RESUMEN

Leucoptera coffeella (Lepidoptera: Lyonetiidae) is one of the main pests in coffee crops. The economic injury level (EIL) is the lowest density of the pest at which economic damages match the costs of control measures. The economic threshold (ET) is the density of the pest at which control measures must be taken so that this population does not reach the EIL. These are the main indices used for pest control decision-making. Control of L. coffeella is carried out by manual, tractor, airplane or drone applications. This work aimed to determine EILs and ETs for L. coffeella as a function of insecticide application technology in conventional and organic Coffea arabica crops. Data were collected over five years in commercial C. arabica crops on seven 100 ha central pivots. The cost of control in organic crops was 16.98% higher than conventional. The decreasing order of control cost was manual > drone > airplane > tractor application. Coffee plants were tolerant to low densities (up to 15% mined leaves) of the pest that caused losses of up to 6.56%. At high pest densities (54.20% mined leaves), losses were high (85.62%). In organic and conventional crops and with the use of different insecticide application technologies, EIL and ET were similar. The EIL and ET were 14% and 11% of mined leaves, respectively. Therefore, these indices can be incorporated in integrated pest management programs in C. arabica crops. The indices determined as a function of insecticide application technology in organic and conventional coffee are important as they serve producers with different technological levels. Additionally, EILs and ETs can contribute to more sustainable production, as control methods will only be employed when the pest density reaches these indices.

RESUMEN

BACKGROUND: 4-hydroxychlorothalonil (HCT, R182281), a transformation product of the fungicide chlorothalonil, was recently identified in human serum and breast milk. There are indications that HCT may be more toxic and environmentally persistent than chlorothalonil. OBJECTIVE: Our aim was to investigate serum concentrations of HCT in pregnant women in Sweden and Costa Rica. METHODS: We developed a quantitative analytical method for HCT using liquid chromatography tandem mass spectrometry. We measured HCT in 1808 serum samples from pregnant women from the general population in Sweden (1997-2015) and in 632 samples from 393 pregnant women from an agricultural population in Costa Rica (2010-2011). In Swedish samples, we assessed time trends and investigated seasonality. In the Costa Rican samples, we evaluated variability between and within women and explanatory variables of HCT concentrations. RESULTS: HCT was detected in all serum samples, and the limit of detection was 0.1 µg/L. The median HCT concentration in the Swedish samples was 4.1 µg/L (interquartile range [IQR] of 2.9 - 5.8 µg/L), and 3.9 times higher in the Costa Rican samples (median: 16.1 µg/L; IQR: 10.6 - 25.0 µg/L). We found clear seasonal variation with higher concentrations in the first half of each year among Swedish women. In the Costa Rican study, women working in agriculture and living near banana plantations had higher HCT concentrations, whilst higher parity and having a partner working in agriculture were associated with decreased HCT, and no clear seasonal pattern was observed. IMPACT STATEMENT: For the first time, this study quantifies human exposure to the fungicide chlorothalonil and/or its transformation product 4-hydroxychlorothalonil (HCT, R182281) and finds higher serum concentrations in women from a tropical agricultural setting as compared with women from the general population in Sweden.

RESUMEN

BACKGROUND: Here we report the residual efficacy of the neonicotinoid insecticide clothianidin against pyrethroid-resistant Aedes aegypti. We first conducted a range-finding evaluation of clothianidin on three different substrates (wall, wood, cloth) using three doses (100, 300 and 600 mg a.i. m-2 ) and conducting World Health Organization (WHO) cone bioassays to assess acute (24 h) and delayed (up to 7 days) mortality. In experimental houses located in Merida (Mexico) and using free-flying pyrethroid-resistant Ae. aegypti females, we quantified the acute and delayed mortality after a 24-h exposure to the targeted indoor residual spraying (TIRS) of two clothianidin doses (100 and 300 mg a.i. m-2 ). RESULTS: Range-finding studies with WHO cones showed low (<50%) acute mortality for all surfaces, doses and times post spraying. Delayed mortality was higher, with average values above or close to the 60% mark (and 95% confidence interval estimates crossing 80% for the 600 mg a.i. m-2 dose). In experimental houses, a similar low acute mortality was quantified (range of mortality across 12 months was 2-44% for 100 mg a.i. m-2 and 8-61% for 300 mg a.i/m2 ). However, delayed mortality showed a strong effect of clothianidin on free-flying Ae. aegypti, with values above 80% up to 7 months post-TIRS. CONCLUSION: Novel residual insecticide molecules have a promising outlook for Ae. aegypti control and can contribute to the expansion and adoption of TIRS in urban areas. clothianidin can contribute to the control of resistant Ae. aegypti and provide residual control for up to 7 months after application. © 2022 Society of Chemical Industry.

