Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Front Plant Sci ; 15: 1337560, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38988636

RESUMO

Over the years, thrips have transitioned from a minor nuisance to a major problem, significantly impacting the yield and quality of cotton. Unmanned aerial vehicles (UAVs) for plant protection have emerged as an effective alternative to traditional pesticide spraying equipment. UAVs offer advantages such as avoiding crop damage and enhancing pesticide deposition on the plants and have become the primary choice for pesticide application in cotton fields. In this study, a 2-year field experiment found that the thrips population in a cotton field in Xinjiang, China, exhibited gradual growth during the early flowering phase, peaking in late July. The thrips population gradually shifted from the lower canopy to the upper canopy as the cotton flowers opened layer by layer. From 09:00 to 11:00 (GMT+8) and 19:00 to 21:00 (GMT+8), thrips mainly flew outside the flowers, while from 17:00 to 19:00 (GMT+8), they mostly inhabited the inner whorls of flowers. The insecticides 10% cyantraniliprole oil dispersion and 10% spinetoram suspension concentrate, sprayed by UAV, had the best control effect on thrips, with 80.51% and 79.22% control effect after 7 days of spraying, respectively. The optimal spraying time for 10% cyantraniliprole oil dispersion was 19:00 (GMT+8), and the control effect on thrips reached 91.16% at 7 days of spraying. During the cotton flowering period, thrips inhabited flowers in the evening and flew outside during the day. The best control effect on thrips was achieved with UAV-sprayed 10% cyantraniliprole oil dispersion at 19:00 (GMT+8).

2.
J Colloid Interface Sci ; 607(Pt 1): 633-644, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34520906

RESUMO

In this work, ultrasonic spray technology is utilized for build up MXene and MoS2 nanosheets to three-dimensional MXene/MoS2 fold microspheres by one-step method. By skillfully assembling two kinds of functional two-dimensional materials, the microspheres have abundant heterogeneous interfaces and huge specific surface area. The optimum feed ratio of MXene and MoS2 is determined by comparing the absorbing properties, and the mass ratio is 5:1. With 30% filler, the material shows the best absorption performance. At 10.4 GHz, the minimal reflection loss (RLmin) reach -51.21 dB, and the thickness is merely 2.5 mm. At the thickness in 1.6 mm, the efficacious absorption bandwidth (RL < -10 dB) reaches 4.4 GHz. The outstanding microwave absorbing properties with MXene/MoS2 folded microspheres is resulted in the multiple interfaces in the heterostructure and above the average conductivity of MXene. The results show that MXene/MoS2 folded microsphere is a prospective electromagnetic absorbing material. The construction of MXene/MoS2 folded microsphere provides an effective method to devise new high-performance microwave absorbing materials.

3.
Biomed Microdevices ; 23(2): 21, 2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33821351

RESUMO

Cervical degenerative disease is a common and frequently occurring disease, which seriously affects the health and quality of the life of patients worldwide. Anterior cervical decompression and interbody fusion is currently recognized as the gold standard for the treatment of degenerative cervical spondylosis. Polyetheretherketone (PEEK) has become the prevailing material for cervical fusion surgery. Although PEEK has excellent biocompatibility, it is difficult to form bone connection at its bone-implant interface due to its low surface hydrophilicity and conductivity. It is widely accepted that Ti has excellent osteogenic activity and biocompatibility. In this study, a Ti-PEEK composite cage was prepared by coating Ti on the surface of a PEEK cage using a vacuum plasma spraying technique to enhance the osteogenic property of PEEK. The Ti-PEEK samples were evaluated in terms of their in vitro cellular behaviors and in vivo osteointegration, and the results were compared to a pure PEEK substrate. The skeleton staining and MTS assay indicated that the MC3T3-E1 cells spread and grew well on the surface of Ti-PEEK cages. The osteogenic gene expression and western blot analysis of osteogenic protein showed upregulated bone-forming activity of MC3T3-E1 cells in Ti-PEEK cages. Furthermore, a significant increase in new bone formation was demonstrated on Ti-PEEK implants in comparison with PEEK implants at 12 weeks in a sheep cervical spine fusion test. These results proved that the Ti-PEEK cage exhibited enhanced osseointegrative properties compared to the PEEK cage both in vitro and in vivo.


Assuntos
Osteogênese , Titânio , Animais , Benzofenonas , Humanos , Polietilenoglicóis , Polímeros , Porosidade , Ovinos , Vácuo
4.
J Environ Sci Health B ; 56(3): 251-258, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33370160

