Variação da taxa de aplicação e pontas de pulverização no controle da ferrugem asiática na cultura da soja
Carregando...
Data
2021-07-29
Autores
Freitas, Bianca Rezende de
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A ferrugem da soja, causada pelo fungo Phakopsora pachyrhizi, é a principal e uma das mais destrutivas doença da cultura da soja. A eficiência do controle químico do patógeno está relacionada com o fungicida, momento de aplicação e tecnologia de aplicação mais adequada. Assim, o objetivo do trabalho foi avaliar o efeito da redução da taxa de aplicação, usando pontas de pulverização de jato plano inclinado e jato plano com pré-orifício no controle da ferrugem asiática na cultura da soja, bem como sobre a produtividade da cultura. O experimento foi realizado durante as safras agrícolas de 2019/2020 e 2020/2021 na área experimental pertencente à Fazenda de Ensino, Pesquisa e Extensão (FEPE), localizada na Faculdade de Ciências Agronômicas, Botucatu - SP. O delineamento experimental foi em blocos ao acaso e os tratamentos distribuídos no esquema fatorial 2 x 3 + 1, sendo duas pontas de pulverização combinadas com três taxas de aplicação (60, 90 e 120 L ha-1), mais um tratamento adicional sem aplicação (controle), em cinco repetições. A avaliação da cobertura da pulverização foi realizada em papel hidrossensível e a avaliação dos depósitos da pulverização, em papel filtro, de forma simultânea com as três pulverizações, que foram realizadas nos estádios reprodutivos R1, R3 e R5.2 da cultura da soja, sendo utilizado o fungicida de contato mancozebe na primeira aplicação e nas duas últimas o fungicida mancozebe associado a trifloxistrobina mais protioconazol. A severidade da doença foi avaliada com a finalidade de definir a eficácia de controle dos tratamentos, bem como seu efeito sobre a produtividade da cultura. A menor taxa de aplicação apresentou melhor controle da doença e maior produtividade. A ponta ADI com a menor taxa de aplicação apresentou melhor cobertura no terço inferior do dossel e a ponta 3D com a mesma taxa apresentou melhor cobertura no terço superior. A deposição da calda no terço superior da planta foi melhor com a ponta ADI na taxa de 90 L ha-1 e no terço inferior com a mesma ponta na taxa de 120 L ha-1.
Soybean rust, caused by the fungus Phakopsora pachyrhizi, is the main and one of the most destructive diseases of the soybean crop. The efficiency of chemical control of the pathogen is related to the fungicide, application time and most suitable application technology. Thus, the objective of this work was to evaluate the effect of reducing the application rate, using inclined flat jet spray tips and flat jet with pre-orifice on the control of Asian rust in soybean crop, as well as on the crop yield. The experiment was carried out during the agricultural seasons of 2019/2020 and 2020/2021 in the experimental area belonging to the Teaching, Research and Extension Farm (FEPE), located at the School of Agricultural Sciences, Botucatu - SP. The experimental design was in randomized blocks and the treatments distributed in a 2 x 3 + 1 factorial scheme, with two spray tips combined with three application rates (60, 90 and 120 L ha-1 ), plus an additional treatment without application (control), in five repetitions. The evaluation of spray coverage was carried out on water-sensitive paper and the evaluation of spray deposits, on filter paper, simultaneously with the three sprays, which were carried out in the reproductive stages R1, R3 and R5.2 of the soybean crop, being the contact fungicide mancozeb was used in the first application and the fungicide mancozeb associated with trifloxystrobin plus prothioconazole in the last two. Disease severity was evaluated in order to define the effectiveness of treatments control, as well as their effect on crop yield. The lowest application rate showed better disease control and higher productivity. The ADI tip with the lowest application rate showed better coverage in the lower third of the canopy and the 3D tip with the same rate showed better coverage in the upper third. Spray deposition in the upper third of the plant was better with the ADI tip at the rate of 90 L ha-1 and in the lower third with the same tip at the rate of 120 L ha-1 .
Soybean rust, caused by the fungus Phakopsora pachyrhizi, is the main and one of the most destructive diseases of the soybean crop. The efficiency of chemical control of the pathogen is related to the fungicide, application time and most suitable application technology. Thus, the objective of this work was to evaluate the effect of reducing the application rate, using inclined flat jet spray tips and flat jet with pre-orifice on the control of Asian rust in soybean crop, as well as on the crop yield. The experiment was carried out during the agricultural seasons of 2019/2020 and 2020/2021 in the experimental area belonging to the Teaching, Research and Extension Farm (FEPE), located at the School of Agricultural Sciences, Botucatu - SP. The experimental design was in randomized blocks and the treatments distributed in a 2 x 3 + 1 factorial scheme, with two spray tips combined with three application rates (60, 90 and 120 L ha-1 ), plus an additional treatment without application (control), in five repetitions. The evaluation of spray coverage was carried out on water-sensitive paper and the evaluation of spray deposits, on filter paper, simultaneously with the three sprays, which were carried out in the reproductive stages R1, R3 and R5.2 of the soybean crop, being the contact fungicide mancozeb was used in the first application and the fungicide mancozeb associated with trifloxystrobin plus prothioconazole in the last two. Disease severity was evaluated in order to define the effectiveness of treatments control, as well as their effect on crop yield. The lowest application rate showed better disease control and higher productivity. The ADI tip with the lowest application rate showed better coverage in the lower third of the canopy and the 3D tip with the same rate showed better coverage in the upper third. Spray deposition in the upper third of the plant was better with the ADI tip at the rate of 90 L ha-1 and in the lower third with the same tip at the rate of 120 L ha-1 .
Descrição
Palavras-chave
Tecnologia de aplicação, Ponta de pulverização, Redução de volume, Glycine max, Application technology, Spray tip, Volume reduction