120 resultados para Spray boom
Resumo:
The use of water-sensitive papers is an important tool for assessing the quality of pesticide application on crops, but manual analysis is laborious and time-consuming. Thus, this study aimed to evaluate and compare the results obtained from four software programs for spray droplet analysis in different scanned images of water-sensitive papers. After spraying, papers with four droplet deposition patterns (varying droplet spectra and densities) were analyzed manually and by means of the following computer programs: CIR, e-Sprinkle, DepositScan and Conta-Gotas. The diameter of the volume and number medians and the number of droplets per target area were studied. There is a strong correlation between the values measured using the different programs and the manual analysis, but there is a great difference between the numerical values measured for the same paper. Thus, it is not advisable to compare results obtained from different programs.
Resumo:
ALS-inhibiting herbicides usually provide adequate weed control in irrigated rice fields. After consecutive years of use, the Cyperaceae species, globe fringerush (Fimbristylis miliacea) began to show resistance to ALS (acetolactate synthase) inhibitors. Globe fringerush is one of the most problematic herbicide-resistant weeds in irrigated rice in the state of Santa Catarina in the South of Brazil. The objective of this research was to examine cross resistance of globe fringerush to ALS inhibitors, under field conditions. Two experiments were conducted in a rice field naturally infested with ALS-resistant globe fringerush in Santa Catarina, in the 2008/09 and 2009/10 cropping seasons. The experimental units were arranged in randomized complete block design, with five replicates, consisting of two factors (herbicide and dose) in a 4 x 5 factorial arrangement. ALS herbicides included bispyribac-sodium, ethoxysulfuron, pyrazosulfuron-ethyl and penoxsulam. Six-leaf globe fringerush was sprayed with herbicide doses of 0, 0.5, 1, 2 and 4X the recommended doses in a spray volume of 200 L ha-1. The number of rice culm, filled and sterile grains, plant height, dry shoot biomass and grain yield were recorded. Globe fringerush control was evaluated 28 and 70 days after herbicide application (DAA); shoots were harvested at 13 weeks after herbicide application and dry weight recorded. Competition with globe fringerush reduced the number of culm and rice grain yield. The globe fringerush biotype in this field was resistant to all ALS herbicides tested. Penoxsulam had the highest level of activity among treatments at 28 and 70 DAA, but the control level was only 50% and 42%, respectively, in the second year of assessment. This was not enough to prevent rice yield loss. Alternative herbicides and weed control strategies are necessary to avoid yield losses in rice fields infested with ALS-resistant biotypes of globe fringerush.
Resumo:
The system of rice intensification has emerged as a promising rice production package but weed infestation could lead to incomplete benefits from the system. A two-year field study was performed to determine an appropriate method of weed management in SRI. Weed management treatments were manual hoeing 20, 40 and 60 days after transplanting (DAT), hoeing with rotary hoe at 20, 40 and 60 DAT, hoeing with rotary hoe at 20 DAT + spray with sorghum and sunflower water extracts at 15 L ha-1 40 DAT, manual hoeing 20 DAT + spray with sorghum and sunflower water extracts, both in equal amount, at 15 L ha-1 40 DAT, orthosulfamuron at 145 g a.i. ha-1 7 DAT, weedy check and weed free. Manual hoeing at 20, 40 and 60 DAT was the treatment that exhibited the maximum kernel yield i.e. 5.34 and 4.99 t ha-1., which was 8.4 and 7.2% higher than orthosulfamuron and 61.0 and 64.9% higher than weedy check, during both years of study, respectively. The highest weed suppression was also achieved by manual hoeing at 20, 40 and 60 DAT with weed control efficiency of 87.89 and 82.32% during 2010 and 2011, respectively. Manual hoeing at 20, 40 and 60 DAT is an eco-friendly, non-chemical weed control method to increase kernel yield of fine rice under SRI.
