Eucalyptus Urograndis Research Articles

Artificial neural networks for classifying the productive capacity of a forest stand in the Jari region, western Pará

The growth and production of a forest stand depend on indicators such as the site's productive capacity, which can be defined as the site's potential to produce wood, or another product in each location, for a given species or clone. This study compared traditional methods and artificial neural networks in the classification of the productive capacity of sites in Eucalyptus urograndis plantations located in the Jari region, western Pará state. For this, 593 permanent circular plots of 500 m² each were randomized, where 38,072 trees were monitored annually from 2013 to 2017. In each plot, the diameter at the height of 1.30 from the ground (DBH, in cm) and the total height (Ht, in meters) of nine trees were measured. Three traditional methods were evaluated: guide-curve method (GC), difference equation method (DE), and parameter prediction method (PP). The statistical criteria used to assess the quality of the classification were: BIAS (%), mean squared error (RMSE (%)), and Pearson correlation coefficient (r). Artificial neural networks were superior to traditional methods, indicating the potential of the algorithm to model the productive capacity of a site for forest stands.

EVALUATION OF DIFFERENT COMBATING COMBINATIONS AGAINST LEAF-CUTTING ANTS IN Eucalyptus urograndis PLANTINGS

Leaf-cutting ants, genera Atta and Acromyrmex, are one of the main pests in forestry crops. They can affect forest productivity and increase mortality rates in plantations, making their control essential. Thus, this study aimed to evaluate different treatments for combating leaf-cutting ants and their results on the forest inventory of survival. Six treatments were evaluated in an area of approximately 14.000 hectares of Eucalyptus urograndis (Eucalyptus urophylla S. T. Blake × Eucalyptus grandis W. Hill), namely: 1) control, 2) pre-harvest combat, 3) pre-planting combat, 4) two or more pre-planting combats, 5) pre-harvest and pre-planting combat, and 6) pre-harvest combat with two or more pre-planting combats. The analyzed variables were: planted area (ha), planting survival (%), dead attacked seedlings (%), live attacked seedlings (%), and total attacked seedlings (%). Treatment comparisons were conducted using multivariate analysis of variance and discriminant analysis. Treatments that involved combat against ants only before harvesting or combined with pre-planting showed the best performance among the evaluated treatments. The most efficient treatment was the one that combated the ants before harvesting with just one repetition, resulting in reduced silvicultural costs.

Production of High-Value Green Chemicals via Catalytic Fast Pyrolysis of Eucalyptus urograndis Forest Residues

Lately, pyrolysis has attracted significant attention due to its substantial potential for bio-oil production, with the ability to serve as a renewable energy source and/or facilitate the production of valuable chemical compounds. The chemical compounds generated and their amounts are completely influenced by the traits and chemical makeup of the initial biomass. In this work, the catalytic fast pyrolysis of Eucalyptus urograndis canopy was carried out using a pyrolyzer coupled to gas chromatography/mass spectrometry (Py-GC/MS) at different temperatures and in the presence and absence of catalysts. Elemental composition analysis was employed to characterize the chemical composition of the biomass. The results showed a biomass with a carbon percentage of 50.20%, oxygen of 43.21%, and hydrogen of 6.34%, as well as a lower calorific power of 17.51 MJ/kg. The Py-GC/MS analyses revealed the presence of several noteworthy compounds, including acetic acid (C2H4O2) and, in smaller quantities, hydrogen (H2), furfural (C5H4O2), and levoglucosan (C6H10O5). The technical-economic evaluation revealed that the production of acetic acid, furfural, hydrogen, and levoglucosan commands a high market price. Additionally, a single production cycle is anticipated to yield a favorable technical-economic balance, generating approximately USD 466.10 /ton of processed biomass. This outcome is achieved through the process of catalytic fast pyrolysis, where CuO has been identified as the most suitable catalyst.

