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The use of herbicides applied at pre-emergence is an important measure for managing Amaranthus hybridus. However, the presence of straw and rainfall regime after application may alter the efficacy of these herbicides. This study was carried out with the objective of evaluating the effect of different straw mass on the soil surface and different rainfall regimes on the efficacy of imazethapyr + flumioxazin in controlling Amaranthus hybridus. Three greenhouse experiments were conducted and replicated for two years. Experiment 1 consisted of five Brachiaria humidicola straw mass (0, 2, 4, 6 and 8 Mg ha-1) with 20 mm rainfall simulation after herbicide application; in experiment 2, six times to the first rainfall (0, 3, 6, 9, 12 and 15 days) after herbicide application were assessed; and experiment 3 involved four rainfall volumes (0, 10, 30 and 50 mm) after herbicide application. The presence of straw did not alter the efficacy of imazethapyr + flumioxazin, even at the highest mass assessed (8 Mg ha-1) and rainfall of 20 mm. In the absence of herbicide, the highest B. humidicola weight reduced emergence of A. hybridus by 63% when compared to the straw-free treatment. The herbicide imazethapyr + flumioxazin demonstrated flexibility in response to rainfall regime, with total control of A. hybridus even after15 days of drought and up to 50 mm of rain after spraying. The herbicide imazethapyr + flumioxazin was effective against A. hybridus in all straw and rainfall situations evaluated.

É notório que as alterações climáticas globais têm causado impactos sobre a agricultura induzindo perdas de potencial produtivo em diversas regiões brasileiras. O objetivo deste trabalho foi avaliar a ocorrência de estiagem através da relação evapotranspiração real e evapotranspiração potencial (ETR/ETP) no estado do Paraná. Foram utilizados dados diários de precipitação pluvial e temperatura do ar, coletados pelas estações meteorológicas do Instituto de Desenvolvimento Rural do Paraná IAPAR-EMATER (IDR-Paraná), no período de 1976 a 2020 para as regiões: Central, Sul, Norte, Litoral, Noroeste e Sudoeste do estado. Os dados de ETP foram estimados a partir do método estabelecido por Thornthwaite (1948) e os de ETR obtidos pelo Balanço Hídrico Climatológico proposto por Thornthwaite e Mather (1955), sendo considerado como estiagem quando a razão entre ETR/ETP apresentou valor

The desiccation time of high-biomass pasture and nitrogen (N) fertilization of pasture and soybean can influence the soybean sowing, establishment and growth. The objective of this study was to evaluate how the time of desiccation of the preceding pasture of Urochloa brizantha cv. BRS Piatã, cultivated at three levels of N, and by the soybean N fertilization affect soybean growth and N accumulation. Three N rates (0; 150 and 300 kg ha-1), broadcast as urea on the U. brizantha pasture were evaluated separately in each N level, every one considered as one experiment. In each experiment, five times of pasture desiccation were evaluated (60; 45; 30; 15, and 1 day before soybean sowing) and two levels of soybean N fertilization: 30 kg ha-1 (urea) broadcast at sowing or without N fertilization. A randomized complete block design with five replications was used. Early desiccation of U. brizantha pasture favors the establishment of soybean and promotes an increase in biomass and N accumulation in the vegetative stages, however these differences are not observed during the grain filling, regardless the soybean N fertilization. The soybean yield was not influenced by the desiccation time. N fertilization with 30 kg ha-1 at sowing intensifies soybean growth at the vegetative phase, but after full flowering, there were no effects on biomass and grain yield, independently of the desiccation time.

Recent searches stress that soybean yield might be doubled in Brazilian conditions, so that base fertilization is pivotal, once it might interfere over the chemical and microbiological soil indicators and hence, over the crop grain yield. It was aimed to assess alterations in the chemical and microbiological soil indicators, in the short term, and the soybean biometric and grain yield performance as a function of different fertilizers for base fertilization, in two sowing dates. An experiment comprised of two sowing dates was carried out in 2019/2020 season on a dystroferic Red Latossol, in north Parana state. It were assessed five treatments comprising: 1) control; 2) mineral fertilizer; 3) organomineral fertilizer; 4) mineral fertilizer mixed to granulated gypsum; and 5) slow release mineral fertilizer. Randomized block design with four replicates was the design adopted. It were assessed chemical and microbiological soil indicators; final stand; first pod insertion height; plant height; stem diameter; number of pods per plant; number of grains per plant; number of grains per pod; grain mass per plant; one thousand grain mass and grain yield. There is no base fertilization effect over the chemical soil indicators in the short term, however, there is effect over the microbiological soil indicators. Biometric and grain yield performance are decreased as sowing date is delayed, regardless of the base fertilization employed.

