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Dicamba is a post-herbicide, showing some activity in soil, and its dynamics can be influenced by several factors, including the presence of straw. Brazil has more than 50% of its production area in a no-till system; thus, a good amount of the herbicide is intercepted by the straw. This study aimed to evaluate dicamba dynamics in straw and weed control efficacy when sprayed as a PRE herbicide. For this, five different studies were conducted: we utilized different straw amounts (1) and different drought periods (2) for straw sprayed with dicamba and dicamba + glyphosate to evaluate its release from straw, different straw amounts (3), different drought periods (4), and wet and dry straw (5) to evaluate pre-emergence weed control (Bidens pilosa and Ipomoea grandifolia) and dicamba availability in medium-texture soil. Around 80% of dicamba was released from the straw after 100 mm of rainfall. One day after dicamba application, 65–70% of dicamba was released from the straw with 20 mm of rainfall, while for 7 and 14 DAA, 60% was released. Dicamba was efficient in controlling the pre-emergence of both species studied, and the amount of straw did not interfere in weed control; however, dicamba was less available in the soil after rainfall when sprayed in the straw than when sprayed directly in the soil. Up to 80% of dicamba can be released from the straw after 100 mm of rainfall and weed control was efficient for the species studied; however, the carryover effect in sensitive crops might become an issue.

Resumo A presença de fármacos residuais no ambiente é um problema crescente e de abrangência global, com ampla quantidade de pesquisas visando sua quantificação. Porém, seu comportamento e efeitos, tanto no ambiente quanto para o ser humano, ainda não são bem conhecidos. Neste trabalho foram avaliados sete fármacos: Atenolol, Carbamazepina, Clonazepan, Ibuprofeno, Paracetamol, Sinvastatina e Fluoxetina, em amostras de lodo proveniente de uma estação de tratamento de esgotos do sistema público. A extração dos compostos na matriz foi baseada na sua lixiviação em água e a quantificação analítica foi determinada por um sistema de cromatógrafo líquido de ultra performance, acoplado ao espectrômetro de massas. Os resultados indicam a possível movimentação de alguns fármacos da fase aquosa para a sólida. Observou-se que a compostagem do lodo pode favorecer a biodegradação ou mobilização dos compostos, pois houve redução significativa nas concentrações, quando comparados os valores obtidos antes e após o processo de compostagem. A não detecção de um composto não significa necessariamente que ele tenha sido degradado por microrganismos, entretanto, estudos pretéritos chegaram a resultados semelhantes, o que corrobora para a adequação da proposta metodológica e dos procedimentos adotados, contribuindo para a produção de resultados confiáveis.

ABSTRACT The use of pre-emergent herbicides is important for the current agricultural production systems that present weeds resistant to herbicides. Considering the complexity of using these products, the objective of this work was to evaluate their selectivity and residual weed control in soybean crops and their effect on the weeds Amaranthus hybridus, Bidens pilosa, Digitaria insularis, Eleusine indica, and Euphorbia heterophylla. The herbicide selectivity experiments were conducted under field conditions in the 2017/18 and 2019/20 crop seasons and the herbicide efficacy experiments were conducted under greenhouse conditions. The herbicides s-metolachlor and flumioxazin can be applied on day of the soybean sowing without causing significant grain yield losses. Diclosulam and sulfentrazone are safe for soybean crops when applied at least 14 days before sowing. The herbicides used proved to be good options for weed management systems for soybean crops; flumioxazin and sulfentrazone were the herbicides that promoted the best control for all evaluated weed species and ensured a residual effect of at least 30 days.

Mefenpyr-diethyl is a foliar-acting safener of the pyrazoline chemical group, and after its absorption, the metabolization and detoxification of herbicides occur in treated plants. Studies have demonstrated the protective effect of this safener for the herbicide fenoxaprop-P-ethyl in grass. Thus, this work aimed to evaluate whether a tank mixture of mefenpyr-diethyl has a protective response to haloxyfop-methyl in non-perennial bahiagrass. The experiment had a completely randomized design and was carried out in a greenhouse, using five replications with a 10x2 factorial scheme and ten doses of haloxyfop-methyl (0.00, 0.24, 0.49, 0.97, 1.95, 3.90, 7.79, 15.59, 31.28, and 62.35 g a.i. ha-1) in the presence or absence of a tank mixture of mefenpyr-diethyl (50 g a.i. ha-1). Phytotoxicity and electron transport rate (ETR) were evaluated at 7, 14, 21, and 28 days after application (DAA), in addition to plant height and dry biomass at 28 DAA. In general, phytotoxicity increased due to the higher levels of the herbicide haloxyfopmethyl. The application of mefenpyr-diethyl, in turn, provided lower levels of phytotoxicity, as well as lower reductions in ETR, height, and dry biomass when compared to untreated plants. These results show the safener action of a tank mixture of mefenpyrdiethyl on low doses of haloxyfop-methyl in non-perennial bahiagrass.

