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Influência da temperatura e da luminosidade no desenvolvimento de Guignardia citricarpa, agente causal da mancha preta dos frutos cítricos
Timossi, Adriano J.;Goes, Antonio de;Kupper, Katia C.;Baldassari, Ricardo B.;Reis, Renato F. dos;
Fitopatologia Brasileira , 2003, DOI: 10.1590/S0100-41582003000500004
Abstract: four experiments were carried out at the fcav-unesp-campus of jaboticabal to evaluate the effect of temperature (15, 18, 20, 21, 24, 25, 27, 30, 33 e 35 + 1 oc), and three light regimes (dark, continuous light and a 12/12 hour photoperiod) on the production of guignardia citricarpa pseudothecia in citrus (citrus sp.) areas of the states of s?o paulo and rio de janeiro. in addition, the effects of those temperatures and periods of incubation (2, 8 and 16 h) on ascospore germination were also studied. disks of rangpur lime (citrus limonia) leaves measuring 12 mm in diameter were autoclaved and transferred to petri dishes containing 2% water-agar with the abaxial surface facing the medium. four disks were placed in each plate equally spaced from each other. two disks from colonies of phyllostica citricarpa with 21 days of incubation were deposited in the center of each plate and incubated at the different temperatures. the effect of temperature on the photoperiod of 12/12 in the germination of ascospore of g. citricarpa was also evaluated. the generalized beta function was at 26, 22.5 and 27.5 oc for conditions of darkness and light respectively. pseudothecium production was observed in the photoperiod of 12/12 h. mature ascospores were observed after 14 days of incubation, at 27 oc. the highest percentage of germinated ascospores was obtained at temperatures around 24 oc, after 16 h of incubation.
Influência da temperatura e da luminosidade no desenvolvimento de Guignardia citricarpa, agente causal da mancha preta dos frutos cítricos  [cached]
Timossi Adriano J.,Goes Antonio de,Kupper Katia C.,Baldassari Ricardo B.
Fitopatologia Brasileira , 2003,
Abstract: O presente trabalho teve como objetivo avaliar sob condi es de laboratório, o efeito de temperatura (15, 18, 20, 21, 24, 25, 27, 30, 33 e 35 ± 1 masculineC) nas condi es escuro, luz contínua e fotoperíodo 12/12 h, na produ o de pseudotécios de isolados de Guignardia citricarpa, provenientes de regi es cítricolas dos Estados de S o Paulo e Rio de Janeiro. Discos de folhas de limoeiro 'Cravo' (Citrus limonia), de 12 mm de diametro, foram autoclavados e depositadas (parte abaxial) na superfície do meio de cultura constituído por ágar-água 2%. Foram colocados quatro discos de folhas por placa onde, de forma conjunta e intercalar aos mesmos, depositaram-se dois discos obtidos de col nias de Phyllosticta citricarpa, com 21 dias de incuba o. Foi, também, estudado o efeito da temperatura e do tempo de incuba o (2, 8 e 16 h) na germina o dos ascósporos. Após 21 dias de incuba o, a ótima temperatura ajustada pela fun o beta generalizada, para produ o de pseudotécios deu-se a 26 e 22,5 a 27,5 degreesC, sob condi o de escuro e de luz, respectivamente. Observou-se também produ o de pseudotécios a 27 masculineC em fotoperíodo 12/12 h. Em estudo complementar foi verificado que, aos 19 dias, a 27 masculineC, cerca de 90% dos pseudotécios haviam alcan ado a maturidade, com abundante produ o de ascósporos. A maior porcentagem de ascósporos germinados foi constatada na temperatura de 24 masculineC, após 16 h de incuba o. Dentre as vantagens alcan adas, incluem-se a possibilidade (i) da produ o massal de ascósporos em curto período de tempo, e (ii) da padroniza o do inóculo, tanto qualitativa, quanto quantitativa.