Os danos fisiológicos em cafeeiros causados pelo estresse de frio podem variar de acordo com intensidade, tempo de exposição, genótipos, idade e status nutricional das plantas. O objetivo deste trabalho foi avaliar os danos foliares, fisiológicos e bioquímicos decorrentes da exposição das mudas de café a temperaturas negativas e, assim, determinar a temperatura mínima letal para genótipos que poderão ser úteis em futuras pesquisas de cafeeiros mais resistentes ao frio. Foram avaliadas quatro progênies de Coffea arabica com introgressão de Coffea racemosa, três progênies de C. arabica com introgressão de Coffea liberica e a espécie C. racemosa, além das cultivares de C. arabica Mundo Novo IAC 376-4 e Catuaí Vermelho IAC 81, as quais foram usadas como controles suscetíveis. As plantas foram submetidas às temperaturas de -2, -3, -4 e -5 ºC em câmara climática de crescimento. As avaliações dos danos foliares e fisiológicos das mudas foram feitas pelo critério visual (método qualitativo) e por métodos quantitativos: fotossíntese, razão entre a fluorescência variável e máxima do fotossistema II (Fv/Fm), condutividade elétrica de solução de embebição dos discos foliares e teor de proteína. O delineamento experimental foi inteiramente casualizado em esquema fatorial 5x10, sendo 5 níveis de temperaturas e 10 genótipos, com 4 repetições. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de agrupamento de médias Scott-Knott a 5% de significância. Realizou-se correlação de Pearson entre os dados para as médias dos genótipos. Os danos visuais foram detectados a partir de -3 °C e quando correlacionados com os demais parâmetros fisiológicos, observou-se resistência somente para a espécie C. racemosa. Temperaturas entre -4 e -5 °C foram as mais adequadas para testar resistência ao frio em progênies de café.

Photosystem-inhibiting herbicides, such as diquat, act by inducing oxidative stress. However, oxidative damage impairs translocation, resulting in regrowth of the plants. The aim was to evaluate the effectiveness of diquat in controlling the growth of sourgrass exposed to different periods of darkness after application of the herbicide, as well as to evaluate the photosynthetic activity and the production of reactive oxygen species. Two experiments (field and greenhouse) were conducted by applying diquat (200 g a.i. ha-1) on sourgrass plants at the 3 to 4 tiller stage. The treated plants were subjected to different periods of darkness after diquat application (0, 1, 2, 3, 4, 5, and 6 h), in addition to the control treatment without any application. Growth inhibition and mass evaluations of the sourgrass plants were performed in both experiments, whereas photosynthetic activity and H2O2 accumulation in the leaves were evaluated in the greenhouse experiment. The results showed an increase in the sourgrass growth inhibition with an increase in the period of darkness after application. There was a need for a minimum of 6 h of darkness after diquat application to fully inhibit growth (100%) of the sourgrass, whereas plants that remained in the sun since application exhibited less than 50% inhibition. The increase in the period of darkness after diquat application resulted in a reduction in photosynthetic activity and, consequently, lower accumulation of H2O2. Thus, the maintenance of sourgrass in the dark for at least 6 h enables total control of the growth of the plants, preventing regrowth.

Esta pesquisa tem como objetivo compreender a educação especial em contexto indígena e as brincadeiras da aldeia Jeripancó da terra indígena Ouricuri, situada no município de Pariconha no estado de Alagoas, pondo em questão as relações construídas, visto que a brincadeira é um elemento que compõem a infância, evidenciando aspectos culturais, sociais e históricos como elementos de aprendizagem e desenvolvimento. Nesse sentido, o âmbito educacional torna-se espaço para desenvolver e mostrar o sentido da brincadeira na formação pessoal e profissional de cada sujeito em particular a pessoa indígena com deficiência, uma vez que as ações pedagógicas por meio de atividades lúdicas direcionam estímulos significantes na aprendizagem, considerando ainda, uma reflexão acerca da prática educativa. A metodologia utilizada nesta pesquisa de campo foi descritiva pautada em Gil (2008), utilizando-se de uma abordagem qualitativa, conforme Oliveira (2012). O período de realização da coleta de dados teve a duração de aproximadamente cinco meses a contar do momento do levantamento bibliográfico. Da análise temático-categorial emergiram categorias a fim de facilitar a discussão dos resultados, a partir da pesquisa de revisão integrativa sobre a educação especial em um espaço geográfico indígena e as brincadeiras das crianças indígenas Jeripancó. Assim, esta pesquisa oferece uma interface dual entre a educação especial e a educação escolar indígena, de forma que possam contribuir para a sobrevivência das culturas indígenas promovendo o desenvolvimento permanente, sem a perda da identidade étnica e de sua cidadania. SPECIAL EDUCATION IN INDIGENOUS CONTEXTS AND JERIPANCÓ ETHNICITY GAMES This research aims to understand special education in indigenous context and the Jeripancó village ethnic games from the Ouricuri indigenous land, located in the municipality of Pariconha in the state of Alagoas, calling into question the relationships built, since the game is an element that make up the childhood, highlighting cultural, social and historical aspects as elements of learning and development. In this sense, the educational scope becomes a space to develop and show the sense of games in the personal and professional training of each person, in particular the indigenous person with a disability, since the pedagogical actions through playful activities direct significant stimuli in learning, considering also, a reflection about the educational practice. The methodology used in this field research was descriptive based on Gil (2008), using a qualitative approach, according to Oliveira (2012). The data collection period lasted approximately five months from the moment of the bibliographic survey. From the thematic-categorical analysis, categories emerged in order to facilitate the discussion of the results, based on an integrative review research on special education in an indigenous geographic space and the Jeripancó indigenous children games. Thus, this research offers a dual interface between special education and indigenous education, so that they can contribute to the survival of indigenous cultures by promoting permanent development, without losing ethnic identity and citizenship. KEYWORDS: Special Education; Indigenous Education; Game; Jeripancó ethnicity. EDUCACIÓN ESPECIAL EN CONTEXTOS INDÍGENAS Y JUEGOS DE JERIPANCÓ Esta investigación tiene como objetivo comprender la educación especial en un contexto indígena y los juegos de la aldea Jeripancó de la tierra indígena Ouricuri, ubicada en el municipio de Pariconha en el estado de Alagoas, cuestionando las relaciones construidas, ya que el juego es un elemento que conforman la infancia, mostrando aspectos culturales, sociales e históricos como elementos de aprendizaje y desarrollo. En este sentido, el ámbito educativo se convierte en un espacio para desarrollar y mostrar el sentido del juego en la formación personal y profesional de cada sujeto, en particular del indígena con discapacidad, ya que las acciones pedagógicas a través de actividades lúdicas dirigen estímulos significativos en el aprendizaje, considerando también, una reflexión sobre la práctica educativa. La metodología utilizada en esta investigación de campo fue descriptiva con base en Gil (2008), utilizando un enfoque cualitativo, según Oliveira (2012). El período de recolección de datos duró aproximadamente cinco meses desde el momento del levantamiento bibliográfico. Del análisis temático-categórico surgieron categorías para facilitar la discusión de los resultados, a partir de una investigación de revisión integradora sobre la educación especial en un espacio geográfico indígena y los juegos de los niños indígenas Jeripancó. Así, esta investigación ofrece una doble interfaz entre la educación especial y la educación escolar indígena, para que puedan contribuir a la supervivencia de las culturas indígenas promoviendo el desarrollo permanente, sin perder la identidad étnica y la ciudadanía. PALABRAS CLAVE: Educación Especial; Educación Escolar Indígena; Juego; Etnia Jeripancó.