Leaf angle, light interception and chlorophyll contents of bean and soybean grown in integrated cropping systems

ABSTRACT This study aimed to evaluate the dynamics of solar radiation and the morphological and physiological responses of bean and soybean plants grown in two integrated cultivation systems and under full sun. Two experiments were conducted in southern Brazil, one with beans (in-season) and the other with soybeans (off-season). The experimental design used was randomised blocks in a bifactorial 2 × 2 arrangement with an additional treatment, characterised by two forest arrangements (6 × 6 m and 12 × 12 m); two forest species (Peltophorum dubium and Eucalyptus urograndis); and full sun, with three repetitions. The transmissivity of solar radiation, intercepted solar radiation, leaf inclination angle, light extinction coefficient (k), and chlorophyll content (a, b, total, and a/b ratio) were measured. The dynamics of solar radiation were modified by the arrangement of trees and the canopy characteristics of the forest species. Shading significantly influenced the levels of chlorophyll a, b, and total chlorophyll, while no variation was observed in the angle of inclination of the leaves. It is recommended to cultivate beans intercropped with the forest species E. urograndis in the 12 × 12 intercropped arrangement, while for soybean cultivation, intercropping with the two forest species studied in the 12 × 12 intercropped arrangement is recommended.

Green Lacewing Chrysoperla externa Is Attracted to Volatile Organic Compounds and Essential Oils Extracted from Eucalyptus urograndis Leaves.

Plant herbivore interactions have long been recognized as a complex interplay influenced by various factors, including plant volatile emissions. Understanding the role of these volatiles in mediating plant predator interactions is crucial for developing sustainable pest management strategies. This study investigated the olfactory preferences of Chrysoperla externa larvae for volatiles emitted by Eucalyptus urograndis leaves, focusing on both seedlings and essential oils (EOs). We used Y-tube olfactometry to compare larval preferences between the clean air and various plant treatments, including undamaged and herbivore-damaged leaves. Chemical analysis of EOs revealed higher concentrations of oxygenated monoterpenes and sesquiterpenes in young and damaged leaves, particularly linalool, which has been implicated in insect attraction. Our results showed a significant preference for volatiles emitted by young damaged leaves over clean air for both seedlings (χ2 = 11.03, p = 0.001) and EOs (χ2 = 9.76, p = 0.002). Chrysoperla externa larvae are significantly attracted to specific volatiles from damaged E. urograndis leaves, suggesting these compounds could serve as cues for natural enemy foraging. Our findings enhance the understanding of plant-predator dynamics and suggest potential applications of eucalyptus plantations to sustain C. externa populations for biocontrol purposes.

Potential of integrated trees-pasture-based systems for GHG emission mitigation and improving soil carbon dynamics in the Atlantic forest biome, Southeastern of Brazil

Brazilian cattle production is mainly carried out in pastures, and mitigating the livestock's greenhouse gas (GHG) emissions has become an essential prerequisite. The importance of planted forests in beef cattle pasture-based integrated systems has been widely recognized in the context of GHG emission mitigation. Adopting the intensification and integration with forest and crops of pasture-based livestock production systems are alternatives to optimizing the soil and tree carbon (C) sequestration; however, research on tropical conditions is still necessary. This long-term trial evaluated the potential of C sequestration (soil + trees) of the forest and the grazing systems with two replicate areas of 3 ha each: 1. continuous stocking rate (CLS) – pasture under continuous stocking; 2. agropastoral or crop-livestock system (AGROP) – pasture under rotational stocking in rotation with corn; 3. agrosilvipastoral or crop-livestock-forestry system (AGROSIL) - similar to AGROP but including eucalyptus; 4. silvipastoral or livestock-forestry system (SIL) - pasture under rotational stocking + eucalyptus and 5. Atlantic Forest (FOR). Soil samples were analysed for texture, C and bulk density in eight soil layers from three to eight trenches for each treatment, then C stock and C accumulation rates were calculated. Data from Eucalyptus urograndis of the SIL and AGROSIL systems with 333 trees. ha−1 during five first years and 166 trees. ha−1 in subsequent years were collected (five- and eight-years old trees) and used to define the wood volume and acquire wood rings. Elemental analyzer CHN performed soil and trees C content. Equations for determining stem volume and tree biomass and, afterward, the C pools of the tree trunks were proposed. The potential of GHG emission mitigation (t CO2 e.. ha−1. year−1) by annual C sequestration (soil or soil + trees) was calculated, including the wood used for the lumber-mill scenario. The participation of the C stock from the 0–30 cm soil layer was between 45 % and 53 % of the total C stock in the 0–100 cm soil layer. Regardless of the elevated C soil accumulation rates, 0.88, 2.54, and 1.74 t C. ha-1. year−1 in the conversion stages CLS → AGROP; AGROP → SIL; AGROP → AGROSIL, respectively, it was not possible to compensate for the negative result of the Forest → CLS conversion (-2.55 t C. ha-1. year−1) because this stage lasted 12 years, while the implementation of AGROSIL and SIL systems had only six years. However, when C tree accumulation rates were considered, the potential of GHG emission mitigation (t CO2 e. ha−1. year−1) by annual C sequestration (soil +trees) was 19.89 to AGROSIL and 18.97 to SIL, including the wood used for the lumber-mill scenario. Based on these results, it can be concluded that C sequestration in trees-pasture integrated systems occurs in layers deeper, with the diverse species contributing in different soil layers; there is a positive effect of improved land-use management, with the use of integrated systems on annual C soil sequestration and the trees consists of an important strategy to improve the GHG mitigation.

