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BAKHTIN E ANÁLISE DE DISCURSO CRÍTICA NA CINEBIOGRAFIA
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Os últimos 50 anos foram marcados por grandes avanços tecnológicos devido às necessidades econômicas, civis e militares da população mundial. Na década de 70, o surgimento do sistema norte-americano denominado como Navstar-GPS (Navigation System Using Timing And Ranging - Global Positioning System) foi responsável por revolucionar o posicionamento e a navegação. Em paralelo, o governo da extinta União Soviética desenvolveu um sistema concorrente ao GPS, denominado GLONASS (Globalnaya Navigazionnaya Sputnikovaya Sistema). À medida que esses sistemas foram aprimorados, outros países começaram a utilizá-los em aplicações de grande relevância, tais como navegação aérea, marítima e mesmo terrestre, além de muitas outras atividades em que o conhecimento da posição se faz necessário. Com o passar do tempo, outros países começaram a investir recursos financeiros para desenvolver e colocar em órbita seus próprios satélites de posicionamento. Desde março de 2018, a constelação da União Europeia, denominada como Galileo, se tornou operante. O Galileo é o primeiro sistema desenvolvido para fins civis a priori. Apesar de ser novo em comparação aos sistemas americano e russo, espera-se que a constelação Galileo forneça uma melhora significativa em sua acurácia para posicionamento, proporcionando maior segurança e qualidade nos produtos obtidos. Nesse sentido, o presente artigo visa avaliar os ganhos e perdas obtidos considerando as componentes das coordenadas no sistema geodésico local, N (norte), E (leste e perpendicular a N) e U (normal ao elipsoide de referência), no posicionamento relativo com linhas de base longas na região brasileira, com a incorporação do sistema Galileo no posicionamento pelo GNSS. Como resultados obteve-se ganhos planialtimétricos de até 25%.
O cupuaçu é uma fruta amazônica com sabor exótico e ricas propriedades nutricionais. Entretanto, o despolpamento gera um grande volume de resíduos agroindustriais. O objetivo deste trabalho foi realizar o aproveitamento integral do cupuaçu na elaboração de um produto de panificação. Foram realizadas as análises de pH da polpa; análise de composição de umidade, cinzas, proteínas, lipídios e carboidrato total da polpa, casca e sementes de cupuaçu; e análise sensorial do produto desenvolvido. A polpa apresentou pH de 3,65 e nela foram obtidos os maiores teores de umidade. Já as sementes apresentaram maiores teores de cinzas e lipídeos. Enquanto as cascas apresentaram maiores valores de carboidratos totais. O panetone com farinha da casca de cupuaçu, recheado com geleia de cupuaçu e cupulate obteve boa aceitação entre os avaliadores, obtendo pontuação máxima na escala hedônica com 73% para o sabor e acima de 50% para os itens de aroma, aparência e textura. Quanto à intenção de consumo, 58,1% dos provadores o comeriam sempre e mais de 80% certamente comprariam o produto. Dessa forma, o panetone formulado a partir do cupuaçu e seus resíduos agroindustriais apresentou-se como um produto com maior valor nutricional, presença de compostos bioativos e sensorialmente aceito por consumidores potenciais, indicando ser uma opção de uso racional e sustentável de matéria-prima, diminuindo custos e desperdício, valorizando o fruto e a cadeia de produção do cupuaçu na região Amazônica.
Least-squares collocation (LSC) is a widely used method applied in physical geodesy to separate observations into a signal and noise part but has received only little attention when interpolating velocity fields. The advantage of the LSC is the possibility to filter and interpolate as well as extrapolate the observations. Here, we will present several extensions to the traditional LSC technique, which allows the combined interpolation of both horizontal velocity components (horizontal velocity (HV)-LSC), the separation of velocity observations on different tectonic plates, and the removal of stationarity by moving variance (the latter as HV-LSC-ex(tended)2). Furthermore, the covariance analysis, which is required to find necessary input parameters for the LSC, is extended by finding a suitable variance and correlation length using both horizontal velocity components at the same time. The traditional LSC and all extensions are tested on a synthetic dataset to find the signal at known as well as newly defined points, with stations separated on four different plates with distinct plate velocities. The methodologies are evaluated by calculation of a misfit to the input data, and implementation of a leave-one-out cross-validation and a Jackknife resampling. The largest improvement in terms of reduced misfit and stability of the interpolation can be obtained when plate boundaries are considered. In addition, any small-scale changes can be filtered out using the moving-variance approach and a smoother velocity field is obtained. In comparison with interpolation using the Kriging method, the fit is better using the new HV-LSC-ex2 technique.
Este trabalho teve como objetivo caracterizar manteigas comerciais obtidas a partir dos frutos amazônicos bacuri (Platonia insignis), cacau (Theobroma cacao), cupuaçu (Theobroma grandiflorum), murumuru (Astrocaryum murumuru), tucumã (Astrocaryum aculeatum) e ucuuba (Virola surinamensis) quanto às propriedades físico-químicas e ao perfil de ácidos graxos. Para tanto, as manteigas foram analisadas de acordo com os métodos oficiais descritos pela American Oil Chemists' Society (AOCS) quanto aos teores de ácidos graxos livres, índice de acidez, dienos conjugados, índice de peróxidos, p-anisidina, valor totox, índices de saponificação, iodo e refração, ponto de fusão e matéria insaponificável. As manteigas apresentaram acidez acima do limite estabelecido pela regulamentação, evidenciando degradação hidrolítica, sobretudo nas de cupuaçu e ucuuba. Ao contrário para os índices de peróxidos, a formação de compostos primários foi abaixo do limite máximo permitido pela regulamentação. A manteiga de bacuri apresentou o maior valor totox, pelos mais altos índices de peróxidos e p-anisidina. Em geral, as manteigas apresentaram elevadas quantidades de ácidos graxos saturados. Maiores quantidades de ácido graxo monoinsaturado (oleico) foram encontradas nas manteigas de cupuaçu, bacuri e cacau. Palavras-chave: Ácidos graxos. Propriedades físico-químicas. Manteigas vegetais. Physicochemical characterization of amazonian fruit butters Abstract This study aimed to characterize commercial butters obtained from Amazonian fruits bacuri (Platonia insignis), cocoa (Theobroma cacao), cupuaçu (Theobroma grandiflorum), murumuru (Astrocaryum murumuru), tucumã (Astrocaryum aculeatum) and ucuuba (Virola surinamensis) regarding the physicochemical properties and the fatty acid profile. For this purpose, the butters were analyzed according to the official methods described by the American Oil Chemists' Society (AOCS) regarding the levels of free fatty acids, acidity index, conjugated dienes, peroxide index, p-anisidine, totox value, saponification, iodine and refraction, melting point and unsaponifiable matter. The butters showed acidity above the limit established by regulation, showing hydrolytic degradation, especially in cupuaçu and ucuuba. In contrast to the peroxide values, the formation of primary compounds was below the maximum limit allowed by regulation. Bacuri butter had the highest totox value, due to the higher levels of peroxides and p-anisidine. In general, the butters showed high amounts of saturated fatty acids. Higher amounts of monounsaturated fatty acid (oleic) were found in cupuaçu, bacuri and cocoa butters. Keywords: Fatty acids. Physicochemical properties. Vegetable butters.
