Aerobiology of Cercospora kikuchii

Neste estudo, foram quantificados os conídios de Cercospora kikuchii [crestamento foliar em soja (Glycine max)]presentes no ar, sua relação com a intensidade da doença e com os fatores ambientais [temperatura, umidade relativa do ar (UR), precipitação e molhamento foliar] no período de novembro a março de 2006/07 e 2007/08 em Brasília, DF. Para tanto, foi instalada uma armadilha volumétrica captaesporos ‘Burkard’ de sete dias em campo experimental com soja. Houve maior captura de conídios no período diurno, com mais de 60% dos esporos coletados entre 8h e 15h. Os dados climáticos variaram de acordo com a safra, mas, de modo geral, em ambos os experimentos, o período de maior captura de esporos ocorreu quando houve redução da precipitação e do molhamento foliar. A UR acima de 80% e temperatura entre 20 e 24ºC foram mais favoráveis para a captura de conídios e a intensidade do crestamento foliar. Nos dois anos de avaliação, a maior quantidade de esporo capturado ocorreu quando a soja se apresentava no estádio R6-R7, assim como a intensidade da doença foi maior após o início do estágio reprodutivo da cultura. Apesar da quantidade de conídio capturado em 2006/07 ter sido maior que em 2007/08, o padrão da flutuação aérea de conídios foi semelhante. _________________________________________________________________________________ ABSTRACTThe objective of this study was to evaluate the relation of airborne released conidia of Cercospora kikuchii [cercospora leaf blight of soybean (Glycine max)] with the disease intensity and some environmental factors [temperature, relative humidity (RH), precipitation and leaf wetness period) under experimental field conditions in Brasília, DF, Brazil. The evaluation was from November to March of 2006/07 and 2007/08. Data for the amount of airborne conidia were collected using a Burkard’s seven-day volumetric spore trap set in a field with soybean. Most of the conidia were collected during the day, with over 60% of the spores collected between 8h and 15h. Climatic data varied according to the crop period, but for both periods the highest amount of spores occurred with reduction of precipitation and leaf wetness period. RH above 80% and temperature from 20 to 24ºC were more favorable to capture of conidia and disease intensity. For both crop period of evaluation the major amount of spores were collected when plant stage was R6-R7, as well as, disease intensity increased after beginning of reproductive stage of soybean. Although the number of captured conidia in the 2006/07 crop period was higher than in 2007/08, the variation of fluctuation of airborne spores occurred similarly

Hourly and daily changes on airborne urediniospores of Phakopsora pachyrhizi

The Asian rust (Phakopsora pachyrhizi) is one of the most destructive diseases of soybean in Brazil. Despite its importance, little is known about the airborne inoculum production dynamics of pathogen throughout the soybean cycle in Brazil. The objective of this study was to assess the temporal variation of air collected P. pachyrhizi urediniospores using a Burkard 7-day-spore-trap during 2006-2007 and 2007-2008, from November to March of each soybean (MSoy-8001) growing season. The disease severity was quantified on soybean planted in October 18, 2006 and in October 30, 2007. From November/06 through March/07 were collected over 175,000 urediniospores, and, over 131,000 from November/07 to March/08. In 06-07, most of the spores were collected from January 9, 2007 through February 1st, 2007 (±3,000 urediniospores day-1), and, in 07-08 most urediniospores was collected from February 8, 2008 throughout March 2, 2008 (±2,000 urediniospores day-1). The maximum amount of urediniospores collected in a single day in 06-07 (±15,000; 1/25/2007) was higher than in 07-08 (±12,000; 2/13/2008). In both soybean growing seasons most of the hourly urediniospores was collected from 10:00 am through 6:00 pm and the highest number from December to March, was at 3:00 pm (±16,000 in 06-07 and ±14,000 in 07-08). The disease started earlier in 2006-07 [38 days after planting (DAP)] than in 07-08 (58 DAP). The amount of collected airborne spores was positively correlated to disease severity, leaf wetness, and, precipitation along both soybean growing seasons. However, during a 24h-day evaluation, the major amount of hourly collected spores was negatively correlated to the leaf wetness and air relative humidity