First record of Trichogramma pretiosum parasitizing Iridopsis panopla eggs in eucalyptus in Brazil

Abstract Iridopsis panopla Prout (Lepidoptera: Geometridae) is an important lepidopteran defoliator of eucalyptus. I. panopla eggs were collected naturally in a commercial plantation of Eucalyptus urograndis W. Hill (Myrtaceae) in Três Lagoas, Mato Grosso do Sul, Brazil. After nine days, the natural emergence of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) occurred from I. panopla eggs. Parasitism was evaluated under laboratory and field conditions, this being the first record for eucalyptus in Brazil. Based on the biological characteristics evaluated in the laboratory, I. panopla eggs are suitable for T. pretiosum reproduction. The obtained percentage parasitism, particularly when 72,000 adult females of T. pretiosum per hectare were employed, provide valuable insights regarding the potential of T. pretiosum as an effective biological control agent against I. panopla in eucalyptus plantations.

Physiological changes induced by hardening in seedlings of eucalyptus as a function of growth stages

Hardening appears as an interesting strategy to improve the quality of seedlings in forest nurseries, favoring their survival in the field. Thus, the objective of this research was to show the physiological alterations resulting from the application of methyl jasmonate and stem flexion in three stages of growth in Eucalyptus urograndis seedlings. The experiment was carried out in Marechal Cândido Rondon, Paraná, and Eucalyptus urograndis seedlings were used. Treatments consisted of weekly applications of methyl jasmonate (MeJA), daily imposition of stem flexion and a control treatment. Analyzes included quantification of flexural stiffness, lignin content in stems and roots, phenolic compounds in leaves and roots, electrolyte leakage in roots and field survival. In seedlings of Eucalyptus urograndis at 100 days after emergence (DAE) and at the three distances used to evaluate flexural rigidity, the highest averages were observed in seedlings submitted to chemical and mechanical treatments, coinciding with the increase in lignin content in the stem. In the roots, after quantifying the extravasation of electrolytes in Stage I, the means decreased with the application of treatments. In the field phase, there were no statistically significant differences between seedling survival assessments, quantified every 15 days, for a period of 90 days after planting. However, seedlings in Stage I were lost because they were too young and could not tolerate the stressful conditions observed in the field.

Influência de plantações de eucalipto na comunidade de macroinvertebrados bentônicos em nascentes neotropicais