Desenvolvimento e valida o de modelo de previs o para mancha preta dos citros em fun o de variáveis meteorológicas Development and validation of a forecast model for citrus black spot according to meteorological variables  [cached]
Mariana Vilela Lopes Ninin,Marcel Bellato Spósito,érika Auxiliadora Giacheto Scaloppi,José Carlos Barbosa
Summa Phytopathologica , 2012,
Abstract: A mancha preta dos citros é uma doen a causada pelo fungo Guignardia citricarpa que produz les es em frutos em variedades de laranja doce comerciais, causando a queda precoce dos frutos, diminuindo a produtividade e levando a sua deprecia o para o mercado de fruta fresca. O objetivo do trabalho foi desenvolver e validar um modelo de favorabilidade climática da mancha preta dos citros relacionado a ocorrência dos sintomas da doen a no Estado de S o Paulo. Desenvolveu-se um sistema empírico com base em um banco de dados da ocorrência da doen a e das condi es climáticas, em campo, nos municípios de Barretos/SP e Gavi o Peixoto/SP, durante as Safras 2007/2008 e 2008/2009. A variedade de laranjeira doce utilizada nos experimentos foi a 'Valência' enxertada sobre limoeiro 'Cravo', com 10 anos de idade. Para a incidência da mancha preta foi avaliada a porcentagem de frutos com sintomas na planta e para a severidade, a porcentagem de casca lesionada por fruto. Na análise de regress o as variáveis climáticas e os dados de intensidade de doen a de Barretos foram selecionados no procedimento 'stepwise'. As melhores equa es de regress o foram selecionadas pelo coeficiente de determina o (R2) e pela significancia da regress o no teste F (P < 0,05 e P < 0,01) que resultou na equa o Y= -502,43 + 9,61 X10 + 4,78 X30 + 0,54 X46 - 7,9 X50 em que Y=índice de Favorabilidade, X10 é a temperatura média, X30 é a umidade relativa média, X46 é o molhamento foliar e X50 é a temperatura média durante o molhamento foliar, determinados com dados de intervalos de sete dias. Procedeu-se a valida o no campo no município de Gavi o Peixoto durante a Safra 2008/2009, realizando a correla o entre a incidência e severidade observadas no experimento e os dados previstos que foram os determinados pela equa o, sendo que a correla o mostrou-se positiva para a incidência da doen a com um R2=0,87. Citrus black spot is a disease caused by Guignardia citricarpa which produces lesions in fruits of commercial varieties of sweet orange, causing premature fall of fruits, decreasing the yield and leading to depreciation of the fresh fruit market. The aim of this study was to develop and validate a model of climate favorability for citrus black spot related to the occurrence of the disease symptoms in the state of S o Paulo (SP). An empirical system was developed based on a data bank of the disease occurrence and the climate conditions in the field in the municipalities of Barretos/SP and Gavi o Peixoto/SP, during the 2007/2008 and 2008/2009 crop cycles. The sweet orange variety used in the expe
Eficacia de tres estrobilurinas para el control de mancha rojiza (Guignardia mangiferae) y mancha negra (Guignardia citricarpa) en frutos de limón, en Tucumán, República Argentina Efficiency of three strobilurins to control reddish spot (Guignardia mangiferae) and black spot (Guignardia citricarpa) in lemon fruits in Tucumán, Argentina  [cached]
Gabriela M. Fogliata,M. Lorena Mu?oz,Alejandro A. Rojas,L. Daniel Ploper
Revista Industrial y Agrícola de Tucumán , 2011,
Abstract: La Argentina lidera la producción e industrialización mundial de limón. Tucumán produce el 87% del total nacional, destinando 65% para su industrialización y 35% para su comercialización como fruta fresca, principalmente en exportaciones. Para ello, se requieren frutos de calidad y libres de enfermedades, especialmente de aquellas causadas por patógenos considerados cuarentenarios en los mercados de destino. En Tucumán, están presentes la mancha negra de los cítricos, causada por Guignardia citricarpa (Phyllosticta citricarpa), patógeno cuarentenario para importantes mercados consumidores, y en mayor prevalencia, la mancha rojiza o moteado, causada por G. mangiferae (P. capitalensis), hongo no cuarentenario. Ambas enfermedades se controlan con fungicidas cúpricos, estrobilurinas, mancozeb y bencimidazoles. Se realizaron cinco ensayos para evaluar la eficacia de tres estrobilurinas, azoxistrobina, pyraclostrobin y trifloxistrobin, para controlar mancha rojiza (campa as 2004/2005, 2005/2006 y 2006/2007) y mancha negra (2007/2008 y 2008/2009) en frutos de limón en Tucumán. Se realizaron una y dos aplicaciones de estrobilurinas con oxicloruro de cobre, en un esquema de cuatro y cinco aplicaciones de cúpricos, cada treinta días desde caída de pétalos. Se utilizaron tratamientos con oxicloruro de cobre solo o en mezcla con mancozeb, como testigos químicos. Se evaluó la incidencia de las enfermedades en julio y se calculó la eficacia de los tratamientos. Los más eficaces para controlar mancha negra y mancha rojiza fueron los que incluyeron una o dos aplicaciones de estrobilurinas, sin diferencias entre sí, superando al cúprico e igualando o superando a la mezcla cúprico-mancozeb. Estos resultados demostraron la eficacia de las estrobilurinas para controlar mancha negra y mancha rojiza en frutos de limón. Argentina leads lemon world production and industrialization. The province of Tucumán generates 87% of national production, processing 65% of this production in factories and commercializing 35% as fresh fruit, mainly for exports, which requires high quality, disease-free fruits. Two fungal species of Guignardia are present in Tucumán: one is G. citricarpa (Phyllosticta citricarpa) and the other is G. mangiferae (P. capitalensis). The former is the causal agent of citrus black spot, a quarantine pathogen for major consumer markets, and the latter is a cosmopolitan fungus which causes red spot in lemon in Tucumán. Both diseases are controlled with copper, strobilurins, mancozeb, and benzimidazols. Five field experiments were conducted to evaluate the efficacy o
