Academic literature on the topic 'Rainfastness'

A greenhouse study was designed to evaluate a series of silicone adjuvants for increasing efficacy and rainfastness of Na-acifluorfen, isopropylamine-glyphosate, and Na-bentazon on velvetleaf and common lambsquarters. Silicone adjuvants were identified that increased both herbicide efficacy and rainfastness at 0.9 to 1.2 L ha-1. Specificity of adjuvants for specific target weed species and herbicides was evident. Effective silicone adjuvants were identified that did not increase soybean injury by Na-acifluorfen or Na-bentazon beyond that observed with crop oil concentrate. The efficacy of the best silicone adjuvant did not appear to be solely a function of reduced surface tension of the spray solution.

Greenhouse studies were conducted to evaluate the effectiveness of Kinetic, a silicone adjuvant that appeared to increase the efficacy and rainfastness of the isopropylamine salt of glyphosate on velvetleaf, sicklepod, barnyardgrass, guineagrass, yellow foxtail, and yellow nutsedge. Simulated rainfall of 1.3 cm in 5 min at 15 and 60 min after herbicide treatment reduced glyphosate efficacy on all weeds. Kinetic enhanced glyphosate efficacy when yellow nutsedge and guineagrass were subjected to post-spray rainfall at 60 min. On velvetleaf, sicklepod, and yellow foxtail, Kinetic improved glyphosate efficacy when the critical rain-free period was reduced to 15 min. Kinetic failed to provide rainfastness for barnyardgrass, thereby indicating a specificity of Kinetic for certain weed species.

Greenhouse experiments were conducted to evaluate the influence of three organosilicone surfactants (Silwet L-77®, Silwet® 408, and Sylgard® 309) and two blends of organosilicone surfactants with conventional adjuvants (Dyne-Amic® and Kinetic®) on the rainfastness of primisulfuron in velvetleaf. Four conventional adjuvants, Rigo Oil Concentrate, Agri-Dex®, methylated soybean oil, and X-77® were selected for comparison. Primisulfuron at 40 g ai/ha was applied alone or with the organosilicones, blends, or X-77 at 0.25% (v/v); the other adjuvants were tested at 1% (v/v). Simulated rainfall (1.25 cm/0.5 h) was applied at 0.25, 0.5, 1, or 2 h after treatment. Control ratings were made at 5-d intervals and shoot fresh weights were recorded 20 DAT. The organosilicone surfactants significantly increased the rainfastness of primisulfuron, even when simulated rainfall was applied at 0.25 or 0.5 h after treatment. Rigo Oil Concentrate and Kinetic also increased rainfastness when rainfall was applied 1 h after treatment. Differences among adjuvants were not as apparent when rainfall was applied 2 h after treatment. Regardless of the timing of simulated rainfall after treatment, there were significant differences between treatments and nontreated check; however, control was not acceptable in several instances.

Autumn leaf scars are an important pathogen infection site for European canker on apples Trials were undertaken to evaluate the effects of adjuvants on spray coverage of new leaf scars and determine if adjuvants could (1) impart any significant rainfastness to protectant captan sprays and (2) provide any redistribution of captan during a rain event postleaf drop Retention on fresh leaf scars was increased with the use of organosiliconelatex sticker adjuvants only Rain had little effect on spray residues but these adjuvants could improve rainfastness of captan due to their effects on spray retention Retention on stem wood and around leaf nodes was increased by up to sevenfold with the use of superspreadertype adjuvants due to redistribution of spray runoff from leaves High initial deposits resulted in postrain residues on leaf scars threefold higher than a captan spray alone Redistribution of captan onto exposed leaf scars in rain appears likely with these adjuvants

The ability of sage (Salvia officinalis) extract to control grapevine downy mildew under greenhouse and field conditions was tested. The persistence and rainfastness of sage extract were also investigated. Sage extract provided a high level of sustained disease control in artificially inoculated, potted grapevine under greenhouse conditions. However, even small amounts of simulated rainfall (10 mm) significantly reduced efficacy of sage extract. In a field experiment in 2006, sage extract provided 94% reduction in disease incidence and 63% reduction in area under the disease progress curve for disease severity on berries and leaves, respectively, reaching a level of disease control not significantly different from that provided by copper hydroxide. In 2007, the sage extract provided only a partial reduction (less than 30%) of downy mildew on leaves, probably as a result of a long rainy period between two of the consecutive treatments. Overall, sage extract effectively controlled grapevine downy mildew and could be a promising alternative to copper in organic viticulture. However, the low rainfastness of this treatment adversely affected its efficacy.