Resumo:
The aim of this study was to assess the effectiveness of glyphosate, as Rodeo(r) formulation, to control Eichhornia crassipes, Pistia stratiotes, Salvinia molesta, Salvinia herzogii and Urochloa subquadripara, under greenhouse conditions. The doses assessed were (480, 960, 1440, 1920, 2400, 2880, 3360 and 3840 g ha-1 of glyphosate) with 0.5% of the Aterbane(r) BR surfactant and a control, with no herbicide application. All experiments were conducted in a completely randomized experimental design with ten replications. Applications were carried out by precision backpack sprayer at a CO2 constant pressure of 25 psi and spray solution consumption of 200 L ha-1. Product effectiveness was determined by assessing the growth inhibitions and phytotoxicity signals during the periods of 3, 7, 15, 21, 30 and 45 days after application (DAA). At 45 DAA, the highest glyphosate dose (3840 g ha-1) displayed 100% effectiveness for all four macrophyte species. Under greenhouse conditions, the glyphosate in formulation Rodeo(r) with 0.5% of Aterbarne(r) BR surfactant showed excellent effectiveness, inhibiting the growth of the floating aquatic macrophytes. This procedure can be included on the tillage plans for these species.
Resumo:
Trinexapac-ethyl and sulfometuron-methyl are the most widely used ripeners in sugarcane. The application is performed by airborne spraying. Thus, if weather conditions are unfavorable, spray drift to neighboring areas may occur. The objective of this study was to assess the selectivity of the plant growth regulators trinexapac-ethyl and sulfometuron-methyl, used as sugarcane ripeners, to eucalyptus (Eucalyptus urograndis) young plants. The experiment was installed in an eucalyptus commercial yield area, in the municipality of Tambaú, state of São Paulo, Brazil, and arranged in a 2 x 8 factorial design in randomized blocks with four replications. The treatments studied were trinexapac-ethyl and sulfometuron-methyl, sprayed in eight doses, 0; 1.0; 2.5; 5.0; 10; 25; 50 and 100% of the dose used in sugarcane as ripeners (200 g ha-1 of trinexapac-ethyl and 15 g ha-1 of sulfometuron-methyl). Chemical ripeners were applied on eucalyptus plants with 48 cm in height on average; 10.1 branches; 4.5 mm of stem diameter and 44.3 cm of crown diameter, at 46 days after seeding. Trinexapac-ethyl was selective to eucalyptus and stimulated crown diameter growth. At higher doses, sulfometuron-methyl promoted severe noticeable injuries in eucalyptus plants, such as apical bud death. However, during the assessment period the plants recovered and the visual symptoms of phytotoxicity and growth alterations were not observed at 60 days after application. The plant growth regulators trinexapac-ethyl and sulfometuron-methyl were selective to eucalyptus young plants.
Exploring Herbicidal Potential of Aqueous Extracts of Some Herbaceous Plants Against Parthenium Weed
Resumo:
To assess the phytotoxic potential of Achyranthes aspera, Alternanthera philoxeroides, Datura metel and Rumex dentatus against Parthenium hysterophorus, 5% (w/v on dry weight basis) aqueous extracts from root, stem, leaf, flower and whole plant were tested through a Petri plate-based germination and pot-cultured seedling bioassays. Achyranthes aspera and A. philoxeroides inhibited parthenium weed germination more than extracts from other species. Whole plant, leaf and fruit extracts of A. aspera reduced the germination percentage (5%); leaf extract from A. philoxeroides caused lower germination index (0.4), higher mean germination time (14 d) and longer time to 50% germination (13.5 d) of parthenium weed. In the foliar spray bioassay, A. aspera reduced parthenium weed shoot growth more than the other species whereas R. dentatus caused more reduction in root growth. Whole plant extract from A. aspera caused maximum reduction in parthenium weed seedling vigor index (98%) and seedling biomass (96%). The aqueous extracts of A. aspera and A. philoxeroides contained higher concentrations of phenolics viz. gallic (16.9 mg L-1), caffeic (7.4 mg L-1), chromatotropic (63.8 mg L-1), p-coumaric (10.5 mg L-1), m-coumaric (3.1 mg L-1), syringic (9.21 mg L-1) and 4 hydroxy-3-methoxy benzoic (118.6 mg L-1) acids compared with extracts of the other two species tested.
