RESUMOPalavras-chave adicionais: Citros, Guignardia citricarpa, favorabilidade climática Citrus black spot is a disease caused by Guig nardia citric arpa which produces lesions in fruits of commercial va rieties 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 a nd va lida te a model of clima te fa vora bility for citru s black spot related to the occurrence of the disease symptoms in the state of São Paulo (SP). An empirical system was developed based on a data ba nk of the disease occurrence and the climate conditions in the field in the municipalities of Barretos/SP and Gavião Peixoto/SP, during the 2007/2008 and 2008/2009 crop cycles. The sweet orange variety used in the experiments was 'Valencia' grafted onto 'Rangpur' lime aged 10 years. For black spot incidence, the percentage of fruits with symptoms in the pla nt wa s eva lu a ted, a nd for severity, the percentage of sk in lesions per fru it was assessed. In the regression Ninin, M.V.L.; Spósito, M.B.; Scaloppi, E.A.G.; Barbosa, J.C.; Barreto, M. Development and validation of a forecast model for citrus black spot according to meteorological variables. Summa Phytopathologica, v.38, n.4, p.288-293, 2012. a na lysis, the climate varia bles and the da ta rela ted to the disease intensity in Barretos were selected in the 'stepwise' procedu re. The best regression equ a tions were selected by the coefficient of determination (R 2 ) and by the significance of regression in the F test (P <0.05 and P <0.01), which resulted in the equation Y = -502.43 + 9.61 X 10 + 4.78 X 30 + 0.54 X 46 -7.9 X 50 , where Y = Favorability Index, X 10 is the average temperature, X 30 is the average relative humidity, X 46 is the leaf wetness and X 50 is the average temperature during leaf wetness, determined with data from 7 -day intervals. Validation was ca rried ou t in the field in Ga viã o Peixoto Municipa lity during the 2008/2009 crop cycle, correlating the incidence and severity observed in the experiment with the predicted da ta that were determined by the equation, and the correlation was positive for the disease incidence with R 2 = 0.87.A mancha preta dos citros é uma doença causada pelo fungo Guignardia citricarpa que produz lesões em frutos em variedades de laranja doce comerciais, causando a queda precoce dos frutos, diminuindo a produtividade e levando a sua depreciação para o mercado de fruta fresca. O objetivo do trabalho foi desenvolver e validar um modelo de fa vorabilidade climá tica da mancha preta dos citros relacionado a ocorrência dos sintomas da doença no Estado de São Paulo. Desenvolveuse um sistema empírico com base em um banco de dados da ocorrência da doença e das condições climáticas, em campo, nos municípios de Barretos/ SP e Gavião Peixoto/SP, durante as Safras 2007Safras /2008Safras e 2008Safras /2009. A variedade de laranjeira doce utilizada nos experimentos foi a 'Valência' enxertada sobre limoeiro 'Cravo', com 10 anos de ida...
Among the disease causing leaf spot in cotton, the gray mildew (Ra mul aria areol a Atk.) has become import ant due to environmental conditions favorable for development of the disease susceptible cultivars, consecutive and intensive and extensive cultivation. This work evaluated the resistance of the cultivars Delta Opal, Acala 90, Makina, Delta Penta and Sure Grow 821 to resistance the R. areola, in field conditions in FCAV-UNESP. The disease occurred under natural infection and, its severity was evoluated weekly, in thirty previously marked plants using the Lima, L.L.; Barreto, M.; Giacheto Scaloppi, É.A.G. Cotton cultivars resistance to Ramularia areola. Summa Phytopathologica, v.36, n.1, p.57-60, 2010.Keywords: Gossypium hirsutum , Cultivars reaction, Curves of progress of diseases. Palavras-chave adicionais:Chaves Adicionais: Gossypium hirsutum, Resistência de Cultivares, Curvas de Progresso de Doenças. RESUMODentre as doenças causadoras de manchas foliares em algodoeiro, a ma ncha de ra mu lá ria ( Ra mu la ria a re o la Atk ) tem se torna do importante em virtude das condições climá ticas fa vorá veis para o desenvolvimento do patógeno, aliadas ao uso de cultivares suscetíveis, pla ntio consecu tivo e extenso. Neste tra ba lho a va lia ra m-se os cultivares Delta Opa l, Acala 90, Mak ina, Delta Penta e Sure Grow 8 21 qua nto à resistência a R. a re o la , em condições de campo na FCAV-UNESP, no ano de 2006. A severidade da doença, que ocorreu por infecção natural das plantas pelo fungo, foi avaliada semanalmente Lima, L.L.; Barreto, M.; Giacheto Scaloppi, É.A.G. Reação de cultivares de algodoeiro a Ramularia areola. Summa Phytopathologica, v.36, n.1, p. 57-60, 2010. em trinta pla ntas devidamente marca da s, u tiliza ndo-se u ma escala descritiva de notas: 1 = 0%, 2 = até 5%, 3 = de 5,1 a 25%, 4 = de 25,1 a 5 0 % e 5 = a cima de 5 0 % de área folia r com sintoma s. Fora m elaboradas curvas de progresso da doença para os cinco cultivares e o modelo monomolecular foi o que melhor se a ju stou a os da dos, em comparação com o logístico, o exponencial e o modelo de Gompertz. A análise dos dados indicou que houve diferença significativa entre os genótipos, sendo que Delta Opal, Makina e Sure Grow 821 mostraram-se mais suscetíveis e Delta Penta e Acala 90 mais resistentes ao fungo.following rating scale: 1 = 0%, 2 = up to 5%, 3 = 5,1 to 25%, 4 = 25,1 to 50% and 5 = over of 50% of foliar area with symptoms. The monomolecular model was better adjusted to the data in comparison with the logistic, exponential and Gompertz models, for elaboration of the curves of progress of the disease. The analysis of the data indicated significant differences between t he genotypes.The cultivars Delta Opal, Makina and Sure Grow 821 were more susceptible and Delta Penta and Deltapine Acala 90 more resistant to gray mildew.A cultura do algodão (Gossypium hirsutum L.) no Brasil se estende praticamente por duas regiões: a região meridional, que compreende os estados de São Paulo, Paraná, Mato Grosso, Mato Grosso do Sul, G...
