Efeito de fungicidas no controle in vitro de Colletotrichum gloeosporioides, agente etiológico da antracnose do mamoeiro (Carica papaya l.)

Abstract

Effects of fungicides on the in vitro control of Colletotrichum gloeosporioides, the anthracnosis etiologic agent of the Papaya tree (Carica papaya L.). Giltembergue Macedo Tavares 1 , Paulo Estevão de Souza RESUMOCom o objetivo de avaliar a eficiência de alguns fungicidas sobre Colletotrichum gloeosporioides, agente etiológico da antracnose do mamoeiro (Carica papaya L.), testes in vitro foram conduzidos no Laboratório de Epidemiologia/UFLA. Para tanto, utilizou-se o método de incorporação do fungicida ao meio de cultura BDA para avaliação da inibição do crescimento micelial e lâmina escavada contendo água com fungicida para germinação de conídios. Os fungicidas testados foram: azoxystrobin, chlorotalonil, hipoclorito de sódio, imazalil, oxicloreto de cobre, prochloraz, propiconazol, tebuconazol, thiabendazol e tiofanato metílico, nas concentrações de 0, 1, 10, 100, 500 e 1.000 ppm para avaliar a inibição do crescimento do micélio e 0, 1, 10, 50 e 100 ppm para testar inibição da germinação de conídios. Os fungicidas azoxystrobin, chlorotalonil, imazalil, prochloraz, propiconazol e tebuconazol apresentaram alta eficiência na inibição do crescimento micelial. Os fungicidas dos grupos dos benzimidazóis (thiabendazol e tiofanato metílico) mostraram baixa eficiência e ineficiência, respectivamente, no controle do patógeno, demonstrando uma tolerância do isolado em estudo a estes produtos. O hipoclorito de sódio também apresentou baixa eficiência no controle do crescimento micelial do fungo. Quanto à inibição da germinação dos conídios, os fungicidas que demonstraram maior eficiência em baixas concentrações foram: chlorotalonil e hipoclorito de sódio. Termos para indexação: Colletotrichum gloeosporioides, Carica papaya, controle químico, mamoeiro. ABSTRACTThe efficiency of fungicides on Colletotrichum gloeosporioides was evaluated in vitro in the Laboratory of Epidemiology and Diseases Management of the Department of Phytopathology /UFLA. The fungicides were applied either in BDA medium or in glass slide chambers, the latter to assess the effects on conidial germination. The fungicides tested were: azoxystrobin, chlorothalonil, sodium hypochloride, imazalil, copper oxychloride, prochloraz, propiconazol, tebuconazol, thiabendazol and thiophanate-methyl in the concentrations of 0, 1, 10, 100, 500 and 1.000 ppm to evaluate the inhibition of the mycelial growth and in the concentrations of 0, 1, 10, 50 and 100 ppm to test inhibition of the conidial germination. The fungicides azoxystrobin, chlorotalonil, imazalil, prochloraz, propiconazol and tebuconazol presented high efficiency in the inhibition of the mycelial growth. The fungicides of the benzimidazol group (thiabendazol and thiophanate-methyl) showed low efficiency in the control of C. gloeosporioides. Sodium hypochloride showed low efficiency in the control of the mycelial growth of the fungus. For inhibition of the conidial germination, the fungicides oxychloride, chlorothalonil and sodium hypochloride showed high efficiency, even at low concentrations. C. gloeosp...

Fungicides and alternative products in the mycelial growth and germination control of Alternaria tomatophila

“…Tavares and Souza (2005), evidenced the low efficacy of copper oxychloride on the mycelial growth of Colletotrichum gloeosporioides. The biofertilizer used in this review did not inhibit mycelial growth of early blight, but there are several examples in the literature demonstrating its effect on pathogenic fungi.…”

“…Copper oxychloride showed intermediate levels of inhibition, and increased as the concentration was increased. Contact fungicides, chlorothalonil and mancozeb, evaluated by Tofoli When the copper oxychloride was evaluated on the conidia germination effect of Colletotrichum gloeosporioides that fungicide performed better in concentration of 1 ppm with only 10% of germinated conidia, while systemic action fungicide as azoxystrobin, chlorothalonil, imazalil, propiconazil, tebuconazole, among others, were effective at concentrations above 50 ppm (Tavares and Souza, 2005).…”

“…Conidial germination was assessed in two viewing fields of (40X objective) and randomly selected by analyzing 100 conidia per field. Those showing any emission germ tube were considered germinated conidia, regardless of its length (Silva et al, 2009;Tavares and Souza, 2005). The percent inhibition of conidial germination (PIG) was then calculated, where:…”

In vitro antimicrobial activity and alternative control of anthracnose in papaya

“…After 12 days of propagation, the suspension of conidia in the culture was adjusted to 1.4 × 10 5 conidia.mL -1 , using a hemocytometer. The spore germination test followed the methodology described by TAVARES; SOUZA (2005).…”

Effects of Fungicides for Non Target Fungi Alternaria cassiae

“…This characterize the ergosterol biosynthesis way as essential for fungal growth (Alcazar Fuoli et al, 2008). Tebuconazole also was toxic with low concentrations for Colletotrichum gloeosporioides, IC50 < 1.0 mg L -1 , which causes diseases in papaya (Tavares and Souza, 2005) and it showed high patogenecity in vitro for Lasiodiplodia theobromae, IC50 of 0.42 mg L -1 (Locatelli et al, 2015). Captan offers risk for A. cassiae and it can unbalance the fungal content in the soil.…”