Abstract Aim The high sensitivity of springs to anthropic impacts is largely due to the high existing aquatic-terrestrial connectivity. The degradation of these ecosystems can be caused by land use, such as eucalyptus monoculture. The aim of this study was to test the influence of Eucalyptus urograndis plantations on the richness and diversity of the benthic macroinvertebrate community and on the environmental variables measured in springs in the Atlantic Forest domains. Methods Ten springs (5 in native forest areas and 5 in eucalyptus area) were sampled in the dry period of 2017. The organisms were screened and identified at the family level. For each spring, dissolved oxygen, temperature, pH, turbidity, electrical conductivity, total dissolved solids, total nitrogen, nitrite, nitrate, ammonia, total phosphorus, vegetation cover, granulometric characterization and organic matter were also measured. Results: The t-test showed that some environmental variables differed, with the eucalyptus areas having higher values of total dissolved solids and electrical conductivity, and lower values of coarse sand. In the present study, the richness and diversity of the benthic fauna of springs were significantly lower in eucalyptus sites than in native sites. Nonetheless, the composition of the communities did not differ. The Indicator Species Analysis (IndVal) associated Acari, Hydropsychidae, Leptoceridae, Nematoda, Psychodidae, and Tipulidae with areas of native forest. Conclusions Our results show that Brazilian springs are affected by eucalyptus monocultures reducing the richness and diversity of benthic macroinvertebrates and also changing water environmental properties. Thus, we verified that previous studies elsewhere in the world also apply to neotropical areas where eucalyptus is not native.

Eucalyptus urograndis physiological and hormonal changes under drought conditions in response to trinexapac-ethyl

Previous studies have reported that trinexapac-ethyl (TE) stimulates growth of well-watered (WW) eucalypt plants. However, the physiological and hormonal changes in response to this chemical remain unclear. Furthermore, there are reports that this chemical attenuates drought responses in grasses. This research investigated the hormonal and physiological response of Eucalyptus urograndis (Clone 1407) plants treated with TE, cultivated under WW and drought conditions. The experiment was carried out in a greenhouse up to 42 days after application of 0, 90 and 150 g ha−1 of TE. Eucalypt growth, hormone concentration, gas exchange, maximum quantum yield of photosystem II and total relative chlorophyll content were evaluated. TE increased growth of WW plants by up to 65%. Drought restricted the stimulatory effects of TE on eucalypt growth, despite an increase of at least 102% in gibberellin A4 (GA4), trans-zeatin (tZ) and N6-isopentenyladenine (iP) concentrations after application. GA4 stood out as an indicator of drought stress as it increased almost 6-fold compared to WW eucalypt. TE caused a hormonal imbalance in eucalypt up to 42 days after application, increasing GA1 concentration as a short-term effect (8 days) and GA8 as a medium-term effect (42 days). Gibberellin homeostasis was not reestablished until 42 days after TE treatment. These results provide insights into eucalypt hormonal response to TE. Future research should be conducted under field conditions to understand how long such positive effects would be detected over time in short-rotation eucalypt plantations.

Evaluation of Fungicides as Protective and Curative Treatments against Canker Disease of Eucalyptus urograndis Caused by Chrysoporthe deuterocubensis in Malaysia

Over the years, Eucalyptus plantations have rapidly expanded in Sarawak, Malaysia, accounting for 19% of the total forest plantation area. In a routine forest health surveillance conducted in 2022 at Sarawak, Malaysia, tree stands of Eucalyptus urograndis (Eucalyptus grandis × Eucalyptus urophylla hybrid) were detected with symptoms of stem canker disease caused by Chrysoporthe infection. Given the limited information on the chemical control of Chrysoporthe stem canker disease, there is a growing need to develop effective chemical control strategies to protect and cure Chrysoporthe infection on E. urograndis trees. Therefore, this study aimed to identify the causal pathogen of this stem canker disease in 7-year-old E. urograndis trees in Sarawak, Malaysia, and evaluate the efficacy of various fungicides as curative or protectant treatments on canker infection using artificial inoculation methods. Fungal isolates were first collected and subjected to molecular identification and pathogenicity analysis. Then, in vitro efficacy tests were evaluated using five licensed fungicides: thiram, prochloraz manganese chloride, copper hydroxide, dimethomorph, and mancozeb. Subsequently, the performance of these fungicides was assessed through preventive and curative field experiments on 10-year-old E. urograndis trees using the artificial inoculation technique. Based on the morphological and phylogenetic analysis of the ITS1/ITS4, β-tubulin 2 (BT2), and the combined ITS1/ITS4 and BT2 sequences extracted from 20 fungal isolates, Chrysoporthe deuterocubensis was identified as the causal pathogen of the canker disease, with isolate CHRY18 recording the highest virulence. The in vitro efficacy tests showed that prochloraz manganese chloride achieved 100% inhibition against C. deuterocubensis at 1.0 mg/mL. In the preventive experiment, thiram significantly inhibited C. deuterocubensis infection, yielding the shortest lesion length (19.40 mm) compared to the non-treated control (47.48 mm) at 20 weeks post-inoculation. In the curative experiment, a significant reduction of 54.7% in lesion length was observed in inoculated symptomatic trees after 20 weeks of post-fungicide treatment with copper hydroxide. In conclusion, this study demonstrated prochloraz manganese chloride, thiram, and copper hydroxide as effective chemical controls of C. deuterocubensis stem canker on E. urograndis.