Th e c i t ru s ca n k er, c a us ed by t h e b a ct eri um X a n t ho mo n a s axonopodis pv. citri Valterin et alii 1995, is a known disease world-wide known and it is always a serious threat for the brazilian citriculture. The objective of the present study was to analyze t he c li m at ic cond it i on s of th e S ta te of S ão Pa ulo i n ord er t o develop zone maps of great risk for citrus canker epidemics. metheorological station showed problems in the data series, these had been surpassed of the nearest station. After the accounting of the indexes had been calculated the percentages of days favorable to the occurrence of the disease in the period of one year. From this information, the thematic maps of the state of São Paulo had been generated, with the space distribution of the percentage of days favorable to the occurrence of citrus canker. The region the n ort h wes t regi on of t h e s t a t e wa s t h e on e t h a t p res en t ed t h e greatest percentage of days favorable to the occurrence of the disease.
Sporulation of both Erythricium salmonicolor and its anamorphic stage Necator decretus, causal agent of citrus pink disease in BrazilThe sporulation of Erythricium salmonicolor and its anamorph Necator decretus, causal agent of pink disease is reported for the first time on citrus in Brazil.A rubelose dos citros tem causado danos significativos à citricultura paulista nos últimos anos. A doença concentra-se nos galhos e ramos, sendo mais severa em árvores vigorosas e em pomares adensados. Os sintomas iniciais consistem em lesões com desprendimento da casca e exsudação de goma. Posteriormente, observam-se cordões miceliais e crescimento micelial róseo sobre os ramos afetados ( Figura 1A). Internamente, nesses ramos, observa-se descoloração dos tecidos. Quando essas lesões atingem a base dos galhos, pode ocorrer a morte de toda a copa da planta. Mesmo com o avanço dessa doença nos últimos anos, até então nenhuma estrutura reprodutiva do patógeno havia sido relatada em citros no Brasil (Feichtenberger et al., Manual de Fitopatologia, Vol. 2, p.239.
Devido à escassez de estudos epidemiológicos da ferrugem alaranjada da cana-de-açúcar no Brasil e a importância dessa cultura no agronegócio brasileiro, objetivou-se neste trabalho determinar a influência da temperatura e do período de molhamento foliar na epidemiologia dessa doença. Foram utilizadas plantas da cultivar SP89-1115 com vinte dias de idade inoculadas com o fungo Puccinia kuehnii na concentração de 2 x10 4 de uredósporos/mL. O delineamento experimental utilizado foi inteiramente casualizado (DIC) em esquema fatorial 5x7 sendo cinco temperaturas (17,5 ; 20,0 ; 22,5 ; 25, RESUMOferrugem alaranjada foram 20,0; 22,5 e 25,0°C sendo esta última a melhor. Nas temperaturas de 22,5 e 25,0°C com 20 horas de molhamento foliar foram observadas que as pústulas apresentaram-se em maior número decrescendo com 24 horas de molhamento. Não foi observado sintomas da doença nos períodos de molhamentos foliares de 0, 4 e 8 horas em todas as temperaturas testadas. Também não ocorreu a doença na temperatura de 27,5°C em todas as combinações dos períodos de molhamentos foliares testados. Estudos de epidemiologia dessa doença são importantes para traçar estratégias de controle e futuramente desenvolver um sistema de previsão para a ferrugem alaranjada da cana-de-açúcar. ABSTRACTConsidering the lack of epidemiological studies on orange rust of sugarcane in Brazil and the importance of this crop in the Brazilian agribusiness, the aims of this study were to determine the influence of temperature and leaf wetness duration on the epidemiology of this disease. Twenty-day-old plants of the cultivar SP 89-1115 were inoculated with the fungus Puccinia kuehnii at a concentration of 2 x 10 4 urediniospores.mL. Experimental design was completely randomized (DIC), in 5x7 factorial arrangement, representing five temperatures (17.5, 20.0, 22.5, 25.0 and 27.5°C) and seven leaf wetness periods (0, 4, 8,12,16, 20 v.43, n.2, p.132-135, 2017. three replicates. Ideal temperatures for orange rust development were 20.0, 22.5 and 25.0°C, of which the latter was the best. At temperatures of 22.5 and 25.0°C, pustules increased in number with 20 hours leaf wetness but decreased with 24 hours wetness. No disease symptoms were observed at 0, 4 and 8 hours leaf wetness for all tested temperatures. Similarly, the disease did not occur at a temperature of 27.5°C for all tested combinations of leaf wetness duration. Epidemiological studies of this disease are important to devise control strategies and eventually develop a forecasting system for orange rust of sugarcane.
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