Arthur Barroso

Universidade Federal do Paraná | UFPR · Departamento de Fitotecnia e Fitossanitarismo

The intensive global use of glyphosate has led to the evolution of glyphosate resistant (GR) weed species, including the economically damaging horseweed (Conyza sumatrensis). We evaluated the glyphosate resistance mechanisms of C. sumatrensis. While 5-enolpyruvylshikimate-3-phosphate synthase activity was similar between the glyphosate resistant (G...

The intensive global use of glyphosate has led to the evolution of glyphosate resistant (GR) weed species, including the economically damaging horseweed (Conyza sumatrensis). We evaluated the glyphosate resistance mechanisms of C. sumatrensis. While 5-enolpyruvylshikimate-3-phosphate synthase activity was similar between the glyphosate resistant (G...

Residual herbicides and cover crops are important tools inside an integrated weed management program. The straw produced in crop rotation can interacts with herbicides. The aim of this study was to evaluate the interaction of diclosulam, sulfentrazone, imazethapyr, flumioxazin, s-metolachlor and pyroxasulfone with black oat, cereal rye, common vetc...

O uso de associações de herbicidas, entre outras práticas são fundamentais no manejo de buva (Conyza spp.). Acredita-se que utilização, na entressafra, de atrazine/mesotrione em associação com auxinas sintéticas, com aplicação sequencial seja eficaz no manejo da buva. Objetivou-se avaliar a eficácia de atrazine/mesotrione em associação com auxinas...

Background: Eleusine indica (L.) Gaertn. (goosegrass) is globally a major weed in cropping systems. It has evolved resistance to glyphosate due to single Pro-106-Ser (P106S) or double Thr-102-Ile + Pro-106-Ser (TIPS) EPSPS target site mutations. Here, experiments were conducted to evaluate the single effect of soybean competition and its combined...

ABSTRACT Weed competition is a challenge to rice monocropping growers in the context of herbicide resistant weeds and difficult weeds to manage using chemical control. Diversifying crop rotations through integrated crop-livestock systems (ICLS) can be an alternative to face this challenge. As weed seedbank reflects management practices, this study...

Even though glyphosate resistance in Chloris elata Desv. was initially reported in 2014, the resistance mechanisms have not yet been completely elucidated. Previous research found evidence of a non‐target site mechanism limiting the herbicide from reaching its enzyme target. We investigated the foliar morphology of C. elata biotypes at different le...

O objetivo da aplicação de um herbicida é atingir o alvo com quantidades determinadas de calda e ingrediente ativo, tendo a menor quantidade de produto perdido possível. Contudo, por vários fatores, têm-se perdas para o ambiente, uma delas é a deriva, que é todo volume de calda que não atinge o alvo ou é perdido para o ambiente, onde, além de danos...

Os herbicidas do grupo das auxinas sintéticas, como o 2,4-D, afetam as plantas de maneira semelhante a auxina ácido indolacético. O objetivo da aplicação de um herbicida é atingir o alvo com quantidades determinadas de calda e ingrediente ativo, tendo a menor quantidade de produto perdido possível. Contudo, por vários fatores, têm-se perdas para o...

A falta de informações e resultados mais pontuais sobre o manejo e condução dos sistemas de integração milho-braquiária, causam pouco interesse por parte dos produtores. Problema esse que pode ser revertido partindo da divulgação de dados sobre o ganho de produtividade e o retorno financeiro ocasionado pela diminuição de insumos nas áreas de cultiv...

A interferência de plantas daninhas na cultura do amendoim é um dos principais fatores limitantes do crescimento, desenvolvimento e produtividade da cultura. Em virtude disso, a busca por alternativas para o controle de plantas daninhas é necessária para realização do manejo da cultura. Desta forma, objetivou-se avaliar os efeitos fitotóxicos de di...

Weeds are a concern to farmers mainly by reducing crop yield, especially in organic farming where herbicides are not an option. Additionally, reducing reliance on herbicides is among the goals to achieve sustainable crop production. By investigating alternatives for weed control, several studies have shown that grassland is more competitive with we...

Chloris elata is an important weed for grain and sugarcane crops. In addition to its aggressiveness, it may show resistance to glyphosate herbicide. In this context, the aim of this study was to assess the effectiveness of glyphosate formulations, isolated or in association with ACCase inhibitors, in controlling C. elata (putatively resistant to gl...