RESUMO

This study aimed to assess, in a microcosm condition, the efficacy of electrostatic spraying of herbicide imazamox in the control of Salvinia molesta and the effects of decomposition of plant material on water quality. The herbicide rates used were 600, 700, 800, and 900 g ai ha-1 and spray volume of 50 L ha-1 in electrostatic application. Control effectiveness was assessed at 7, 15, 30, 45, and 60 days after application (DAA), expressed in percentage (0-100%) of visible injury symptoms in the plants, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), chlorophyll a and pheophytin a contents at 0, 7, 15, 30, 45, and 60 DAA, and fresh and dry biomass at 60 DAA. Imazamox was effective in controlling 63% of S. molesta with 900 g ai ha-1 in 45 DAA and 30% with 800 g ai ha-1 in 30 DAA, and reduced 82.3% and 17.5% of fresh weight and 62.6% and 9.3% of dry weight of plant at 60 DAA, respectively. The imazamox spray reduced chlorophyll a with all doses applied and increased BOD5 in 45 DAA with 900 g ai ha-1 and COD in all assessment periods, but for temperature, dissolved oxygen, electrical conductivity, and pH, there was no significant effect after spraying. The herbicide imazamox reduced S. molesta plants with 900 g ai ha-1, without causing significant effects on environmental indicators of water quality. Electrostatic spraying of herbicide can be used in management strategies of aquatic plants to reduce plant density in water bodies and maintain the colonization of plants at a level not harmful to the aquatic biota.


Assuntos
Herbicidas/farmacologia , Imidazóis/farmacologia , Traqueófitas/efeitos dos fármacos , Qualidade da Água , Análise da Demanda Biológica de Oxigênio , Biomassa , Clorofila A/metabolismo , Relação Dose-Resposta a Droga , Indicadores Ambientais , Herbicidas/administração & dosagem , Imidazóis/administração & dosagem , Eletricidade Estática , Temperatura , Traqueófitas/metabolismo
5.
J Environ Sci Health B ; 51(12): 888-893, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27768529

RESUMO

The objective of this study was to evaluate the effects of nozzle types and 2,4-D formulations on spray deposition on different targets. Two field experiments were carried out in a completely randomized design, and treatments were arranged in a factorial scheme. Species in experiment 1 were Sumatran fleabane (Conyza sumatrensis) and Brazil pusley (Richardia brasiliensis) and in experiment 2 were soybeans (Glycine max) and Benghal dayflower (Commelina benghalensis). For both experiments, the first factor corresponded to spray nozzles with different settings (AD 110.015 - 61 and 105 L ha-1; AD 015-D - 75 and 146 L ha-1; XR 110.0202 - 200 L ha-1; and ADIA-D 110.02 - 208 L ha-1) and the second factor consisted of two formulations of 2,4-D (amine and choline). The formulation of 2,4-D choline has contained Colex-D™ Technology. Similar or higher spray deposition was observed on the leaves and artificial targets when using 2,4-D choline as compared to the 2,4-D amine formulation, and these differences in deposition were more evident for nozzles applying lower spray volumes. Deposition was more affected by nozzle type when amine formulation was used, compared to choline formulation.


Assuntos
Ácido 2,4-Diclorofenoxiacético/administração & dosagem , Agricultura/instrumentação , Agricultura/métodos , Brasil , Commelina , Conyza/efeitos dos fármacos , Dimetilaminas/administração & dosagem , Desenho de Equipamento , Plantas Daninhas/efeitos dos fármacos , Distribuição Aleatória , Glycine max
6.
Pest Manag Sci ; 71(1): 105-13, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24585700

RESUMO

BACKGROUND: Wheat ears are difficult targets from the aspect of fungicide spraying. Sideward-spraying nozzle types may enhance the ear coverage, which may possibly lead to higher effectiveness in the management of Fusarium head blight (FHB). RESULTS: On average, sideward-spraying Turbo TeeJet Duo nozzles resulted in 1.30 and 1.43 times higher prothioconazole-desthio and tebuconazole contents and Turbo FloodJet nozzles in 1.08 and 1.34 times higher prothioconazole-desthio and tebuconazole contents in wheat ears by comparison with those achieved with vertically-spraying XR TeeJet nozzles. In contrast, the vertically-spraying XR TeeJet nozzles resulted in 1.57 and 1.31 times higher prothioconazole-desthio and tebuconazole contents in the flag leaf blade. The degradation of the active ingredient (AI) depended on the year, the cultivar and the plant organ, but not on the spraying method. There was no clear relationship between the efficacy of a given nozzle type and the outcome of the FHB epidemic. CONCLUSIONS: The ear coverage and therefore the AI content have been improved with the two sideward-spraying nozzle types. There was no effective translocation of the AI content between the ears and flag leaf blades. Prothioconazole and tebuconazole proved to be highly effective in the management of FHB, but the FHB resistance of the cultivar was also decisive.