Asunto(s)

Aedes , Insecticidas , Piretrinas , Animales , Femenino , Insecticidas/farmacología , Piretrinas/farmacología , Control de Mosquitos , Resistencia a los Insecticidas , Neonicotinoides/farmacología

RESUMEN

Agriculture is one of the most important commercial activities worldwide since it contributes to a great amount of the nation's gross domestic product, labor opportunities, and food production. However, on the other hand, current industrial agriculture is extremely dependent on chemicals, both pesticides and fertilizers that are a serious threat to the health of people and the environment. Despite the advent of new technologies like unmanned aerial spraying systems (UASS), regulations surrounding the aerial spraying of pesticides to accommodate the benefits and limitations necessary to ensure the protection of humans and ecosystems are still scarce. High concentrations of chemical substances released by drones in a spray solution at improper altitudes, inappropriate ambient temperatures, or with incorrect droplet sizes increase the risk of phytotoxicity effects and spreading to non-target areas, potentially contaminating non-resistant neighboring crops, agricultural workers, and surrounding communities. Following the increase in the number of aircraft, the contamination events due to the drift events of pesticides increased parallelly. Research points out that “technical drift” may reach up to 19% of the sprayed volume, which does not reach the target, but goes to the soil, water, air, nearby plantations, and communities. Exposure to pesticides in smaller and regular doses can lead to chronic health conditions, which is much more difficult to study and prove. In some cases, illnesses develop years or decades after exposure but still are of great concern since the use of pesticides, notably in highly agricultural countries, has increased greatly to reach food and commodities demand.

RESUMEN

The objective of this work has been to evaluate the efficiency of the effect of the addition of four types of adjuvants in the spray solution used in the soybean (Glycine max L.) crop. The experimental design was the randomized blocks with five treatments based on the application of adjuvants, as follows: without adjuvant (control) and with the adjuvants Blend®, Tech-Plus®, LI700®, and Protect®. For qualification, the number of droplets, relative dispersion, volume median diameter, volume applied to the target, droplet density, and percentage of coverage in the upper, middle, and lower third positions of the crop, as well as yield components, 1000-grain weight, and productivity were measured. In the upper third, the adjuvant Protect® presented the lowest relative dispersion, resulting in greater droplet spectrum homogeneity. In the middle third, the application with the adjuvant LI700® promoted greater effectiveness, and the application without adjuvants provided a greater number of droplets in the lower third of the crop. In the middle and lower position, the adjuvant Protect® presented a low-quality application, manifested by the lower number of droplets, applied volume, and droplet density. There was no significant difference in yield components resulting from the adverse weather conditions during the experiment. The addition of adjuvants showed greater application efficiency in the upper and middle third of the.(AU)

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O objetivo deste trabalho foi avaliar a eficiência do efeito da adição de quatro tipos de adjuvantes na calda de pulverização empregada na aplicação da cultura da soja (Glycine max L.). O delineamento experimental foi de blocos ao acaso, com cinco tratamentos baseados na aplicação de adjuvantes, sendo: sem adjuvante (testemunha), e com adjuvantes Blend®, Tech-Plus®, LI700® e Protect®. Para qualificação foi mensurado o número de gotas, dispersão relativa, diâmetro médio volumétrico, volume aplicado no alvo, densidade de gotas e porcentagem de cobertura nas posições terço superior, médio e inferior da cultura, bem como, componentes de rendimento, massa de mil grãos e produtividade. No terço superior, o adjuvante Protect® apresentou a menor dispersão relativa, resultando em maior homogeneidade do espectro de gotas. No terço médio, aplicação com adjuvante LI700® promoveu maior efetividade na aplicação, sendo que a aplicação sem adjuvantes, proporcionou maior número de gotas no terço inferior da cultura. Na posição mediana e inferior, o adjuvante Protect® apresentou uma baixa qualidade de aplicação, manifesta pelo menor número de gotas, volume aplicado e densidade de gotas. Não houve diferença significativa nos componentes de rendimento, fato advindo das condições climáticas adversas durante o experimento. A adição de adjuvantes demonstrou maior eficiência de aplicação no terço superior e médio da cultura.(AU)

Asunto(s)

Glycine max/crecimiento & desarrollo , Adyuvantes Inmunológicos/efectos adversos , Producción de Cultivos

RESUMEN

The pandemic by COVID-19 is causing a devastating effect on the health of the global population. Currently, there are several efforts to prevent the spread of the virus. Among those efforts, cleaning and disinfecting public areas have become important tasks and they should be automated in future smart cities. To contribute in this direction, this paper proposes a coverage path planning method for a spraying drone, an unmanned aerial vehicle that has mounted a sprayer/sprinkler system, that can disinfect areas. State-of-the-art planners consider a camera instead of a sprinkler, in consequence, the expected coverage will differ in running time because the liquid dispersion is different from a camera's projection model. In addition, current planners assume that the vehicles can fly outside the target region; this assumption can not be satisfied in our problem, because disinfections are performed at low altitudes. Our method presents i) a new sprayer/sprinkler model that fits a more realistic coverage volume to the drop dispersion and ii) a planning method that efficiently restricts the flight to the region of interest avoiding potential collisions in bounded scenes. The algorithm has been tested in several simulation scenes, showing that it is effective and covers more areas with respect to two approaches in the literature. Note that the proposal is not limited to disinfection applications, but can be applied to other ones, such as painting or precision agriculture.