Weed densities, species, costs of control, crop value and interference periods should be considered for weed management. With this regard, three experiments were carried out to evaluate weed control periods and weed density in a new soybean cultivar. In ths first trial, control efficacy was measured by visual phytotoxicity of four weed species I. h...

Sourgrass (Digitaria insularis) is one of the main weeds in the soybean crop. In order to control its growth, an increase of herbicide rates is required to simplify its management as it a plant with high vegetative capacity and seed production. It implies to select the herbicide-resistent Digitaria insularis biotypes. Nevertheless, some information...

Together, Conyza bonariensis, C. canadensis and C. sumatrensis show 105 reported cases of biotypes resistant to herbicides like glyphosate, paraquat, and acetolactate synthase (ALS) inhibi-tors. The application of pre-emergent herbicides combined with burndown herbicides is believed to be effective in controlling Conyza spp. during soybean pre-sowi...

Crop rotation is critical in the management of herbicideresistant weed species. This study aimed to evaluate the effect of intercropping systems of maize with brachiaria or crotalaria on qualitative and quantitative parameters of the weed seedbank, along the succession of pearl millet, maize and common bean. Moreover, the effect of these crop rotat...

Herbicide mixtures, use of multiple sites of action, and other weed management practices are necessary to avoid cases of biotype resistance. The aim of this study was to evaluate the efficiency of imazapic/imazapyr and other herbicides in mixtures to control Digitaria insularis at burndown before soybean sowing. This field research was conducted in...

This study characterized the germination of seeds of Chloris polydactyla (synonymy Chloris elata) and Chloris barbata at varying temperature, luminosity, soil texture and cover. The first experiment was conducted in laboratory to determine the temperature and light effects on germination of these species. The experimental design was a 2x7 factorial...

The seed germination and the early plant growth of corn (Zea mays) and soybean (Glycine max) sowed after cropping and under straw residues (simulating crop rotations) of oat (Avena sativa), ryegrass (Lolium multiflorum) and wheat (Triticum aestivum) were investigated in pot experiments carried out under controlled conditions. The germination rates...

Weeds reduce the productive potential of crops. Plants of the Ipomoea genus, besides competing for water, light, space and nutrients, create problems in crop harvests due to their volatile stems. The objective of this work was to evaluate the growth and development of five Ipomoea species. For such, Ipomoea grandifolia, Ipomoea hederifolia, Ipomoea...

Herbicide resistant is associated with morphological, physiological and metabolic alterations in weeds. These alterations may reflect changes in the nutritional status of resistant plants and their growth it can be inferred in greater adaptability and competitive ability of the resistant biotypes. Thus, the objective of this research was to determi...

Sugarcane is one of the main agricultural cultivations of Brazil, and one of the crops in which herbicides are most applied. In the 2017/2018 season, the estimated sugarcane production was 694.54 million tons, with an estimated increase of 0.9% in yield for this season. In order to evaluate the use of herbicides in this crop in the São Paulo State...

Abstract The new technology of sugarcane planting, known as one-eye-set seedlings, offer a high standard of plant health and vegetative vigor. However, there are no reports in the literature that evaluate the weed competition with one-eye-set sugarcane seedlings, and the periods in which weed communities need to be controlled in this system. Two in...

Glyphosate is the most used herbicide worldwide and glyphosate-tolerant soybean planted in almost all cultivated areas. In Brazil, the area cultivated with transgenic soybean reaches more than 90%. Recently, the application of glyphosate in tolerant soybean has assumed the possibility to injury the crop under certain conditions and herbicides formu...

The repetitive use of herbicides with the same mechanism of action causes the selection of resistant weeds, such as ryegrass. Considering the occurrence of ryegrass (Lolium multiflorum) in eucalyptus, a crop on which glyphosate is used, it is necessary to study its interference. The objective of this study was to evaluate the effect of densities (0...

Weed interference reduces the productive potential of crops. Among the control methods used, chemical ones occupy a major position. The repeated application of the same mechanism of action selects tolerant plants. Among the species that affect sugarcane, crabgrass is one of them. This study has aimed to know the tolerance of different populations o...

