Vagner Tebaldi de Queiroz

Insecticidal activity of citronella grass essential oil on Frankliniella schultzei and Myzus persicae

The thrips, Frankliniella schultzei, and green peach aphid, Myzus persicae, cause direct damage to plants of economic importance and transmit phytoviruses, causing large economic losses. Chemical constituents of essential oils present a wide range of biological activities. The aim of this work was to evaluate insecticidal activity of essential oil from citronella grass, Cymbopogon winterianus, on F. schultzei and M. persicae. This essential oil was obtained by steam distillation and components were identified by GC/FID and GC/MS. A Potter spray tower was used to spray insects with the essential oil. The major constituents are geraniol (28.62%), citronellal (23.62%) and citronellol (17.10%). Essential oil of C. winterianus at 1% (w v-1) causes mortality in F. schultzei and M. persicae at 34.3% and 96.9%, respectively. The LC50 value for M. persicae was 0.36% and LC90 0.66%. Thus, citronella grass essential oil at 1% (w v-1) is more toxic to M. persicae than F. schultzei. This essential oil shows promise for developing pesticides to manage M. persicae.

Chemical Composition of Essential Oil from Eucalyptus citriodora Leaves and Insecticidal Activity Against Myzus persicae and Frankliniella schultzei

Abstract Essential oils, volatile compounds obtained from plants, provide an alternative approach for controlling agricultural pests due to problems with conventional chemical products, such as insect resistance, environmental issues and human health concerns. This work aimed to extract essential oil from Eucalyptus citriodora to assess its chemical composition and insecticidal activity against the green peach aphid (Myzus persicae) and thrips (Frankliniella schultzei). The essential oil was obtained by hydrodistillation using the Clevenger apparatus and analyzed by gas chromatography with a flame ionization detector and mass spectrometry (GC-FID and GC-MS). A Potter tower was used to spray the insects with the essential oil solutions. The major components found in E. citriodora essential oil were citronellal (29.31 %), geraniol (27.63 %), β-citronellol (14.88 %) and δ-cadinene (6.32 %). Mortality of M. persicae and F. schultzei nymphs were 85.5 % and 34.8 %, respectively, using essential oil at 1 % (w v−1). Estimated values of LC50 (0.40 % w v−1) and LC90 (1.15% w v−1) for M. persicae evidences the potential use of E. citriodora essential oil in controlling this pest.

Spatial and temporal distribution of urban heat islands

The formation of an urban heat island (UHI) is one of the most common impacts of the urbanization process. To mitigate the effects of UHI, the planning of urban forests (e.g., creation of parks, forests and afforestation streets) has been the major tool applied in this context. Thus, the aim of this study is to evaluate the spatial and temporal distribution of heat islands in Vila Velha, ES, Brazil using the mono-window algorithm. The study followed these methodological steps: 1) mapping of urban green areas through a photointerpretation screen; 2) application of the mono-window algorithm to obtain the spatial and temporal patterns of land surface temperature (LST); 3) correlation between LST and the normalized difference vegetation index (NDVI) and normalized difference build-up index (NDBI); 4) application of ecological evaluation index. The results showed that the mean values of LST in urban areas were at least 2.34 to 7.19°C higher than undeveloped areas. Moreover, the positive correlation between LST and NDBI showed an amplifying effect of the developed areas for UHI, while areas with a predominance of vegetation attenuated the effect of UHI. Urban centers, clustered in some parts of the city, received the worst ecological assessment index. Finally, the adoption of measures to guide the urban forest planning within urban centers is necessary to mitigate the effect of heat islands and provide thermal comfort in urban areas.