RESUMEN

BACKGROUND: Haiti is planning targeted interventions to accelerate progress toward malaria elimination. In the most affected department (Grande-Anse), a combined mass drug administration (MDA) and indoor residual spraying (IRS) campaign was launched in October 2018. This study assessed the intervention's effectiveness in reducing Plasmodium falciparum prevalence. METHODS: An ecological quasi-experimental study was designed, using a pretest and posttest with a nonrandomized control group. Surveys were conducted in November 2017 in a panel of easy access groups (25 schools and 16 clinics) and were repeated 2-6 weeks after the campaign, in November 2018. Single-dose sulfadoxine-pyrimethamine and primaquine was used for MDA, and pirimiphos-methyl as insecticide for IRS. RESULTS: A total of 10 006 participants were recruited. Fifty-two percent of the population in the intervention area reported having received MDA. Prevalence diminished between 2017 and 2018 in both areas, but the reduction was significantly larger in the intervention area (ratio of adjusted risk ratios, 0.32 [95% confidence interval, .104-.998]). CONCLUSIONS: Despite a moderate coverage, the campaign was effective in reducing P. falciparum prevalence immediately after 1 round. Targeted MDA plus IRS is useful in preelimination settings to rapidly decrease the parasite reservoir, an encouraging step to accelerate progress toward malaria elimination.

Asunto(s)

Insecticidas , Malaria , Haití/epidemiología , Humanos , Insecticidas/farmacología , Malaria/tratamiento farmacológico , Malaria/epidemiología , Malaria/prevención & control , Administración Masiva de Medicamentos , Control de Mosquitos

RESUMEN

In 2017-2019, we conducted the field and vegetation experiments at the field station of Russian State Agrarian University, Moscow Timiryazev Agricultural Academy to study the effect of sodium selenite on the yield and grain quality indicators of white lupine, Dega variety, and spring wheat, Yubileynaya-80 variety. The best way found to use selenium is to spray vegetative plants with 0.01% aqueous sodium selenite solution. The studies have shown an increase in grain yield by 15-17%, crude protein content by 9-15% and crude fat content by 5-7% when treated with sodium selenite. The obtained grain yield of white lupine has a higher feed and nutritional value and is suitable for feeding animals and preparing various types of feed and feed additives. The optimal way to use selenium is spraying vegetative plants before shooting. Treatment with sodium selenite contributes to an increase in wheat yield by 1.5 times. We have established the positive effect of sodium selenite on the quality indicators of wheat grain. An increase in the content of raw gluten and glassiness of grain has been noted, which determines high bread-making qualities.

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Em 2017-2019, conduzimos os experimentos de campo e vegetação na estação de campo da Universidade Agrária Estatal Russa, Academia Agrícola Timiryazev de Moscou, para estudar o efeito do selenito de sódio nos indicadores de rendimento e qualidade de grãos de tremoço branco, variedade Dega, e trigo de primavera, variedade Yubileynaya-80. A melhor maneira encontrada para usar o selênio é pulverizar as plantas vegetativas com solução aquosa de selenito de sódio a 0,01%. Os estudos mostraram um aumento no rendimento de grãos em 15-17%, teor de proteína bruta em 9-15% e teor de gordura bruta em 5-7% quando tratados com selenito de sódio. O rendimento de grãos obtido de tremoço branco tem maior valor alimentar e nutricional e é adequado para alimentação de animais e preparação de vários tipos de rações e aditivos alimentares. A maneira ideal de usar o selênio é pulverizar plantas vegetativas antes de fotografar. O tratamento com selenito de sódio contribui para um aumento no rendimento do trigo em 1,5 vez. Estabelecemos o efeito positivo do selenito de sódio nos indicadores de qualidade do grão de trigo. Observou-se um aumento no teor de glúten cru e vítreo do grão, o que determina altas qualidades de panificação.

