10 research outputs found
Neem oil and crop protection: from now to the future
A major challenge of agriculture is to increase food production to meet the needs of the growing world population, without damaging the environment. In current agricultural practices, the control of pests is often accomplished by means of the excessive use of agrochemicals, which can result in environmental pollution and the development of resistant pests. In this context, biopesticides can offer a better alternative to synthetic pesticides, enabling safer control of pest populations. However, limitations of biopesticides, including short shelf life, photosensitivity, and volatilization, make it difficult to use them on a large scale. Here, we review the potential use of neem oil in crop protection, considering the gaps and obstacles associated with the development of sustainable agriculture in the not too distant future7FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2014/20273-4; 2013/12322-2; 2014/20286-9; 2015/15617-9; 2015/17120-
Neem Oil and Crop Protection: From Now to the Future
In current agricultural practices, the control of pests is often accomplished by means of the excessive use of agrochemicals, which can result in environmental pollution and the development of resistant pests. A major challenge of agriculture is to increase food production to meet the needs of the growing world population, without damaging the environment. In this context, biopesticides can offer a better alternative to synthetic pesticides, enabling safer control of pest populations. However, limitations of biopesticides, including short shelf life, photosensitivity, and volatilization, make it difficult to use them on a large scale. Here, we investigate the potential use of neem oil in crop protection, considering the gaps and obstacles associated with the development of sustainable agriculture in the not too distant future
Estudos sobre a paz e cultura da paz
Segundo o autor, a cultura da paz implica uma mudança quer na
forma como a “alta cultura” lida com a realidade quer no tipo de
abordagem que o senso comum faz às relações sociais, sendo que a
ruptura com a ideologia conservadora, ou seja, com o senso comum
realista só é possível graças a estas alterações. O autor realça tanto a
importância que os estudos sobre a paz têm para o surgimento de um
conceito amplo de paz, desenvolvido por Johan Galtung, como o facto
destes estarem estrategicamente orientados para a transformação do
sistema internacional. Sequentemente, conclui que a paz é uma categoria moral e cultural que só pode ser alcançada através do comportamento quotidian
In vitro manipulation of the bacterial community to improve the performance of bioflocs in aquaculture systems
Abstract Although biofloc technology is already recognized as advantageous and practical for aquaculture for the effects of maintaining water quality and improving the health status and resistance of cultivated animals against pathogens, little is known about the way of action involved. This study aimed to evaluate the performance of bacterial groups as inducers in the formation of flocs compared to a system with spontaneous formation. Therefore, three microsystems were built in 3L tanks with constant aeration to induce the biofloc aggregation with addition of bacterial consortiuns with differentiated functions. It was used a control, without addition of bacterial consortium; B1 with addition of probiotic bacteria consortium; and B2, with adding nitrifying bacteria consortium. During the experimental period were evaluated physicochemical variables and quantifications of bacterial cultivable groups: Heterotrophic Bacteria and Vibrio. Also was the microscopic characterization of the flakes and tests of antimicrobial activity against pathogenic bacteria. Systems B1 and B2 showed promising results in relation to control (spontaneous bioflocs), showing more homogeneous flake formation, antimicrobial activity against the tested pathogens and greater biological diversity in the systems. The bacteria used in these tests were able to optimize the formation of microbial aggregates, showing potential for application in cultivation systems, in order to obtain improvements in productivity
Removal of glyphosate herbicide from water using biopolymer membranes
Enormous amounts of pesticides are manufactured and used worldwide, some of which reach soils and aquatic systems. Glyphosate is a non-selective herbicide that is effective against all types of weeds and has been used for many years. It can therefore be found as a contaminant in water, and procedures are required for its removal. This work investigates the use of biopolymeric membranes prepared with chitosan (CS), alginate (AG), and a chitosan/alginate combination (CS/AG) for the adsorption of glyphosate present in water samples. The adsorption of glyphosate by the different membranes was investigated using the pseudo-first order and pseudo-second order kinetic models, as well as the Langmuir and Freundlich isotherm models. The membranes were characterized regarding membrane solubility, swelling, mechanical, chemical and morphological properties. The results of kinetics experiments showed that adsorption equilibrium was reached within 4 h and that the CS membrane presented the best adsorption (10.88 mg of glyphosate/g of membrane), followed by the CS/AG bilayer (8.70 mg of glyphosate/g of membrane). The AG membrane did not show any adsorption capacity for this herbicide. The pseudo-second order model provided good fits to the glyphosate adsorption data on CS and CS/AG membranes, with high correlation coefficient values. Glyphosate adsorption by the membranes could be fitted by the Freundlich isotherm model. There was a high affinity between glyphosate and the CS membrane and moderate affinity in