Glyphosate is a nonselective herbicide of systemic action that inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase, thus compromising amino acid production and consequently the growth and development of susceptible plants. The objective of this study was to evaluate the hormetic effect of glyphosate on the morphology, physiology, and biochemistry of coffee plants. Coffee seedlings (Coffea arabica cv Catuaí Vermelho IAC-144) were transplanted into pots filled with a mixture of soil and substrate and subjected to ten doses of glyphosate: 0, 11.25, 22.5, 45, 90, 180, 360, 720, 1440, and 2880 g acid equivalent (ae) ha−1. Evaluations were performed using the morphological, physiological, and biochemical variables. Data analysis for the confirmation of hormesis occurred with the application of mathematical models. The hormetic effect of glyphosate on coffee plant morphology was determined by the variables plant height, number of leaves, leaf area, and leaf, stem, and total dry mass. Doses from 14.5 to 30 g ae ha−1 caused the highest stimulation. In the physiological analyses, the highest stimulation was observed upon CO2 assimilation, transpiration, stomatal conductance, carboxylation efficiency, intrinsic water use efficiency, electron transport rate, and photochemical efficiency of photosystem II at doses ranging from 4.4 to 55 g ae ha−1. The biochemical analyses revealed significant increases in the concentrations of quinic acid, salicylic acid, caffeic acid, and coumaric acid, with maximum stimulation at doses between 3 and 140 g ae ha−1. Thus, the application of low doses of glyphosate has positive effects on the morphology, physiology, and biochemistry of coffee plants.

The aim of this work was to evaluate the use of the naphthalic anhydride safener on the protection of common bean cultivars BRS-Estilo (carioca) and BRS-Esplendor (black) from negative effects of herbicides. Two experiments were conducted, one for each cultivar in a complete randomized design with five replications, in a 6 × 3 factorial scheme, with six herbicide treatments: bentazon, fluazifop-P + fomesafen, bentazon + imazamox, fomesafen, cloransulam, and control without application, and three naphthalic anhydride treatments: without application, foliar application, and application via seed treatment. Visible injuries at 7, 14 and 21 days after application, photosystem II electron transport rate, and plant dry weight were evaluated. The naphthalic anhydride applied via foliar, and seed treatment reduced significantly the visible injuries in relation to the control when using the herbicides bentazon, fluazifop-P + fomesafen, bentazon + imazamox, and cloransulam. The photosystem II electron transport rate was protected by anhydride applied via foliar and seed treatment when using the herbicides bentazon, fluazifop-P + fomesafen and bentazon + + imazamox. The application of naphthalic anhydride via seed treatment protected the BRS-Estilo and BRS-Esplendor common bean cultivars, with no reductions in the plant dry weight when using the herbicides fluazifop-P + fomesafen, and fomesafen. The use of naphthalic anhydride via seed treatment and foliar application protected BRS-Estilo and BRSEsplendor common bean cultivars, from the negative effects of fluazifop-P + fomesafen and fomesafen herbicides. Thus, this practice has potential to be used in common beans.

2,4-D and dicamba are used in the postemergence management of eudicotyledonous weeds in different crops, most of which are grown under no-tillage systems. Due to the application methods for these products, their dynamics in straw and their residual action in soil have rarely been explored. Thus, the objective of this study was to evaluate the dynamics of 2,4-D and dicamba that have been applied to corn straw and to verify their relationship with residual control action in weeds. In the dynamics experiments, the herbicides were applied to 5 t ha−1 of straw, and rainfall simulations were performed with variable amounts and at different periods after application to evaluate herbicide movement in the straw. In the residual action experiments, the species Digitaria insularis, Conyza spp., Bidens pilosa, Amaranthus hybridus, Euphorbia heterophylla, and Eleusine indica were sown in trays, and 2,4-D and dicamba were applied directly to the soil, to the soil with the subsequent addition of the straw, and to the straw; all of these applications were followed by a simulation of 10 mm of rain. The physical effect of the straw and the efficacy of the herbicides in terms of pre-emergence control of the weed species were evaluated. The leaching of 2,4-D and dicamba from the corn straw increased with a higher volume of rainfall, and the longer the drought period was, the lower the final amount of herbicide that leached. The presence of the corn straw on the soil exerted a physical control effect on Conyza spp.; significantly reduced the infestation of D. insularis, B. pilosa, A. hybridus, and E. indica; and broadened the control spectrum of 2,4-D and dicamba, assisting in its residual action and ensuring high levels of control of the evaluated weeds. In the absence of the straw, 2,4-D effectively controlled the pre-emergence of D. insularis, Conyza spp., and A. hybridus, and dicamba effectively controlled D. insularis, Conyza spp., B. pilosa, A. hybridus, E. heterophylla, and E. indica.

The application of remote sensing techniques and prediction models for soybean rust (SBR) monitoring may result in different fungicide application timings, control efficacy, and spraying performance. This study aimed to evaluate the applicability of a prediction model as a threshold for disease control decision-making and to identify the effect of different application timings on SBR control as well as on the spraying technology. There were two experimental trials that were conducted in a 2 × 4 factorial scheme: 2 cultivars (susceptible and partially resistant to SBR); and four application timings (conventional chemical control at a calendarized system basis; based on the prediction model; at the appearance of the first visible symptoms; and control without fungicide application). Spray deposit and coverage at each application timing were evaluated in the lower and upper region of the soybean canopy through quantitative analysis of a tracer and water-sensitive papers. The prediction model was calculated based on leaf reflectance data that were collected by remote sensing. Application timings impacted the application technology as well as control efficacy. Calendarized system applications were conducted earlier, promoting different spray performances. Spraying at moments when the leaf area index was higher obtained poorer distribution. None of the treatments were capable of achieving high spray penetration into the canopy. The partially resistant cultivar was effective in holding disease progress during the crop season, whereas all treatments with chemical control resulted in less disease impact. The use of the prediction model was effective and promising to be integrated into disease management programs.