Asunto(s)

Triticum/crecimiento & desarrollo , Selenito de Sodio , Lupinus/crecimiento & desarrollo

RESUMEN

Coffee is the most appreciated beverage in worldwide; Brazil is the largest producer and exporter of this commodity. Organochlorine endosulfan was banned from the country in 2013 due to its teratogenic agent-related features. Since then, coffee plantations have experienced increased Hypothenemus hampei infestation rates. The aim of the current study is to assess variations in the rates of Coffea arabica fruits brocaded by H. hampei after the application of entomopathogenic fungal species Beauveria bassiana IBCB66. Experiments were carried out with 'Catuaí' and 'Mundo Novo' cultivars between 2018 and 2020, during the borer transit period. Three experiments were carried out based on the application of the aforementioned fungal species on the investigated coffee plant species, both by spraying and sprinkling, at 30-day intervals; 10 fruits were collected per face of each useful plant in each repetition. The experiment has followed a randomized blocks design with five treatments, including the control, and five repetitions, each. Beauveria bassiana Ecobass (IBCB66) wettable powder spray, at the concentration of 2 × 1013·ha­1, was used in experiments I and II. On the other hand, the mix used in experiment III was prepared with blastospores at concentration of 5 × 1012·ha­1 blastospores + 0.1% Silwet. The sprinkling process in all three experiments has used dry aerial conidia at concentration of 2 × 1013·ha­1. Collected data were subjected to analysis of variance (ANOVA), which was followed by Fisher's test at 5% probability level, in the SISVAR software. More than 35,000 fruits were assessed. In addition to variations between experiments, results have evidenced that the rate of brocaded fruits remained high.

Asunto(s)

Esporas Fúngicas , Control Biológico de Vectores/métodos , Coffea/parasitología , Gorgojos , Beauveria , Riego por Aspersión

RESUMEN

Cowpea [Vigna unguiculata (L.) Walp] is cultivated in tropical and subtropical regions worldwide, but its production is usually limited by boron (B) deficiency, which can be mitigated by applying B via foliar spraying. In plants with nutrient mobility, the residual effect of foliar fertilization increases, which might improve its efficiency. An experiment was carried out to evaluate the concentration and mobility of the B isotopic tracer (10B) in different organs of cowpea plants, after the application of this micronutrient in the growing media and also to leaves. Treatments were designed based on B fertilization as follows: without B in the growth media, with 10B applied via foliar spraying (10B-L), with B in the growth media (substrate) and 10B via foliar spraying (10B-L + B-S), and with 10B in the growth media (substrate) without foliar spraying (10B-S), and a control without fertilization. A redistribution of 10B was observed in new leaves when the element was supplied via foliar spraying, resulting in greater leaf area, dry mass and dry matter production of aerial parts, and also the whole plant. 10Boron was redistributed when applied via foliar spraying in cowpea plants, regardless of the plant's nutritional status, which in turn might increase internal B cycling.

RESUMEN

BACKGROUND: Indoor residual spraying (IRS) of insecticides is a key method to reduce vector transmission of Trypanosoma cruzi, causing Chagas disease in a large part of South America. However, the successes of IRS in the Gran Chaco region straddling Bolivia, Argentina, and Paraguay, have not equalled those in other Southern Cone countries. AIMS: This study evaluated routine IRS practices and insecticide quality control in a typical endemic community in the Bolivian Chaco. METHODS: Alpha-cypermethrin active ingredient (a.i.) captured onto filter papers fitted to sprayed wall surfaces, and in prepared spray tank solutions, were measured using an adapted Insecticide Quantification Kit (IQK™) validated against HPLC quantification methods. The data were analysed by mixed-effects negative binomial regression models to examine the delivered insecticide a.i. concentrations on filter papers in relation to the sprayed wall heights, spray coverage rates (surface area / spray time [m2/min]), and observed/expected spray rate ratios. Variations between health workers and householders' compliance to empty houses for IRS delivery were also evaluated. Sedimentation rates of alpha-cypermethrin a.i. post-mixing of prepared spray tanks were quantified in the laboratory. RESULTS: Substantial variations were observed in the alpha-cypermethrin a.i. concentrations delivered; only 10.4% (50/480) of filter papers and 8.8% (5/57) of houses received the target concentration of 50 mg ± 20% a.i./m2. The delivered concentrations were not related to those in the matched spray tank solutions. The sedimentation of alpha-cypermethrin a.i. in the surface solution of prepared spray tanks was rapid post-mixing, resulting in a linear 3.3% loss of a.i. content per minute and 49% loss after 15 min. Only 7.5% (6/80) of houses were sprayed at the WHO recommended rate of 19 m2/min (± 10%), whereas 77.5% (62/80) were sprayed at a lower than expected rate. The median a.i. concentration delivered to houses was not significantly associated with the observed spray coverage rate. Householder compliance did not significantly influence either the spray coverage rates or the median alpha-cypermethrin a.i. concentrations delivered to houses. CONCLUSIONS: Suboptimal delivery of IRS is partially attributable to the insecticide physical characteristics and the need for revision of insecticide delivery methods, which includes training of IRS teams and community education to encourage compliance. The IQK™ is a necessary field-friendly tool to improve IRS quality and to facilitate health worker training and decision-making by Chagas disease vector control managers.