Eficacia de tres estrobilurinas para el control de mancha rojiza (Guignardia mangiferae) y mancha negra (Guignardia citricarpa) en frutos de limón, en Tucumán, República Argentina
Fogliata,Gabriela M.; Mu?oz,M. Lorena; Rojas,Alejandro A.; Ploper,L. Daniel;
Revista industrial y agr?-cola de Tucum??n , 2011,
Abstract: argentina leads lemon world production and industrialization. the province of tucumán generates 87% of national production, processing 65% of this production in factories and commercializing 35% as fresh fruit, mainly for exports, which requires high quality, disease-free fruits. two fungal species of guignardia are present in tucumán: one is g. citricarpa (phyllosticta citricarpa) and the other is g. mangiferae (p. capitalensis). the former is the causal agent of citrus black spot, a quarantine pathogen for major consumer markets, and the latter is a cosmopolitan fungus which causes red spot in lemon in tucumán. both diseases are controlled with copper, strobilurins, mancozeb, and benzimidazols. five field experiments were conducted to evaluate the efficacy of three strobilurins, azoxystrobin, pyraclostrobin and trifloxystrobin, to control red spot (during the 2004/2005, 2005/2006 and 2006/2007 crop seasons) and citrus black spot (in the 2007/2008 and 2008/2009 seasons) in lemon fruits in tucumán. one or two applications of strobilurins were made with copper oxychloride, in a program of four or five copper applications, every thirty days from petal fall. treatments with copper oxychloride, alone or mixed with mancozeb, were used as chemical controls. the most effective treatments were those that included one or two strobilurin applications, without differences between them. they outdid copper treatments, equaling or surpassing copper-mancozeb mixture. these results demonstrated the efficacy of strobilurins to control both black spot and red spot in lemon.
Avalia??o da mancha preta dos citros em diferentes variedades de laranjeira doce
Rossetto, Marcos Paulo;Azevedo, Fernando Alves de;Martelli, Ivan Bortolato;Schinor, Evandro Henrique;
Bragantia , 2011, DOI: 10.1590/S0006-87052011000100010
Abstract: the citrus black spot - cbs (guignardia citricarpa kiely) has been responsible for great losses in brazil, where all commercial varieties of sweet orange are susceptible. given the economic losses that this disease causes to the brazilian citrus industry, this study aimed to evaluate the susceptibility of sweet orange varieties with late harvest to cbs. a total of 36 varieties were evaluated in cordeirópolis city, and 35 located at conchal city, in two years (2007 and 2008), both in s?o paulo state, brazil, in randomized block design assays with three replications. by using a diagrammatic scale specific to the cbs, the severity of cbs was quantified between the months from june to november (2007 and 2008), data was used to calculate the area under disease progress curve. all varieties were susceptible to cbs, however imperial and valência pálida israel were less susceptible than the others at both locations.
Resistência à mancha preta dos citros avaliada por curvas de progresso da doen?a
Spósito, Marcel B.;Bassanezi, Renato B.;Amorim, Lilian;
Fitopatologia Brasileira , 2004, DOI: 10.1590/S0100-41582004000500010
Abstract: citrus (citrus spp.) black spot, caused by guignardia citricarpa, is responsible for serious damage to citriculture in the state of s?o paulo. the main varieties of oranges (citrus sinensis) in s?o paulo are 'hamlin', 'pera', 'valência' and 'natal'. the literature suggests that late varieties such as 'valência' and 'natal' are most susceptible to citrus black spot, because these varieties are severely affected at harvest time. nevertheless, there is no information about the temporal disease progress in the field. resistance of the orange varieties 'hamlin' (early), 'pera' (mid-season), and 'valência' (late) to citrus black spot was assessed in a commercial grove, under conditions of natural infection. disease severity and disease incidence were assessed in 100 fruits of 100 plants of each variety, every 15 days, from the first appearance of symptoms in the field until harvest. the monomolecular model was fitted to the data of the disease progress curves for the three varieties. the rate parameter (r) of the disease progress curve was not different for the three varieties. varieties 'hamlin', 'pera' and 'valência' present the same degree of susceptibility to the mpc.