Assuntos
Fungicidas Industriais/administração & dosagem , Fusarium , Triazóis/administração & dosagem , Triticum/química , Fungicidas Industriais/análise , Doenças das Plantas , Folhas de Planta/química , Sementes/química , Triazóis/análise
7.
Arq. Inst. Biol ; 80(2): 177-182, 20130000.
Artigo em Português | LILACS, VETINDEX | ID: biblio-1462230

RESUMO

Eichhornia crassipes is one of the main weeds found in aquatic environments, being undesirable for many activities. The aim of this study was to evaluate the translocation of glyphosate and imazamox in E. crassipes. Eight intervals were studied for cutting leaves that received herbicides: 2, 4, 6, 8, 12 and 24 hours after application (HAA), and a treatment with no cutting (untreated). The glyphosate dose was 2,160 g a.e. ha-1 (commercial product - Rodeo) + 0.5% v v-1 Aterbane adhesive spreader and imazamox at 290.4 g i.a. ha-1 (commercial product - Clearcast). The treatments were installed in a completely randomized design with four replications. Glyphosate showed a bad control for all the periods of leaf cutting. The imazamox did not provide control within 12 HAA, while from 24 HAA onward the control was effective. There was not a great mobility of the glyphosate molecule in water hyacinth plants, a period above 24 hours being needed for a satisfactory translocation. For imazamox at least 24 hours were needed after herbicide application for the translocation to occur along with subsequent control.


Entre as diversas plantas daninhas encontradas em ambientes aquáticos, a Eichhornia crassipes é uma das principais, sendo espécie indesejável para muitas atividades. O objetivo deste trabalho foi avaliar a translocação de glyphosate e imazamox em plantas de E. crassipes. Foram estudados oito intervalos de tempo para o corte das folhas que receberam os herbicidas: 2, 4, 6, 8, 12 e 24 horas após a aplicação (HAA) dos produtos, além de um tratamento sem corte das plantas (testemunha). Utilizaram-se glyphosate na dose de 2.160 g e.a. ha-1 (produto comercial - Rodeo) + 0,5% v v-1 do espalhante adesivo aterbane e imazamox na dose de 290,4 g i.a. ha-1 (produto comercial - Clearcast). Os tratamentos foram instalados em um delineamento experimental inteiramente casualizado com quatro repetições. O glyphosate apresentou um controle insatisfatório quando realizado os cortes das folhas em todos os períodos avaliados. O herbicida imazamox não proporcionou controle em até 12 HAA, enquanto que a partir de 24 HAA do herbicida o controle foi eficiente. Não houve uma grande mobilidade da molécula de glyphosate nas plantas de aguapé, sendo necessário um período superior a 24 horas para uma translocação satisfatória. Já para o imazamox um tempo de mínimo de 24 horas após a aplicação do herbicida foi suficiente para que ocorresse a translocação e um posterior controle.


Assuntos
Eichhornia , Flora Aquática , Herbicidas
8.
Arq. Inst. Biol. (Online) ; 78(1): 63-69, jan-mar, 2011. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-1396313

RESUMO

Objetivou-se nesse trabalho avaliar a eficácia de diferentes herbicidas aplicados em pósemergência na de secação do milheto com diferentes doses e volumes de calda de aplicação. Para a dessecação do milheto foram utilizadas doses de 0, 25, 50 e 100% dos herbicidas glyphosate (1.440 g ha-1), em três formulações comerciais (Round up Original, Round up Transorb e Round up WG), paraquat + diuron (500 + 250 g ha-1) e amônio-glufosinato (800 g ha-1). Em todos os tratamentos foram utilizados dois volumes de aplicação (200 e 400 L ha-1). Manteve-se uma testemunha sem aplicação de herbicidas. Os efeitos dos tratamentos foram avaliados visualmente aos 3, 7, 14, 21 e 28 dias após aplicação. Ao final das avaliações foi determinada a massa seca das plantas. O estudo de campo foi instalado no delineamento em blocos casualizados. No final do estudo, aos 28 DAA, todos os tratamentos apresentaram controle total das plantas de milheto, independente da dose e do volume de aplicação, exceto para os tratamentos com paraquat + diuron e amônio-glufosinate na menor dose (25% da dose), nos dois volumes de aplicação, que apresentaram ainda controles considerados bons a muito bom, sendo que para esses dois herbicidas houve efeito do volume de calda, na qual o controle foi superior com o uso de volume menor.


The objective of this work was to evaluate the efficacy of different herbicides applied in post-emergence in the desiccation of pearl millet with different doses and spray volumes. For the desiccation, doses at 0, 25, 50 and 100% of the herbicide glyphosate (1,440 g ha-1) were used in 3 formulations (Original Round up, Round up Transorb and Round up WG), paraquat + diuron (500 + 250 g ha-1) and glufosinateammonium (800 g ha-1). In all treatments, 2 spray volumes (200 and 400 l ha-1) were used, and there was 1 treatment (control) without the application of herbicides. The treatment effects were evaluated visually at 3, 7, 14, 21 and 28 days after application (DAA). At the end of the evaluations, the dry mass of the plants was determined. The field trial was carried out in randomized block design. At the end of the study, at 28 DAA, all treatments presented total control of plant pearl millet, regardless of the dose and spray volume, except the treatments with paraquat + diuron and glufosinate-ammonium at the lower dose (25%), in 2 spray volumes, which nevertheless showed good and very good control, these two herbicides presenting an effect of volume, in which the control was higher with the use of smaller volume.


Assuntos
Pennisetum/fisiologia , Herbicidas/administração & dosagem , Herbicidas/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...