Asunto(s)

Enfermedad de Chagas/transmisión , Insecticidas/farmacología , Control de Mosquitos/métodos , Mosquitos Vectores/efectos de los fármacos , Triatoma/efectos de los fármacos , Animales , Bolivia , Enfermedad de Chagas/parasitología , Composición Familiar , Femenino , Humanos , Masculino , Control de Mosquitos/instrumentación , Mosquitos Vectores/fisiología , Piretrinas/farmacología , Triatoma/fisiología , Trypanosoma cruzi/fisiología

RESUMEN

OBJECTIVE: Failure to control domestic Triatoma infestans in the Chaco is attributed to vulnerable adobe construction, which provides vector refuges and diminishes insecticide contact. We conducted a pilot to test the impact of housing improvement plus indoor residual spraying (IRS) on house infestation and vector abundance in a rural community in the Bolivian Chaco. METHODS: The intervention included three arms: housing improvement + IRS [HI], assisted IRS [AS] in which the team helped to clear the house pre-IRS and routine IRS [RS]. HI used locally available materials, traditional construction techniques and community participation. Vector parameters were assessed by Timed Manual Capture for 2 person-hours per house at baseline and medians of 114, 173, 314, 389 and 445 days post-IRS-1. A second IRS round was applied at a median of 314 days post-IRS-1. RESULTS: Post-intervention infestation indices and abundance fell in all three arms. The mean odds of infestation was 0.29 (95% CL 0.124, 0.684) in the HI relative to the RS arm. No difference was observed between AS and RS. Vector abundance was reduced by a mean 44% (24.8, 58.0) in HI compared to RS, with no difference between AS and RS. Median delivered insecticide concentrations per house were lower than the target of 50 mg/m2 in >90% of houses in all arms. CONCLUSION: Housing improvement using local materials and community participation is a promising strategy to improve IRS effectiveness in the Bolivian Chaco. A larger trial is needed to quantify the impact on reinfestation over time.

Asunto(s)

Materiales de Construcción/normas , Vivienda/normas , Insectos Vectores , Insecticidas/administración & dosificación , Triatoma , Trypanosoma cruzi , Animales , Bolivia , Enfermedad de Chagas/prevención & control , Participación de la Comunidad , Proyectos Piloto , Población Rural

RESUMEN

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.

Asunto(s)

Herbicidas/farmacología , Imidazoles/farmacología , Tracheophyta/efectos de los fármacos , Calidad del Agua , Análisis de la Demanda Biológica de Oxígeno , Biomasa , Clorofila A/metabolismo , Relación Dosis-Respuesta a Droga , Indicadores Ambientales , Herbicidas/administración & dosificación , Imidazoles/administración & dosificación , Electricidad Estática , Temperatura , Tracheophyta/metabolismo

RESUMEN

The article contains an analysis of the marketing authorizations and the consumption of pesticides in the last decade, as well as their effects on human health and the environment. In the period between 2010 and 2018, the amount of pesticides sold in Brazil increased more than twice as much as the cultivated area in the country. The permissiveness of pesticide governance in Brazil is illustrated by the fact that, of the total chemical active ingredients with register in the country in July 2020, 121 (30.0%) had no use allowed in the European Union (EU). The reason for the ban on the use in the EU of products authorized in Brazil, in the referred period, is associated with the adverse effects on humans and other organisms resulting from exposure to chemical ingredients of pesticides, already described in the scientific literature. Soybean, corn, cotton and sugar cane are among those that had the largest number of new pesticides authorized for use in Brazil between January 2019 and June 2020. Another lack of rigor in pesticide governance is illustrated by the drift, which causes acute and chronic damage to third parties. Another weakness of the Brazilian standard refers to the establishment of a dose value, below which, they would be safe. However, experimental results from studies have shown, for example, that pesticides based on glyphosate, melation and pyriproxifem caused the death of fish embryos in just 24 hours of exposure, regardless of the concentration used, challenging the hypotheses that there is safe dose for exposure to such pesticides. Thus, it is urgent that there is a need not only to increase the scientific rigor of the studies on the subject, but also to promote the public participation in decisionmaking process ensuring the access to all information contained in the dossiers accompanying requests for registration and authorization

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artigo contém uma análise das autorizações para a comercialização e o consumo de agrotóxicos no país na última década, bem como os seus efeitos na saúde humana e no meio ambiente. No período entre 2010 e 2018, a quantidade de agrotóxicos comercializados no Brasil aumentou mais do que o dobro do que cresceu a área cultivada no país. A permissividade da gestão de agrotóxicos no Brasil é ilustrada pelo fato de que, do total de ingredientes ativos químicos com registro no país em julho de 2020, 121 (30%) não tinham uso permitido na União Europeia (EU). A razão da proibição do uso na EU dos produtos autorizados no Brasil, no período referido, está associada aos efeitos adversos a humanos e a outros organismos resultantes da exposição aos ingredientes químicos de agrotóxicos, já descritos na literatura científica. Soja, milho, algodão e cana-de-açúcar constam entre as culturas que tiveram o maior número de novos agrotóxicos com uso autorizado no Brasil entre janeiro de 2019 e junho de 2020. Outra falta de rigor na gestão de agrotóxicos é ilustrada pela deriva, que causa danos agudos e crônicos a terceiros. Adicionalmente, a fragilidade da norma brasileira refere-se ao estabelecimento de um valor de dose, abaixo da qual eles seriam seguros. Contudo, resultados experimentais de estudos mostraram, por exemplo, que os agrotóxicos à base de glifosato, melation e piriproxifem causaram a morte de embriões de peixes em apenas 24 horas de exposição, independentemente da concentração utilizada, desafiando assim a hipótese de que existe dose segura para a exposição a tais produtos. Dessa forma, é urgente não só aumentar o rigor científico dos estudos sobre o tema, mas também promover a participação pública nas tomadas de decisão, garantindo o acesso a todas as informações contidas nos dossiês que acompanham as solicitações de registro e de autorização dos agrotóxicos.

