Technical parameters for the white mold control using air- assisted hydraulic sprayer / Parâmetros técnicos para o controle do mofo-branco na cultura do feijão utilizando pulverizador hidráulico de barra com assistência de ar

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The white mold, caused by the fungus Sclerotinia sclerotiorum, is one of the most destructive diseases of the bean plant in the world, especially in crops under conditions of mild temperatures and high soil and air humidity. In general, primary infections caused by this fungus start due to the presence of free water and an exogenous energy source, usually senescent petals of flowers fallen on the ground or retained in plants. Therefore, for an efficient control of this fungus, it is necessary an increased flower coverage, especially for those located in the lower parts of the bean plants. The general objective of this work was to estimate the main operational parameters of a boom sprayer, with and without air assistance, for white mold control, seeking to achieve the certification of this culture. The specific objectives were: to determinate the technical characteristics and the level of the noise emitted by the set formed by a tractor and spray and the uniformity of the air distributed along the air-assisted spray bar; evaluate the uniformity of spray liquid distribution with or without air assistance; analyze the characteristics of the populations and the spectrum of the droplets produced during the spray with or without air assistance; quantify and evaluate the distribution of the liquid sprayed in the plant canopy based on an spectrophotometric analysis; and evaluate the effectiveness of the white mold control using the hydraulic sprayer with and without air assistance in the spray bar in the field. This work was carried out using a hydraulic spray, Falcon Vortex model, Jacto brand, with a 600 L tank and an air-assisted spray bar with 14 m of length. To pull and trigger the spray, it was used a Valtra 800 tractor, with an engine with a nominal power of 62,5 kW (85 hp). The essays for the determination of air and liquid distribution along the bar were carried out in the Laboratory of Agricultural Mechanization of the Department of Agricultural Engineering of the Federal university of Viçosa, in the city of Viçosa. The study on droplet population, level of noise and deposition of sprayed volume were carried out in a commercial bean crop of the Pérola cultivar, irrigated in the development phase R6, belonging to the Fazenda Agro-Reservas do Brasil, located in the city of Unaí, MG. It was concluded that: the profiles of the wind distribution are irregular in all the rotations and heights studied; the fan-type hydraulic nozzles presented the lowest variation coefficient; the set formed by tractor and spray emitted levels of sound next to the ear of the operator, above the limits allowed by the Regulatory Standard (NR 15) of the Ministry of Work and Employment. In general, the air assistance improved the target cover and the droplet density per cm2 of leaf in the medium and lower parts of the bean plant; the air assistance provides a better deposition of the bean plant liquid; a higher volume of application increased the deposition along the plant; and there was a significant increase in the productivity of the bean plant when the volume of application was increased and when the air assistance was on.

ASSUNTO(S)

fitossanitários engenharia agricola deposição de calda qualidade de aplicação chemical products application quality deposition of the bean plant liquid

ACESSO AO ARTIGO

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