ABSTRACT This study aimed to develop and validate the digital image processing software to quantify leaf coverage, employing the correlation of defoliation values and NDVI with various gradients of defoliation severity of the Asian soybean rust pathosystem. The digital images were obtained from the experiment conducted in 2013/2014. To conduct the experiment, 4 treatments (3 replicates) were adopted, considering the useful floor area of each plot (4 linear meters, 3 lines spaced at 0.45 m). The gradients of defoliation were obtained by treatment with fungicide to control Asian soybean rust. The quantification of the disease severity was performed through diagrammatic scale. The NDVI values were obtained using the GreenSeeker®, conducting the equipment above the plants. The digital photos were obtained in three heights and subsequently processed in software. Then the defoliation sampling was held in 10 plants through treatment. The image processing data correlated with defoliation (94.22%) and with NDVI (89.27%), and we also observed the correlation of defoliation with NDVI (96.12%). These data suggests the use of digital images as an alternative to quantify the vegetation cover, with the advantage of being a dynamic and fast method that does not require experience from the assessor to quantify soybean defoliation.

Glyphosate-resistant sourgrass is difficult to control, particularly when perennial, and strategies that improve the control efficiency against this grass and preserve the useful life of graminicides are warranted. Therefore, the present study aimed to answer the following questions: (i) Does fractionating the doses of ACCase inhibitors improve the control of perennial sourgrass? (ii) Does alternating the chemical groups cyclohexanediones (DIMs) and aryloxyphenoxypropanoates (FOPs) improve the control of perennial sourgrass, and does the order of their application affect sourgrass control efficiency? (iii) Does the addition of glyphosate to ACCase inhibitors improve to the control of perennial sourgrass resistant to 5-enol-pyruvyl-shiquime-3-phosphate synthase inhibitors? Two field experiments (I and II) were performed in 2018 and repeated in 2019. In experiment I, the treatments included a single or fractional application clethodim + quizalofop-P-ethyl (216 + 108 g a.i. ha-1), clethodim (216 g a.i. ha-1), and quizalofop-P-tefuryl (108 g a.i. ha-1), applied in the order of clethodim followed by quizalofop-P-tefuryl and vice versa, as well as a control treatment. In experiment II, the treatments included a single or fractional application of clethodim + quizalofop-P-ethyl (216 + 108 g a.i. ha-1) and clethodim (108 g a.i. ha-1), isolated or associated with glyphosate, as well as a control treatment. In both experiments, the interval between the fractional applications was 7 days. Percentage of control, number of tillers per plant, and height of sourgrass plants were determined. Compared with the unfractionated application, the fractionation of clethodim + quizalofop-P-ethyl and clethodim increased control by respectively 20-24 and 25-30%. Fractionated clethodim has greate control, and less regrowth and height of the sourgrass plants. The order of application of the chemical groups FOPs and DIMs affected control efficiency, and better results were obtained with the application of quizalofop-P-tefuryl followed by clethodim. The addition of glyphosate potentiates the action of graminicides, particularly when fractionated, even on resistant sourgrass, with a 26% increase in efficiency and resulting in satisfactory control ( > 80%).

O objetivo desta discussão é compreender processos que levaram à conformação de uma região popular e tecnicamente reconhecida como o Quadrilátero Ferrífero, situada no entorno da Região Metropolitana de Belo Horizonte. Metodologicamente, os levantamentos e as análises verificaram que, historicamente, a produção desse espaço regional deu prioridade ao desenvolvimento da atividade minerária, sobretudo pela atuação de capitais transnacionais ou estrangeiros. Em termos de organização do capital e de fluxos de mais valor estabelecidos nessa escala, o espaço regional do Quadrilátero Ferrífero encontra-se hierarquizado em relação a Belo Horizonte, principal centralidade da RMBH. Por outro lado, nota-se que a quase totalidade dos mananciais que abastecem essa região estão no Quadrilátero, em locais crescentemente afetados pela mineração. Nesse cenário, apontam-se a necessidade e a urgência de que essa área seja progressivamente reconhecida como um Quadrilátero Aquífero, pautado em lógicas de conservação ambiental e de reprodução da vida.