Dicamba can be included in weed management programs for Brazilian agricultural crops, such as Conyza spp. and Amaranthus spp., and it is essential to implement good management practices that include salts with low volatility levels and appropriate associations to maintain volatility at acceptable levels. The objective of this study was to evaluate the volatilization of dicamba diglycolamine (DGA) salt associated with different glyphosate salts and volatility reducers. Laboratory and field studies were conducted with the application of DGA alone and in mixtures with three glyphosate formulations (potassium salt, ammonium salt, and di-ammonium salt) with and without a volatility reducer. Under laboratory conditions, the sprayed targets (corn straw) were sent to a vapor collection system for subsequent determination of the amount of volatilized dicamba. In the field, the treatments were applied in a tray containing clay soil, and then, these trays were arranged in soybean rows for 48 h under plastic tunnels. The plant injury and the concentrations of the dicamba in the soybean plants at different distances from the tray were determined. The methodologies used in this study were adequate for understanding the volatility of DGA. The volatility of the dicamba DGA salt used was reduced and was managed through the use of volatility reducers and the correct formulation of glyphosate in the mixture. The VR was efficient in reducing the volatility for dicamba alone and DGA in combination with all glyphosate salts. The combination of dicamba DGA salt with glyphosate potassium salt and a volatility reducer was the mixture with the lowest volatility and is the most suitable combination to recommend to farmers.

The objective of this work was to evaluate the effect of applying mixtures of chemical ripeners on the technological quality and agricultural productivity of sugarcane. The experimental design consisted of randomized blocks arranged in split- split-plots with four blocks, the main plots being constituted by sugarcane varieties SP803280 and SP801842. The subplots consisted of the application of the following products with their respective mixtures: control - absence of ripener; Sulfometrom methyl + glyphosate; ethephon + glyphosate; glyphosate and compounds of organic carboxylic radicals + glyphosate. The sub-subplots were composed of evaluation times: 0; 15 and 30 days after applying the products. Samples from each plot were collected manually and sent to the laboratory for the determination of soluble Brix solids (% broth); Sucrose content in the broth - Pol (% broth); Reducing sugars (RS%); Total reducing sugars (TRS%); Fiber (%); Purity (%); Humidity (%) and Total recoverable sugar TRS (kg t-1). The plots were fully harvested and the stems were taken for weighing and for characteristics determination: Yield per hectare (TCH) and Yield of sugar per hectare (TAH). The SP803280 variety was more responsive to the use of mixtures of chemical ripeners. For the technological characteristics, sulfometurom methyl (0.02 kg ha-1) + glyphosate (0.15 L ha-1) presented the best results from 15 days after application. Mixtures of chemical ripeners did not increase the yields of stalks and sugar per area.

This study aimed to identify the response of wandering jew (Commelina benghalensis L.) plants to different doses of glufosinate ammonium and the sensitivity of plants populations to the herbicide. Two studies were conducted, both in a greenhouse, and were repeated at different times. In the first study, two experiments were conducted to examine the dose-response curve using seven different doses of the glufosinate ammonium herbicide (0, 50, 100, 200, 400, 800, and 1600 g a.i. ha-1) with four replicates each. In the second study, which examined the range in sensitivity of wandering jew plants to glufosinate ammonium, 26 plants were sprayed with a dose of 200 g a.i. ha-1 herbicide. Visual assessments of percent injury and measurements of leaf tissue ammonium content were conducted. The use of untreated wandering jew control plants allowed for the correlation of glufosinate ammonium treatment with the ammonium concentrations in treated plant tissues; the ammonium concentration increased as a function of herbicide application, albeit not linearly with the dose. Ammonium content varied among individuals of the wandering jew plant population.

The process of mechanical harvesting of sugarcane generates a large deposition of straw on the soil surface, providing a coverage that several studies have found important for reducing the weed population. Although such coverage reduces weed infestations, additional management, including chemical control, is still needed. Thus, this study aimed to evaluate the leaching of atrazine, pendimethalin, metribuzin, clomazone, diuron and hexazinone in sugarcane straw. The experiment was conducted at the School of Agronomic Engineering at UNESP (Sao Paulo State University) - Botucatu/SP. The sugarcane straw was collected in the field, cut and placed in quantities of 10t ha-1 in the capsules used as experimental units. The experimental design was completely randomized, using six herbicide treatments and four replications. Within 24 hours after the herbicides were applied in capsules with straw, five different rainfalls (5, 10, 20, 50 and 100mm) were simulated. The leached water was collected for chromatographic analysis. The herbicide percentages that crossed the straw layer were statistically correlated with the rainfall amount by the Mitscherlich model that compares the facility of herbicide removal from sugarcane straw. In summary, pendimethalin did not present quantified transposition of the product by sugarcane straw even with a rain simulation of 100 mm. Furthermore, two different profiles of facility to transpose the herbicides in straw were found: one for metribuzin and hexazinone that crossed quickly through the straw layer and another for atrazine, diuron and clomazone that required more rainfall to be leached from coverage to the soil according to the maximum removable amount of each herbicide.