Agronomic and physiological responses of corn intercropped with palisadegrass growing in full sun or in a crop‐livestock‐forestry systems

AbstractThere is a need to enhance agricultural intensification and diversification by establishing alternative crop‐livestock‐forestry systems. Our objective was to compare the production and physiological characteristics of corn (Zea mays L.) either intercropped with Marandu palisadegrass [Brachiaria (syn. Urichloa) brizantha (Hochst. ex A. Rich.) R. D. Webster] growing in full sun (FS), or in a crop‐livestock‐forestry with single‐row (CLFs) and triple‐row (CLFt) groves of Eucalyptus urograndis (hybrid of Eucalyptus grandis W. Hill ex Maiden and Eucalyptus urophylla S. T. Blake). In the CLFs and CLFt, the trees were spaced at 37 m (90 tree ha−1) and 30 m (135 tree ha−1), respectively. The experiment was carried out for 2 years in a randomised complete block with three replications in a strip‐split‐plot arrangement with measurements at 5 sites between groves (7 and 13 m on the south face, central, and 7 and 13 m on the north face). The forage mass for full sun, CLFs, and CLFt was 10.9, 9.5, and 6.2 Mg DM ha−1 in 2017 and 28.9, 21.5, and 14.0 Mg DM ha−1 in 2018, while the grain yield was 3.38, 3.34, and 1.66 Mg DM ha−1 in 2017 and 7.90, 4.66, and 2.55 Mg DM ha−1 in 2018. The forage mass (10.1 Mg DM ha−1 in 2017 and 23.9 Mg DM ha−1 in 2018) and grain yield (3.3 Mg DM ha−1 in 2017 and 5.0 Mg DM ha−1 in 2018) in the central and 13 m north distances were greater than in the 7 m north and south, with less light transmission and red: far‐red ratio. We concluded that corn intercropped with palisadegrass in an integrated crop‐livestock‐forestry system was negatively affected by the reduction in radiation transmission, resulting in reduced corn height, forage mass, and grain yield than in the full sun.

The Effect of Soaking Root Fertilizer on Promoting the Seedling Early Growth and Root Development of Eucalyptus urograndis

We examined the feasibility of applying soaking root fertilizer to Eucalyptus urograndis seedlings by dipping the roots, and the effectiveness of the method for improving the overall growth quality of the seedlings by affecting root growth. The seedlings of E. urograndis in the Southern National Forest Seedling Demonstration Base in China were dipped with seven kinds of soaking root fertilizer formulas, while another group of clear water was set as a control. We regularly investigated the relationship between root traits and other seedling traits, and the formulas conducive to the high-quality growth of seedlings in one month and two months were screened by principal component analysis (PCA). The feasibility of applying soaking root fertilizer by dipping the roots was analyzed by comparing the difference between the formula and the control. The F2 formula had the best promoting effect on the growth and biomass of seedlings and the highest ground diameter within one month. The biomass, cumulative height growth, and average crown width were also the highest in the two months, but the decreasing growth height in F2 was also obvious, along with reduced photosynthesis and root morphology. The F8 and F4 formulas as compound fertilizers showed the potential of a high growth rate and high quality. The seedlings on which they were all applied had an excellent photosynthetic capacity and a well-developed root system. A correlation analysis showed that root traits were significantly correlated with some aboveground indices of seedlings (growth, biomass and nutrients, etc.), among which the root K concentration was very significantly correlated with photosynthetic capacity, and the root P was very significantly correlated with seedling biomass. Dipping roots mainly promoted the uptake of P and K nutrients by roots, which had a positive effect on seedling photosynthesis and the root system, and thus improved the growth increment and growth quality of seedlings. A principal component analysis showed that dipping roots significantly promoted the growth traits of seedlings, and the best-performing formula for dipping roots was F8 at one month of growth. F4 was the best choice for growth at two months. F4 showed excellent performance in all trait indices and was the only treatment where an increase in the rhizome-to-stem ratio occurred, indicating that the nutrient distribution of F4 seedlings was uniform and efficient, which compensated for the deficiency of the follow-up fertility of the quick-acting complex fertilizer. The scientific formula of soaking root fertilizer can be economically applied by dipping roots to synchronously promote early growth and quality of seedlings, which can provide a theoretical basis for the early large-scale cultivation of E. urograndis and other plants.