the case of the CS/AG membrane. Physico-chemical characterization of the membranes showed low values of solubility in water, indicating that the membranes are stable and not soluble in water. The SEM and AFM analysis showed evidence of the presence of glyphosate on CS membranes and on chitosan face on CS/AG membranes. The results showed that the glyphosate herbicide can be adsorbed by chitosan membranes and the proposed membrane-based methodology was successfully used to treat a water sample contaminated with glyphosate. Biopolymer membranes therefore potentially offer a versatile method to eliminate agricultural chemicals from water supplies151353360CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçãosem informação2013/05135-1The authors are grateful for the financial support provided by the grant #2013/05135-1, São Paulo Research Foundation (FAPESP), CNPq, CAPES, and FUNDUNES
Основные характеристики наноразмерных систем доставки, предназначенных для применения в сельском хозяйстве
Due to the excessive use of chemical agents in agriculture, numerous problems have arisen, such as contamination of the environment, intoxication of non-target organisms and the development of resistance mechanisms by pests. To overcome these challenges, several sustainable technological approaches are being explored, and nanotechnology is one of them. This review aims to provide insights into the use of nanotechnology related to the agricultural sector. Articles were selected using the Web of Science and Science Direct databases; more than 50 manuscripts between 2015 and 2019 were reviewed. This review includes systems based on nanotechnology, in particular, for the sustained release of active ingredients for pest control, nutrition and plant growth. Nanoparticle-based formulations have great potential to increase agricultural productivity and reduce health and environmental impacts. However, there are certain technological challenges that must be addressed to allow the adoption of this technology for wider use in agri-food productionЧрезмерное использование химических веществ в сельском хозяйстве привело к возникновению множества проблем, в частности загрязнению окружающей среды, токсическому воздействию на организмы, не являющихся мишенями, а также к развитию механизмов устойчивости у вредителей. Для преодоления этих вызовов изучается ряд устойчивых технологических подходов, одним из которых выступает нанотехнология. Данный обзор призван дать представление об использовании нанотехнологий применительно к сельскохозяйственному сектору. Статьи отбирали с помощью баз данных Web of Science и Science Direct; было проанализировано более 50 рукописей за период с 2015 по 2019 год. Обзор описывает нанотехнологические системы, в частности, для замедленного высвобождения активных ингредиентов для борьбы с вредителями, для питания и роста растений. Препараты на основе наночастиц имеют большой потенциал для повышения продуктивности сельского хозяйства и снижения воздействия на здоровье и окружающую среду. Тем не менее остаются определенные технологические проблемы, которые должны быть решены для более широкого использования этих технологий в производстве продуктов питани
Zein Nanoparticles as Eco-Friendly Carrier Systems for Botanical Repellents Aiming Sustainable Agriculture
Botanical
repellents represent one of the main ways of reducing
the use of synthetic pesticides and the contamination of soil and
hydric resources. However, the poor stability and rapid degradation
of these compounds in the environment hinder their effective application
in the field. Zein nanoparticles can be used as eco-friendly carrier
systems to protect these substances against premature degradation,
provide desirable release characteristics, and reduce toxicity in
the environment and to humans. In this study, we describe the preparation
and characterization of zein nanoparticles loaded with the main constituents
of the essential oil of citronella (geraniol and <i>R</i>-citronellal). The phytotoxicity, cytotoxicity, and insect activity
of the nanoparticles toward target and nontarget organisms were also
evaluated. The botanical formulations showed high encapsulation efficiency
(>90%) in the nanoparticles, good physicochemical stability, and
effective
protection of the repellents against UV degradation. Cytotoxicity
and phytotoxicity assays showed that encapsulation of the botanical
repellents decreased their toxicity. Repellent activity tests showed
that nanoparticles containing the botanical repellents were highly
repellent against the <i>Tetranychus urticae</i> Koch mite.
This nanotechnological formulation offers a new option for the effective
use of botanical repellents in agriculture, reducing toxicity, protecting
against premature degradation, and providing effective pest control
Geraniol Encapsulated in Chitosan/Gum Arabic Nanoparticles: A Promising System for Pest Management in Sustainable Agriculture
The nanoencapsulation of botanical
compounds (such as geraniol)
is an important strategy that can be used to increase the stability
and efficiency of these substances in integrated pest management.
In this study, chitosan/gum arabic nanoparticles containing geraniol
were prepared and characterized. In addition, evaluation was made
of the biological activity of geraniol encapsulated in chitosan/gum
arabic nanoparticles toward whitefly (Bemisia tabaci). The optimized formulation showed a high encapsulation efficiency
(>90%) and remained stable for about 120 days. The formulation
protected
the geraniol against degradation by UV radiation, and the in vitro
release was according to a diffusion mechanism that was influenced
by temperature. An attraction effect was observed for Bemisia tabaci, indicating the potential of this
type of system for use in pest management, especially in trap devices