There are conflicting reports on the effect of potassium phosphite with or without glyphosate in plants. Some of them indicate that potassium phosphite may cause injuries when applied alone, while others point out that it can reduce the injury caused by glyphosate, when applied in association with this herbicide. This study aimed at evaluating the effect of potassium phosphite alone or in association with glyphosate on visual injury, dry matter accumulation, phytotoxicity indicator compounds levels and aromatic amino acid contents in maize plants. Treatments consisted of isolated or associated application of two glyphosate doses (72 g ha-1 and 720 g ha-1) and one potassium phosphite dose (Fosway - 3 L ha-1). The visual evaluations of injury and harvesting were performed at 2, 4, 10 and 15 days after application. The potassium phosphite applied alone did not cause injury to plants, and its association with glyphosate, regardless of the dose tested, did not protect the plants against the injury and dry mass reduction caused by the herbicide. There was an accumulation of shikimic and quinic acids on the plants subjected to the highest dose of glyphosate with or without phosphite. The potassium phosphite treatments with or without glyphosate showed higher tryptophan levels and did not alter the phenylalanine and tyrosine contents in the plants.

Este estudo teve como objetivo investigar a tolerância ou susceptibilidade das espécies de capim-colchão (Digitaria ciliaris, D. horizontalis e D. nuda) a herbicidas inibidores do fotossistema II (FSII), por meio da técnica da fluorescência, utilizando a taxa de transferência de elétrons do FSII como indicador. Para isso, foi conduzido um experimento em esquema fatorial 3x6, com três espécies de capim-colchão e seis tratamentos (ametryn, hexazinone, diuron+hexazinone, amicarbazone, diuron, tebuthiuron e testemunha) aplicados em pós-emergência. Foi monitorada a taxa de transporte de elétrons (ETR) do FSII em intervalos de tempo crescente e aferida a massa seca das plantas aos 21 dias após a aplicação. A partir dos dados da ETR, calculou-se um valor numérico representativo da taxa de inativação da ETR. Os resultados demonstraram que todas as espécies de capim-colchão estudadas são susceptíveis aos herbicidas ametryn e hexazinone (valores da taxa de inativação da ETR superiores a 10.000). Os herbicidas diuron e tebuthiuron apresentaram menores taxas de inativação da ETR para a D. nuda (3.585 e 3.497, respectivamente) e maiores para as espécies D. ciliaris e D. horizontalis (acima de 10.000), enquanto que o herbicida amicarbazone apresentou valor intermediário para D. nuda (7.967). O monitoramento da ETR foi eficiente para verificar a atuação dos herbicidas nas diferentes espécies estudadas

Uma das limitações para sustentabilidade do sistema de cultivo em plantio direto é a rápida decomposição da matéria seca. Um dos mecanismos conhecidos para minimizar este processo e potencializar a permanência da palhada no solo é alterar as vias metabólicas dos polímeros de lignina com aplicação de subdoses de herbicida, interferindo diretamente na resistência à degradação dos restos vegetais pelos microrganismos. Com este objetivo, o herbicida Verdict*R (haloxyfop-methyl) foi aplicado em subdoses nas plantas de aveia-preta e o efeito correlacionado com a altura das plantas, produtividade da matéria seca e metabolismo de lignina. Ensaios preliminares em casa de vegetação foram realizados para determinar as faixas de subdoses a serem aplicadas no experimento definitivo em campo. Os resultados obtidos demonstraram aumento de 24% na produtividade de matéria seca dos experimentos conduzidos em casa de vegetação com a aplicação de 3,125g do ingrediente ativo de haloxyfop-methyl por hectare (i.a. ha-1) nesta subdose, não foram observadas alterações na altura e no metabolismo de lignina nas plantas de aveia-preta. No campo, a concentração de 2,5g i. a. ha-1 do haloxyfop-methyl já foi suficiente para reduzir em 9% a taxa de lignificação sem interferir na altura e produtividade das plantas, sendo este resultado favorável à velocidade de degradação da palhada no plantio direto

O objetivo do trabalho foi avaliar o efeito de adjuvantes sobre a deriva em aplicações da mistura de 2,4-D + glyphosate. O experimento foi conduzido em condições de campo em delineamento inteiramente casualizado. Os tratamentos corresponderam às soluções com a mistura dos herbicidas 2,4-D + glyphosate (670 e 1068g ha-1, respectivamente) adicionando-se os adjuvantes (v v-1): óleo mineral (0,5%); agente antideriva (0,09%); espalhante adesivo A (0,1%); fertilizante líquido (0,05%); espalhante adesivo B (0,25%); e somente os herbicidas (testemunha). Foram utilizados para determinação de deriva fios de náilon externos à área de aplicação (1, 5, 10, 20, 50, 100 e 200m de distância) com quatro repetições e seis cilindros de espuma posicionados sobre a barra do pulverizador para coleta de gotas sujeitas à deriva. As aplicações foram realizadas simultaneamente, utilizando-se um sal traçador específico em cada solução de aplicação para quantificar os depósitos por meio de espectrofotômetro. Não foi possível verificar efeito dos adjuvantes sobre a deriva nas diferentes distâncias da área de aplicação. Com base nas gotas coletadas acima da barra de pulverização, constatou-se que a suscetibilidade à deriva foi menor com o óleo mineral e o agente antideriva. O risco de deriva foi maior com o fertilizante líquido e o espalhante adesivo B.