Characterisation of Chrysoporthe cubensis and Chrysoporthe deuterocubensis, the Stem Canker Diseases of Eucalyptus spp. in a Forest Plantation in Malaysia

Commercial plantations of Eucalyptus species have been established in Malaysia, especially during the past 10 years, with the aim of sustaining the supply of wood and timber products for industrial use in Malaysia. As part of an assessment of fungal diseases affecting Eucalyptus species in four regions in Malaysia, including Kelantan, Pahang, Sabah, and Selangor, stem canker disease was discovered to be a widespread disease infecting Eucalyptus species in Malaysia. This study aimed to identify the fungus-causing stem canker disease, test its pathogenicity in Eucalyptus, and determine the mating type of isolates from the infected trees. The fungi were identified based on morphology and through comparisons of DNA sequence data from the ITS, β-tubulin 2 gene, and TEF-1α gene regions. Phylogenetic analyses showed that the causal agent of the stem canker was Chrysoporthe cubensis infecting Eucalyptus plantations in Pahang and Chrysoporthe deuterocubensis infecting Eucalyptus plantations in Kelantan, Sabah, and Selangor. We believe this is the first report of Chrysoporthe cubensis-infected Eucalyptus in Malaysia and Southeast Asia, while Chrysoporthe deuterocubensis is the first-reported species infecting Eucalyptus pellita in Malaysia. Moreover, the fact that the mating-type MAT1-1 and MAT1-2 genes and the pheromone genes ppg1, ppg2, pre1, and pre2 were identified in all isolates indicates that Chrysoporthe cubensis and Chrysoporthe deuterocubensis are homothallic mating systems. Pathogenicity was tested on a 3-year-old standing tree, 1-year-old seedling, and detached healthy leaves, which were re-isolated for fulfilling Koch’s postulates. In pathogenicity trials, both Chrysoporthe cubensis and Chrysoporthe deuterocubensis gave rise to lesions on wounded Eucalyptus. Both Chrysoporthe spp. were equally pathogenic to Eucalyptus urograndis and Eucalyptus pellita and should be regarded as a biosecurity concern in Malaysia’s forest plantation industry.

Evaluation of Buffel Grass Forage Production, Soil Microbial Biomass, and Enzymatic Activity in Silvopastoral Systems

The adoption of silvopastoral systems enables the achievement of sustainable intensification using multiple arrangements and species in the same area. This study aimed to evaluate the forage production of buffel grass and determine soil microbial biomass and enzymatic activity in two arrangements of a silvopastoral system. The study design was a randomized block with four replicates using a 2 x 4 factorial arrangement. The factors were two arrangements of the silvopastoral systems (buffel + Eucalyptus urograndis = SPS1 and buffel + pigeon pea + E. urograndis = SPS2) and four distances from the E. urograndis trees (2, 4, 6, and 8 m). Soil sampling was carried out at 0–5, 5–10, and 10–20 cm depths to evaluate microbial nitrogen (Nmic) and carbon (Cmic), while the activity of β-glucosidase and urease enzymes was evaluated at 0–5 and 5–10 cm. Buffel grass in the SPS1 showed higher canopy height, total dry mass, and root mass values. In SPS1, the highest total dry mass (3290.7 kg·ha−1) was observed at 8 m from the trees. At a 5–10 cm depth, Cmic was higher at 2 m than 8 m from the trees. The highest value of Nmic was found at 5–10 cm, at a distance of 2 m. The SPS2 showed a higher Nmic than the SPS1 at the 10–20 cm depth. The β-glucosidase activity was higher at a distance of 2 m in SPS1 at 0–5 and 5–10 depths. Urease activity was lower at 8 m at both depths. Thus, we observed the highest values of root-and-shoot biomass of buffel grass in SPS1 system at 8 m from the E. urograndis trees. However, the soil microbial response indicated that the intensification using tree, legume and grass in silvopastoral systems increased soil microbial activity.