The electrical conductivity test indirectly evaluates cell membrane disorganization by quantifying the electrolytes released into the water after tissue imbibing. The objective of this work was to evaluate methodological variations in the electrical conductivity test, for it to serve as an indicator of low temperature-induced damages and estimate the cold tolerance of bean plants. Cultivar IPR Uirapuru plants were subjected to minimum temperatures of 4 °C, 2 °C, 0 °C, -1 °C, -2 °C, -3 °C, and -4 °C for 1 h in a growth chamber under controlled conditions. After the treatment period, the response of plants to cold stress was evaluated by determination of the total protein content, and catalase (CAT) and ascorbate peroxidase (APX) enzymatic activities, and evaluation of photosystem II (Fm/Fv) efficiency and leaf anatomy. These results were compared with those obtained in the electrical conductivity test, which was performed in plants under cold stress as well as under a non-stress environment, with 2, 4, 6, and 8 leaf discs immersed in 30 mL of distilled water for 24 h in BOD, at temperatures of 25 °C, 30 °C, and 35°C. Analysis of variance was performed using a completely randomized design, and for electrical conductivity, a number of discs × cold stress temperature combinations were used for each soak temperature. The averages were compared using the Turkey's test at 5% and 10% probability. Pearson correlation coefficient (r) between the conductivity averages and other cold stress evaluation data was also performed. The results showed a marked reduction in the ratio (Fv/Fm) only in the treatments at -3 °C and -4°C, which indicated tissue death. At temperatures below 0°C, there was a collapse of the leaf blade tissues, and it was not possible to differentiate the palisade parenchyma from the spongy parenchyma in the treatments at -2°C, -3°C, and -4°C. There was an increase in the protein content since the temperature -3°C. The enzyme activity of CAT decrease at -4°C whereas that of APX increased. In the electrical conductivity test, there was a significant interaction between soak temperature and the number of discs, and an increase in conductivity of the solution with a decrease in temperature was verified in several treatments, among which, the combination that best correlated with the other tests was 25°C with six leaf discs. It was concluded that the electrical conductivity test presents results similar to those obtained from other physiological, biochemical, and anatomical tests, and therefore, it can be used to evaluate the damage caused by low temperatures in bean plants.

ABSTRACT The aim was: (i) to propose a regression model for the association between injury in Roundup Ready (RR) cotton plants and drift of auxins, isolated or associated with glyphosate; (ii) to evaluate the effect of adding glyphosate to dicamba and 2,4-D auxinic herbicides on the physicochemical properties of the spray solutions; and (iii) to validate the wind tunnel as a tool to perform herbicide injury prediction. Three experiments were conducted using the following spray solutions: glyphosate (0.225 kg a.e. ha-1); dicamba (0.120 kg a.e. ha-1); 2,4-D (0.168 kg a.e. ha-1); glyphosate + dicamba (0.225 + 0.120 kg a.e. ha -1) and glyphosate + 2,4-D (0.225 + 0.168 kg a.e. ha-1). Experiment I assessed drift in wind tunnel at distances of 5, 10 and 15 m from the nozzle spray drift. Experiment II assessed injury on cotton plants arranged at the same distances as in experiment I. Experiment III studied the physicochemical characteristics of the spray solutions used in experiment I, assessing surface tension, pH and density. The collected drift and injury are directly proportional, following a simple linear regression model, with increased drift and injury potential at 5 m from the sprayer. The addition of glyphosate to 2,4-D and dicamba herbicides reduced surface tension and pH of the spray solutions. The wind tunnel, besides evaluating drift potential, was found to be an alternative for the prediction of injury in RR cotton plants.

A ampla capacidade de adaptação da videira a diferentes climas e o aprimoramento da tecnologia de produção foram fundamentais para a expansão da produção em boa parte do território brasileiro, tornando umas das principais frutas produzidas no país, com notória importância socioeconômica. A espécie apresenta vulnerabilidade decorrente a sua sensibilidade a doenças fúngicas, demonstrando a importância de estudos climáticos para aprimorar suas técnicas de produção e manejo. Dessa forma, o objetivo deste trabalho foi realizar o zoneamento agrícola de risco climático para a videira na Bacia Hidrográfica do Rio Paraná III. Foram selecionadas as três principais variedades comerciais para o Estado, sendo estas: Uvas rústicas (Vitis labrusca), Uvas finas de mesa (Vitis vinifera) e Uvas finas para vinificação (Vitis vinifera). Para isso foram utilizados dados meteorológicos de 43 estações com série temporal de 1976-2018. A análise do risco climático foi pautada nas exigências climáticas da espécie, sendo estas, precipitação, deficiência hídrica anual, temperatura média, umidade relativa e o risco de geada tardia. Para as uvas finas de mesa e uvas rústicas todas as regiões avaliadas se mostraram aptas para o plantio. Por ser mais sensível a propagação de doenças, as uvas finas para a vinificação apresentaram restrição na porção leste e em pequenas áreas do Sul e Oeste da Bacia. As principais variáveis meteorológicas restringentes foram a umidade relativa do ar elevada e a temperatura.