The transformation of passive distribution systems to more active ones thanks to the increased penetration of distributed energy resources, such as dispersed generators, flexible demand, distributed storage, and electric vehicles, creates the necessity of an enhanced test system for distribution systems planning and operation studies. The value of the proposed test system, is that it provides an appropriate and comprehensive benchmark for future researches concerning distribution systems. The proposed test system is developed by modifying and updating the well-known 33 bus distribution system from Baran & Wu. It comprises both forms of balanced and unbalanced three-phase power systems, including new details on the integration of distributed and renewable generation units, reactive power compensation assets, reconfiguration infrastructures and appropriate datasets of load and renewable generation profiles for different case studies.
This study analyzed the use of the ultrasound-assisted method as an alternative to obtain munguba oil. The extraction provided a 47.70 % yield of an oil with appropriate quality, evaluated by assessing the %FFA as oleic acid, iodine, peroxide, and saponification values, in addition to the refractive index and density. The oil presented thermal stability up to 300 °C, was constituted mainly by palmitic acid (C16:0), and presented a total phenolic content of 55.02 ± 1.872 µgEAG g-1. Results suggest that the ultrasound-assisted method has the potential to obtain vegetable oils without compromising their characteristics and quality, as well as optimize extraction time, solvent volume, and operational costs. Moreover, munguba oil presents itself as a suitable and sustainable alternative as an adjuvant in food products, pharmaceuticals, cosmetics, and biofuels.
Glyphosate is the main tool for weed management in Brazilian citrus orchards, where weeds, such as Conyza bonariensis and Digitaria insularis, have been found with resistance to this herbicide. Field prospections have allowed the identification of a possible new case of glyphosate resistance. In this work, the susceptibility levels to glyphosate on three Amaranthus viridis L. populations, with suspected resistance (R1, R2, and R-IAC), collected in citrus orchards from the São Paulo State, Brazil, as well as their accumulation rates of shikimic acid, were determined. The fresh weight of the susceptible population (S) was reduced by 50% (GR 50) with~30 g ea ha −1 glyphosate, while the GR 50 values of the R populations were between 5.4 and 11.3 times higher than that for S population. The LD 50 (herbicide dose to kill 50% of individuals of a weed population) values of the S population were ≤150 g ea ha −1 glyphosate, while the LD 50 of the R populations ranged from 600 to 920 g ea ha −1. Based on the reduction of fresh weight and the survival rate, the R1 population showed the highest level of glyphosate resistance, which had GR 50 and LD 50 values of 248 and 918 g ea ha −1 glyphosate, respectively. The S population accumulated 240 µg shikimic acid at 1000 µM glyphosate, while the R1, R2, and R-IAC populations accumulated only 16, 43, and 33 µg shikimic acid, respectively (between 5.6 to 15 times less than the S population). Enzyme activity assays suggested that at least one target site-type mechanism was involved in resistance. This result revealed the first report of glyphosate resistance in A. viridis reported in the world.
The ultrasound-assisted extraction (UAE) is an alternative approach for the total lipid content determination in food samples. The high extraction efficiency, being less time-consuming and with the possibility of using less toxic solvents are the main advantages of UAE. It is, thus, an excellent alternative to be applied as a laboratory experiment for undergraduate students. The UAE procedure was optimized and the extraction parameters, such as extractor solvent, time and frequency of the ultrasound, were evaluated. The accuracy of the UAE procedure was evaluated by comparing the obtained results with those found by the traditional lipids extraction approach. The results showed that the lipids content found in the analyzed samples by using UAE were in agreement with the results obtained by the traditional lipids extraction. Therefore, the optimized UAE procedure was proposed as a laboratory experiment to 15 groups of undergraduate students to introduce the subjects of an alternative approach for total lipids determination in food samples. The results obtained showed that 80% of the student groups found results for total lipid contents in agreement with those found by traditional lipids extraction method. The proposed UAE procedure as a laboratory experiment proved to be simple and easy to be applied to undergraduate students.
The management of soil cover plants (intercropping) in orchards can contribute to increase productivity of citrus trees. Thus, the present research aimed to evaluate different planting systems for Tahiti acid lime grafted onto Flying Dragon trifoliate orange, a dwarfing rootstock, at high planting density (1,157 trees ha–1). The study was set up in four tillage systems, using Urochloa ruziziensis as an intercrop species in the orchard, and conducted for 5 years: no-tillage (NT), no-tillage and no-herbicide (NT-NH), minimum tillage (MT) and conventional tillage (CT; without intercropping). Dry matter (DM) production of biomass in the row and interrow of the orchard was evaluated yearly, as well as weed density, soil physical and chemical characteristics, plant water and nutritional status, and fruit yield of trees. Greater deposition of DM of biomass was observed in the row of citrus planting for treatments NT and NT-NH compared to CT and MT treatments, which led to reduced undesirable weed populations. The NT treatment also provided increases of 79% in potassium (K) nutrient concentrations in the leaves of trees and 60% in exchangeable K in the soil surface layer, in the first 2 years evaluated. The maintenance of the Urochloa ruziziensis mulch in the NT system also provided higher soil volumetric moisture content and consequently lower soil resistance penetration and water stress on trees, evidenced by the predawn plant leaf water potential (<1 MPa). Moreover, the NT treatment provided an average increase of 56% of fruit yield from trees compared to the CT treatment during three harvests. This long-term study demonstrated the contribution of the no-tillage system using a favorable cover crop to increase the yield of Tahiti acid lime fruits and maintain the soil quality most required for the sustainability of citrus production.
Helicoverpa armigera caterpillars are polyphagous and exhibit high migratory potential. Given the traits of this pest, alternative hosts located in or near the crop stand may support the survival and permanence of H. armigera in the field. The aim of this study was to investigate Conyza sp. as a food source for H. armigera caterpillars in scenarios with conventional and Bt soybean. Two experiments were conducted in biochemical oxygen demand incubators. The first assessed consumption of conventional soybean, Bt soybean and Conyza sp. leaves by 3rd and 5th instar caterpillars, with no choice given (no-choice test). The second test evaluated the food preference of 3rd instar H. armigera larvae, with two choices given (dual-choice test). Fifth instar larvae favored Conyza sp. leaves to Bt soybean, but preferred conventional soybean to both of these options. The survival of 3rd instar caterpillars did not differ statistically regardless of the plant species used as a food source. Fifth instar larvae fed Bt soybean exhibited lower survival rates when compared to Conyza sp. and conventional soybean. In dual-choice test arenas, soybean leaf consumption was superior to Conyza sp. Conventional soybean consumption was also greater when offered in conjunction with Bt soybean. Caterpillars offered Conyza sp. and Bt soybean leaves only consumed the weed species. Conyza sp. plants can serve as a food source for H. armigera larvae, which showed a preference for Conyza sp. leaves to Bt soybean.
