93 research outputs found

    Metamitron replacing carbaryl in post bloom thinning of apple trees.

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    Carbaryl or the mixture of carbaryl with NAA (naphthalene acetic acid) or BA (benzyladenine) are the post-bloom chemical thinners most widely used in apple thinning in Brazil. The marketing restriction of carbaryl demands new options of apple post-bloom thinners, requiring the evaluation of others compounds for this purpose. Metamitron is one of the substances that may be used in chemical thinning of apples. Metamitron was evaluated at two concentrations, alone or in mixture with BA, in "MaxiGala", "Fuji Suprema" and "Fred Hough" apple cultivars. Applications of metamitron at 384 mg L-1 and at 768 mg L-1 in a mixture with BA, ranging from 40 mg L-1 to 80 mg L-1, sprayed on fruits with diameter ranging from 5 to 25 mm were compared ith the standard treatment and hand thinning. The experimental design was a randomized complete block with 4-6 repetitions of a single plant. The variables analyzed were: fruit set (%); percentage of floral clusters with 1, 2, 3, 4 or more fruits; fruit yield (kg); verage fruit fresh mass (g) and percentage of dropped fruit after thinning. Metamitron alone or in combination with BA reduced production per plant and significantly increased the fresh weight of fruits in all cultivars tested. Metamitron at 800 mg L-1 resulted in excessive fruit thinning, especially in ?MaxiGala? cultivar. Metamitron or metamitron + BA have potential to compose the program of chemical thinning of apple trees to replace carbaryl. Index terms: Plant growth regulators, concentration, fruit set, fruit production. O carbaryl ou a mistura de carbaryl com ANA (ácido naftaleno acético) ou BA (Benziladenina) são os produtos mais utilizados no raleio químico da macieira no Brasil. Com o cancelamento do registro do carbaryl como raleante de pós-floração, são necessárias novas alternativas, sendo importante testar diferentes raleantes com esta finalidade. Dentre as substâncias passíveis de utilização no raleio da macieira insere-se o metamitron. O objetivo deste estudo foi avaliar a resposta da aplicação de metamitron no raleio das macieiras ?Fuji Suprema?, ?MaxiGala? e ?Fred Hough?. O uso de metamitron foi testado em duas concentrações, só ou em mistura de tanque com BA, e comparado com BA e BA + etefom, em três cultivares de macieira: ?Maxigala?, ?Fuji Suprema? e ?Fred Hough?. Aplicações de 384 mg L-1 e 768 mg L-1 de metamitron em mistura com BA de 40 mg L-1 e 80 mg L-1 aplicado em frutos de 5 a 25 mm de diâmetro foram comparadas com ?tratamento-padrão? e raleio manual. Foi usado o delineamento experimental em blocos ao acaso com cinco a seis repetições. As variáveis analisadas foram: frutificação efetiva (%), percentagem de cachos florais com 1; 2; 3; 4 ou mais frutos por inflorescência, produção por planta (kg), número de frutos por planta, massa média dos frutos (g) e percentagem de queda de frutos após o raleio. O metamitron só, ou em combinação com BA, reduziu a produção por planta e aumentou a massa média dos frutos em todas as cultivares estudadas. Metamitron a 768 mg L-1 resultou em excessivo raleio, especialmente na ?MaxiGala?. Metamitron ou metamitron + BA tem potencial para compor o programa de raleio químico da macieira em substituição ao carbaryl. Termos para indexação: Regulador de crescimento, concentração, frutificação efetiva, produção

    Induction of senescence and foliar abscission in apple trees with the use of abscisic acid.

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    Aims: Evaluate the effects of different concentrations of abscisic acid (ABA) on adult plants of productive age of ?Daiane? and ?Fuji Suprema?, to follow the ecophysiological effects and their efficiency in inducing leaf senescence, sprouting and productivity, in the Midwestern region of the state of Santa Catarina. Study Design: The experiment was arranged in a randomized block design with six replications. Place and Duration of Study: The experiment was carried out in the municipality of Caçador, Brazil (latitude 26º50?07? S, longitude 50º58?32? W, altitude 969 meters), during the growing seasons of 2013/2014 and 2014/2015. Methodology: The apple fruit tree were submitted to the following treatments: 1) Control (without treatment), 2) abscisic acid 750 mg L-1 , 3) abscisic acid 750 + 750 mg L-1 , 4) abscisic acid 1500 mg L-1 and 5) abscisic acid 1500 + 1500 mg L-1 . ABA applications in the first year were carried out on May 2, 2013 in treatments 2, 3, 4, and 5, and after 11 days (05/13/13) the plants of treatments 3 and 5 were sprayed again. In the second year, ABA applications were carried out on May 6 and 15, 2014, following the same application methodology described for the first year. As the source of abscisic acid (ABA) the commercial product ProTone® (20% i.a.) was used, without the use of adjuvant. The exogenous application of ABA was effective in promoting the senescence and leaf fall of the ?Daiane? and ?Fuji Suprema? cultivars. In the 2013/2014 season, the concentration of 750 mg L-1 was enough to induce 100% leaf fall in 'Daiane' plants. However, a difference was observed between the concentrations of ABA used. There was a difference between concentrations and number of applications. Lower concentrations were efficient and deflated as much as the higher concentration. The application of ABA induces the abscission of apple leaves in early autumn in 'Daiane' and 'Fuji Suprema' apple plants. The ABA does not affect shoots of axillary buds and anticipates the beginning of shoots

    Taxa fotossintética em macieiras tratadas com metamitron.