Os resíduos de plantas que permanecem no solo em um sistema de integração lavoura-pecuária constituem em uma importante reserva de nutrientes para a cultura em sucessão. O objetivo do trabalho foi avaliar a liberação de cálcio (Ca), magnésio (Mg) e enxofre (S) de palha de pastagem de Urochloa brizantha cv. BRS Piatã, cultivada em três doses de nitrogênio (N) e submetida a duas épocas de dessecação em relação à semeadura da soja. O experimento foi conduzido em Londrina, Paraná, entre março de 2016 e março de 2018. Foram avaliadas três doses de N na pastagem de U. brizantha cv. BRS Piatã (0; 150 e 300 kg N ha-1), constituindo três piquetes distintos. Em cada piquete foram avaliadas duas épocas de dessecação da pastagem (60 e 15 dias antes da semeadura da soja), com quatro repetições. Os teores de Ca e S na palha de pastagem de U. brizantha não variam com o tempo de decomposição, enquanto os teores de Mg foram reduzidos, independentemente da adubação nitrogenada e da época de dessecação. A quantidade de Ca liberada pela palha de pastagem de U. brizantha até o final do ciclo da soja em sucessão foi de, aproximadamente, 15 kg ha-1, independentemente da adubação nitrogenada e da época de dessecação. A quantidade de Mg liberada pela U. brizantha até o final do ciclo da soja em sucessão variou de 10 a 15 kg ha-1, com tendência de haver maior quantidade liberada na presença de adubação nitrogenada na pastagem. A quantidade de S liberada pela U. brizantha até o final do ciclo da soja em sucessão variou de 4 a 6 kg ha-1, com tendência de haver menor quantidade liberada na presença de adubação nitrogenada na pastagem, independentemente da época de dessecação.

Abstract: The objective of this work was to determine the nitrogen, phosphorus, and potassium released by N-fertilized Urochloa brizantha straw, desiccated before sowing of no-tillage soybean (Glycine max) in succession. The pasture was grown in three paddocks, each fertilized with one N rate (0, 150, or 300 kg ha-1), and assessed at two desiccation periods (60 or 15 days before soybean sowing), in four replicates. Nitrogen fertilization of U. brizantha pasture increases N and K cycling and the release of these nutrients to the subsequent soybean crop. The quantity of K released by U. brizantha straw fertilized with 150 or 300 kg ha-1 N (about 80 kg ha-1 K) offsets that contained in an export of up to 4 Mg ha-1 soybean grains, assuming zero K losses in the system. An early desiccation of the U. brizantha pasture does not improve K uptake by the soybean crop, since 50% of the nutrient is released in the first 20 days after desiccation. The dynamics of P release from U. brizantha straw (about 6 to 10 kg ha-1 during the soybean crop) is not influenced by N fertilization and the time of pasture desiccation.

Thermal discomfort is one of the main causes of production losses in animals fully exposed to solar radiation under extensive livestock farming. The inclusion of trees in this farming system is the most efficient strategy to decrease the temperature and increase animal productivity without the need to explore new areas. In this context, the objective of this study was to characterize the microclimate in a silvopastoral system (SPS), a refuge area, and an open pasture, and evaluate thermal comfort and the ingestive behavior of animals under shade. The study was conducted at the Agronomic Institute of Paraná (IAPAR), located in Ibiporã, Paraná state, Brazil, in three areas with distinct management systems: a SPS of Eucalyptus grandis with Tifton 85 (Cynodon spp.), a woodland of Leucena leucocephala that provided shade to cattle, and a pasture in full sun (PFS). Automatic meteorological stations were installed in the SPS (one station beside the tree lines and the other in an average distance perpendicular to the rows), one in the refuge area, and one in the PFS. The measured variables were air temperature and relative humidity. The mean temperatures of the shaded treatments were compared to those of the PFS using a t-test. The mean values of the temperature and humidity index (THI) were calculated for each season of the year. The animal ingestion behavior in the SPS was analyzed in three typical days in different seasons of the year. Significant differences were observed between shade treatments and full-sun pasture, with a temperature decrease ranging from 0.4 to 1.6 °C in the shaded systems. The comparison of animal thermal comfort between the study areas in different seasons of the year indicated that there were no significant differences in thermal comfort between the SPS and refuge area relative to the PFS, suggesting a need to monitor the animals’ body temperature to better estimate thermal comfort. The evaluation of the ingestive behavior evidenced the animals’ preference to perform activities under tree shade and that the SPS led to changes in their food habits, optimizing grazing time. Therefore, the trees directly affected the microclimate of the studied environments, attenuating the temperature, protecting the animals against direct solar radiation, and providing better thermal comfort.

A phenomenon called thermal inversion, in which there is the accumulation of colder and denser air in the layers closer to the soil, occurs in radiative frost nights, resulting in a temperature gradient with differences between the meteorological screen and grass, which vary depending on cooling conditions. Knowing this temperature difference assists in taking preventive measures against radiative frosts, as well as in estimating the probability of their occurrences. In this context, this study aimed to verify the adjustment of different probability distributions to determine the differences between the minimum temperature measured in the meteorological screen and grass temperature below 0 °C for eight regions of the Paraná State, as well as the probability of occurring these differences and adjust estimation equations of grass temperature from minimum air temperature. Temperature differences between the screen and grass were calculated and probability distributions of their occurrences were adjusted in order to determine risks per intervals of temperature differences. Estimation equations of grass temperature were adjusted from minimum screen temperatures. Average gradients of minimum temperature were observed between the screen and grass ranging from 4.2 to 6.3 °C in the analyzed regions. The average temperature difference measured in the meteorological screen and grass for the Paraná State was 5 °C. The probabilistic model of normal distribution is the most suitable for determining the probability of occurring the differences between the screen and grass temperatures for the Paraná State. Regional relief and climate conditions influence the magnitude of the minimum temperature gradient measured in the meteorological screen and grass. Estimation equations can be useful to determine the grass temperature based on the minimum air temperature for periods in which there is no such data and thus provide a subsidy for studies of risk analysis of frosts. The results of this analysis are empirical and the equations should be used in regions in which they were adjusted aiming at a higher accuracy.