Amazonian biodiversity products have economic importance mainly in food, pharmaceutical, and cosmetic industries, despite their possibilities of applications has not been extensively developed. This study aimed to perform the chemical characterization of Amazonian non-polar vegetal extracts (buriti oil, tucumã butter, Brazil nut oil, cupuaçu butter, and cocoa butter) employing Fourier transform infrared spectroscopy (FTIR) and gas chromatography with flame-ionization detection (GC-FID). FTIR analysis presented similar spectra whose assignments were based on the correlations with fatty acids. For all extracts, the obtained percentage of fatty acids in the present study presented similarities in comparison to data reported in previous literature. Respect the variations, considered in terms of composition and percentages, could be attributed to the differences of origin of oils, sample conditioning/storage and/or experimental conditions. Finally, the presented findings could be useful to future researches for the chemical characterization and application of Amazon flora extracts, as well as, production of products in food, pharmaceutical, cosmetic, textile and other industrial sectors.
Many animal and plant viruses depend on arthropods for their transmission. Virus-vector interactions are highly specific and only one vector, or a group of vectors from the same family are able to transmit a given virus. Poleroviruses (Luteoviridae) are phloem-restricted RNA plant viruses, which are exclusively transmitted by aphids. Multiple aphid-transmitted polerovirus species commonly infect pepper, causing vein yellowing, leaf rolling and fruit discoloration. Despite low aphid populations, a recent outbreak with such severe symptoms in many bell pepper farms in Israel led to reinvestigation of the disease and its insect vector. Here we report that this outbreak was caused by a new whitefly ( Bemisia tabaci )-transmitted polerovirus, which we coined Pepper whitefly borne vein yellows virus (PeWBVYV). PeWBVYV is highly homologous (>95%) to Pepper vein yellows virus (PeVYV) from Israel and Greece on its 5′ end half, while it is homologous to African eggplant yellows virus (AeYV) on its 3′ half. Koch's postulates were proven by constructing a PeWBVYV infectious clone causing the pepper disease, which was in turn transmitted to test pepper plants by B. tabaci but not by aphids. PeWBVYV is the first report of a whitefly transmitted polerovirus.
Importance
High specificity of virus-vector interactions limits the possibility of a given virus to change vector. Our study reports a new virus from a family of viruses strictly transmitted by aphids, which is now transmitted by whiteflies ( Bemisia tabaci ) and not by aphids. This study constitutes the first report of a polerovirus transmission by whiteflies. Whiteflies are highly resistant to insecticides and disperse to long distances, carrying virus inoculum. Thus, the report of such unusual polerovirus transmission by a super vector has deep implications on the epidemiology of the virus disease, with ramifications on international trade of agricultural commodities.
As plantas daninhas possuem elevada variabilidade genética, e principalmente por este motivo, são adaptadas a ambientes com intensa atividade humana. Embora o controle de plantas daninhas tenha evoluído de maneira positiva nos últimos anos, elas continuam a interferir na produção agrícola. O objetivo desta revisão bibliográfica é apresentar a contribuição da biologia molecular nos estudos aplicados a herbologia. Há lacunas entre o que aprendemos sobre genômica de plantas daninhas e como esses conhecimentos poderiam nos auxiliar no manejo e melhorar a competividade de culturas agrícolas frente às plantas daninhas. Muitos estudos na área da ciência das plantas daninhas podem ser realizados com o emprego de técnicas de biologia molecular, sendo eles: caracterização do genoma de espécies de plantas daninhas, visando à identificação destes com maior acurácia, identificação de espécies resistentes a herbicidas e seu mecanismo de resistência, variabilidade e similaridade genética entre populações de plantas daninhas, identificação de genes envolvidos nos processos de interação entre plantas, dentre outros.
When competing with crops, weeds interfere with their growth and consequently reduce grain yield. The purpose of this research was to determine the periods of interference; PIP (pre-interference period), TPWC (total period of weed control), and CPWC (critical period of weed control) of the weeds Alexandergrass (Urochloa plantaginea) and southern crabgrass (Digitaria ciliares) in maize. The experiment was conducted in a randomized complete block design with four replications, in a no-tillage system. The treatments consisted in maintaining maize in the presence and absence of Alexandergrass and southern crabgrass for increasing periods of 0, 7, 14, 21, 28, 35 and 42 days after emergence (DAE). Southern crabgrass and Alexandergrass weeds originated from the soil seed bank with an average density of 215 and 87 plants m-2, respectively. At the end of each period, PIP or TPWC, the weed and crop dry biomass was determined. At 42 DAE, the height and stem diameter of maize plants were evaluated. At harvest 10 maize plants per experimental unit were evaluated for length of ears, number of rows per ear, and number of grains per row. Yield was measured by taking three central rows from each experimental unit. The results indicate that the PIP was 17 DAE, the TPWC was 32 DAE, and the CPWC was 17 to 32 DAE.
Objetivou-se com este trabalho avaliar a eficácia e a seletividade de herbicidas aplicados isoladamente ou em mistura de tanque na cultura do milho RR®. O delineamento experimental utilizado foi de blocos casualizados com quatro repetições. Os tratamentos avaliados foram: testemunha infestada, testemunha capinada, glyphosate, glyphosate + [atrazine + simazine], glyphosate + [atrazine + simazine], glyphosate + tembotrione, glyphosate + mesotrione, glyphosate + nicosulfuron, glyphosate + 2,4-D, glyphosate + [atrazine + S-metolachlor], glyphosate + [atrazine + S-metolachlor], glyphosate + S-metolachlor, glufosinate ammonium, [nicosulfuron + mesotrione], glyphosate + [nicosulfuron + mesotrione] e glyphosate + [nicosulfuron + mesotrione] + [atrazine + simazine]. A fitotoxicidade ocasionada pelos herbicidas ao híbrido de milho SYN Supremo VIP3 e o controle de Urochloa plantaginea e de Digitaria ciliaris foram avaliados aos 7, 14, 21 e 28 dias após a aplicação dos tratamentos. Na pré-colheita da cultura, determinou-se o controle das plantas daninhas e, em dez plantas por unidade experimental, foram analisadas as variáveis relacionadas aos componentes de rendimento de grãos, como altura de inserção da espiga, comprimento da espiga, o número de fileiras e de grãos por fileiras e por espigas de milho. Na colheita do milho, avaliou-se a massa de mil grãos e a produtividade de grãos. Observou-se que todos os tratamentos herbicidas ocasionaram baixa fitotoxicidade ao milho, exceto a mistura em tanque aplicada em pós-emergência composta por glyphosate + 2,4-D e glyphosate + mesotrione, que demonstraram as maiores injúrias nas quatro épocas avaliadas. A maioria dos herbicidas mostrou bom controle de D. ciliaris e U. plantaginea, com exceção da mistura de glyphosate + 2,4-D na pré-colheita. A mistura em tanque de glyphosate + [atrazine + simazine] aplicada em pós-emergência demonstrou a maior produtividade de grãos. Conclui-se que, dependendo da associação de herbicidas, ocorre efeito sinérgico tanto para o controle das plantas daninhas como para a fitotoxicidade da cultura, sendo a produtividade de grãos a principal variável influenciada.