This study investigated the effect of plant moisture stress and surface of application on the absorption, translocation, and "rainfastness" (short-term ability to retain herbicide) of organosilicone-adjuvated (adjuvant added) [14C]triclopyr amine on greenhouse-grown, 4-month-old red maple (Acerrubrum L.) seedlings. Xylem water potentials were −1.6 and −0.9 MPa and leaf conductances were 0.07 and 0.13 cm s−1 for the stressed and control seedlings, respectively. At 2 h, rainfastness was 13% less for stressed seedlings. Uptake increased with time, and by 72 h no effect of moisture stress treatment was apparent. Abaxial absorption into living leaf tissue was 57% greater at 72 h than was adaxial absorption, but application surface did not significantly affect translocation. Plant moisture stress did, however, reduce translocation of herbicide into the shoots and roots. Organosilicone surfactants may enhance long-term triclopyr uptake in water-stressed seedlings, but do not appear to facilitate translocation in stressed seedlings. Plant moisture status, therefore, should continue to be a concern when scheduling herbicide applications.

Rainfastness is the ability of agrochemical deposits to resist wash-off by rain and other related environmental phenomena. This work reports studies of the rainfastness of selected water-soluble polymers, including poly(vinyl alcohol) (PVA) and chitosan, on Vicia faba leaf surfaces. This was achieved using a novel method involving fluorescent microscopy combined with image analysis. The retention of polymer deposits was analysed via lab-scale washing to simulate rain. PVA over a threshold molecular weight and chitosan were shown to be excellent rainfastness aids. The washing method was ̳scaled up‘ with the use of a raintower and it was shown that the lab-scale washing method was representative of low-tomedium intensity rain (10 mm/h). Physical characterisation indicated that rainfastness correlated with polymer film dissolution, swelling and crystalline properties. It was established that the rainfastness of PVA scaled with increasing molecular weight and crystallinity. Chitosan proved the most effective of the polymers analysed and even samples of moderate molecular weight were able to resist the highest intensity simulated rain. Those polymers which exhibited rainfastness were only soluble in water with a stimulus, such as heating for PVA or decreased pH for chitosan. The microscopy analysis was expanded to assess the rainfastening effect of these polymers on a model agrochemical. This was achieved by following the retention of azoxystrobin – a fluorescently active fungicide. Those polymers which showed retention alone also improved the retention of azoxystrobin. A ̳spot and wash‘ method using mass spectrometry to quantify rainfastness performed alongside fluorescent microscopy analysis further validated the findings.

Conselho Nacional de Desenvolvimento Científico e Tecnológico
Deposition, distribution and tenacity on the leaf surface can influence the efficacy of the fungicide. The effect of rainfall after the spray might run out fungicides of contact from leaf surface. It can also remove the systemic fungicides, if the spray occurs right after the fungicide application. The goals of this work were (i) performance of fungicides due to the drop spectrum under simulated conditions of rainfall on soybean rust control and (ii) determine the interference of rainfall on the biological efficacy of fungicides in different of soybean cultivars to control Phakopsora pachyrhizi. Two experiments were run out in greenhouse conditions. Experiment 1 studied three spray nozzles (twin flat spray - TJ60 11002; extended range flat spray - XR 11002 and wide angle flat spray - TT 11002), spray a fungicide with and without adjuvant, and four intervals of rain after spraying (0, 30, 60 and 120 minutes); two control treatments (without chemical spray and without rain). Experiment 2 rated the performance of four fungicides (Azoxystrobin + Cyproconazol; Pyraclostrobin + Epoxyconazol, Pycoxistrobin + Cyproconazol and Tebuconazol 250 EC) sprayed on seven cultivars (Coodetec 214 RR, Coodetec 219 RR, Monsoy 8000 RR, Monsoy 8080 RR, Fundacep 56 RR, FMT Tabarana and Nidera 7636 RR). Treatments were exposed to simulated rain at intervals of 0, 30, 60, 120 and 240 minutes after spray. The fungicides were sprayed with CO2 pressurized sprayer. The simulated rain produced a precipitation intensity of 20 mm/4min. The simulated rain caused negative