RESUMEN

A aplicação de agroquímicos vem sendo pesquisada e aprimorada ao longo dos anos, porém ainda há uma carência de pesquisas relacionadas à tecnologia de aplicação na cultura da cebola. Neste trabalho,objetivou-se avaliar a interação de diferentes pontas de pulverização e pressões de trabalho sobre a deposição de calda em plantas de cebola e no solo. O experimento foi constituído de 16 tratamentos e cinco repetições, organizados em esquema fatorial 4 x 4, combinando quatro pontas de pulverização (MF 110 015, AD 110 015, TT 110 015 e ADIA 110 02) e quatro pressões de trabalho (207, 276, 345 e 414 kPa). O trabalho foi conduzido em casa de vegetação com plantas cebolas transplantadas em vasos de 8 dm-3 preenchidos com solo. Plantas de cebola com cinco a seis folhas completamente desenvolvidas e placas de Petri acondicionadas no solo foram os alvos biológicos, onde se avaliou a deposição de calda nas plantas e no solo. Utilizou-se o corante azul brilhante como traçador, após a aplicação esse foi recuperado com água destilada e quantificado em espectrofotômetro, para determinação da deposição. A deposição de calda na cebola foi afetada somente pelo fator ponta de pulverização, já no solo foi influenciada pelo modelo de ponta de pulverização, pressão de trabalho e pela interação entre ambos. Concluiu-se que a ponta de impacto (TT 110 015) e a jato plano com indução de ar (ADIA 110 02) foram os modelos que apresentaram maior deposição de calda nas plantas de cebola e no solo. A pressão de trabalho não afetou a deposição de calda nas plantas de cebola. O aumento de pressão incrementou a deposição de calda no solo para as pontas de jato plano (MF 110 015), pré-orifício (AD 110 015) e com indução de ar (ADIA 110 02), contudo não afetou a deposição na ponta de impacto (TT 110 015).

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Pesticide application has been researched and improved over the years, yet there is still a lack of research related to the application technology on onion crops. This work aimed to evaluate the interaction of different spray nozzles and working pressures on the spray deposition on onion plants and the soil. The experiment consisted of sixteen treatments and five replicates, carried out in a 4 x 4 factorial scheme, combining four spray nozzles (MF 110 015, AD 110 015, TT 110 015, and ADIA 110 02) and four working pressures (207 kPa, 276 kPa, 345 kPa, and 414 kPa). The assay was carried out in a greenhouse with onions plants transplanted in pots with a volume of 8 dm-3 with soil. Fully developed onion plants with five to six leaves and soil-conditioned Petri dishes were the biological targets for assessing the spray deposition on the plants and the soil. Bright blue coloring was used as a tracer and, after the application, it was recovered with distilled water and quantified using a spectrophotometer to determine the deposition. Spray deposition on the onion plants was affected only by the spray nozzle factor, while deposition on the soil was influenced by the spray nozzle model, working pressure, and the interaction between them. We concluded that the impact (TT 110 015) and air induction (ADIA 110 02) nozzles were the models that presented the highest spray deposition on the onion plants and the soil. The working pressure did not influence the spray deposition on the onion plants. The increase in working pressure raised the spray deposition on the soil for the flat fan (MF 110 015), pre-orifice (AD 110 015), and air induction (ADIA 110 02) nozzles but did not affect the deposition with the impact nozzle (TT 110 015).