Bioactive compounds are extracted from natural sources and they have beneficial effects on human health. Fruits and vegetables are rich in carotenoids, phenolic compounds, Vitamin C, among others. Extraction processes for these compounds depend on several factors such as the technique that is used, the raw material, and the organic solvent. Conventional techniques generally require large amounts of organic solvents, high energy expenditure, and are time consuming, which has generated interest in new technologies that are referred to as clean or green technologies. These can reduce or eliminate the use of toxic solvents, and thus preserve the natural environment and its resources. The aim of this review is to discuss recent techniques used to extract bioactive compounds from natural sources, in order to reduce the economic and ecological impact of these processes.
O objetivo do trabalho foi avaliar a eficácia de herbicidas aplicados em pré-emergência, em diferentes doses e épocas, antes da semeadura de soja sob condição de déficit hídrico, para o controle de plantas voluntárias de algodão, tolerante aos herbicidas glyphosate e amônio glufosinate, e Eleusine indica. O ensaio foi conduzido no município de Formosa do Rio Preto/BA, durante a safra 2015/16, utilizando o delineamento experimental de blocos ao acaso, com quatro repetições e dez tratamentos, sendo: glyphosate + diclosulam (960 + 25,2 g ha-1 e.a./i.a.) e glyphosate + diclosulam (960 + 35 g ha-1 e.a./i.a.), aplicados aos 50, 20 e 0 dias antes da semeadura (DAS), glyphosate + flumioxazin (960 + 50 g ha-1 e.a./i.a.), glyphosate + sulfentrazone (960 + 150 g ha-1 e.a./i.a.) e glyphosate + sulfentrazone (960 + 200 g ha-1 e.a./i.a.) aplicados 0 DAS, além de um tratamento controle. Avaliações visuais de controle foram efetuadas aos 7 e 0 DAS, aos 14 e 45 dias depois da semeadura (DDS) e a produtividade da soja estimada. A aplicação do herbicida diclosulam é eficaz no controle de algodão voluntário, quando aplicado 50, 20 e 0 DAS, nas doses de 25,2 e 35 g ha-1 i.a. O tratamento sulfentrazone é eficaz, quando aplicado 0 DAS nas doses de 150 e 200 g ha-1 i.a., enquanto o herbicida flumioxazin não é eficaz. No controle de Eleusine indica o diclosulam foi o melhor tratamento quando aplicado 0 DAS a 25,2 e 35 g ha-1 i.a. A produtividade foi considerada igual entre tratamentos.
This study recorded the choice of dry plant of Conyza spp as oviposition site by cicada Quesada gigas (Olivier, 1790). We presented issues of natural history of the cicadas that indicate the inability of immatures to complete life cycle in this species of plant. Some implications on cultures where Q. gigas has economic importance are also discussed.
In this present studies, characterization of raw and ripen of banana peels waste of Musa aluminata balbisiana (MBS), Musa acuminata Cavendish subgroup (MCS) and Musa acuminata Colla (MES) were performed using proximate analysis. The results shows that the peel waste of MCS is contained the higher moisture content (87.58%) followed by MBS and MES with the percentage of 86.57% and 82.97% respectively. However, the volatile content was showed that MES was exhibited the higher percentage with the values of 4.18%, meanwhile, followed by MBS and MCS with the values of 0.57% and 0.18 % respectively. At the optimum condition of soxhlet extraction method, the extraction recovery of MBS, MCS and MES were 39.53 %, 62.42 % and 39.53 % respectively and oil obtained were 3.6 ml, 5.3 mL and 3.0 mL respectively. Morphological study revealed that there are existed a bundle of follicular gel which contribute to the presence of oil in banana peel wastes.
Distributed generation (DG) sources are being installed in distribution networks worldwide due to their numerous advantages over the conventional sources which include operational and economical benefits. Random placement of DG sources in a distribution network will result in adverse effects such as increased power loss, loss of voltage stability and reliability, increase in operational costs, power quality issues etc. This paper presents a methodology to obtain the optimal location for the placement of multiple DG sources in a distribution network from a technical perspective. Optimal location is obtained by evaluating a global multi-objective technical index (MOTI) using a weighted sum method. Clonal selection based artificial immune system (AIS) is used along with optimal power flow (OPF) technique to obtain the solution. The proposed method is executed on a standard IEEE-33 bus radial distribution system. The results justify the choice of AIS and the use of MOTI in optimal siting of DG sources which improves the distribution system efficiency to a great extent in terms of reduced real and reactive power losses, improved voltage profile and voltage stability. Solutions obtained using AIS are compared with Genetic algorithm (GA) and Particle Swarm optimization (PSO) solutions for the same objective function. Copyright © 2017 Institute of Advanced Engineering and Science. All rights reserved.
Background
The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is among the 100 worst invasive species in the world. As one of the most important crop pests and virus vectors, B. tabaci causes substantial crop losses and poses a serious threat to global food security.
Results
We report the 615-Mb high-quality genome sequence of B. tabaci Middle East-Asia Minor 1 (MEAM1), the first genome sequence in the Aleyrodidae family, which contains 15,664 protein-coding genes. The B. tabaci genome is highly divergent from other sequenced hemipteran genomes, sharing no detectable synteny. A number of known detoxification gene families, including cytochrome P450s and UDP-glucuronosyltransferases, are significantly expanded in B. tabaci. Other expanded gene families, including cathepsins, large clusters of tandemly duplicated B. tabaci-specific genes, and phosphatidylethanolamine-binding proteins (PEBPs), were found to be associated with virus acquisition and transmission and/or insecticide resistance, likely contributing to the global invasiveness and efficient virus transmission capacity of B. tabaci. The presence of 142 horizontally transferred genes from bacteria or fungi in the B. tabaci genome, including genes encoding hopanoid/sterol synthesis and xenobiotic detoxification enzymes that are not present in other insects, offers novel insights into the unique biological adaptations of this insect such as polyphagy and insecticide resistance. Interestingly, two adjacent bacterial pantothenate biosynthesis genes, panB and panC, have been co-transferred into B. tabaci and fused into a single gene that has acquired introns during its evolution.
Conclusions
The B. tabaci genome contains numerous genetic novelties, including expansions in gene families associated with insecticide resistance, detoxification and virus transmission, as well as numerous horizontally transferred genes from bacteria and fungi. We believe these novelties likely have shaped B. tabaci as a highly invasive polyphagous crop pest and efficient vector of plant viruses. The genome serves as a reference for resolving the B. tabaci cryptic species complex, understanding fundamental biological novelties, and providing valuable genetic information to assist the development of novel strategies for controlling whiteflies and the viruses they transmit.
Electronic supplementary material
The online version of this article (doi:10.1186/s12915-016-0321-y) contains supplementary material, which is available to authorized users.