Agroclimatic zoning for eucalyptus in the southern mesoregion of Bahia State, Brazil

Forestry promotion is one of the approaches to forestry production with an increasing tendency in Brazil. The objective of this work was to present an agroclimatic zoning (AGZ), based on environmental conditions necessary for the planting of four species of eucalyptus in the southern mesoregion of Bahia State, Brazil, on a surface of 54,642.35 km². AGZ was proposed for Eucalyptus grandis Hill, E. urophylla, E. camaldulensis and Eucalyptus urograndis (E. grandis X E. urophylla), using geographic information systems for crossing spatial variables of temperature, precipitation, water deficit, evapotranspiration, soils, altitude, slope, conservation units and land use. The region showed planting aptitude of 27.93, 11.87, 3.74 and 1.70%, for E. grandis, E. urophylla, E. camaldulensis and Eucalyptus urograndis, respectively. The AGZ is an important alternative to minimize, in the long term, the negative effects of a monoculture with a high rate of transpiration that could compromise environmental sustainability and reduce water availability in a region.

Antimicrobial activity and chemical profile of wood vinegar from eucalyptus (Eucalyptus urophylla x Eucalyptusgrandis -clone I144) and bamboo (Bambusa vulgaris).

Microbial resistance to drugs is a public health problem; therefore, there is a search for alternatives to replace conventional products with natural agents. One of the potential antimicrobial agents is wood vinegar derived from the carbonization of lignocellulosic raw materials. The objectives of the present work were to evaluate the antibacterial and antifungal action of two kinds of wood vinegar (WV), one of Eucalyptus urograndis wood and another of Bambusa vulgaris biomass, and determine their chemical profile. The antimicrobial effect was assessed against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enteritidis, Escherichia coli, Streptococcus agalactiae, and Candida albicans. The minimum inhibitory concentration and the minimum bactericidal and fungicidal concentrations were determined. Micrographs of the microorganisms before and after exposure to both kinds of wood vinegar were obtained by scanning electron microscopy. The chemical profile of the eucalyptus and bamboo vinegar was carried out by gas chromatography and mass spectrometry (GC/MS). Both types of WV presented significant antimicrobial activity, with the bamboo one having a higher efficiency. Both studied pyroligneous extracts seem promising for developing natural antimicrobials due to their efficiency against pathogens. GC/MS analyses demonstrated that the chemical profiles of both kinds of WV were similar but with some significant differences. The major component of the eucalyptus vinegar was furfural (17.2%), while the bamboo WV was phenol (15.3%). Several compounds in both WVs have proven antimicrobial activity, such as acetic acid, furfural, phenol, cresols, guaiacol, and xylenols. Together, they are the major in the chemical composition of the organic fraction of both WVs. Bamboo vinegar had a more expressive content of organic acids. Micrographs of microorganisms taken after exposure to both kinds of wood vinegar displayed several cell modifications. The potential of both types of wood vinegar as a basis for natural antimicrobial products seems feasible due to their proven effect on inhibiting the microorganisms' growth assessed in this experiment.