Glyphosate has been associated with control failures for Spermacoce verticillata in some Brazilian States. The objective of this work was to evaluate and determine the possible causes of this and propose alternative herbicides to use. Glyphosate was applied at three plant stages of development (2–4 leaves, 4–6 leaves and full bloom) where foliar ab...

The benefits of glyphosate tolerant crops technology are well-known, and its acceptance by farmers is undeniable. However, results of recent research indicate that, in some situations, glyphosate applied to herbicide-tolerant soybean crops may have phytotoxic effects affecting nutritional balance, photosynthesis and others biochemical process in pl...

Background: Weeds reduce crop yields, and among the methods used to control these plants, chemical use is preferred. However, the repeated application of herbicides with the same mechanism of action selects for resistant populations. The aim of this study was to evaluate glyphosate resistance in Lolium multiflorum (Lam.) and relate the resistance...

This research was carried out to evaluate the interference periods and phytosociological indexes of the weed community on sweet sorghum, hybrid CVSW 80007, cultivated for two seasons in a year. The treatments were based on an increased duration of weed presence and weed absence after sowing (0, 4, 7, 14, 21, 28, 35, 42, 56 and 68 days after crop em...

Sourgrass is one of the most problematic weeds of Brazil. It is an aggressive species in the allocation of resources from the environment and reported to be glyphosate resistant in several states of the country. This work has aimed to verify environmental effects on seed germination and seedling emergence of sourgrass. Laboratory and field trials w...

Allelochemicals are important and innovative tools for weed control as they neither harm the environment nor increase weed management costs. The secondary metabolites can be extracted by water or soaking and later applied in soil or leaves. This study evaluated the leaf extracts of Cymbopogon citratus, affecting germination of Bidens pilosa and B....

The objective was to determine whether a change occurs in the critical period of weed interference prevention in narrow row corn with the use of atrazine and whether there is influence of the herbicide on crop yield components. The treatments consisted of periods without or with an initial weed control (0, 21, 35, 49, 63, 77, and 91 days after emer...

Weed herbicide resistance has been a challenge in agriculture. The objective of this study was to detect sourgrass (Digitaria insularis (L.) Fedde) glyphosate-resistant plants and to evaluate the growth and polymorphism rate between the resistant and susceptible biotypes, as a subsidy for the integrated management of species. An experiment was cond...

The interference of weeds in maize production may be reflected in grain yield losses that vary as a function of the density, stage and degree of aggressiveness of the species present. In the agricultural ecosystem, crops and weeds demand light, water, nutrients and space, which are frequently not available in sufficient quantities, leading to compe...

O surgimento de plantas daninhas resistentes tem aumentado os custos e prejudicado a produção dos cultivos pela interferência de plantas daninhas com o cultivo e perda de efetividade dos herbicidas de ampla utilização com amplo espectro de controle e baixo custo, como o glyphosate. Deste modo, o trabalho objetivou identificar populações de C. polyd...

Weed resistance to herbicides is a natural phenomenon that exerts selection on individuals in a population. In Brazil, glyphosate resistance was recently detected in Digitaria insularis. The objective of this study was to elucidate mechanisms of weed resistance in this plant, including genetic variability, allelism, amino acid substitutions, gene e...

Sourgrass(Digitaria insularis, L. Mez ex Ekman)is a weed that requires high rates of glyphosate ((N-[phosphonomethyl]-glycine) forcontrol, verylittle of the herbicide applied isabsorbed by theleaves. Morphological and histological differences in leaves of glyphosate-resistant and glyphosate-susceptible plantsshould explain the contrast of variance...

To gain a better understanding of the physiology of the herbicide aminocyclopyrachlor in young plants of trumpet flower, the uptake and translocation were evaluated after the application of herbicide. This was determined by treating individual leaves with formulated herbicides plus (14)C-aminocyclopyrachlor after the application of the formulated h...

A luz, a temperatura e a dormência são fatores que influenciam a germinação das sementes e estão estritamente ligados à emergência de plantas daninhas. Objetivou-se com este trabalho avaliar a germinação de Sorghum arundinaceum e Sorghum halepense submetidas a diferentes condições de temperatura e luminosidade, bem como avaliar mecanismos de quebra...

Weeds cause big losses in the crops yields. Drought combined with high temperatures can influence and enhance this effect. The present study was designed to determine the periods prior of weed interference on bean crops subjected to conditions of hydric comfort and drought, using two distinct approaches: arbitrary level of 5% productivity loss and...