There is an increasing policy interest in pesticide taxation schemes as a measure to reduce harmful effects of pesticide use. The effectiveness of such tax depends, however, on the price elasticity of demand for pesticides. Moreover, information on these demand elasticities and their determinants is of crucial relevance for policy-making and normative modeling approaches. In this article, we present a meta-analysis based on studies that have estimated pesticide demand elasticities in Europe and North America. Our meta-analysis reveals that the own-price elasticities of demand for pesticides are, with a median of −0.28, significantly smaller than zero, but also significantly larger than −1, i.e. to be inelastic. We find that the demand for pesticides for special crops is less elastic than that for arable and grassland. In addition, the demand for herbicides is more elastic than for other pesticides. Studies that consider only short-term horizons and little flexibility for farmers to adjust to price changes generate significantly less elastic pesticide demands. The results also indicate that more recent studies identify lower pesticide price elasticities of demand. Furthermore, we find that peer-reviewed studies tend to find more inelastic results compared to grey literature.
Weeds compete with crops for essential inputs, but they are also important hosts for pests, both during the crop and between crops. Hairy fleabane (Conyza bonariensis) is an important weed growing in both summer and winter crops. The aim of this study was to evaluate the occurrence and population fluctuations of soybean pests using hairy fleabane as an alternative host. Samples of hairy fleabane plants were collected fortnightly over twelve months at two sites (Boa Vista do Incra and São Vicente do Sul) in Rio Grande do Sul state, Brazil. The results showed that hairy fleabane plants provided shelter to important soybean pests, including the pentatomid stink bugs Edessa meditabunda, Piezodorus guildinii, Dichelop sp. and Euschistus heros, especially after soybean maturation, and also served as an alternative food source. This weedy species was also an important alternative host for caterpillars such as Anticarsia gemmatalis, Chrysodeixis includens, Spodoptera spp. and Helicoverpa gelotopoeon. © 2016, Sociedade Brasileira da Ciencia das Plantas Daninha. All rights reserved.
A herança genética da resistência ao glyphosate em capim-amargoso (Digitaria insularis) pode ajudar a entender sua disseminação, porém a mesma não foi previamente caracterizada. Estas informações são essenciais para o entendimento da evolução de resistência à herbicidas na agricultura e o fluxo gênico entre plantas resistentes e suscetíveis. Portanto, o objetivo desta pesquisa foi investigar a herdabilidade dos genes de resistência entre os biótipos resistente e suscetível ao glyphosate, através da determinação da suscetibilidade dos biótipos na progênie F1. Para isso foi comparada a suscetibilidade da geração F1 dos biótipos resistente (MG) e suscetível (S), que permaneceram isolados ou induzidos à polinização cruzada através do acondicionamento de panículas em sacos de polinização. O grau de suscetibilidade ao glyphosate foi medido através de curvas de dose-resposta da progênie F1. A geração F1 de plantas oriunda de um possível cruzamento entre os biótipos demonstrou o mesmo padrão de suscetibilidade ao glyphosate que a progênie oriunda da planta mãe. Comparando as médias dos biótipos resistentes com os suscetíveis ao glyphosate foi calculado um fator de resistência de 4,01. Conclui-se que não há a transferência de genes de resistência após indução ao cruzamento entre biótipos, sendo necessários mais estudos para determinar se isso ocorreu devido à espécie ser exclusivamente autógama ou se a resistência é poligênica, não seguindo o modelo de hereditariedade monogênica. Desta forma, a dispersão da resistência do capim-amargoso pode ser atribuída à disseminação de suas sementes, e não à transferência gênica entre biótipos pela polinização cruzada entre plantas, pois o trabalho evidência fecundação cruzada em taxas imperceptíveis pelo estudo.
Biopesticides have the potential to play an important role in sustainable, environmentally safe pest control. A diverse range of biopesticides employ chemical modes of action. This review explores three such biopesticides: a fungus used in weed control, beneficial bacteria controlling fungal and bacterial disease and a virus active against insect pests. Through these case studies, we demonstrate that biopesticides rely on both chemical and biochemical approaches and complementary biological modalities. Hence, biopesticides are more complex than synthetic pesticides. The latter typically utilize a single chemical with a single mode of action, while the former often have more complex or holistic modes of action. The success of current and future biopesticides could be enhanced through increased research focusing on the chemistry involved.
A correta identificação de um inseto de interesse econômico é premissa básica para a solução de qualquer problema entomológico. Ela facilita a busca e a obtenção de toda a informação bibliográfica previamente existente sobre o tema. Entretanto, a identificação é uma atividade difícil, que demanda tempo considerável, tornando-se muitas vezes desestimulante para os não especialistas.
Fatores associados à grande biodiversidade e tamanho reduzido dos insetos, aliados à escassez de informação biológica, complexidade das chaves de identificação disponíveis, dificuldade na interpretação de termos técnicos, além da ausência de ilustrações com boa resolução, justificam o quanto laboriosa é a identificação de insetos.
A idéia pela elaboração de um livro que reduzisse as dificuldades de identificação mencionadas anteriormente surgiu a partir da dissertação de mestrado: “Chave Pictórica de Identificação de Famílias de Insetos Praga-Agrícolas”, de autoria de Ricardo Toshio Fujihara, atualmente Doutorando em Zoologia pelo IBB/UNESP, Botucatu, SP. Em seu trabalho foi desenvolvido um sistema em mídia digital para a reprodução de chaves dicotômicas em formato HTML, com baixo custo e incluindo imagens digitalizadas para auxiliar na identificação de famílias de insetos de importância agrícola, considerando-se às dificuldades até então enfrentadas.
Posteriormente, com a colaboração dos professores Luiz Carlos Forti (Prof. Ass. Dr. Da FCA/UNESP, Botucatu, SP), Maria Christina de Almeida (Prof. Adj. Dr. da UFPR, Curitiba, PR) e Edson Luiz Lopes Baldin (Prof. Ass. Dr. da FCA/UNESP, Botucatu, SP), em conjunto com outros pesquisadores da área foi desenvolvido o livro Insetos de Importância Econômica: Guia Ilustrado para Identificação de Famílias.
O objetivo deste material é disponibilizar informações atuais e mais completas sobre as principais famílias de insetos de importância econômica. De forma prática e didática, visa auxiliar no processo de identificação, por meio de chaves ilustradas e esquemas que complementam o estudo e aprendizado em Entomologia Geral. É uma obra que atende a todos os entusiastas da área de entomologia, principalmente professores, pesquisadores e estudantes.
O livro foi divido em 13 capítulos. Nos capítulos 1, 2 e 3 são abordados conhecimentos gerais sobre a morfologia externa, interna e a reprodução e desenvolvimento dos insetos. O capítulo 4 contempla a “Chave para ordens da Classe Insecta (adultos)”. Os capítulos de 5 a 13 descrevem, de maneira geral, as principais ordens e famílias de importância econômica que ocorrem no Brasil, e apresentam ao seu final, chaves de identificação para a maioria das famílias abordadas no texto.