Resumo:
The objective of this study was to evaluate the efficiency of application and the efficacy of control of water hyacinth (Eichhornia crassipes) with the use of the diquat herbicide done with two application volumes associated to three droplets classes. Three experiments were conducted; in the first, the application efficiency was evaluated; in the second, the control efficiency and; in the third, the droplet spectrum. They were conducted in a completely randomized design with five, four and six replicates, respectively. The treatments were arranged in a 2 x 3 factorial design, with two application volumes (100 and 200 L ha-1) and three droplets classes (fine, extremely coarse and ultra-coarse) to the first and second experiment and the third comprised two diquat concentrations in spray solution (2 and 4 g i.a. L-1) and three droplets classes (fine, extremely coarse and ultra-coarse). The application efficiency was determined by the coverage by droplets, spray deposition and active ingredient of the herbicide (diquat). The efficacy was measured by the control and the percentage of plants with regrowth at 50 days after application. The spectrum of droplets produced per each nozzle model used to obtain the droplets classes were analyzed. According to the parameters analyzed, using the droplets classes extremely thick and ultra thick can provide greater certainty in the application of diquat in the aquatic environment associated with the deposition of the active and sufficient coverage to control Eichhornia crassipes with both application volumes
Resumo:
In Rubiaceae, anthraquinones and naphthoquinones are secondary metabolites characteristic of the subfamily Rubioideae, in which Rudgea jasminoides is included. Thin-layer chromatography using specific solvent systems and spray reagents indicated the presence of anthraquinones constitutively produced by cell suspension cultures of R. jasminoides. GC/MS analysis detected 1,4-naphthohydroquinone as a product of biosynthesis only after elicitation of the cells with yeast extract (Saccharomyces cerevisiae). The latter compound is probably a phytoalexin produced by suspension cultures of R. jasminoides.
Resumo:
Vertebrate gap junctions are aggregates of transmembrane channels which are composed of connexin (Cx) proteins encoded by at least fourteen distinct genes in mammals. Since the same Cx type can be expressed in different tissues and more than one Cx type can be expressed by the same cell, the thorough identification of which connexin is in which cell type and how connexin expression changes after experimental manipulation has become quite laborious. Here we describe an efficient, rapid and simple method by which connexin type(s) can be identified in mammalian tissue and cultured cells using endonuclease cleavage of RT-PCR products generated from "multi primers" (sense primer, degenerate oligonucleotide corresponding to a region of the first extracellular domain; antisense primer, degenerate oligonucleotide complementary to the second extracellular domain) that amplify the cytoplasmic loop regions of all known connexins except Cx36. In addition, we provide sequence information on RT-PCR primers used in our laboratory to screen individual connexins and predictions of extension of the "multi primer" method to several human connexins.
Resumo:
Gap junctions are clusters of intercellular channels directly connecting the cytoplasm of adjacent cells. These channels are formed by proteins named connexins and are present in all metazoan organisms where they serve diverse functions ranging from control of cell growth and differentiation to electric conduction in excitable tissues. In this overview we describe the presence of connexins in the cardiovascular and lympho-hematopoietic systems giving the reader a summary of the topics to be covered throughout this edition and a historical perspective of the discovery of gap junctions in the immune system.
Resumo:
The Tradescantia micronucleus test is a sensitive bioassay for mutagenesis that may be employed both under field and laboratory conditions. This test has been standardized mostly on the basis of the results obtained with clone 4430. However, this clone is not well adapted to tropical weather, frequently showing problems with growth and flowering. In addition, it is attacked by parasites and insects, a fact that limits its use in field studies aiming at the biomonitoring of air pollution. In the city of São Paulo, Tradescantia pallida (Rose) Hunt. var. purpurea Boom is widely distributed as an ornamental plant in gardens and along roadsides and streets, mostly because of its natural resistance and its easy propagation. In this report, we present dose-response curves indicating that the sensitivity of T. pallida and clone 4430 to X-radiation (1, 10, 25 and 50 cGy) is similar. The results confirm our previous suggestion that T. pallida represents a good alternative for in situ mutagenesis testing in tropical regions, especially biomonitoring studies in which the exposure conditions may not be fully controllable.