effect on the performance of spraying nozzles and the effectiveness of Phakopsora pachyrhizi and powdery mildew control. Fungicide application with no addition of adjuvant affected the efficacy of soybean rust control due to the occurrence of rain immediately after the spraying. The drops produced by the nozzles XR showed the best drop deposition to the control of the soybean rust. In the absence of adjuvant it was observed less negative effect caused by the rain. When the adjuvant was added to the fungicide, it provided less control than the nozzle TT at 0 and 30 minutes after spraying. It was observed relationship between influences of the rainfastness on the efficiency of disease control provided by fungicides in different levels for the seven cultivars tested. The cultivars Msoy 8000 and Nidera 7636 were more showed higher product washing soon after spraying showing AUCPD superior to the other cultivars when sprayed azoxystrobin + cyproconazol. However the cultivars CD 214, CD 219 and FMT Tabarana suffered minor effect due to the rainfastness. It showed significant differences from the other cultivars as much to the final severity of rust as the AUCPD for the same fungicide. Occurrence of rain immediately after the spraying of pyraclostrobin + epoxyconazol was observed superiority in the disease control of the cultivars Cep 56, Nidera 7636 and CD 219 with smaller values of severity and final AUCPD. The efficiency of control of the fungicide pycoxistrobin + cyproconazol was less affected in cultivars Cep 56 and Nidera 7636 by rainfastness. The fungicide tebuconazol was little affected by rainfastness when sprayed in cultivars Cep 56 and CD 219, but in the CD 214 and Nidera 7636 was negative effect of rain. Yield per plant and weight of a thousand grains showed similar trend considering the final severity and AUCPD of the soybean rust.
A deposição, distribuição e tenacidade na superfície foliar influenciam a eficiência de um fungicida. A ação da chuva, logo após a pulverização, pode remover principalmente fungicidas de contato e também os sistêmicos das superfícies foliares das culturas. O presente trabalho teve por objetivos (i) avaliar o desempenho de pontas de pulverização no controle de doenças da soja em condições de chuva simulada e (ii) determinar impacto da chuva na eficiência biológica de fungicidas em variedades de soja para controle da ferrugem asiática. Foram instalados dois experimentos em casa de vegetação no município de Itaara/RS, no experimento 1 foram testadas três pontas de pulverização (jato plano duplo TJ60 11002; jato leque plano de uso ampliado XR 11002 e leque plano defletor TT 11002), um fungicida com e sem adjuvante e quatro intervalos de chuva após a aplicação (0, 30, 60 e 120 minutos); mais dois tratamentos testemunhas, uma sem controle químico e outra sem chuva. No experimento 2 foi avaliado o comportamento de quatro fungicidas (Azoxistrobina + Ciproconazol + Nimbus; Piraclostrobina + Epoxiconazol, Picoxistrobina + Ciproconazol + Nimbus e Tebuconazole 250 CE) aplicados em sete cultivares (Coodetec 214 RR, Coodetec 219 RR, Monsoy 8000 RR, Monsoy 8080 RR, Fundacep 56 RR, FMT Tabarana e Nidera 7636 RR) quando submetidos à chuva simulada aos 0, 30, 60, 120 e 240 minutos após a aplicação. A aplicação dos tratamentos fungicidas foi realizada com auxílio de pulverizador costal pressurizado à CO2. A chuva simulada foi obtida através de equipamento mecânico munido de aspersor Vejeet 80100, produzindo precipitação de intensidade de 20 mm. Os resultados obtidos mostraram que a chuva causou efeito negativo no desempenho das pontas de pulverização e na eficiência de controle de ferrugem asiática e oídio no experimento 1. Quando não foi utilizado adjuvante em combinação com o fungicida a eficiência de controle foi prejudicada pela ocorrência de chuva logo após a aplicação. A ponta XR apresentou o melhor desempenho no controle da ferrugem da soja quando sem adição de adjuvante, apresentando menor efeito negativo da chuva. Quando foi adicionado adjuvante à calda essa ponta proporcionou controle inferior a TT aos 0 e 30 minutos após a aplicação. No experimento 2 foi verificado que a rainfastness influenciou a eficiência de controle proporcionado pelos fungicidas, em diferentes magnitudes para as sete cultivares testadas. As cultivares Msoy 8000 e Nidera 7636 foram mais suscetíveis a lavagem do fungicida logo após a aplicação apresentando AACPF superior às demais cultivares quando aplicado Azoxistrobina + Ciproconazol, já