Asunto(s)

Agroquímicos , Análisis del Suelo , Cebollas , Hojas de la Planta/química , Trituración de Residuos Sólidos

RESUMEN

This study evaluated leaf supply of zinc (Zn) and boron (B) using either soluble or sparingly soluble fertilizers in young sweet orange trees. Three experiments were set up in a greenhouse to compare two sources and four doses (control, low, adequate and high) of fertilizers as follows: (i) Experiment I (B): boric acid and calcium borate; (ii) Experiment II (Zn): Zn sulfate and Zn oxide; and (iii) Experiment III (B + Zn): boric acid + Zn Sulfate and Zn Borate. The sparingly soluble sources were effective in increasing the Zn and B leaf concentration. Dry matter of the aerial part increased 18 % with B applications in adequate concentration independent of the B fertilizer sources. In contrast, trees did not grow well with applications of adequate concentration of Zn as Zn Sulfate or high Zn concentration as Zn borate. Superoxide dismutase activity in leaves increased with applications of low concentration of Zn as Zn oxide and decreased with high concentration of Zn from either source. Polyphenol oxidase activity increased with application of adequate concentration of B as boric acid and high concentration of B as calcium borate. Furthermore, the upper concentrations of Zn were toxic in orange trees when the source was Zn sulfate. Increases in plant growth without damage to leaf tissue and positive responses of key enzymes of orange trees in a range of nutrient concentration applications demonstrated the practical use of sparingly soluble fertilizers to supplying B and Zn foliarily to plants.

Asunto(s)

Citrus/química , Compuestos de Boro , Compuestos de Zinc , Micronutrientes/administración & dosificación , Fertilizantes

RESUMEN

A aplicação de agroquímicos vem sendo pesquisada e aprimorada ao longo dos anos, porém ainda há uma carência de pesquisas relacionadas à tecnologia de aplicação na cultura da cebola. Neste trabalho,objetivou-se avaliar a interação de diferentes pontas de pulverização e pressões de trabalho sobre a deposição de calda em plantas de cebola e no solo. O experimento foi constituído de 16 tratamentos e cinco repetições, organizados em esquema fatorial 4 x 4, combinando quatro pontas de pulverização (MF 110 015, AD 110 015, TT 110 015 e ADIA 110 02) e quatro pressões de trabalho (207, 276, 345 e 414 kPa). O trabalho foi conduzido em casa de vegetação com plantas cebolas transplantadas em vasos de 8 dm-3 preenchidos com solo. Plantas de cebola com cinco a seis folhas completamente desenvolvidas e placas de Petri acondicionadas no solo foram os alvos biológicos, onde se avaliou a deposição de calda nas plantas e no solo. Utilizou-se o corante azul brilhante como traçador, após a aplicação esse foi recuperado com água destilada e quantificado em espectrofotômetro, para determinação da deposição. A deposição de calda na cebola foi afetada somente pelo fator ponta de pulverização, já no solo foi influenciada pelo modelo de ponta de pulverização, pressão de trabalho e pela interação entre ambos. Concluiu-se que a ponta de impacto (TT 110 015) e a jato plano com indução de ar (ADIA 110 02) foram os modelos que apresentaram maior deposição de calda nas plantas de cebola e no solo. A pressão de trabalho não afetou a deposição de calda nas plantas de cebola. O aumento de pressão incrementou a deposição de calda no solo para as pontas de jato plano (MF 110 015), pré-orifício (AD 110 015) e com indução de ar (ADIA 110 02), contudo não afetou a deposição na ponta de impacto (TT 110 015).(AU)

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Pesticide application has been researched and improved over the years, yet there is still a lack of research related to the application technology on onion crops. This work aimed to evaluate the interaction of different spray nozzles and working pressures on the spray deposition on onion plants and the soil. The experiment consisted of sixteen treatments and five replicates, carried out in a 4 x 4 factorial scheme, combining four spray nozzles (MF 110 015, AD 110 015, TT 110 015, and ADIA 110 02) and four working pressures (207 kPa, 276 kPa, 345 kPa, and 414 kPa). The assay was carried out in a greenhouse with onions plants transplanted in pots with a volume of 8 dm-3 with soil. Fully developed onion plants with five to six leaves and soil-conditioned Petri dishes were the biological targets for assessing the spray deposition on the plants and the soil. Bright blue coloring was used as a tracer and, after the application, it was recovered with distilled water and quantified using a spectrophotometer to determine the deposition. Spray deposition on the onion plants was affected only by the spray nozzle factor, while deposition on the soil was influenced by the spray nozzle model, working pressure, and the interaction between them. We concluded that the impact (TT 110 015) and air induction (ADIA 110 02) nozzles were the models that presented the highest spray deposition on the onion plants and the soil. The working pressure did not influence the spray deposition on the onion plants. The increase in working pressure raised the spray deposition on the soil for the flat fan (MF 110 015), pre-orifice (AD 110 015), and air induction (ADIA 110 02) nozzles but did not affect the deposition with the impact nozzle (TT 110 015).(AU)

Asunto(s)

Cebollas , Análisis del Suelo , Trituración de Residuos Sólidos , Agroquímicos , Hojas de la Planta/química