Resumo:
After myocardial infarction (MI), activation of the immune system and inflammatory mechanisms, among others, can lead to ventricular remodeling and heart failure (HF). The interaction between these systemic alterations and corresponding changes in the heart has not been extensively examined in the setting of chronic ischemia. The main purpose of this study was to investigate alterations in cardiac gene and systemic cytokine profile in mice with post-ischemic HF. Plasma was tested for IgM and IgG anti-heart reactive repertoire and inflammatory cytokines. Heart samples were assayed for gene expression by analyzing hybridization to AECOM 32k mouse microarrays. Ischemic HF significantly increased the levels of total serum IgM (by 5.2-fold) and total IgG (by 3.6-fold) associated with a relatively high content of anti-heart specificity. A comparable increase was observed in the levels of circulating pro-inflammatory cytokines such as IL-1β (3.8X) and TNF-α (6.0X). IFN-γ was also increased by 3.1-fold in the MI group. However, IL-4 and IL-10 were not significantly different between the MI and sham-operated groups. Chemokines such as MCP-1 and IL-8 were 1.4- and 13-fold increased, respectively, in the plasma of infarcted mice. We identified 2079 well annotated unigenes that were significantly regulated by post-ischemic HF. Complement activation and immune response were among the most up-regulated processes. Interestingly, 21 of the 101 quantified unigenes involved in the inflammatory response were significantly up-regulated and none were down-regulated. These data indicate that post-ischemic heart remodeling is accompanied by immune-mediated mechanisms that act both systemically and locally.
Resumo:
Oito modelos matemáticos bi-paramétricos, existentes na literatura e com larga aplicação na predição de isotermas de adsorção foram submetidos à análise. O guaraná (Paullinia cupana) em pó objeto deste estudo, foi obtido em "spray dryer", a partir de um extrato hidroalcoólico. Ajustaram-se os pontos experimentais das isotermas de adsorção de umidade do produto à 15°C, 25°C e 35°C, por análise de regressão não-linear. Para estudar o efeito da temperatura nos parâmetros dos modelos utilizaram-se regressões dos tipos: linear, exponencial, logarítmica e inversa. Utilizou-se para fazer os ajustes o aplicativo STATGRAPHICS 5.1. Entre os modelos testados os que apresentam melhores resultados foram as equações de Handerson, Oswin e Mizrahi.
Resumo:
Os objetivos desta pesquisa foram a caracterização química de um autolisado (AT) de levedura (Saccharomyces sp. ), subproduto da fermentação alcoólica e de seus derivados, fração solúvel (Ex) e insolúvel (FI). O autolisado integral (AT) e o extrato (Ex), depois de desidratados por atomização (spray dryer) foram utilizados como enriquecedores do gosto e do aroma de biscoitos salgados do tipo água e sal. A adição ao biscoito de 5% de Ex elevou o escore de aminoácidos essenciais (EAE) de 38% para 60% e o índice de utilização líquida da proteína (NPR) de 1,0 para 2,0 (100%). Houve ainda uma melhora significativa na aceitabilidade e na preferência dos biscoitos enriquecidos, pelos consumidores.
Resumo:
Avaliou-se o processo de secagem por nebulização em "spray dryer" para a obtenção de leite bubalino em pó. Foram realizadas análises físico-químicas no leite in natura e no leite desidratado, para averiguar perdas de macronutrientes ocorridas durante a secagem; análises microbiológicas para assegurar a qualidade higiênico-sanitária do processo e produto e análises sensoriais para estabelecer a aceitabilidade do produto. Foram obtidas isotermas de adsorção e dessorção de umidade a 25°C, para o produto em pó, visando observar o seu comportamento higroscópico. O leite bubalino em pó obtido apresentou como características físicoquímicas: 3,4% de umidade, 23,2% de proteínas, 46,1% de gordura, 4,2% de cinzas, 0,5% de lecitina de soja e 22,6% de carboidratos totais. De acordo com os exames microbiológicos está apto para o consumo humano. O produto foi caracterizado como integral por não ter sofrido qualquer padronização. As perdas ocorridas para a maioria dos macronutrientes durante o processamento, foram inferiores a 5% e apenas o teor de proteínas apresentou variação superior a 15%, devido à desnaturação da caseína em temperatura superior a 80°C. O produto apresentou isotermas de adsorção do tipo III, mesmo comportamento apresentado pelo leite bovino. Através da isoterma de dessorção determinou-se o valor de umidade equivalente à monocamada, obtendo-se o valor médio de 4,4g H2 O/100g b.s., o que validou o processo utilizado. O comportamento de histerese apresentado pelo produto foi similar ao do leite em pó integral, sendo a sua aceitabilidade de 74%, muito próxima a 80% obtido para um leite em pó integral comercial.