as cultivares CD 214, CD 219 e FMT Tabarana foram as que sofreram menor impacto da rainfastness com diferenças significativas das outras cultivares tanto na severidade final da ferrugem como na AACPF para o mesmo fungicida. Com ocorrência de chuva logo após a aplicação de piraclostrobina + epoxiconazol foi observada superioridade no controle da doença nas cultivares Cep 56, Nidera 7636 e CD 219 que apresentaram menores valores de severidade final e AACPF. A eficiência de controle do fungicida picoxistrobina + ciproconazol foi menos afetada nas cultivares Cep 56 e Nidera 7636 pela rainfastness. O fungicida tebuconazol foi pouco afetado pela rainfastness quando aplicado nas cultivares Cep 56 e CD 219, já na CD 214 e Nidera 7636 ocorreu impacto negativo da chuva. Para peso de grãos por planta e peso de mil grãos foi observada a mesma tendência de resposta verificada para severidade final e AACP da ferrugem da soja.

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The addition of adjuvants can improve the quality of agricultural chemical sprays and have been an usual practice on the last years. The work presents two papers aiming to study the influence of adjuvant apply on the agricultural spray. The first article, entitled "Influence of adjuvants on the physicochemical characteristics of insecticides spray solution and electron microscope images of the deposits on wheat and corn leaves" evaluate changes in physical and chemical characteristics of the spray solution with the insecticides Thiamethoxam, Imidacloprid and Lambda-cyhalothrin. Were measured the surface tension, droplet contact angle on wheat and maize leaf, droplet coverage and images were made with a scanning electron microscope to better understand the deposit of these insecticides. Adjuvants alter the spray solution physical characteristics improving its wettability, furthermore, the addition of adjuvants may interfere with the deposit characteristics of the tested insecticides. The second article entitled "Tank-mix-adjuvants might improve deposit formation and cuticular penetration, and reduce rain-induced removal of chlorantraniliprole", aimed to verify the interaction of clorantraniliprole insecticide with commercial adjuvants. In this assay, have been studied aspects as adjuvant effect on the deposits formation, cuticular penetration through apple cuticles, droplet coverage and rain effect on the removal of the insecticide in wheat and maize crops. The results showed that the adjuvants play a crucial role in the hydrophobic cover sheet by changing the characteristics of the spray solution, thereby improving the wettability. Furthermore, adjuvants may enhance the absorption of clorantraniliprole insecticide.
A adição de adjuvantes pode melhorar a qualidade das pulverizações agrícolas e tem sido uma prática usual nos últimos anos. O presente trabalho apresenta dois artigos que tem como objetivo, estudar a influencia da utilização de adjuvantes nas pulverizações. O primeiro artigo, intitulado Influência de adjuvantes nas características físico-químicas de caldas de pulverização de inseticidas e imagens de microscópio eletrônico dos depósitos em folhas de trigo e milho avaliou as mudanças nas características físicas e químicas da calda de pulverização com os inseticidas tiametoxam, Imidacloprido e lambda-cialotrina. Sendo mensurada a tensão superficial, o ângulo de contato da gota, em folhas de trigo e milho, a cobertura de gotas e realizadas imagens com microscópio eletrônico de varredura. Os adjuvantes alteram as características físicas da calda, melhorando a sua molhabilidade, além disso, a adição de adjuvantes pode interferir nas características de formação do depósito dos inseticidas testados. O segundo artigo intitulado Tank-mix-adjuvants might improve deposit formation and cuticular penetration, and reduce rain-induced removal of chlorantraniliprole , objetivou verificar a interação do inseticida clorantraniliprole com adjuvantes comerciais. Foram estudados aspectos como efeito dos adjuvantes na formação dos depósitos, penetração cuticular, por meio de cutículas de maça, cobertura de gotas e efeito da chuva na remoção do inseticida, nas culturas do trigo e milho. Os resultados mostraram que os adjuvantes tem um papel essencial na cobertura de folhas hidrofóbicas, alterando as características da calda de pulverização e melhorando assim a molhabilidade da mesma. Além disso, se pode concluir que os adjuvantes podem melhorar a absorção do inseticida clorantraniliprole.