O presente trabalho foi realizado na Fazenda Experimental Lageado, da Universidade Estadual Paulista em Botucatu, SP objetivando avaliar os custos envolvidos na produção do milho produzido submetido ao efeito hormético, tendo como referência a produção tradicional do cereal, ambos cultivados em sistema de plantio direto. Para avaliação foram determinados os custos envolvidos nas operações de máquinas agrícolas e insumos. Os resultados observados permitiram concluir que o custo por hectare para produção do milho sob efeito hormético foi de R$1.530,20, sendo 0,89% maior do que os custos para produção de milho tradicional (R$ 1.516,63), porém o milho hormético produziu maior volume de matéria seca que o tradicional.

A multiscreening method was experimentally validated for pesticide and antimicrobial residues in spiked eggs at levels of 5, 50, and 500 μg L−1. The residue extraction was performed with acetonitrile and 1% formic acid. The extracted material was stored at −70°C until detection and quantitation within 24-hour period by LC-MS/MS. Pesticide and antimicrobial residue recovery performed adequate standard deviation and the results were from 94.10% (ampa) to 9.20% (carbaryl) for pesticides and from 95.70% (enrofloxacin) to 46.20% (sulfathiazole) for antimicrobial. The method was highly accurate, considering the linearity for all pesticide and antimicrobial residues (r2>0.99), with quantitation limits ranging from 0.78 to 6.25 μg L−1 for pesticides and 0.78 to 3.13 μg L−1 for antibiotics. A highly correlation coefficient (r>0.99) was found, except for carbaryl. Although time extraction and carbaryl recovery remain to be improved, the method has shown a rapid pesticide and antimicrobial residue detection.

O objetivo deste estudo foi buscar in silico os ESTs do Banco de dados do Genoma de Eucalyptus (FORESTs, 2001) correlacionados com genes de alongamento celular envolvidos com crescimento de forma geral. Utilizando bibliotecas de cDNA, nós identificamos agrupamentos de ESTs semelhantes às proteínas controlando alongamento celular registradas no National Center of Biotechnologies Information – NCBI (2002). A busca mostrou similaridade para os seguintes agrupamentos de ESTs: o agrupamento EGEZLV2207D07.g com a enzima esterol delta redutase, EGEQRT4200A01.g com a proteína LKB biossintética de brassinosteróide, EGJMLV2220C06.g com EMBL-transportador mitocondrial half ABC, EGACST6260F07.g e EGMCFB1086B12.g com esterol 22 alfa hidroxilase (CYP90) (P450) e EGEQSL1051D09.g com EGEZSL5201E08.g para aproteína copine. The objective of study was in silico mining of ESTs from Eucalyptus ESTs database (FORESTs, 2001) correlated with cell elongation genes of growth character. Using cDNA libraries, we identified similar EST clusters to the proteins involved on control of cell elongation have been registered on National Center of Biotechnologies Information – NCBI (2002). The data mining has shown similarities for the following ESTs clusters: EGEZLV2207D07.g with delta sterol reductase, EGEQRT4200A01.g with LKB brassinosteroid biosynthetic protein, EGJMLV2220C06.g with EMBL-transporter of mitochondrial half ABC, EGACST6260F07.g and EGMCFB1086B12.g with steroid 22-α hydroxylase, and EGEQSL1051D09.g with EGEZSL5201E08.g for copine protein.

Three trials were carry out at Garça Municipal County, São Paulo, Brazil in order to study the effects of sowing depth of three castor bean cultivars submitted or not to dinitroaniline herbicides application in pre-emergency. The three cultivars chosen as fllow: AL Guarany 2002 variety and Iris and Savana hybrids. The experiments were disposed in randomized complete blocks, with fifteen treatments and four replications, by using factorial scheme 5x3, composed by sowing in 2,5; 5,0; 10,0; 15,0 and 20,0 cm depths with application in pre-emergency condition of the herbicides: trifluralin (1125 g a.i. ha-1), pendimethalin (1500 g a.i. ha-1) and check without herbicide (hand-hold check). Only the sowing depths of 2.5 and 20.0 significantly reduced the initial development of castor bean cultivars AL Guarany 2002 and Iris, without interfering in characteristics number of leaves, stem diameter, insertion height of first raceme and yield. Trifluralin application has increased significantly AL Guarany 2002 yield, in sowings from 5.0 cm deep, unlike Iris and Savana hybrids, where most of sowing depths studied, resulted in yield declines. Pendimethalin herbicide presented high selectivity mainly for AL Guarany 2002 and Savana cultivars, characterizing, generally as the safest option castor bean crop.Três experimentos foram conduzidos no município de Garça-SP com o objetivo de avaliar os efeitos da profundidade de semeadura em três cultivares de mamoneiras submetidas ou não à aplicação de herbicidas dinitroanilinas em pré-emergência. As três cultivares utilizadas foram a variedade AL Guarany 2002 e os híbridos Íris e Savana. Os experimentos foram dispostos em delineamento de blocos casualizados, com quinze tratamentos e quatro repetições, utilizando-se esquema fatorial 5x3, representado pela semeadura nas profundidades de 2,5; 5,0; 10,0; 15,0 e 20,0 cm na condição de aplicação em pré-emergência dos herbicidas trifluralin (1125 g i.a. ha-1), pendimethalin (1500 g i.a. ha-1) e testemunha sem herbicida e capinada. Apenas as profundidades de semeadura 2,5 e 20,0 cm reduziram significativamente o desenvolvimento inicial dos cultivares de mamoneira AL Guarany 2002 e Íris, sem interferir nas características número de folhas, diâmetro de caule, altura de inserção do primeiro racemo e produtividade. A aplicação de trifluralin incrementou significativamente a produtividade da variedade AL Guarany 2002, em semeaduras a partir de 5,0 cm de profundidade, ao contrário dos híbridos Íris e Savana, onde na maioria das profundidades de semeadura estudadas, ocorreram decréscimos de produtividade. O herbicida pendimethalin apresentou elevada seletividade principalmente para AL Guarany 2002 e Savana, caracterizando-se, de forma geral, como a opção mais segura para a cultura da mamona.