As imagens digitalizadas e esquematizadas nestes capítulos representam seu maior diferencial, com relação às chaves de identificação encontradas na literatura brasileira. Embora algumas das famílias descritas no texto e presentes nas chaves não apresentam importância econômica, são de ocorrência comum nas coleções entomológicas e, portanto, importantes discriminantes para as dicotomias, auxiliando no processo de identificação. O livro apresenta também um glossário, que facilita a compreensão e entendimento da terminologia utilizada ao longo da obra.
Considerando-se à carência de materiais relativos à Entomologia Geral no Brasil, este livro poderá representar uma importante contribuição. Suas imagens em alta resolução são pioneiras neste tipo de publicação e poderão reduzir o tempo e facilitar o aprendizado na identificação das principais famílias de insetos de importância econômica que ocorrem no Brasil.
Alimentos fritos são muito consumidos no Brasil e no mundo. Sabe-se que a fritura é um processo complexo e oferece riscos à saúde humana. Um dos objetivos desta revisão foi apresentar as principais alterações físicas (escurecimento, viscosidade e formação de espuma) e químicas (hidrólise e auto-oxidação) que ocorrem nos óleos e/ou gorduras durante o processo de fritura. Outro objetivo foi abordar os principais fatores envolvidos na degradação do óleo e/ou da gordura de fritura (temperatura e tempo de fritura; relação superfície/volume; tipo de aquecimento; tipo de óleo; adição de óleo novo; natureza e quantidade do alimento frito; presença de contaminantes metálicos e equipamento utilizado, além da presença de antioxidantes). Foram também apresentados alguns métodos de controle de qualidade de óleo ou de gordura de fritura existentes (quantificação de compostos polares totais, acidez, índice de peróxidos, valor de p-anisidina e métodos rápidos de quantificação). Por fim, foram relacionadas as regulamentações vigentes sobre o processo de fritura, os efeitos dos compostos degradados sobre a saúde humana e algumas recomendações para a melhoria da qualidade do óleo ou da gordura de fritura formuladas pelo Informe Técnico nº 11 da Agência Nacional de Vigilância Sanitária.
Cover crops represent a potentially important biological filter during weed community assembly in agroecosystems. This filtering could be considered directional if different cover-crop species result in weed communities with predictably different species composition. We examined the following four questions related to the potential filtering effects of cover crops in a field experiment involving five cover crops grown in monoculture and mixture: (1) Do cover crops differ in their effect on weed community composition? (2) Is competition more intense between cover crops and weeds that are in the same family or functional group? (3) Is competition more intense across weed functional types in a cover-crop mixture compared with cover crops grown in monocultures? (4) Within a cover-crop mixture, is a higher seeding rate associated with more effective biotic filtering of the weed community? We found some evidence that cover crops differentially filtered weed communities and that at least some of these filtering effects were due to differential biomass production across cover-crop species. Monocultures of buckwheat and sorghum-sudangrass reduced the number of weed species relative to the no-cover-crop control by an average of 36 and 59% (buckwheat) and 25 and 40% (sorghum-sudangrass) in 2011 and 2012, respectively. We found little evidence that competition intensity was dependent upon the family or functional classification of the cover crop or weeds, or that cover-crop mixtures were stronger assembly filters than the most effective monocultures. Although our results do not suggest that annual cover crops exert strong directional filtering during weed community assembly, our methodological framework for detecting such effects could be applied to similar future studies that incorporate a greater number of cover-crop species and are conducted under a greater range of cover-cropping conditions.
In Brazil, the tomato is cultivated in almost all geographic regions even though its yield is significantly reduced by pests and diseases. Among these pests and diseases, whitefly is a major problem that causes direct and indirect damage due to its role in transmission of geminiviruses. The aim of the present study was to compare the degree of resistance to the silverleaf whitefly of tomato plant lines rich in acyl sugars (AS), zingiberene (ZGB), and 2-tridecanone (2-TD) and to establish whether selection for strains with higher densities of glandular trichomes promotes sufficient resistance to this insect pest. The investigated lines were developed by performing back-crossings in tomato (Solanum lycopersicum) from the interspecific crossing of S. lycopersicum x S. habrochaites var. glabratum 'PI 134417'. Lines rich in AS, ZGB, and 2-TD were tested for their levels of resistance to B. tabaci biotype B. Two tomato plant lines (TOM-584 and TOM-679) with normal AS levels and one wild specimen (PI 134417) with high 2-TD content were used as controls. TOM-687, ZGB-703, and TOM-622 were less preferred by B. tabaci for oviposition, and nymphs exhibited a poorer survival rate on those plant lines than on the susceptible controls, TOM-584 and TOM-679. Allelochemical-rich lines exhibited pest resistance, whereas the controls did not, and the allelochemical-rich lines did not differ significantly from each other in the level of resistance. The results show that the development of tomato plant lines rich in 2-TD, ZGB and AS is an effective option for indirect selection for resistance to B. tabaci biotype B. All lines selected based on high trichome density except for BPX-365F-751-05-01-03 exhibited fewer nymphs than the susceptible controls, indicating that selection for more glandular trichomes was generally effective in promoting increased resistance to the silverleaf white flay.
O presente trabalho foi conduzido na Estação Experimental da Universidade Federal do Tocantins, Gurupi-TO, Brasil. O experimento foi instalado com o objetivo de avaliar durante 60 dias, em campo, a interferência de oito espécies utilizadas freqüentemente como adubos verdes (Mucuna aterrima, Mucuna pruriens, Crotalaria ochroleuca, Crotalaria spectabilis, Canavalia ensiformis, Cajanus cajan, Pennisetum americanum e Sorghum bicolor, híbridoBR304) sobre a comunidade infestante. As espécies de plantas daninhas mais freqüentes na área do experimento foram: Digitaria horizontalis, Hyptis lophanta e Amaranthusspinosus. Foram realizadas amostragens aos 15, 30, 45 e 60 dias após a formação da cobertura, utilizando um quadrado de amostragem equivalente a 0,25 m2. As plantas daninhas foram devidamente identificadas, coletadas, secas e pesadas. O delineamento experimental utilizado foi inteiramente casualizado e constou de nove tratamentos, com quatro repetições cada. Verificou-se que as espécies C. spectabilis, S. bicolor, C. ochroleuca, M. aterrima e M.pruriens reduziram significativamente o número e o peso da matéria seca da população das plantas daninhas avaliadas (D. horizontalis, H. lophanta e A. Spinosus), principalmente as duas últimas, enquanto P. americanum mostrou-se a menos eficiente nesse aspecto.