O controle químico de pragas, para muitas culturas agrícolas é uma das principais táticas em programas de manejo integrado de pragas (MIP), trazendo benefícios reais e diminuindo as perdas por insetos-praga, além do aumento na produção de alimentos e fibras, proteção de produtos armazenados e proteção de pragas e doenças de seres humanos. O controle de pragas em soja e milho tem sido realizado, em sua maioria, utilizando-se plantas Bt e produtos químicos, este último, além das diversas vantagens citadas, pode ter desvantagens, principalmente quando utilizado de maneira inadequada, com potencial de causar diversos problemas no agroecossistema, além de desequilíbrios ambientais. Devido a importância da cultura da soja e do milho para o Brasil e para o mundo, como base da alimentação animal e humana, reconhecendo o grande uso e papel dos inseticidas como uma das principais táticas usadas para o controle de insetos-praga destas culturas, se faz necessário estudos que tratem da melhor forma de uso dos inseticidas e estudos que avaliem possíveis efeitos adversos destas moléculas em insetos benéficos, para que estejam de acordo com as premissas do MIP. Para viabilizar esta importante tática de controle, realizou-se estudos com os seguintes objetivos: 1) Estudar a toxicidade residual dos inseticidas indoxacarb (Avatar®), chlorantraniliprole (Premio®), spinosad (Tracer®) e teflubenzuron (Nomolt 150®) para C. includens em soja, em ensaio com e sem simulação de chuva; 2) Estudar a toxicidade residual dos inseticidas indoxacarb (Avatar®), chlorantraniliprole (Premio®), spinosad (Tracer®) e teflubenzuron (Nomolt 150®) para S. frugiperda em milho, em ensaio com e sem simulação de chuva; 3) Avaliar efeito letal e subletal de inseticidas recomendados para soja e milho sobre o predador Doru luteipes. Para o primeiro objetivo, teflubenzuron (15 g i. a. ha-1); spinosad (36 g i. a. ha-1); chlorantraniliprole (5, 10 e 20 g i. a. ha-1); indoxacarb (30, 60 e 90 g i. a. ha-1) não tiveram a eficácia afetada quando submetidos à simulação de chuva em todos os tempos avaliados. Quanto a toxicidade residual ao longo do tempo, teflubenzuron, chlorantraniliprole e indoxacarb, nas duas condições, com e sem simulação de chuva, tiveram redução da eficácia após o 5° dia. Diferentemente, os inseticidas spinosad (36 g i. a. ha-1) e indoxacarb (90 g i. a. ha-1), nas duas condições, não tiveram redução da eficácia até 15 dias após aplicação, e em todos os tempos avaliados foram mais eficazes do que os demais inseticidas. Para o segundo objetivo, spinosad (36 g i. a. ha-1) e chlorantraniliprole (10, 20 e 30 g i. a. ha-1) mantiveram a eficácia até o 15º dia após pulverização. Quanto aos efeito da simulação da chuva, spinosad (36 g i. a. ha-1), chlorantraniliprole (10, 20 e 30 g i. a. ha-1) e indoxacarb (90 g i. a. ha-1) mantiveram a eficácia. O inseticida chlorantraniliprole na maior dose utilizada e recomenda para o controle da praga na cultura foi o mais efetivo dentre todos, quanto a toxicidade residual e sob ação da simulação de chuva. Quanto ao terceiro objetivo, ensaio de efeito letal, Tracer, Premio e Avatar foram classificados como nocivos (classe 4), e somente Nomolt foi inócuo (classe 1). No ensaio de efeito subletal apenas o inseticida Nomolt teve parâmetros avaliados. Apesar disso, causou efeitos adversos ao predador, como: aumento do período de pré-oviposição; aumento do período embrionário e diminuição da fecundidade; não sendo, portanto, recomendado para utilização em programas de MIP, pois, altera a capacidade de desenvolvimento e reprodutiva da tesourinha predadora. Os resultados obtidos nesses estudos proveram importantes informações para o refinamento do uso de moléculas inseticidas e classificação desses quanto a seletividade ao predador generalista D. luteipes, agregando informações práticas para o manejo de pragas na cultura da soja e milho.