Efeito do manejo cultural e químico na incidência e severidade da mancha-preta dos citros
Scaloppi, Eliana Mayra Torrecillas;Aguiar, Ronilda Lana;Goes, Antonio de;Spósito, Marcel Bellato;
Revista Brasileira de Fruticultura , 2012, DOI: 10.1590/S0100-29452012000100015
Abstract: the citrus plants has several phytosanitary problems, including citrus black spot (guignardia citricarpa). control of this disease is based on cultural practices and application of fungicides. the effect of the weed management and chemical control was evaluated. the experiments were carried out in sweet orange orchards in mat?o, rio claro and mogi gua?u municipalities in the state of s?o paulo, brazil. in the experiment of weed management, the use of ecological brushcutter was compared with the use of mechanical rake and brush combined, at 35 days after 2/3 of petals fallen. chemical control was carried out by two spraying of protective fungicide and from 2 to 5 spraying of systemic and protective fungicides 45 days after 2/3 of petals fallen. the range of these spraying was 35 days and in all of them emulsifiable mineral oil (0.25%) was added. the area under the curve of the incidence progress and severity of the disease was evaluated using data from five evaluations that were realized every 15 days from the physiological maturity of the fruits. the use of chemical control associated with weed management decreased the intensity of the disease in all areas evaluated.
Resistência a benzimidazóis por Guignardia citricarpa
Rodrigues, Maria Beatriz Calderan;Andreote, Fernando Dini;Spósito, Marcel Bellato;Aguillar-Vildoso, Carlos Ivan;Araújo, Welington Luiz;Pizzirani-Kleiner, Aline Aparecida;
Pesquisa Agropecuária Brasileira , 2007, DOI: 10.1590/S0100-204X2007000300004
Abstract: the objective of this work was to evaluate the resistance of guignardia citricarpa to pyraclostrobine and carbendazim fungicides, through: growth analysis in culture media amended with the fungicides; leaf decomposition; and production of reproductive structures on leaves naturally infected with these fungi. g. citricarpa was isolated from symptomatic fruits of sweet orange (citrus sinensis) cultivated in area with intense fungicide application. the sensibility to fungicides of g. citricarpa isolates was evaluated with pyraclostrobine and carbendazim, in the doses 0.5, 1 e 2 μg ml-1 a.i., to verify the effect of selection pressure caused by continuous use of these compounds. although, reduction on leaf decomposition and on the number of reproductive structures were observed after application of pyraclostrobine and carbendazim, 7.5% of the isolates, evaluated in culture media, exhibited resistance to carbendazim, suggesting that the use of this agrochemical must be combined to other active principles in a consortium to reduce the chances of resistance occurrence. no resistance to pyraclostrobine was observed among tested isolates, what indicates that this could be an alternative compound to be used in combination to carbendazim, to minimize the chance of resistance occurrence.
Influência do alinhamento de plantio na severidade da mancha-preta-dos-citros, produ??o e qualidade do suco
Andrade, André Gustavo de;Pimenta, Adriano Alves;Goes, Antonio de;
Revista Brasileira de Fruticultura , 2009, DOI: 10.1590/S0100-29452009000400016
Abstract: the levels of incidence and severity of disease symptoms are a result of the host-pathogenenvironment integration. in this context, a favorable environment, in particular, depends on the level of humidity, intensity of solar radiation, luminosity and leaf wetness among other factors. on the other side, the magnitudes of these factors' expressions are dependent upon the plant's cycle and size, and possibly the crop alignment as well. in the present study, five properties distributed along the citrus agricultural belt of s?o paulo were selected. with similar orchards and crop orientation going north-south, east-west, northeast-southwest and northwest-southeast, from which samples of 50 fruits from ten plants of the same central tree line were collected. these fruits were taken to a laboratory and analyzed for severity levels of citrus black spot (guignardia citricarpa), production and juice quality. it was concluded that the fruits from crops in the east-west orientation presented lower symptom severity, while the north-south orientation, had the highest levels. also, the farms located further south of s?o paulo state, showed lower levels of the disease, probably due to the fact that such areas have shorter periods of disease occurrences. in relation to production, the north-south and east-west crop orientations produced the highest amount of boxes per plant, while the northwest-southeast and northeast-southwest had the lowest production levels. as for the juice quality, there was no concluding data to establish a defined standard in terms of ratio and obrix on the respective crop alignment. the relation between the latitude and ratio value was declared to be consistently lower in citrus orchards located further south in the state of sao paulo.
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