Abstract: The objective of this work was to determine models for the estimation of leaf wetness percentage at three heights in the soybean (Glycine max) canopy, using meteorological variables from stations installed at the crop site and at an agrometeorological station. The experiment was conducted in three harvest seasons, in an area cropped with soybean, in the municipality of Londrina, in the state of Paraná, Brazil. To collect the meteorological variables, electronic trees were installed at four heights (0.3, 0.6, 0.9, and 1.7 m) in the crop and a station was installed in an agrometeorological station. The data were separated according to days with and without rain, and the analyses of correlation and of simple and multiple regressions were carried out, in order to obtain models with equations for leaf wetness estimation. Most of the equations that did not use the data of the sensors installed at 1.7 m, especially those of the models based on variables only from the agrometeorological station, presented low reliability. The models obtained with meteorological data only from the soybean crop show high reliability and use a lower amount of variables, which makes them a good alternative for wetness estimation.

A densidade de semeadura e o espaçamento entre as fileiras podem influenciar no crescimento e desenvolvimento das culturas. O objetivo do trabalho foi avaliar a dinâmica do crescimento de duas cultivares de soja com tipo de crescimento indeterminado, em diferentes arranjos espaciais de plantas, compostos por espaçamentos entre fileiras e densidades de semeadura. O experimento foi conduzido nas safras 2013/14 e 2014/15 com delineamento experimental em blocos completos casualizados, esquema fatorial 2 x 4 x 3, com três repetições. Os tratamentos constituíram-se da combinação de duas cultivares: BRS 359 RR e BMX Potência RR, de quatro espaçamentos entre fileiras: 20 cm (reduzido); 20/80 cm (fileira dupla); 50 cm (usual) e 50 x 50 cm (cruzado) e três densidades de semeadura: 150, 300 e 450 mil sementes viáveis ha-1. Foram avaliados o índice de vegetação por diferença normalizada (NDVI) e a porcentagem da cobertura do solo pelo dossel. O NDVI e a porcentagem de cobertura do solo pelo dossel de cultivares modernas de soja, com tipo de crescimento indeterminado, são mais afetados pelos espaçamentos entre fileiras no início do ciclo de desenvolvimento, mas na fase de enchimento de grãos as diferenças são menores. A densidade de 150 mil sementes viáveis ha-1 ocasiona menor NDVI e cobertura do dossel no início do ciclo, entretanto no final do ciclo essa diferença se dissipa e todas as densidades apresentam pleno fechamento do dossel.

Combining forest and crop species into a production system may enhance its sustainability. This study aimed to evaluate the yield components, yield and grain quality of soybean cultivars, in an agroforestry system containing Eucalyptus grandis. A complete randomized block design, in a split-plot arrangement, with three replications, was used. Four soybean cultivars were allocated into the plots (BRS 359 RR, BRS 360 RR, BMX Potência RR and NA 5909 RR). The subplots consisted of five positions between the rows of E. grandis (spaced in 28 m - close to the trees on the east and west sides, intermediate position on the east and west sides and at the center of the row). The yield components and soybean grain yield reduce significantly the closer the plants are seeded to the rows of E. grandis. However, the oil and protein contents in soybean grains are not influenced by the position between rows, regardless of the cultivar. Among all evaluated cultivars, NA 5909 RR presents the best agronomic performance in the agroforestry system containing eucalyptus.

No contexto da tragédia socioambiental de Bento Rodrigues, MG, onde a ruptura de uma barragem de rejeitos minerários acarretou uma série de impactos ambientais na Bacia Hidrográfca do Rio Doce, há um capital, de grande força econômica, a coordenar todo um circuito produtivo minerário em escala global. Diante disso, é aqui desenvolvida uma discussão que busca articular esse circuito produtivo minerário, mundial, com um colapso local cujas repercussões atingiram dimensões regionais e nacionais. É também buscada a compreensão das alianças entre tal capital e o Estado brasileiro, responsáveis por um cenário cujo recurso mineral, pertencente à sociedade brasileira, é direcionado aos circuitos globais mediante grandes impactos negativos, baixos custos e alta lucratividade para as empresas minerárias. Essas confgurações mostram-se propícias para o estabelecimento de relações de dependência econômica entre a atividade minerária e determinados territórios e grupos sociais. Tais relações potencializam fragilidades que, em casos extremos como o vivenciado em Bento Rodrigues, MG, levam ao colapso de estruturas produtivas e ensejam situações de destruição de grandes proporções.

Aiming at assessing the performance of alternative methods to Penman-Monteith FAO56 for estimating the reference evapotranspiration (ETo) for Londrina, Paraná, Brazil, the methods temperature radiation, Hicks-Hess, Hargreaves-Samani (1982), Turc, Priestley-Taylor, Tanner-Pelton, Jensen-Haise, Makkink, modified Hargreaves, Stephens-Stewart, Abtew, global radiation, Ivanov, Lungeon, Hargreaves-Samani (1985), Benavides-Lopez, original Penman, Linacre, Blaney-Morin, Romanenko, Hargreaves (1974), McCloud, Camargo, Hamon, Kharrufa, McGuiness-Bordne, and Blaney-Criddle were compared to that standard method recommended by FAO. The estimations were correlated by linear regression and assessed by using the Person’s correlation coefficient (r), concordance index (d), and performance index (c) using a set of meteorological data of approximately 40 years. The methods modified Hargreaves, Stephens-Stewart, Abtew, global radiation, Ivanov, Lungeon, Hargreaves-Samani (1985), Benavides-Lopez, original Penman, and Linacre should be avoided, as they did not present excellent results. The methods McCloud, Camargo, Hamon, Kharrufa, McGuinness-Bordne, Blaney-Criddle, Hargreaves (1974), Romanenko, and Blaney-Morin were classified as very bad, not being recommended. In contrast, the methods temperature radiation, Hicks-Hess, Hargreaves-Samani (1982), Turc, Priestley-Taylor, Tenner-Pelton, Jensen-Haise, and Makkink presented excellent performance indices and can be applied in the study region.