Chemical pest control for many agricultural crops is one of the main tactics in integrated pest management (IPM) programs, bringing real benefits and decreasing losses by pest insects, as well as increased food and fiber production, protection of stored products and protection of pests and diseases of humans. Pest control in soybean and corn has been mostly carried out using Bt plants and chemical products, for the latter, in addition to the several advantages cited, may have some disadvantages, especially when used improperly, with the potential to cause several problems in the agroecosystem, as well as environmental impacts. Owing to the importance of soybean and corn cultivation to Brazil and to the world, as a basis of animal and human feeding, recognizing the great use and role of insecticides as one of the main tactics used to control insect pests of these crops, it is necessary to study the best use of insecticides and studies that evaluate the possible adverse effects of these chemical molecules on beneficial insects, so that they are in accordance with the IPM premises. To enable this important control tactic, studies were carried out with the following objectives: 1) To study the residual toxicity of insecticides indoxacarb (Avatar®), chlorantraniliprole (Premio®), spinosad (Tracer®) and teflubenzuron (Nomolt 150®) for C. includens in soybeans, with and without rainfastness; 2) To study the residual toxicity of insecticides indoxacarb (Avatar®), chlorantraniliprole (Premio®), spinosad (Tracer®) and teflubenzuron (Nomolt 150®) for S. frugiperda in maize, with and without rainfastness; 3) To evaluate the lethal and sublethal effect of insecticides recommended for soybean and corn on the earwing predator Doru luteipes. For the first objective, teflubenzuron (15 g a. i. ha-1); spinosad (36 g a. i. ha-1); chlorantraniliprole (5, 10 and 20 g a. i. ha-1); indoxacarb (30, 60 and 90 g a. i. ha-1) were not affected when submitted to rainfastness at all evaluated times. Concerning for residual toxicity over time, teflubenzuron, chlorantraniliprole e indoxacarb, under both conditions, with and without rainfastness, had a reduction in efficacy after 5 day. In contrast, the insecticides spinosad (36 g a. i. ha-1) and indoxacarb (90 g a. i. ha-1), in both conditions had no efficacy reduction until 15 days after application and at all times evaluated were more effective than the other insecticides. For the second objective, spinosad (36 g a. i. ha-1) e chlorantraniliprole (10, 20 and 30 g a. i. ha-1) maintained efficacy until the 15th day after spraying. As for the effects of rainfastness, spinosad (36 g a. i. ha-1), chlorantraniliprole (10, 20 and 30 g a. i. ha-1) and indoxacarb (90 g a. i. ha-1) remained effective. The insecticide chlorantraniliprole at the highest dose used and recommended for the control of the pest in the crop was the most effective of all, regarding residual toxicity and under the action of the rainfastness. About the third objective, lethal effect bioassay, Tracer, Premio e Avatar were classified as harmful (class 4), and only Nomolt was innocuous (class 1). In the test of sublethal effect, just the insecticide Nomolt had parameters evaluated. Nevertheless, it caused adverse effects to the predator, such as: increased pre-oviposition period; increase in the embryonic period and decrease in fecundity; therefore, it is not recommended for use in IPM programs, because it modify the developmental and reproductive capacity of predatory earwings. The results obtained in these studies provided important information for the refinement of the use of insecticidal molecules and the classification of these as the selectivity to the generalist predator D. luteipes, adding practical information for pest management in soybean and corn crops.