RESUMEN

This study evaluated leaf supply of zinc (Zn) and boron (B) using either soluble or sparingly soluble fertilizers in young sweet orange trees. Three experiments were set up in a greenhouse to compare two sources and four doses (control, low, adequate and high) of fertilizers as follows: (i) Experiment I (B): boric acid and calcium borate; (ii) Experiment II (Zn): Zn sulfate and Zn oxide; and (iii) Experiment III (B + Zn): boric acid + Zn Sulfate and Zn Borate. The sparingly soluble sources were effective in increasing the Zn and B leaf concentration. Dry matter of the aerial part increased 18 % with B applications in adequate concentration independent of the B fertilizer sources. In contrast, trees did not grow well with applications of adequate concentration of Zn as Zn Sulfate or high Zn concentration as Zn borate. Superoxide dismutase activity in leaves increased with applications of low concentration of Zn as Zn oxide and decreased with high concentration of Zn from either source. Polyphenol oxidase activity increased with application of adequate concentration of B as boric acid and high concentration of B as calcium borate. Furthermore, the upper concentrations of Zn were toxic in orange trees when the source was Zn sulfate. Increases in plant growth without damage to leaf tissue and positive responses of key enzymes of orange trees in a range of nutrient concentration applications demonstrated the practical use of sparingly soluble fertilizers to supplying B and Zn foliarily to plants.(AU)

Asunto(s)

Compuestos de Boro , Compuestos de Zinc , Citrus/química , Micronutrientes/administración & dosificación , Fertilizantes

RESUMEN

BACKGROUND: Understanding local anopheline vector species and their bionomic traits, as well as related human factors, can help combat gaps in protection. METHODS: In San José de Chamanga, Esmeraldas, at the Ecuadorian Pacific coast, anopheline mosquitoes were sampled by both human landing collections (HLCs) and indoor-resting aspirations (IAs) and identified using both morphological and molecular methods. Human behaviour observations (HBOs) (including temporal location and bed net use) were documented during HLCs as well as through community surveys to determine exposure to mosquito bites. A cross-sectional evaluation of Plasmodium falciparum and Plasmodium vivax infections was conducted alongside a malaria questionnaire. RESULTS: Among 222 anopheline specimens captured, based on molecular analysis, 218 were Nyssorhynchus albimanus, 3 Anopheles calderoni (n = 3), and one remains unidentified. Anopheline mean human-biting rate (HBR) outdoors was (13.69), and indoors (3.38) (p = 0.006). No anophelines were documented resting on walls during IAs. HBO-adjusted human landing rates suggested that the highest risk of being bitten was outdoors between 18.00 and 20.00 h. Human behaviour-adjusted biting rates suggest that overall, long-lasting insecticidal bed nets (LLINs) only protected against 13.2% of exposure to bites, with 86.8% of exposure during the night spent outside of bed net protection. The malaria survey found 2/398 individuals positive for asymptomatic P. falciparum infections. The questionnaire reported high (73.4%) bed net use, with low knowledge of malaria. CONCLUSION: The exophagic feeding of anopheline vectors in San Jose de Chamanga, when analysed in conjunction with human behaviour, indicates a clear gap in protection even with high LLIN coverage. The lack of indoor-resting anophelines suggests that indoor residual spraying (IRS) may have limited effect. The presence of asymptomatic infections implies the presence of a human reservoir that may maintain transmission.

Asunto(s)

Culicidae/parasitología , Malaria Falciparum/epidemiología , Malaria Vivax/epidemiología , Mosquitos Vectores/parasitología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Anopheles/parasitología , Niño , Preescolar , Estudios Transversales , Ecuador/epidemiología , Femenino , Humanos , Malaria Falciparum/parasitología , Malaria Vivax/parasitología , Masculino , Persona de Mediana Edad , Proyectos Piloto , Plasmodium falciparum/fisiología , Plasmodium vivax/fisiología , Prevalencia , Riesgo , Encuestas y Cuestionarios , Adulto Joven

RESUMEN

Commercial aerosolized insecticides can be implemented as a community-based approach to targeted indoor residual spraying against Aedes aegypti, but their efficacy on pyrethroid-resistant mosquitoes has not yet been evaluated. Two commercial aerosolized products (H24 Poder Fulminante Ultra Eficaz®, carbamate, and Baygon Ultra Verde®, pyrethroid) were sprayed on common indoor surfaces e.g., cement, plywood, and cloth, and tested for their residual efficacy on susceptible and field-derived pyrethroid-resistant Ae. aegypti strains using the WHO cone bioassays. Overall, ≥80% 24-h mortality was observed for both products for at least 4 wk regardless of the mosquito strain or surface type used. H24 Poder Fulminante Ultra Eficaz showed the highest residual potency, sustaining >80% mortality for 7-wk posttreatment regardless of mosquito strain and surface type. For Baygon Ultra Verde, the mean mortality of female Ae. aegypti remained >80% for a shorter period (4-6 wk). Nonpyrethroid commercial aerosolized formulations can provide a lasting residual effect indoors compatible with the need for rapid and lasting mosquito control during outbreaks and may be suitable for community-based targeted indoor residual spraying.

Asunto(s)

Aedes , Carbamatos , Insecticidas , Control de Mosquitos , Piretrinas , Animales , Femenino , México , Residuos de Plaguicidas