Objetivou-se avaliar a influência de intervalos sem chuva após a aplicação de misturas de carfentrazone e glyphosate na eficácia de controle sobre Commelina benghalensis. O delineamento experimental foi inteiramente casualizado com 11 tratamentos, sendo duas dosagens da mistura carfentrazone-ethyl + glyphosate, 30 + 960 (com aplicação sequencial aos 21 DAA da mistura 20 + 960 g ha-1) e 50 + 960 g ha-1 de i.a e cinco intervalos de precipitação 0, 3, 6, 12 e 24 horas após a aplicação (HAA), com quatro repetições, sendo uma testemunha absoluta. A mistura foi aplicada em pós-emergência, em seguida realizou-se simulações de chuva nos intervalos predeterminados. Foram feitas avaliações visuais da eficácia de controle (0 a 100 %) aos 7, 14, 21, 28, 35 e 42 DAA.Os resultados foram submetidos à análise de variância pelo teste F e as médias comparadas pelo teste t em nível de 10 % de probabilidade. Observou-se que a aplicação dos herbicidas carfentrazone + glyphosate nas doses avaliadas e mesmo na aplicação seqüencial não apresentaram controle da C. benghalensis. Os resultados com a segunda aplicação são superiores à aplicação única, sendo a melhor absorção da mistura de carfentrazone + glyphosate pela C. benghalensis quando há um maior intervalo entre a aplicação e ocorrência de chuva e que é necessário intervalo mínimo de 6 HAA para o controle intermediário da C. benghalensis.

Trata-se de um estudo sobre “datamining”envolvendo genes ligados ao crescimento decontrole não hormonal, utilizando o banco dedados de ESTs de eucalipto, efetuado atravésdo Projeto Genoma do Eucalipto (FORESTs)comparados ao nível de aminoácidos. Foramidentificados os clusters de ESTsEGBGFB1211D01.g, EGEZRT6201E10.g,EGCCFB1220G07.g, EGRFCL1206E01.g,EGEQST2006A06.g, EGRFCL1206E01.g,EGEQRT3001H05.b e EGBFRT3106G11.g,similares às proteínas de celulose sintase e suassubunidades controlando o crescimento emArabidopsis thaliana, Gossipium hirsutum,Populus tremuloides, Zea mays e Nicotiana alata,registradas no National Center of BiotechnologiesInformation - NCBI, informação valiosa parafuturos programas de melhoramento genético dogênero Eucalyptus.This is a study about data mining ofexpressed sequence tags (ESTs) involved withcellulose synthase growth effect genes resultedfrom the Eucalyptus ESTs Genome Project(FORESTs) compared at aminoacids level. Using asequencing of derived from cDNAs librariesinduced and not induced by bacteria, wereidentified EST clusters EGBGFB1211D01.g,EGEZRT6201E10.g, EGCCFB1220G07.g,EGRFCL1206E01.g, EGEQST2006A06.g,EGRFCL1206E01.g, EGEQRT3001H05.b, andEGBFRT3106G11.g, similar to cellulose synthaseproteins controlling growth effect in Arabidopsisthaliana, Gossipium hirsutum, Populustremuloides, Zea mays, and Nicotiana alata,registered on National Center of BiotechnologiesInformation - NCBI. These mining results areimportant to improve Eucalyptus breeding programs.

Tracer substances, used to evaluate spraying effectiveness, ordinarily modify the surface tension of aqueous solutions. This study aimed to establish a method of using tracers to evaluate distribution and amount of spray deposits, adjusted to the surface tension of the spraying solution. The following products were tested: 0.15% Brilliant Blue, 0.15% Saturn Yellow in 0.015% Vixilperse lignosulfonate, and 0.005% sodium fluorescein, and mixtures of Brilliant Blue plus Saturn Yellow and Brilliant Blue plus sodium fluorescein at the same concentrations. Solutions were deposited on citrus leaves and stability was determined by measuring fluorescence and optical density of solutions without drying, dried in the dark and exposed to sunlight for 2, 4 and 8 h. These values were compared to those obtained directly in water. The static surface tension of the tracer solution was determined by weighing droplets formed during a period of 20 to 40 seconds. The Brilliant Blue and Saturn Yellow mixture at 0.15% was stable under all conditions tested. It was not absorbed by the leaves and maintained the same surface tension as that of water, thus permitting concentration adjustment to the same levels used for agrochemical products, and allowing the development of a qualitative method based on visual evaluation of the distribution of the pigment under ultraviolet light and of a quantitative method based on the determination of the amount of the dye deposited in the same solution. Spray deposition could be evaluated at different surface tensions of the spraying solution, simulating the effect of agrochemical formulations.