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O presente trabalho teve por objetivos verificar o efeito da remoção pela chuva de diferentes formulações de flutriafol, em condições de laboratório, aplicadas com e sem a adição de óleo na calda de pulverização, assim como verificar a influencia do óleo no espectro de gotas. O experimento considerou dez caldas resultantes da interação de cinco tratamentos contendo o flutriafol (quatro formulações de flutriafol isolado e uma mistura de flutriafol com tebuconazole), todas aplicadas com e sem óleo mineral. As dez caldas foram aplicadas sobre plantas de soja que receberam posteriormente lavagem por chuva simulada em laboratório com quatro intervalos de tempo entre a aplicação e a chuva. As chuvas foram simuladas em duas etapas, sendo uma lâmina inicial de 5 mm seguida de uma lâmina complementar de 15 mm. As coletas foram realizadas com quatro repetições, sendo cada uma delas constituída de um vaso com quatro plantas. A avaliação da concentração de flutriafol nas soluções resultantes da lavagem das plantas foi realizada através da quantificação dos resíduos do fungicida na água pelo método de cromatografia gasosa e espectrometria de massa (GCMS). Após a aplicação das caldas, as plantas foram retiradas do laboratório e deixadas à temperatura ambiente, a espera do tempo decorrido para a simulação da chuva, de acordo com cada tratamento. Após a simulação das lâminas de chuva as plantas foram cortadas dos vasos e lavadas em saco plástico contendo 200 mL de água destilada. Todas as lavagens foram realizadas em 4 intervalos: 0 h (no momento da aplicação), 1 h, 2 h e 48 h após a aplicação. Para o cálculo do percentual extraído, as quantidades de flutriafol nas soluções de lavagem foram comparadas à quantidade total depositada nas plantas, a qual foi representada...
The present study had for objectives to verify the effect of rainfastness of different flutriafol formulations, in laboratory conditions, applied with and without the oil adjuvant in the spray solution, as well as to verify the influence of the oil on the droplet spectrum. The experiment considered ten spray solutions related to five treatments containing flutriafol (four formulations of flutriafol and a flutriafol mixture with tebuconazole), all applied with and without mineral oil. The ten solutions were applied on soybean plants that were washed by simulated rainfall in laboratory with four time intervals between the application and the rainfall. Rainfall was simulated by one initial precipitation of 5 mm followed by a complementary 15 mm rainfall. Each vase with four plants was considered one replication. The washing solutions from the vases were collected and the flutriafol concentration on those solutions was evaluated through the quantification of the residues of the fungicide in the water using the Gas Chromatography-Mass Spectrometry (GC-MS). After the spray application the plants were removed of the laboratory and left to room temperature, the wait of the time elapsed for the simulation of the rain, in agreement with each treatment.After the simulated rain the plants were cut out of the vases and washed by immersion in plastic sack containing 200 mL of distilled water. All of the washing solutions (from the rain and the immersion process) were accomplished in 4 intervals: 0 h (in the moment of the spray application), 1 h, 2 h and 48 h after the application. For the calculation of the flutriafol extracted, the amounts of fungicide in the wash solutions were compared to the total amount deposited in the plants, which was represented by the sum of the amounts of the assets recovered in the washing... (Complete abstract click electronic access below)

This research focused on the characterization of organosilicone surfactants and their effects on sulfonylurea herbicide activity. The project included efficacy tests, rainfastness studies in the greenhouse, radiotracer studies on herbicide uptake, fluorescent dye studies on surface deposition, and various measurements of physico-chemical properties. In measuring physico-chemical properties, a logistic dose response relationship was found between adjuvant concentration and contact angle on parafilm. An AsymSigR relationship existed between adjuvant concentration and surface tension for all the adjuvants. The organosilicones, Silwet L-77, Silwet 408, and Sylgard 309, and Kinetic (a blend of an organosilicone with a nonionic surfactant) gave equilibrium surface tension values around 20 dyne/cm and showed great spreading ability on the foliage of velvetleaf. With the conventional adjuvants, Agri-Dex, methylated soybean oil, Rigo oil concentration, and X-77, and Dyne-Amic (a blend of an organosilicone with a crop oil concentrate), surface tension was rarely below 28 dyne/cm and spreading ability was limited on velvetleaf. In addition, the organosilicone surfactant and Kinetic also lowered dynamic surface tension, which may improve droplet retention on leaf surfaces. The differences in physico-chemical properties between Kinetic and Dyne-Amic confirmed that carefully electing a co-adjuvant for an organosilicone blend is critical to avoid antagonism with trisiloxane molecules and retain the unique physico-chemical properties of organosilicone in the blends. Studies involving structurally-related organosilicones showed that the end structure in the trisiloxane hydrophilic group has little or no effect on surface tension, contact angle, spread pattern, herbicide uptake and translocation, and efficacy of primisulfuron on velvetleaf. It may be suggested that there is not a strict requirement to purify the end structure during the synthesis process, which is time consuming and expensive. When 14C-primisulfuron was combined with organosilicones or the blends, the uptake of 14C at 1 or 2 h after herbicide application was significantly higher than when combined with conventional adjuvants in velvetleaf. In the greenhouse, organosilicone surfactants greatly increased the rainfastness of primisulfuron in velvetleaf. The effect was immediate and dramatic, even when simulated rainfall was applied 0.25 h after treatment. In addition, herbicide efficacy on marginally susceptible weed species, velvetleaf and barnyardgrass, was significantly increased. A very complicated relationship exists between herbicides and adjuvants. The enhancement effects of adjuvants are often herbicide specific, weed species specific, and even environment specific. No one type of adjuvant functions well in all circumstances. Therefore, there is a need to understand the properties and functions of each class of adjuvants and locate the 'right' niche for each individual adjuvant.
