Eficiência e custo do controle químico da mancha de alternaria em tangor murcote
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Data
2009-09-01
Autores
Colturato, Adimara Bentivoglio [UNESP]
Paulossi, Tatiana
Venâncio, Wilson Story
Furtado, Edson Luiz [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Grupo Paulista de Fitopatologia
Resumo
A mancha de alternaria, causada por Alternaria alternata f. sp. citri, afeta tangelos Minneola, tangerinas Dancy, tangores Murcote e, menos freqüentemente, tangelos Orlando, tangerinas Novas, Lees e Sunburst. Esta doença causa desfolha grave, queda de frutos e manchas nas frutas. O objetivo deste trabalho foi estabelecer o melhor fungicida e a melhor dose para o controle da mancha marrom de alternaria. O delineamento experimental foi de parcelas subdivididas em blocos, com 10 tratamentos principais e 3 doses (subparcelas), com 5 repetições. Foram feitas 5 aplicações, com intervalo de 15 dias. Os tratamentos foram: azoxystrobin, pyraclostrobin, trifloxystrobin, trifloxystrobin + tebuconazole (2 aplicações) seguido de 3 aplicações de mancozeb, difenoconazole, trifloxystrobin + propiconazole, iprodione, trifloxystrobin + propineb (2 aplicações) seguido de 3 aplicações de oxicloreto de cobre, oxicloreto de cobre + óleo e testemunha. Simultaneamente foram feitas avaliações de incidência e número de lesões por folha. Ao surgimento dos frutos foram avaliadas a incidência em frutos e a produtividade em Kg/ha. Todos os tratamentos foram superiores à testemunha quanto a produtividade. Entre os produtos utilizados o tratamento com trifloxystrobin + propiconazole foi rentável comparando-se custo e produtividade.
Alternaria brown spot, caused by Alternaria alternata sp. citri, attacks with more intensity the Tangelos Minneola, tangerine Dancy, and Murcotts, and with less intensity the tangelos Orlando and the tangerinas Novas, Lees and Sunburst. This disease causes severe defoliation and drop or necrotic spots in the fruits. The aim of this work was to evaluated the chemical control of brown spot, and to define the most appropriate dosage of fungicide to control it. The experimental design was split-spot, with ten treatments and 3 doses of fungicides, with five replicates, the fungicides were: azoxystrobin, pyraclostrobin, trifloxystrobin, trifloxystrobin + propinebe (2 applications) followed by 3 applications of mancozeb, difenoconazole, trifloxystrobin + propiconazole, iprodione, trifloxystrobin + tebuconazole (2 applications) followed by 3 applications of copper, copper + oil and control without fungicide. It was evaluated the incidence and number of lesions per leaf, as well the incidence of the disease on fruits and yield at the time of fruits appearing (Kg/ha). All treatments were superior to the control for yield. Among them, the treatment with trifloxystrobin + propiconazole was more profitable comparing cost and yield.
Alternaria brown spot, caused by Alternaria alternata sp. citri, attacks with more intensity the Tangelos Minneola, tangerine Dancy, and Murcotts, and with less intensity the tangelos Orlando and the tangerinas Novas, Lees and Sunburst. This disease causes severe defoliation and drop or necrotic spots in the fruits. The aim of this work was to evaluated the chemical control of brown spot, and to define the most appropriate dosage of fungicide to control it. The experimental design was split-spot, with ten treatments and 3 doses of fungicides, with five replicates, the fungicides were: azoxystrobin, pyraclostrobin, trifloxystrobin, trifloxystrobin + propinebe (2 applications) followed by 3 applications of mancozeb, difenoconazole, trifloxystrobin + propiconazole, iprodione, trifloxystrobin + tebuconazole (2 applications) followed by 3 applications of copper, copper + oil and control without fungicide. It was evaluated the incidence and number of lesions per leaf, as well the incidence of the disease on fruits and yield at the time of fruits appearing (Kg/ha). All treatments were superior to the control for yield. Among them, the treatment with trifloxystrobin + propiconazole was more profitable comparing cost and yield.
Descrição
Palavras-chave
Alternaria alternata, programa de aplicação, fungicidas, custo e produtividade, Alternaria alternata, spray program, fungicides, cost, productivity
Como citar
Summa Phytopathologica. Grupo Paulista de Fitopatologia, v. 35, n. 3, p. 210-215, 2009.