Continuing outbreaks of Tomato yellow leaf curl virus (TYLCV) in southern Florida emphasize that the vector of the virus, biotype B of the sweetpotato whitefly (SPWF), Bemisia tabaci (Gennadius) (also known as the silverleaf whitefly, B. argentifolii Bellows & Perring), remains the key insect pest of tomatoes in Southern Florida. Growers rely heavily on insecticidal programs to combat the whiteflies and subsequent virus outbreaks. Transplants in the production house are drenched with the neonicotinoid
O plantio direto do tomateiro é um sistema que busca maior sustentabilidade, porém são escassas as informações sobre o manejo de plantas daninhas nessa nova modalidade de cultivo. O objetivo deste trabalho foi avaliar cinco tipos de cobertura do solo (Brachiaria decumbens, B. ruziziensis, Pennisetum glaucum, comunidade infestante e tratamento sem cobertura vegetal) para plantio direto do tomateiro rasteiro, conduzido no sistema meia estaca, em complementação ao controle químico com herbicidas. P.glaucum foi a espécie que proporcionou maior cobertura do solo até a colheita do tomate; todavia, a taxa de decomposição da palha foi maior que a das demais coberturas. As coberturas de solo compostas pelas gramíneas forrageiras B. decumbens, B. ruziziensis e Pennisetumglaucum reduziram a densidade e a massa seca das plantas daninhas. O uso da comunidade infestante para obtenção de palha promoveu reduzida cobertura do solo e elevada emergência de plantas daninhas, semelhantes às do solo sem cobertura. B. decumbens apresentou rebrota durante o ciclo do tomateiro, o que não ocorreu com B. ruziziensis.
Ultrasound assisted extraction (UAE) is widely used in recent times for its benefits, but it is difficult to find literature that comprehensively addresses the effect of UAE-specific parameters such as temperature, frequency, power, solvent type, and solvent to material ratio on extracted compounds and their functionality. There is no review done so far on the effects of all UAE parameters on polyphenol extracts to guide the design of extraction protocols. This review therefore focuses on the effects of UAE parameters on the yield and composition, as well as the effects of the UAE on the antioxidant, anticancer, and antimicrobial properties of phenolic extracts. Higher extraction temperatures above 50 °C are degradative to polyphenols in extracts; lower frequencies within the power ultrasound range below 40 kHz are most effective; polyphenol yield generally increases with increasing power, but with a threshold, beyond which no significant increase is observed; and higher ultrasound power produces free hydroxyl radicals which degrade polyphenols, especially in the presence of high water content. A comparative assessment of literature showed that, UAE does not only contribute to increased extraction yield of polyphenols, but also better preserves and increases the biological activity of polyphenol extracts compared to traditional maceration and Soxhlet extraction. A full picture of UAE is given to serve as a reference material on the control of UAE parameters for desired results and efficiency.
In this work, waste cupuaçu seeds were calcined for 4 h at 800 °C and evaluated as a heterogeneous catalyst for the biodiesel synthesis. The catalyst (CCS) was characterized by X-ray powder diffraction (XRD), wavelength dispersive x-ray fluorescence (WDXRF), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric and differential thermal analysis (TG-DTA) and soluble alkalinity. The catalytic activity was evaluated by CCS-catalyzed ethanolysis of soybean oil and the process was optimized using response surface methodology (RSM) and analysis of variance (ANOVA). The significance of the different process parameters and their combined effects were established through a central composite design (CCD) and the optimum process (catalyst loading of 10% (w/w) relative to oil mass, reaction time 8 h, ethanol:oil molar ratio 10:1 and temperature 80 °C) resulted in a conversion of 98.36% with good agreement with predicted conversion, 97%. The catalyst was recycled, maintaining its great catalytic activity and resulting in conversions close to 98% in the first two cycles. The high potential of CCS as a catalyst for biodiesel production was demonstrated.
In this paper, ultrasound-assisted extraction (UAE) of oil from Moringa peregrina seeds was studied and compared with the Soxhlet method. Based on the response surface methodology (RSM), the extraction process variables such as liquid-to-solid ratio, ultrasound power, extraction time and temperature were investigated to achieve the highest yield. By screening these parameters, it was concluded that the liquid-to-solid ratio (mL/g) and extraction time were the significant parameters for oil extraction from Moringa peregrina using ultrasound treatment. The best possible range for the liquid-to-solid ratio (5-20 mL/g), extraction time (5-30 min), and optimum ultrasound power (348 W) as well as extraction temperature (30 °C) was obtained according to the single factor experiments. Afterward, the optimum process conditions which were determined by central composition design (CCD) to reach the maximum oil extraction yield (53.101%) were found to be 26.3 min for extraction time and 17.8 mL/g for the liquid-to-solid ratio. In addition, the gas chromatography analysis and the physiochemical characteristics of oil extracts obtained through UAE and Soxhlet techniques including peroxide value (PV), antioxidant activity (DPPH%), total phenolic content (TPC), iodine value (IV), thermal stability, crystallization, and melting behavior were determined and compared.
Agriculture is the major source of livelihood for nearly half of the Indian population. However, the productivity of crops is much lower than many countries and needs enhancement to produce ∼400 million tons of food grains for meeting food demands of a population of 1.7 billion by 2050. Diverse climatic conditions in India favor the most adopted weeds to prevail and cause severe crop yield losses. Weeds also degrade quality of the produce, raise cost of production; harbor and serve as alternate hosts to several insect pests and diseases. Parthenium hysterophorus L.; Phalaris minor Retz.; Leptochloa chinensis (L.) Nees.; Echinochloa spp.; weedy rice; Lantana camara L.; Chromolaena odorata (L.) R.M. King & H. Rob.; Mikania micrantha Kunth., are a few of many major weeds of concern currently in India. Weed management in India is critical to improve crops productivity by minimizing weeds caused crop yield losses and to alleviate other adverse effects of weeds in different ecosystems. In spite of the progress made in evolving weed management technologies for different crops and other ecosystems, weeds continue to be a concern in varying ecosystems. The real challenges of Indian weed research are: managing weeds in small farms; non availability of labor and mechanical tools; inadequate information on weed biology and shifts in weed flora; herbicide resistant weeds; lack of understanding on the impact of climate change on weeds and weed control; popularizing integrated weed management with herbicides use by ensuring safe use to avoid adverse effect on human health, environment and avoid weeds developing herbicide resistance and prevention of entry and management of alien invasive weeds. The greatest opportunity of Indian weed science is the potentiality of appropriate weed management technologies to substantially improve the crops productivity. Thus, weed scientists have a greater role to play in the development, popularization and adoption of location specific effective, economical and eco-friendly weed management technologies for different ecosystems of India.
Weeds represent a significant challenge to successful crop production. Highly effective and sustainable weed control is required in order to meet global food demand. In this context, excessive use of herbicides has resulted in serious environmental and ecological issues. There are several weed control options which neither harm the environment nor require a significant increase in cost of production. Improving crop competition is particularly important and attractive among such options, which can be achieved by using crop cultivars possessing a competitive advantage over weeds, and manipulating the seed rate and direction of crop rows. Crop cultivars possessing traits such as fast germination, quick growth, high biomass, and large leaf area have a competitive advantage over weeds. Sowing such cultivars has been shown to suppress weeds in various crops. The use of high seed rates and narrow row spacing, if properly manipulated, can cause a significant decrease in weed proliferation in the crops. These techniques (cultivar, seed rate, row spacing, and row direction) are under-exploited as weed control methods, and offer considerable potential for achieving environmentally benign weed management. This special issue on ?Eco-friendly Weed Management? will address the role of crop competition in managing weeds in different crops as well as in different countries.