Ph. D.

Orientador: Ulissses Rocha Antuniasi
Banca: Otavio Jorge Grigoli Abi Saab
Banca: Marco Antonio Gandolfo
Banca: Edivaldo Domingues Velini
Banca: Wellington P.A.de Carvalho
Resumo: O presente trabalho teve por objetivos verificar o efeito da remoção pela chuva de diferentes formulações de flutriafol, em condições de laboratório, aplicadas com e sem a adição de óleo na calda de pulverização, assim como verificar a influencia do óleo no espectro de gotas. O experimento considerou dez caldas resultantes da interação de cinco tratamentos contendo o flutriafol (quatro formulações de flutriafol isolado e uma mistura de flutriafol com tebuconazole), todas aplicadas com e sem óleo mineral. As dez caldas foram aplicadas sobre plantas de soja que receberam posteriormente lavagem por chuva simulada em laboratório com quatro intervalos de tempo entre a aplicação e a chuva. As chuvas foram simuladas em duas etapas, sendo uma lâmina inicial de 5 mm seguida de uma lâmina complementar de 15 mm. As coletas foram realizadas com quatro repetições, sendo cada uma delas constituída de um vaso com quatro plantas. A avaliação da concentração de flutriafol nas soluções resultantes da lavagem das plantas foi realizada através da quantificação dos resíduos do fungicida na água pelo método de cromatografia gasosa e espectrometria de massa (GCMS). Após a aplicação das caldas, as plantas foram retiradas do laboratório e deixadas à temperatura ambiente, a espera do tempo decorrido para a simulação da chuva, de acordo com cada tratamento. Após a simulação das lâminas de chuva as plantas foram cortadas dos vasos e lavadas em saco plástico contendo 200 mL de água destilada. Todas as lavagens foram realizadas em 4 intervalos: 0 h (no momento da aplicação), 1 h, 2 h e 48 h após a aplicação. Para o cálculo do percentual extraído, as quantidades de flutriafol nas soluções de lavagem foram comparadas à quantidade total depositada nas plantas, a qual foi representada... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract : The present study had for objectives to verify the effect of rainfastness of different flutriafol formulations, in laboratory conditions, applied with and without the oil adjuvant in the spray solution, as well as to verify the influence of the oil on the droplet spectrum. The experiment considered ten spray solutions related to five treatments containing flutriafol (four formulations of flutriafol and a flutriafol mixture with tebuconazole), all applied with and without mineral oil. The ten solutions were applied on soybean plants that were washed by simulated rainfall in laboratory with four time intervals between the application and the rainfall. Rainfall was simulated by one initial precipitation of 5 mm followed by a complementary 15 mm rainfall. Each vase with four plants was considered one replication. The washing solutions from the vases were collected and the flutriafol concentration on those solutions was evaluated through the quantification of the residues of the fungicide in the water using the Gas Chromatography-Mass Spectrometry (GC-MS). After the spray application the plants were removed of the laboratory and left to room temperature, the wait of the time elapsed for the simulation of the rain, in agreement with each treatment.After the simulated rain the plants were cut out of the vases and washed by immersion in plastic sack containing 200 mL of distilled water. All of the washing solutions (from the rain and the immersion process) were accomplished in 4 intervals: 0 h (in the moment of the spray application), 1 h, 2 h and 48 h after the application. For the calculation of the flutriafol extracted, the amounts of fungicide in the wash solutions were compared to the total amount deposited in the plants, which was represented by the sum of the amounts of the assets recovered in the washing... (Complete abstract click electronic access below)
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