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    Metamitron (MM) um herbicida que inibe a fotossíntese, foi, recentemente, relatado como efetivo para raleio de Pós floração em macieira, porém pouco se sabe sobre o seu período de interferência sobre a taxa fotossintética e possíveis interferências no desenvolvimento dos frutos após sua aplicação. O objetivo deste estudo foi avaliar a resposta da aplicação diferentes concentrações de MM, na taxa fotossintética, índice de clorofila, taxa de crescimento e redução da frutificação em macieiras ‘Fuji Suprema’ e ‘Maxi Gala’. O experimento foi conduzido em pomar experimental no município de Caçador, SC, na safra 2014/2015. O delineamento experimental foi em blocos casualisados com quatro tratamentos (0mg L-1 , 350mg L-1 , 700mg L-1 e 1050mg L-1 de MM) e cinco repetições de uma planta, aplicados na fase em que os frutos se encontravam com diâmetro entre 20mm e 25mm, em ambas as cultivares. As variáveis analisadas foram: taxa fotossintética, índice de clorofila, taxa de crescimento dos frutos e redução da frutificação. Independentemente da concentração de MM aplicada se observou redução da taxa fotossintética em ambas as cultivares de macieira avaliadas. A aplicação de MM não promoveu a queda de frutos, independentemente da concentração aplicada, devido a época de aplicação tardia, porém afetou o crescimento dos frutos na ‘Maxi-Gala’. Aplicações foliares de MM em macieiras ‘Maxi Gala’ e ‘Fuji Suprema’ reduzem a taxa de fotossíntese de forma proporcional a sua concentração. Palavras-chave: Malus domestica Borkh. Raleio químico. Fisiologia vegetal. Physiological changes in apple trees treated with Metamitron Metamitron (MM), a herbicide that inhibits photosynthesis, has recently been reported as effective for post flower blossom thinning, but little is known about its period of interference on the photosynthetic rate and possible interferences in fruit development after its application. The objective of this study was to evaluate the response of the application of different concentrations of MM, in the photosynthetic rate, chlorophyll index, growth rate and fruiting reduction in 'Fuji Suprema' and 'Maxi Gala' apple trees. The experiment was conducted in an experimental orchard in the municipality of Caçador, SC, in the 2014/2015 harvest. The experimental design was in randomized blocks with four treatments (0mg L-1 , 350mg L-1 , 700mg L-1 and 1050mg L-1 of MM) and five replications of a plant, applied in the phase where the fruits were with diameter between 20mm and 25mm, in both cultivars. The analyzed variables were: photosynthetic rate, chlorophyll index, fruit growth rate and fruiting reduction. Regardless of the concentration of MM applied, there was a reduction of the photosynthetic rate in both evaluated apple cultivars. The application of MM did not promote the fruit drop, independently of the concentration applied, due to the time of late application, but affected the fruit growth in 'Maxi-Gala'. Foliar applications of MM in 'Maxi Gala' and 'Fuji Suprema' apple trees reduce the rate of photosynthesis proportionally to their concentration. Keywords: Malus domestica Bork. Chemical thinning. Plant physiology

    Improvement in insulin sensitivity, but without changes in liver enzymes in obese women after 12 weeks of a walking exercise program with self-selected intensity

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    Background: Obesity is related to negative changes in insulin resistance and liver enzymes and is associated with the risk factor for the development of type II diabetes mellitus and nonalcoholic fatty liver disease. A number of studies have demonstrated that aerobic exercise shows promise for disease prevention and treatment in this population. Aim: The objective of the present study was to evaluate the effect of a walking exercise program with self-selected intensity on insulin resistance and liver enzymes in obese women. Methods: Forty-eight obese women (47.8 ± 8.4 years; 88.1 ± 12.0 kg; 158.0 ± 0.1 cm) were divided into two groups: control group (CG; n = 23) and self-selected walking group (SSWG; n = 25). Before and after the exercise program, all subjects underwent anthropometric measurements and blood samples were collected. The intervention consisted of a walking exercise program with self-selected intensity for 12 weeks (3 times/week, totalizing 36 sessions). Results: After the exercise program, fasting glucose, fasting insulin, and HOMA improved only in the SSWG (p 0.05). In addition, there were no differences in liver enzymes after the intervention in both groups (p > 0.05). Conclusions: The results support that a walking exercise program with self-selected intensity improved insulin resistance in obese women. Thus, exercise programs with self-selected intensity seem to be an interesting alternative for improving health and preventing diseases

    COCCÍDEOS DO BRASIL V. COCCIDAE Ceroplastes (Octoceroplastes) hampeli Lizer, 1919

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    COCCÍDEOS DO BRASIL V. COCCIDAE Ceroplastes (Octoceroplastes) hampeli Lizer, 191

    Sobre um duplo ataque ao limbo foliar de Paulownia fortunei Hemsl.

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    Sobre um duplo ataque ao limbo foliar de Paulownia fortunei Hemsl
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