Boron (B) is a low mobility plant micronutrient whose molecular mechanisms of absorption and translocation are still controversial. Many factors are involved in tolerance to Boron excess or deficiency. Recently, the first protein linked to boron transport in biological systems, BOR1, was characterized in Arabidopsis thaliana. This protein is involved in boron xylem loading and is similar to bicarbonate transporters found in animals. There are indications that BOR1 is a member of a conserved protein family in plants. In this work, FORESTS database was used to identify sequences similar to this protein family, looking for a probable BOR1 homolog in eucalypt. We found five consensus sequences similar to BOR1; three of them were then used in multiple alignment analysis. Based on amino acid similarity and in silico expression patterns, a consensus sequence was identified as a candidate BOR1 homolog, helping deeper experimental assays that could identify the function of this protein family in Eucalyptus.

This work was aimed at locating Eucalyptus ESTs corresponding to the PROTOX or PPO enzyme (Protoporphyrinogen IX oxidase, E.C. 1.3.3.4) directly related to resistance to herbicides that promote oxidative stress, changing the functionality of this enzyme. PROTOX, which is the site of action of diphenyl-ether (oxyfluorfen, lactofen, fomesafen), oxadiazole (oxadiazon and oxadiargyl), and aryl triazolinone (sulfentrazone and carfentrazone) herbicides, acts on the synthesis route of porphyrins which is associated with the production of chlorophyll a, catalases, and peroxidases. One cluster and one single read were located, with e-values better than e-70, associated to PROTOX. The alignment results between amino acid sequences indicated that this enzyme is adequately represented in the ESTs database of the FORESTs project.

Herbicides inhibit enzymatic systems of plants. Acetolactate synthase (ALS, EC = 4.1.3.18) and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS, EC 2.5.1.19) are key enzymes for herbicide action. Hundreds of compounds inhibit ALS. This enzyme is highly variable, enabling the selective control of weeds in a number of crops. Glyphosate, the only commercial herbicide inhibiting EPSPS is widely used for non-selective control of weeds in many crops. Recently, transgenic crops resistant to glyphosate were developed and have been used by farmers. The aim of this study was the data mining of eucalypt expressed sequence tags (ESTs) in the FORESTs Genome Project database (https://forests.esalq.usp.br) related to these enzymes. Representative amino acid sequences from the NCBI database associated with ALS and EPSPS were blasted with ESTs from the FORESTs database using the tBLASTx option of the blast tool. The best blasting reads and clusters from FORESTs, represented as nucleotide sequences, were blasted back with the NCBI database to evaluate the level of similarity with available sequences from different species. One and seven clusters were identified as showing high similarity with EPSPS and ALS sequences from the literature, respectively. The alignment of EPSPS sequences allowed the identification of conserved regions that can be used to design specific primers for additional sequencings.

This work was aimed at locating Eucalyptus ESTs corresponding to the GS enzyme (Glutamine Synthetase, EC = 6.3.1.2) and to the D1 protein, which are directly related to resistance to herbicides that promote oxidative stress. Glutamine Synthetase corresponds to the site of action of the herbicide glufosinate. Herbicides that belong to groups such as ureas, uracils, triazines and triazinones act on the D1-Qb complex (receptor of electrons from the Photosystem II) by inactivating it. The clusters EGEQRT3302E01.g, EGEQRT3001F12.b; EGEZLV1203B04.g; EGBGFB1211H06.g and EGEZLV1205F09.g enclosed complete sequences (with 356 amino acids) of the Glutamine Synthetase enzyme. The cluster EGEQSL1054G06.g is a consensus of four reads and enclosed a complete sequence of D1 Protein (with 353 amino acids). The comparison of the sequences of Protein D1 from different species showed that the substitutions of serine (S) by glycine (G) or serine (S) by threonine (T) at the position 264 could produce plants resistant to herbicides that act on electron flow on Photosystem II. The sequence of amino acids corresponding to the cluster EGEQSL1054G06.g had a serine in position 264 indicating sensitivity of the Eucalyptus plants to herbicides that act on this site.

