union for Conservation of Nature (IUCN) and its World Commission on Protected Areas (WCPA). Brazil's nomenclature shows greater similarity to the IUCN standard, although it is not fully adopted, and includes a greater number of classifications than the standard. Italy strictly follows the exact number of categories established by IUCN criteria and has a nomenclature that largely differs from the IUCN standard. Adopting a more standardized nomenclature between countries facilitates international comparisons and promotes a more effective exchange of knowledge on management practices.

Keywords: Environmental legislation; International comparison; Conservation