Fine root dynamics in a tropical integrated crop-livestock-forestry system

Integrated crop-livestock-forestry (ICLF) systems explore synergistic interactions between soil, plant, and animals, maximizing land-use efficiency and sustainability. However, belowground dynamics under ICLF have not been investigated deeply, particularly the role of incorporating dead root material, a forefront strategy for releasing nutrients and storing carbon. To better understand belowground interactions, we conducted a 21-month assessment of fine-root growth and decomposition in an ICLF system, starting when Eucalyptus urograndis trees were three years old. Eucalyptus rows were spaced 15 m apart and integrated with annual crops and pasture. Distances of 1.9, 4.3, and 7.5 m from the trees were evaluated under two successional periods: (i) annual crop, when corn was interspaced with palisade grass (Urochloa brizantha); and (ii) pasture, when palisade grass was grazed. We used the minirhizotron technique to track fine-root production and decomposition down to a depth of 70 cm, capturing 2400 images. Root longevity was estimated per root diameter class (0-0.5-, 0.5–1.0-, and 1.0–2.0-mm) and phenotypical groups (e.g., grasses [corn + palisade grass] and Eucalyptus). Our data showed that root decomposition rate and necromass inputs into the soil were reduced at the closest distance from the Eucalyptus rows (i.e., 1.9 m). The incorporation of decomposed roots was higher in the topsoil (0–28 cm) and declined with increasing soil depths. The total decomposed root incorporation was 101 m m−2 of soil image for 7.5 and 4.3 m inter-row positions, almost twice as high as the recorded at 1.9 m (54 m m−2) from the trees. Daily root decomposition rates increased during the last rainy season, benefited from numerous dead corn roots, and facilitated by higher soil moisture and temperature. Grasses and Eucalyptus roots at 7.5 m from the tree rows had shorter longevity than those at 1.9 m, remaining 88 and 152 days less, respectively. Root diameter influenced the decomposition rate as thicker roots (diameter between 1.0 and 2.0 mm) of grasses and Eucalyptus stood in the soil for 243 and 261 days longer than the finest roots (diameter <0.5 mm). Our results highlight that root necromass accretion and decomposition are heterogeneous in ICLF systems. Furthermore, 3-to-5-year-old Eucalyptus trees drive the interactions, creating microclimate conditions that impair corn and palisade grass root production and reduce root turnover close to the trees. These findings provide a scientific base for managing the ICLF system (spatial and temporal arrangements) and developing models of soil carbon addition via roots in such complex and heterogeneous systems.

Transcription factors of lignin biosynthesis respond to cold and drought in Eucalyptus urograndis

Transcription factors of lignin biosynthesis respond to cold and drought in Eucalyptus urograndis

Growth, nodulation, production, and physiology of leguminous plants in integrated production systems

AbstractChoosing the species suitable for cultivation in intercropped systems is a critical limiting factor for grain and forage production. This study aimed to evaluate the growth, nodulation, production, and physiology of cowpea (Vigna unguiculata) and guandu bean (Cajanus cajan) intercropped with buffel grass (Cenchrus ciliaris) and Eucalyptus urograndis (Eucalyptus grandis × Eucalyptus urophylla) in an integrated production system. Two experiments were conducted simultaneously, arranged in a 2 × 4 factorial scheme. The first factor consisted of the use of two integrated production systems. The second factor consisted of four distances (2, 4, 6, and 8 m) from the eucalyptus planting rows. In the first experiment, crop–forest systems (CFIS: eucalyptus trees and cowpea) and crop–livestock–forest systems (CLFIS: eucalyptus trees, cowpea, and buffel grass) were evaluated. In the second, livestock–forest systems LFIS1 (eucalyptus trees and guandu bean) and LFIS2 (eucalyptus trees, guandu bean, and buffel grass) were evaluated. In cowpea, nodulation was not influenced by production systems and distances, whereas in guandu bean, there was a reduction in the nodules’ number and dry mass with the distance from the trees. Higher growth, biomass production, and photosynthetic activity of cowpea and guandu bean were observed with the increasing distance from the eucalyptus planting rows. However, cowpea increased the 100‐seed weight at 2 and 4 m distances from the eucalyptus rows, improving the grains’ quality close to the trees. The simultaneous cultivation with buffel grass did not affect the leguminous plant yield, promoting greater diversification and increasing the total biomass production of the intercropping.