Este experimento teve por objetivo avaliar os efeitos da cultura da cevada e de períodos de controle das plantas daninhas sobre o crescimento e produção de sementes de Raphanus sativus. Foram considerados dois tratamentos testemunha sem controle das plantas daninhas, com e sem a cultura. Nos oito demais tratamentos, a cultura esteve sempre presente, controlando-se as plantas daninhas até 10, 20, 30, 40, 50, 60, 80 e 100 dias após a emergência da cevada. A comunidade infestante da área era composta quase exclusivamente por R. .sativus. Avaliou-se o número de plantas, acúmulos de matéria seca, número médio de frutos e sementes de nabiça por planta e por unidade de área ; foram ainda avaliados o número médio de sementes por fruto, peso médio de 1.000 sementes e a contribuição das sementes na composição da matéria se catota. A análise dos resultados evidenciou que a espécie Raphanus sativus apresenta elevado potencial reprodutivo, sendo possível concluir pela ineficiência de programas de controle de curta duração, em termos de redução do banco de sementes. A presença da cultura da cevada reduziu tanto o crescimento quanto o número de sementes produzidas pela nabiça (R. sativus). Na ausência da cultura e de práticas de controle foram produzidas 5.074 sementes/m, a partir de 125 plantas/m ainda presentes na colheita da cultura.The objective of this research was to evaluate the effects of barley and weed control periods on the seed production and growth of Raphanus sativus, the major weed in the experimental area. The experiment was carried out in Botucatu, SP, Brazil. Two checks, with and without the crop, were kept weedy from seeding to harvest. In other eight treatments the crop was kept weed free up to 10, 20, 30, 40, 50, 60, 80 and 100 days after emergence. It were evaluated the number of plants, the dry matter accumulation and the number of fruits and seeds per plant and per m2, the weight of 1.000 seeds and the percent of the seeds in the total dry matter accumulation. Raphanus sativus showed a high reproductive potential, producing 5. 074 seed s/m2 if kept without control in the absence of the crop. Barley reduced the growth and the seed production of R. sativus. To reduce de seed production to values lower than the population density of the R. sativus in the checks, the weed should be controlled up to 30-100 days after crop emergence.

Pesquisas científicas de qualidade das águas utilizam modelos de inferência de componentes da água, a partir de outros observados em campo, permitindo uma maior representatividade espacial da variável, além de redução de custos. Pesquisadores da área ambiental utilizam a Profundidade de Secchi no cálculo indireto do coeficiente vertical de atenuação de luz na água e na avaliação da extensão da zona eufótica, para a classificação de tipos de água para os ecossistemas aquáticos brasileiros. O propósito desta pesquisa foi, então, realizar a inferência da profundidade da zona eufótica e do coeficiente vertical de atenuação de luz na água do Reservatório de Itupararanga/SP, utilizando uma imagem multiespectral IKONOS, nas bandas 1 (450 - 520 nm); 2 (520 - 600 nm); 3 (630 - 690 nm); e 4 (760 - 900 nm) e dados espectrais obtidos "in situ" com o espectrorradiômetro FieldSpec UV/VNIR (400 - 900 nm), assim como gerar um modelo de inferência da transparência da água, a partir dos dados disponíveis. Após ajustes e processamentos iniciais, os dados foram submetidos a uma análise de correlação, gerando-se o modelo de inferência, o qual, juntamente com as variáveis medidas "in situ" em pontos amostrais específicos, possibilitaram estimar o coeficiente de atenuação vertical de luz na água do reservatório; classificar a água como clara; e estimar a profundidade da zona eufótica, apresentando-se como estreita (entre 5,94 m e 7,96 m). Com isso concluiu-se que o reservatório em questão apresenta pouca concentração de sólidos em suspensão.

In conservation agriculture, mainly under direct seeding, maintaining the vegetation ground cover is essential, since this serves as a reservoir of nutrients which are slowly released to plants by microorganisms. Some authors have sought to study increases in the amount of straw in the soil, in addition to slowing down the process of decomposition, with hormesis being one of the techniques used. This technique states that all chemical substances are both poisonous and nonpoisonous, with only the dosage determining whether they are lethal or not. This study aimed to evaluate the dry weight and agronomic characteristics of a crop of black oat subjected to hormesis. The experimental design was of randomised blocks, with 12 treatments and 4 replications, giving a total of 48 experimental lots. The treatments were: Haloxyfop-R Methyl Ester at dosages of 0.625, 1.25 and 2.50 g ha-1; Glyphosate at dosages of 12.50, 25.00 and 50.00 g ha-1; 2,4-D dimethylamine salt at dosages of 100.00, 200.00 and 300.00 g ha-1; Alterbane at a dosage of 500.00 g ha-1; Salicylic acid at a dose of 100 g ha-1; and a control. It was concluded that for the subdosages under test, the herbicides 2,4-D at medium dosage and Verdict at low dosage were shown to be the best treatments for conserving straw as ground cover under direct seeding.

ABSTRACT The objective of this article was to evaluate the effects of glyphosate on the initial development of eucalyptus (Eucalyptus urograndis) after its application on brachiaria (signal) grass plants (Brachiaria decumbens). The experiment was conducted in a greenhouse in a completely randomized design. Glyphosate, aminomethylphosphonic acid (AMPA) and shikimic acid concentrations were determined, along with an intoxication evaluation of the eucalyptus plant pointers and dry mass of the plants. Glyphosate was detected in eucalyptus plants after its application on B. decumbens plants, but the eucalyptus plants only presented low intoxication levels in the pointer’s leaves. No AMPA was detected in eucalyptus leaves, and only a dose of 1,440 g e.a. ha-1 of glyphosate reduced the total dry mass of eucalyptus plants. Glyphosate has the potential to cause intoxication in the crop when applied to adjacent plants.