The normalized difference vegetation index (NDVI) obtained via radiometer is important to determine the physiological state of plant, being a promising tool for decision making as to the best time for the application of agricultural pesticides, to analyze the threshold of economic damage. The use of drones with digital camera embedded in agriculture is in broad expansion. Through digital images analyzed in computer programs and correlated with NDVI it is possible to determine the leaf cover in plants. The aim of this study was to confirm the use of digital images at 30 m in height to determine the leaf cover, correlating them with NDVI values obtained on the ground. Therefore, 30 m height photos were taken with the help of a drone and three stages of maize development (N4, N8 and R1), which were considered as treatments; afterwards, the images were analyzed in software to survey the leaf cover. The NDVI data were obtained in the same areas at a height of 0.5 m from the crop canopy, and it were submitted to the Scott Knott Test at 5 % significance and Pearson correlation. There was no statistical difference between methods and the Pearson correlation coefficient value (0,952) confirms strong evidence for correlation between the two methods. Thus, it can be concluded that the use of drone with embedded digital camera has promising use for the determination of leaf cover in maize.

Predictive models of Asian soybean rust have been described by researchers to estimate favorable responses to epidemics. The prediction strategies are based on weather data obtained during period when initial symptoms of the disease are observed. Therefore, this study will evaluate the application of two prediction models of Asian soybean rust, and compare the results from two harvest seasons. The experiments were carried out during the 2011/2012 and 2012/2013 seasons in Londrina, PR. “SIGA spore traps” were installed to monitor the presence of Phakopsora pachyrhizi uredospores, and “Electronic trees,” to collect data on weather variables. Following the detection of the first urediniospores, incidence and disease severity were assessed and compared with the predictions made by the models. The model described by Reis et al. (2004) did not indicate conditions favorable for the development of the first rust lesions following the detection of the first urediniospores during the 2011/2012 season. The premonitory symptoms of rust in the first and second harvest seasons were observed only when the model of Reis et al. (2004) indicated SDVPI close to 15 units. The model of Del Ponte et al. (2006b) overestimated the final rust severity during the two seasons.

Resumo: O objetivo deste trabalho foi avaliar o efeito do atraso da colheita sobre umidade dos grãos, massa de mil grãos e produtividade da soja, assim como identificar as variáveis agrometeorológicas mais importantes durante o período pré-colheita e propor algoritmos empíricos para a estimativa das perdas de produtividade. Os experimentos foram realizados em Castro, PR, e Itaberá, SP, nas safras de 2011/2012 a 2013/2014, da cultivar de soja 'NA5909RG', em sete ambientes. Os tratamentos consistiram de oito momentos de colheita de soja a partir do estádio fenológico R8.2. A análise de grupos de experimentos mostrou interação significativa entre ambientes e momentos de colheita. A umidade e a produção de grãos são influenciadas diretamente pelo número de dias com precipitação pluvial igual ou superior a 3 mm. No estádio fenológico R8.2, são obtidos os maiores valores de produtividade; no entanto, após esse estádio, há declínio da produtividade em consequência do atraso da colheita. As maiores perdas acumuladas de produtividade ocorrem em ambientes com alta frequência de precipitações pluviais e com temperatura e radiação solar global elevadas. Dois algoritmos com base em variáveis agrometeorológicas são propostos para a estimativa da perda de produtividade de soja.

O desconforto térmico é uma das principais causas da queda produtiva da pecuária extensiva a pleno sol, sendo a inserção de árvores no sistema a alternativa mais eficiente para atenuar a temperatura e aumentar a produtividade sem a necessidade de explorar novas áreas. Nesse contexto, objetivou-se caracterizar o microclima em um sistema silvipastoril, uma área de refúgio e a pleno sol, além de estimar o conforto térmico e avaliar o comportamento ingestivo dos animais sob sombra. O estudo foi realizado na estação experimental do Instituto Agronômico do Paraná (IAPAR), localizada em Ibiporã-PR, em três áreas com manejos distintos: um sistema silvipastoril, um bosque que serve como refúgio dos animais e uma pastagem a pleno sol. Foram instaladas estações meteorológicas automáticas no sistema silvipastoril, uma sob a sombra e outra na distância média perpendicular aos renques, na área de refúgio e no pasto a pleno sol. As variáveis medidas foram temperatura do ar e umidade relativa do ar. As temperaturas médias dos tratamentos arborizados foram comparadas com as do pasto a pleno sol por meio do test t. Valores médios de Temperatura e Índice de Umidade (ITU) foram calculados para cada estação do ano. Analisou-se o comportamento ingestivo animal no sistema silvipastoril em três dias representativos de diferentes estações do ano. Constatou-se diferenças significativas entre os tratamentos sombreados e a pastagem a pleno sol, com redução de temperatura variando entre 0,4 a 1,6 °C nos sistemas sombreados. Ao comparar o conforto térmico animal para as estações do ano, não verificou-se diferenças entre o sistema silvipastoril e refúgio em relação ao pleno sol, sendo indicado monitorar a temperatura corporal animal para melhor estimar sua condição de conforto térmico. Entretanto, ao avaliar o comportamento ingestivo animal evidenciou-se a preferência dos animais por realizar suas atividades sob a sombra das árvores; o sistema silvipastoril propiciou mudanças no seu hábito alimentar, otimizando o tempo de pastejo. Conclui-se que o componente arbóreo influenciou diretamente no microclima dos ambientes estudados, atenuando a temperatura e protegendo os animais contra a incidência direta de radiação solar, proporcionando maior conforto térmico.