Talinum paniculatum é uma espécie pertencente à família Portulacacea, conhecida popularmente como maria-gorda, planta daninha em culturas como a cana-de-açúcar, feijão comum, soja, milho e cenoura, além de áreas não agrícolas. Com este trabalho objetivou-se estudar a eficácia de herbicidas no controle de T. paniculatum, assim como seu efeito na mas...

Glyphosate is now the most widely used herbicide; after years of frequent utilization, resistant weeds were selected, mainly due to widespread adoption of glyphosate-resistant crops and no-tillage sowing system. Increasing difficulty in controlling Chloris polydactyla with glyphosate has been noticed in agricultural areas. Here, the susceptibility...

A interferência de plantas daninhas reduz o potencial produtivo das culturas. É de fundamental importância o conhecimento da biologia dessas plantas, incluindo sua habilidade competitiva, no fomento de um manejo integrado de plantas daninhas. Objetivou-se conhecer com este trabalho a interferência de plantas de Capim-branco no estabelecimento inici...

Recent studies indicate that glyphosate applied in post-emergence in RR soybean can eventually cause phytotoxic effects. However, there are many questions that need to be clarified in the scientific and technical contexts, involving the issue of RR soybeans regarding the use of glyphosate. This study has assessed the impact of the application of di...

O glyphosate é um herbicida não seletivo que inibe a produção de aminoácidos aromáticos essenciais à sobrevivência de plantas. Esse herbicida é disponibilizado no mercado em distintas formulações que podem apresentar diferenças no controle de espécies. A mistura de herbicidas é uma ferramenta importante no controle de plantas daninhas resisten...

Glyphosate is a non-selective herbicide that inhibits the production of essential amino acids for plant survival. This herbicide is available in the market in different formulations that can produce different results for weed control. The mixture of herbicides is an important option to control herbicide resistant weeds, and it is an alternative to...

Dentre os tratos culturais realizados nas áreas florestais, o manejo das plantas daninhas é fundamental. Mesmo em baixas densidades, existem espécies que interferem no desenvolvimento da cultura, levando a perdas na qualidade e quantidade do produto colhido, além de ocasionar a redução da eficiência do trabalho e consequentemente, o aumento do cust...

Os beneficios resultantes da tecnologia Roundup Ready sao expressivos, e a aceitacao desta tecnologia pelos produtores rurais e inegavel, dando suporte para o rapido crescimento das areas de milho RR2. Ao mesmo tempo resultados de pesquisas recentes indicam que o glyphosate aplicado em pos-emergencia, em milho RR2, pode, em algumas situacoes, causa...

The aim of this work was to analyze the effect of temperature and light intensity on trumpet flower seed germination, as well as the effect of seeding depth on its emergence. To study the influence of temperature, nine temperature intervals were evaluated, ranging from 15.0 to 40.0 °C. A randomized block design experiment was used with five replica...

A aceitação e o aumento no uso da soja com a tecnologia Roundup Ready (RR) é inegável, isso devido aos benefícios e facilidades proporcionadas por esta ferramenta. Contudo, resultados de estudos indicam que o glyphosate pulverizado em soja RR pode influenciar negativamente o desenvolvimento da cultura e o desempenho das sementes produzidas. Muitas...

RESUMO: A planta daninha buva (Conyza bonariensis, Conyza canadensis e Conyza sumatrensis) está entre as dez principais daninhas encontradas em todo o mundo. Relatos mostram significativas perdas em rendimento em culturas como soja, milho, beterraba, videira, cebola e cenoura, sendo necessário o controle destas plantas. Como a espécie apresenta pop...

Este trabalho teve como objetivo investigar a utilização de doses crescentes do herbicida glyphosate em duas formulações amplamente difundidas, para o controle adequado de plantas de milho voluntárias. O delineamento experimental foi de blocos casualisados, em esquema fatorial 2x5, com quatro repetições. Os tratamentos resultaram da combinação de d...

The research objective was to determine the effects of spacing and seeding density of common bean to the period prior to weed interference (PPI) and weed period prior to economic loss (WEEPPEL). The treatments consisted of periods of coexistence between culture and the weeds, with 0 to 10, 0 to 20, 0 to 30, 0 to 40, 0 to 50, 0 to 60, 0 to 70, and 0...