Effect of greenhouse conditions on the leaf apoplastic proteome of Coffea arabica plants

UNLABELLED This work describes the coffee leaf apoplastic proteome and its modulation by the greenhouse conditions. The apoplastic fluid (APF) was obtained by leaf vacuum infiltration, and the recovered proteins were separated by 2-DE and subsequently identified by matrix assisted laser desorption/ionization time of flight-mass spectrometry, followed by homology search in EST coffee databases. Prediction tools revealed that the majority of the 195 identified proteins are involved in cell wall metabolism and in stress/defense responses. Although most of the proteins follow the classical secretory mechanism, a low percentage of them seem to result from unconventional secretion (leaderless secreted proteins). Principal components analysis revealed that the APF samples formed two distinct groups, with the temperature amplitude mostly contributing for this separation (higher or lower than 10°C, respectively). Sixty one polypeptide spots allowed defining these two groups and 28 proteins were identified, belonging to carbohydrate metabolism, cell wall modification and proteolysis. Interestingly stress/defense proteins appeared as more abundant in Group I which is associated with a higher temperature amplitude. It seems that the proteins in the coffee leaf APF might be implicated in structural modifications in the extracellular space that are crucial for plant development/adaptation to the conditions of the prevailing environment. BIOLOGICAL SIGNIFICANCE This is the first detailed proteomic study of the coffee leaf apoplastic fluid (APF) and of its modulation by the greenhouse conditions. The comprehensive overview of the most abundant proteins present in the extra-cellular compartment is particularly important for the understanding of coffee responses to abiotic/biotic stress. This article is part of a Special Issue entitled: Environmental and structural proteomics.

Geotechnology and landscape ecology applied to the selection of potential forest fragments for seed harvesting

The Atlantic Forest biome is recognized for its biodiversity and is one of the most threatened biomes on the planet, with forest fragmentation increasing due to uncontrolled land use, land occupation, and population growth. The most serious aspect of the forest fragmentation process is the edge effect and the loss of biodiversity. In this context, the aim of this study was to evaluate the dynamics of forest fragmentation and select potential forest fragments with a higher degree of conservation for seed harvesting in the Itapemirim river basin, Espírito Santo State, Brazil. Image classification techniques, forest landscape ecology, and multi-criteria analysis were used to evaluate the evolution of forest fragmentation to develop the landscape metric indexes, and to select potential forest fragments for seed harvesting for the years 1985 and 2013. According to the results, there was a reduction of 2.55% of the occupancy of the fragments in the basin between the years 1985 and 2013. For the years 1985 and 2013, forest fragment units 2 and 3 were spatialized with a high potential for seed harvesting, representing 6.99% and 16.01% of the total fragments, respectively. The methodology used in this study has the potential to be used to support decisions for the selection of potential fragments for seed harvesting because selecting fragments in different environments by their spatial attributes provides a greater degree of conservation, contributing to the protection and conscious management of the forests. The proposed methodology can be adapted to other areas and different biomes of the world.

Toxicidade de óleo de mamona a Helicoverpa zea e a Trichogramma pretiosum

e 3,0% (v v -1 ). A acao do oleo de mamona sobre T. pretiosum foi determinada mediante testes de seletividade e suscetibilidade. As maiores mortalidades de larvas foram observadas no tratamento por contato com as menores concentracoes (0,5 e 1,0%), enquanto com as concentracoes intermediarias (1,5; 2,0 e 2,5%), nao houve diferenca entre as vias de aplicacao. A maior concentracao testada (3,0%), o tratamento por ingestao proporcionou mortalidade superior aquela obtida por contato. O numero de ovos parasitados por T. pretiosum, no teste de seletividade, foi afetado negativamente pelo oleo de mamona, contudo, os demais parâmetros avaliados quanto a seletividade e a suscetibilidade nao foram afetados. O oleo de mamona reduz a sobrevivencia de larvas de H. zea tanto por ingestao quanto por contato. Alem disso, nao prejudica o desenvolvimento de T. pretiosum, desde que as pulverizacoes sejam realizadas apos as liberacoes do parasitoide. Termos para indexacao: Ricinus communis, broca-grande, parasitoide de ovos. Toxicity of Castor bean oil on Helicoverpa zea and Trichogramma pretiosum