Em noites de geada de radiação ocorre um fenômeno denominado de inversão térmica, em que há o acúmulo do ar mais frio e denso nas camadas de ar mais próximas ao solo. Isto resulta em um gradiente de temperatura, com diferenças entre o abrigo meteorológico e a relva que variam dependendo das condições de resfriamento. Conhecer essa diferença de temperatura auxilia na tomada de medidas preventivas contra as geadas de radiação, assim como na estimativa da probabilidade de ocorrência. Neste contexto, o objetivo desse trabalho foi verificar o ajuste de diferentes distribuições de probabilidade para determinar a diferença entre a temperatura mínima medida no abrigo meteorológico e a temperatura de relva abaixo de 0°C para oito regiões do Estado do Paraná, bem como a probabilidade de ocorrência das diferenças e ajustar equações de estimativa da temperatura de relva a partir da temperatura mínima do ar. Foram calculadas as diferenças de temperatura entre o abrigo e a relva e posteriormente foram ajustadas distribuições de probabilidade de ocorrência das diferenças, com a finalidade de determinar os riscos por intervalos de diferenças de temperatura. E, por fim, foram ajustadas equações de estimativa da temperatura de relva a partir da temperatura mínima de abrigo. Foram constatados gradientes médios de temperatura mínima entre o abrigo e a relva variando de 4,2 a 6,3°C nas regiões analisadas. A diferença média de temperatura medida no abrigo meteorológico e a relva para o Estado do Paraná foi de 5°C. O modelo probabilístico de distribuição Normal é o mais indicado para a determinação da probabilidade de ocorrência das diferenças entre a temperatura de abrigo e de relva para o Estado do Paraná. As condições de relevo e clima regionais influenciam na magnitude do gradiente de temperatura mínima medida no abrigo meteorológico e na relva. As equações de estimativa podem ser úteis para determinar a temperatura de relva com base na temperatura mínima do ar, para períodos nos quais há a ausência desses dados e, assim, dar subsídio para estudos de análise de risco de geadas. Os resultados da análise são empíricos e as equações devem ser utilizadas nas regiões nas quais elas foram ajustadas, para maior precisão.

This study analyzed the external factors that influence the yield obtained from photovoltaic modules (Solarex® - MSX 56), as solar irradiance, temperature, placement angle and dust deposition on the photovoltaic modules installed at the facilities of the Medianeira campus of the UTFPR, working under real conditions. To obtain the data it was used a datalogger from Campbell Scientific, Inc, model CR23X. It was observed that under solar irradiance below 550 W m-2 the panel did not convert maximum power, and above this value the panel reached saturation levels. Temperature increase led to reduced voltage, and consequently lower module output power, decreasing the efficiency value by nearly 6% at temperatures 15oC above the Standard Test Conditions (STC) temperature. These panels are usually placed at different angles according to local latitude, remaining fixed in that position. In comparison with a horizontally-placed panel, it was obtained a 4-hour increase in yield when the panel reached saturation value. Dust levels reduced electricity production levels by approximately 16%. These factors must be taken into account for placement and maintenance of photovoltaic systems, so they can function efficiently.

Com objetivo de avaliar o desempenho de métodos alternativos ao Penmam-Monteith-FAO56 para a estimativa da evapotranspiração de referência (ETo) para a cidade de Londrina, Paraná, foram comparados a este método padrão recomendado pela FAO os seguintes métodos: Radiação-Temperatura, Hicks-Hess, Hargreaves-Samani-1982,Turc, Priestley-Taylor, Tanner-pelton, Jensen-Haise,Makkink, Hargreaves-Modificado, Stephens-Stewart, Abtew, Radiação-Global, Ivanov, Lungeon, Hargreaves-Samani-1985, Banavides-Lopez, Penman-Original, Linacre, Blaney-Morin, Romanenko, Hargreaves-1974, McCloud, Camargo, Hamon, Kharrufa, McGuiness-Bordne e Blaney-Criddle. Utilizando um conjunto de dados meteorológicos de aproximadamente 40 anos, as estimativas foram correlacionadas por regressão linear e avaliadas através do coeficiente de correlação de Person “r”, índice de concordância “d” e do índice de desempenho “c”. Os métodos Hargreaves Modificado, Stephens-Stewart, Abtew, Radiação-Global, Ivanov, Lungeon, Hargreaves-Samani-1985, Banvides-Lopez, Penman-Original e Linacre devem ser evitados, pois não apresentaram resultados ótimos. Classificado como “péssimo” os métodos McCloud, Camargo, Hamon, Kharrufa, McGuinness-Bordne, Blaney-Criddle, Hargreaves-1974, Romanenko e Blaney-Morin não são recomendados. E os métodos Radiação-Temperatura, Hicks-Hess, Hargreaves-Samani-1982, Turc, Priestley-Taylor, Tenner-Pelton, Jensen-Haise e Makkink apresentaram índices de desempenhos “ótimos”, e podem ser aplicados para a região em estudo.