Baixa umidade do solo na eficácia de herbicidas aplicados em pré-emergência

The aim of this study was to evaluate the effect of low soil moisture on the efficacy of applying herbicides ametryn + clomazone, sulfentrazone and tebuthiuron in pre-emergence application submitted to simulated rainfalls at different time intervals after application in control of B. pilosa, C. echinatus and U. plantaginea plants. The experiment was carried out in pots with a capacity of 2.5 L in green-house conditions and experimental design was completely randomized with four replications, arranged in a 3x5 factorial (three herbicides and five rains intervals). The herbicides clomazone + ametryn (Sinerge EC) 5.0 L commercial product (cp) ha(-1), sulfentrazone (Boral 500 SC) 1.2 L cp ha(-1) and tebuthiuron (combine SC) 2.0 L cp ha(-1) were applied in pre-emergence and the precipitation of 20 mm were applied under de pots in five time intervals after the herbicide application (0h, 4h, 8h, 12h and 24hours). Visual evaluations of plants control that emerged plants were realized at 14 and 21 days after treatment application and the plant emergence percentage was calculated. The application of these three herbicides in dry soil then rain within 24 hours after application provided C. echinatus plants emergence, reduced B. pilosa emergency but in the end of the experiment effectively controlled these two species and U. plantaginea plants.

Potencial de lixiviação de herbicidas utilizados na cana-de-açúcar em solos contrastantes

The increased use of herbicides, coupled with inadequate use of these molecules, also increased concerns about the risks of environmental contamination and its effects on humans and animals. The objective of this work evaluates the potential for leaching of herbicides in the crop of cane sugar, in contrasting soils. Used samples were used Psament (NR - sandy texture) and Oxisol Red (LR - clay texture). After application of herbicides ametryne (NR 1.60 kg ha(-1) and LR 2.40 kg ha(-1)), clomazone (NR 0.90 kg ha(-1) and LR 1.10 kg ha(-1)) and diuron (NR 1.60 kg ha(-1) and LR 3.20 kg ha(-1)), were irrigated blades of 0, 20, 40, 60, 80 and 100 mm of water in soil columns. Results indicate that ametryne in NR samples submitted to the handling layer of 5-10 cm when applied blades of 20 and 40 mm of water. It was evident that the clomazone, regardless of the soil, did not exceed 0-5 cm water depths of 0 to 20 mm of water and 5-10 cm deep in the blades above 40 mm of water. With blades up to 80 mm, the diuron leaching only in layers 0-5 cm deep in LR. Conclude that the potential of leaching of diuron and ametryne was influenced by soil texture together with the organic matter content, the same was not true for clomazone.

Modelos de fração de cura de mistura e não-mistura na distribuição Weibull Modificada Generalizada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eficácia de herbicidas aplicados em pré-plantio incorporado na cultura da cana-de-açúcar

Pós-graduação em Agronomia - FEIS

Espectro de gotas e potencial de deriva de caldas contendo o herbicida 2,4-d amina em misturas em tanque

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Manejo de azevém (Lolium multiflorum Lam.) resistente ao glyphosate com o uso de diferentes herbicidas

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Intervalos de chuva sobre a eficácia de controle químico de trapoeraba (Commelina benghalensis)

The objective was to evaluate the influence of intervals without rain after the application of mixtures of carfentrazone-ethyl and glyphosate in the effectiveness of control on Commelina benghalensis. The experimental design was completely randomized with 11 treatments, with two rates of the mixture carfentrazone + glyphosate, 30 + 960 (with sequential application at 21 DAA of the mixture 20 + 960 g ha-1) and 50 + 960 g ha-1 of a.i. and five intervals of precipitation 0, 3, 6, 12 and 24 hours after application (HAA), with four repetitions, being an absolute check. The mixture was applied in post-emergence, then was carried out simulations of rain in the predetermined intervals. Were assessed the effectiveness of visual control (0 to 100 %) at 7, 14, 21, 28, 35 and 42 DAA. The results were compared by t test, with 10 % level of probability. It was observed that the application of the herbicides carfentrazone + glyphosate in the evaluated rates and even in the sequential application did not have control of C. benghalensis. The results with the second application are greater than the single application, and the best absorption of the mixture carfentrazone + glyphosate by C. benghalensis when there is a bigger interval between application and rainfall occurrence, and is necessary a minimum interval of 6 HAA for intermediate control of C. benghalensis.

Efeito de diferentes herbicidas, doses e volume de calda na dessecação de milheto [Pennisetum glaucum (L. Leek)]

The objective of this work was to evaluate the efficacy of different herbicides applied in post-emergence in the desiccation of pearl millet with different doses and spray volumes. For the desiccation, doses at 0, 25, 50 and 100% of the herbicide glyphosate (1,440 g ha-1) were used in 3 formulations (Original Round up, Round up Transorb and Round up WG), paraquat + diuron (500 + 250 g ha-1) and glufosinateammonium (800 g ha-1). In all treatments, 2 spray volumes (200 and 400 l ha-1) were used, and there was 1 treatment (control) without the application of herbicides. The treatment effects were evaluated visually at 3, 7, 14, 21 and 28 days after application (DAA). At the end of the evaluations, the dry mass of the plants was determined. The field trial was carried out in randomized block design. At the end of the study, at 28 DAA, all treatments presented total control of plant pearl millet, regardless of the dose and spray volume, except the treatments with paraquat + diuron and glufosinate-ammonium at the lower dose (25%), in 2 spray volumes, which nevertheless showed good and very good control, these two herbicides presenting an effect of volume, in which the control was higher with the use of smaller volume.

Eficácia do glyphosate e 2,4-d no controle de commelina villosa

The aim of this study was to evaluate the efficacy of glyphosate and 2,4-D alone and in combination, in the control of Commelina villosa. We studied two methodologies for evaluating herbicide absorption in eight time intervals for washing (simulating rainfall after application) and cutting of leaves (simulating abortion as a defense strategy): 2, 4, 6, 8, 12, 24 and 48 hours after herbicide application, and a treatment without washing or cutting the leaves in a completely randomized design with four replications in a 3 x 7 + 1 factorial design (three herbicides x seven periods – hours after application). Herbicides and doses tested were: glyphosate (1,440 g ha-1), 2,4-D (720 g ha-1) and a mixture of glyphosate + 2,4-D (1,080 + 720 g ha-1). The simulation of rain interfered negatively in the plant control with glyphosate. The control with the herbicide 2,4-D was affected only for the period of 2 hours. Periods of rain simulation did not influence the control of plants with a mixture of glyphosate + 2,4-D. For the study with the cutting of treated leaves, all treatments regardless of the period of cutting the leaves were influenced negatively in terms of plant control, the plants showing regrowth when treated with 2,4-D alone.

Eficácia biológica e feitos tóxicos de fontes de cobre e diquat para organismos aquáticos

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Aplicação de subdoses dos herbicidas glyphosate, 2,4-d e paraquat em algodoeiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mistura de sabor e violação de CP

Pós-graduação em Física - IFT

Efeito de compostos inorgânicos, herbicidas e extratos foliares no desenvolvimento de microcystis aeruginosa e produção de microcistina

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Efeito de compostos inorgânicos, herbicidas e extratos foliares no desenvolvimento de microcystis aeruginosa e produção de microcistina

Pós-graduação em Agronomia (Proteção de Plantas) - FCA