103 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

    On Lebesgue measure of integral self-affine sets

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    Let AA be an expanding integer n×nn\times n matrix and DD be a finite subset of ZnZ^n. The self-affine set T=T(A,D)T=T(A,D) is the unique compact set satisfying the equality A(T)=dD(T+d)A(T)=\cup_{d\in D} (T+d). We present an effective algorithm to compute the Lebesgue measure of the self-affine set TT, the measure of intersection T(T+u)T\cap (T+u) for uZnu\in Z^n, and the measure of intersection of self-affine sets T(A,D1)T(A,D2)T(A,D_1)\cap T(A,D_2) for different sets D1,D2ZnD_1,D_2\subset Z^n.Comment: 5 pages, 1 figur

    Effects of ultrasound on the performance improvement of wastewater microfiltration through a porous ceramic filter

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    Filtration under an ultrasonic field is a technique that is gaining importance in the wastewater treatment research field, not only due to its ability as a cleaning mechanism, but also as a filtration intensifier. The main objective of this research was the study of the influence of ultrasonic waves on the filtration of theoilfield wastewater (known as produced water) in order to increase the operation performance and filter medium regenerative effectiveness. A 0.016 m2 hollow cylindrical porous ceramic filter was submitted to the filtration of produced water by two mechanisms: conventional filtration under vacuum and filtration under theinfluence of ultrasonic waves. Experiments were carried out using synthetic produced water by analyzing the variables oil and grease content (O&G) and total suspended solids (TSS) for each filtration run. Backwashing of the filter medium with distilled water was also performed to evaluate the regeneration efficiency. During conventional filtration, permeate flux decreased gradually, becoming stable around 0.06 cm3.cm-2.s-1. Furthermore, in the filtration assisted by ultrasound, the permeate flux was around 0.15 cm3.cm-2.s-1. Therefore, ultrasonic waves provided an increase of about 150% in the permeate flux. Moreover, the sonication improved filter medium regeneration effectiveness, even under conditions of high TSS and O&G contents. Taking into consideration the very positive results associated with the application of ultrasonicwaves, this filtration technique is likely to become an important industrial process

    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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