Thermal profiles of buriti pulp oil (Mauritia flexuosa Mart.), tucumã pulp and kernel oils (Astrocarium vulgare Mart.), rubber seed oil (Hevea brasiliensis), passion fruit oil (Passiflora edulis) and ucuúba butter (Virola surinamensis) were analyzed by thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC). Gas chromatography and calculated iodine values were performed to determine the fatty acid profile and to measure the degree of unsaturation in these oils, respectively. The TG curves showed three steps of mass loss, which can be attributed to the degradation of polyunsaturated, monounsaturated and saturated fatty acids. The DSC crystallization and melting curves are reported and depended on the fatty acid composition. Usually, oil samples with a high degree of saturation showed crystallization and melting profiles at higher temperatures than the oils with a high degree of unsaturation. The data obtained by physicochemical analysis of oil samples were analyzed by principal component analysis and hierarchical cluster analysis to increase understanding of the data set, examining the presence or absence of natural groupings between samples.
Voltage stability assessment is a major issue in monitoring the power system stability. Different voltage stability indices (VSIs) have been proposed in the literature for voltage stability assessment. These indices can be used for distributed generation (DG) placement and sizing, detecting the weak lines and buses and triggering the countermeasures against voltage instability. This paper reviews the VSIs from different aspects such as concepts, assumptions, critical values and equations. The review results provide a comprehensive background to find out the future works in this field and select the best VSI for different applications like DG placement and sizing and voltage stability assessment.
The intensive use of synthetic herbicides is questioned for many reasons. Bioherbicides, as integrated weed management tools, however, have the potential to offer a number of benefits such as increased target specificity and rapid degradation. Despite the efforts to identify effective bioherbicide agents in laboratory and field, only thirteen bioherbicides are currently available on the market. Since 1980, the number of biopesticides has increased around the world, while the market share of bioherbicides represents less than 10% of all biopesticides. Nevertheless, weed management implemented at the cropping systems scale needs bioherbicides because of legislation to drive weed management away from heavy reliance on chemicals, the global increase in organic agriculture, the need of both organic and conventional agriculture to increase weed control efficiency, concerns about herbicide resistance, and concern from the public about environmental safety of herbicides. Consequently, we review here the existing products on the market and describe their history, mode of action, efficacy and target weeds. This review is unique because we also discuss the role of bioherbicides in integrated weed management: to manage soil weed seedbanks with seed-targeted agents in addition to primary tillage, to increase the efficacy of mechanical weeding because bioherbicides are more effective on seedlings, to increase the suppression effect of crop cultivars by first slowing weed growth, to terminate cover crops particularly in conservation agriculture, and finally to manage herbicide resistant populations.
Two experiments were carried out under greenhouse conditions to study the accumulation and distribution of dry mass and macronutrients in maize and Ipomoea hederifolia. Plants of both species had grown, separately, in pots with sand substrate and irrigation with nutrient solution. Treatments were represented by the times of evaluation, realized in intervals of 14 days, starting at 21 days after emergence (DAE). A maize plant showed slight growth up to 30 DAE, when dry mass allocation was higher in roots and leaves (80%); while an I. hederifolia plant, up to 50 DAE, when the allocation of dry mass was higher in offshoots and leaves (79). Dry mass accumulation was almost five times greater in maize (134 g per plant) than in I. hederifolia (29 g per plant). The average values of N and K contents were greater in I. hederifolia. Maximum accumulations of macronutrients by maize were 1,431; 474; 1,832; 594; 340, and 143 mg per plant, while by I. hederifolia, 727; 52; 810; 350; 148, and 65 mg per plant, for N, P, K, Ca, Mg, and S, respectively. Mean accumulation rate of dry mass and macronutrients by maize plants was crescent up to 87 DAE, reaching the maximum value at 103 DAE; while being crescent up to 121 DAE by I. hederifolia plants, reaching the maximum value at 138 DAE. Thus, beyond the interference on harvesting process, a population of I. hederifolia also can compete with maize crop for nutrients.
Agriculture is facing an enormous challenge: it must be ensured that enough high-quality food is available to meet the needs of a continuously growing population. Current and future agronomic production of food, feed, fuel and fibers requires innovative solutions for existing and future changes and challenges, like climate change, upcoming resistance to pestsincreased regulatory demands, and renewable raw materials or requirements resulting from food chain partnerships. Modern agricultural chemistry has to support farmers to manage these tasks. Today, so-called "side-effects" of agrochemicals regarding yield and quality are gaining more importance. Agrochemical companies with a strong research and development focus will have the opportunity to shape the future of agriculture by delivering innovative integrated solutions. This review gives a comprehensive overview about the innovative products launched over the last ten years and describes the progress of modern agricultural chemistry and its future prospects.
Brazil is rich in oil plants that have natural antioxidants in their constitution, among which “pequi” (Caryocar coriaceum) stands out, a fruit represented by several species and the most common in the Northeastern Brazilian states such as Ceará and Pernambuco. This fruit has a lot of oil which can be used for nutritional and medicinal purposes. The aim of this research was to study the oil extraction process from pequi pulp, the quality of the extracts, kinetic modeling, and extraction with subcritical propane. Pequi fruits were extracted and their pulps were dried and ground. The oil extracted with subcritical propane was obtained at a pressure range of 5–15 MPa and temperatures of 303.15–333.15 K. The highest yield was 43.69% for the extraction condition of 15 MPa and 333.15 K. Ethanol and ethyl acetate were used in concentrations of 10–25% (volume) as solvent modifiers to obtain yields up to 44.99%. Soxhlet extractions were performed using ethanol and hexane as solvents and higher yield (52.78%) was obtained with the use of ethanol. The fatty acid analysis showed that different experimental conditions did not impact the fatty acid profile. The fatty acids found at greater proportion were palmitic acid (35.4%, in mass) and oleic acid (60.6%, in mass). The phenolic compound content was determined by the Folin-Ciocalteu method and showed no significant difference among the extraction methods used. Different mass transfer models (Crank, Sovová, and Martinez models) reported in the literature were used to model the extraction curves. The Sovová model had the best fit to the experimental data.
Functional and nutritional quality of oils is the most important parameter in food-related areas of study. The applicability of these products depends directly on the cost-benefit analysis and extraction yield. The objective of this study was to evaluate the yield, nutritional quality, and thermaloxidative stability of the Brazil nut oil obtained by supercritical carbon dioxide extraction under different conditions of temperature and pressure. The results showed that the highest extraction yield was obtained at pressure of 300 bar and temperature of 60 °C. The quality and colorimetric evaluations revealed a material with strong tendency to yellow color. Its fatty acid profile showed predominance of unsaturated fatty acids (75%). It was thermally stable under progressive temperature increases up to 300 °C. The oxidative stability showed oxidation induction time around 14.85 h. The spectroscopic profile confirms the quality of the oil obtained without the presence of carbon compounds that could indicate oxidative degradation.