Environmental risk assessment for sustainable pesticide use in coffee production

The extensive use of pesticides in agricultural practices has been associated with human health problems and environmental contamination worldwide. Brazil is the largest consumer of pesticides in the world and Espírito Santo State stands out as the second Brazilian producer of coffee. However, there is no information about environmental impact of coffee producing at Itapemirim River Basin (IRB) region, Espírito Santo State, Brazil; hence a simple and quick method using open access softwares (AGROSCRE and ARAquá Web) to estimate surface entrainment and pesticide leaching potential was carried out. AGROSCRE evaluates the contamination risk of superficial and groundwater by Active Ingredients (AIs), using GOSS Method, GUS index and US EPA criteria, while ARAquá Web estimates AI concentrations in water resources, indicating their suitability based on water quality requirements for different uses. Regarding pesticides used in coffee plantations, there is 44.7% chance of surface water and 23.7% chance of groundwater contamination. Results showed that ametryne, cyproconazole, diuron, epoxiconazole, flutriafol, triadimenol and triazophos pose contamination risk to both surface water and groundwater in the IRB region. Of these, 10.5% of the total AIs are triazoles and fall under environmental classes II and III (Product Very/Dangerous to the Environment). The AIs ametryne, thiamethoxam, iprodione, flutriafol, triazophos, endosulfan, triadimenol, cyproconazole, diuron, pendimethalin, chlorpyrifos, copper II hydroxide, etion, epoxiconazole and paraquat dichloride, were found to be potentially toxic, presenting environmental concentrations ranging from 123.40 μg L-1 to 0.14 μg L-1, which are higher than the safety standard for potable water (0.1 μg L-1). With respect to these AIs, chlorpyrifos, ethion and triazophos showed concentrations higher than EC50 values for aquatic invertebrates and ametryne and diuron for algae. Thus, local residents and environment may be at high risk of pesticide exposure, when these AIs are used in coffee plantations next to surface water or groundwater.

A review on the development of urease inhibitors as antimicrobial agents against pathogenic bacteria

Graphical abstract

Synthesis of Novel Glycerol-Derived 1,2,3-Triazoles and Evaluation of Their Fungicide, Phytotoxic and Cytotoxic Activities

The synthesis of a series of 1,2,3-triazoles using glycerol as starting material is described. The key step in the preparation of these triazolic derivatives is the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), also known as click reaction, between 4-(azidomethyl)-2,2-dimethyl-1,3-dioxolane (3) and different terminal alkynes. The eight prepared derivatives were evaluated with regard to their fungicide, phytotoxic and cytotoxic activities. The fungicidal activity was assessed in vitro against Colletotrichum gloeosporioides, the causative agent of papaya anthracnose. It was found that the compounds 1-(1-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)-1H-1,2,3-triazol-4-yl)-cyclo-hexanol (4g) and 2-(1-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)-1H-1,2,3-triazol-4-yl)propan-2-ol (4h) demonstrated high efficiency in controlling C. gloeosporioides when compared to the commercial fungicide tebuconazole. The triazoles did not present any phytotoxic effect when evaluated against Lactuca sativa. However, five derivatives were mitodepressive, inducing cell death detected by the presence of condensed nuclei and acted as aneugenic agents in the cell cycle of L. sativa. It is believed that glycerol derivatives bearing 1,2,3-triazole functionalities may represent a promising scaffold to be explored for the development of new agents to control C. gloeosporioides.

CARACTERIZAÇÃO QUÍMICA E EFEITO DO ÓLEO ESSENCIAL DE ERVA-DE-SANTA-MARIA SOBRE O ÁCARO-RAJADO DE MORANGUEIRO

The twospotted spider mite, Tetranychus urticae Koch (1836)(Acari: Tetranychidae), is the major pest in strawberry. The objective of this study was the chemical characterization of the essential oil of Chenopodium ambrosioides L. and the evaluation of their effects on twospotted spider mite. The compounds of the essential oil were identified by GC/FID and GC/MS analysis. The mortality and oviposition were evaluated after spraying the oil (2.5, 5.0, 7.5 and 10.0% v v-1) on twospotted spider mite females. The yield of the essential oil was of 0.3% and the compounds identified were (Z)-ascaridol (87%), (E)-ascaridol (5.04%), p-cymeno (4.83%), a-terpinene (1.24%) and piperitone (0.7%). The highest values for mortality and reduction of oviposition observed were 85% and 69%, respectively. C. ambrosioides essential oil is a promising option for the management of twospotted spider mite.