Aerobiology of Cercospora kikuchii

Neste estudo, foram quantificados os conídios de Cercospora kikuchii [crestamento foliar em soja (Glycine max)] presentes no ar, sua relação com a intensidade da doença e com os fatores ambientais [temperatura, umidade relativa do ar (UR), precipitação e molhamento foliar] no período de novembro a março de 2006/07 e 2007/08 em Brasília, DF. Para tanto, foi instalada uma armadilha volumétrica capta-esporos 'Burkard' de sete dias em campo experimental com soja. Houve maior captura de conídios no período diurno, com mais de 60% dos esporos coletados entre 8h e 15h. Os dados climáticos variaram de acordo com a safra, mas, de modo geral, em ambos os experimentos, o período de maior captura de esporos ocorreu quando houve redução da precipitação e do molhamento foliar. A UR acima de 80% e temperatura entre 20 e 24°C foram mais favoráveis para a captura de conídios e a intensidade do crestamento foliar. Nos dois anos de avaliação, a maior quantidade de esporo capturado ocorreu quando a soja se apresentava no estádio R6-R7, assim como a intensidade da doença foi maior após o início do estágio reprodutivo da cultura. Apesar da quantidade de conídio capturado em 2006/07 ter sido maior que em 2007/08, o padrão da flutuação aérea de conídios foi semelhante.The objective of this study was to evaluate the relation of airborne released conidia of Cercospora kikuchii [cercospora leaf blight of soybean (Glycine max)] with the disease intensity and some environmental factors [temperature, relative humidity (RH), precipitation and leaf wetness period) under experimental field conditions in Brasília, DF, Brazil. The evaluation was from November to March of 2006/07 and 2007/08. Data for the amount of airborne conidia were collected using a Burkard's seven-day volumetric spore trap set in a field with soybean. Most of the conidia were collected during the day, with over 60% of the spores collected between 8h and 15h. Climatic data varied according to the crop period, but for both periods the highest amount of spores occurred with reduction of precipitation and leaf wetness period. RH above 80% and temperature from 20 to 24°C were more favorable to capture of conidia and disease intensity. For both crop period of evaluation the major amount of spores were collected when plant stage was R6-R7, as well as, disease intensity increased after beginning of reproductive stage of soybean. Although the number of captured conidia in the 2006/07 crop period was higher than in 2007/08, the variation of fluctuation of airborne spores occurred similarly

Novos isolados de Trichoderma antagônicos a Sclerotinia sclerotiorum

Quarenta e nove isolados de Trichoderma obtidos no centro-oeste do Brasil foram avaliados quanto a sua atividade antagônica in vitro contra Sclerotinia sclerotiorum (agente causal do mofo branco) e identificados com base nas sequências ITS do DNA ribossômico nuclear. Os testes de cultivo pareado mostram que todos os isolados exibiram algum antagonismo, com um máximo de 77% de inibiação micelial e inibição total da produção de escleródios. Dois isolados se destacaram como os mais promissores, considerando ambos os parâmetros avaliados (CEN1253 - T. koningiopsis e CEN1265 - T. brevicompactum). Cinco espécies diferentes foram identificadas: T. harzianum (23), T. spirale (9), T. koningiopsis (8), T. brevicompactum (7) and T. asperellum (2). Estes isolados estão armazenados na Coleção de Fungos para Controle Biológico da Embrapa e as informações obtidas nos experimentos serão incorporadas na base de dados de ativos biológicos, no sistema de informações de recursos genéticos, e disponibilizados para estudos futuros.Forty-nine isolates of Trichoderma from the Brazilian Midwest were evaluated for their antagonistic activity in vitro against Sclerotinia sclerotiorum (causal agent of white mold), which were then identified based on their nuclear ribosomal ITS sequences. Paired culture tests showed that all isolates exhibited some antagonism, with a maximum of 77% mycelial inhibition and complete inhibition of sclerotia production. Two isolates were found to be the most promising biocontrol agents, considering both antagonistic parameters (CEN1253 - T. koningiopsis and CEN1265 - T. brevicompactum). Five different species were identified: T. harzianum (23), T. spirale (9), T. koningiopsis (8), T. brevicompactum (7) and T. asperellum (2). These isolates are stored in the Embrapa Fungi Collection for Biological Control and the information obtained in the experiments will be incorporated into the database of biological assets within the genetic resources information system (Allele) and be made available for further studies

Temporal dynamics of urediniospores and control of the Asian soybean (Glycine max) rust (Phakopsora pachyrhizi)

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Fitopatologia, 2009.Os objetivos do trabalho foram: (a) avaliar genótipos de soja quanto a reação à ferrugem asiática (Phakopsora pachyrhizi); (b) verificar o progresso da doença em campo de soja associados às condições ambientais, correlacionando-as à variação temporal de urediniósporos coletados no ar; (c) determinar a influência do ambiente na infecção por P. pachyrhizi; e (d) avaliar a influência da concentração de urediniósporos de P. pachyrhizi sobre a doença. Os principais resultados são a seguir apresentados. Quanto à reação dos genótipos, resultados semelhantes em estufa e laboratório mostraram os menores valores de doença pelo genótipo GT04-9062. Todavia, em campo, o genótipo menos afetado foi o GT04-9180. Quanto a flutuação aérea de inoculo, houve grande variação na quantidade de esporos coletados entre janeiro e fevereiro de 2007 (~100-600/dia) e 2008 (~50-500/dia). A captura dos urediniósporos realizada em armadilha (Burkard) foi maior entre 11:00 (~65-80/h) e 19:00h (~35-80/h). Houve correlação positiva entre a quantidade de esporos e os fatores ambientais. Quanto a concentração de inóculo, 1 x 105 urediniósporos/ml proporcionou resultados de doença que permitiram a reação diferencial de ferrugem em genótipos com variada susceptibilidade. _________________________________________________________________________________ ABSTRACTThe main objectives of this study were: (a) to evaluate the reaction of soybean (Glycine max) genotypes to the Asian rust (Phakopsora pachyrhizi); (b) to evaluate the association of rust progress to the airborne urediniospores; (c) to evaluate the effects of climate on rust progress; and, (d) to evaluate the effects of spore concentration on disease. The principal results are described as follow. The genotype GT04-9062 was less affected by the disease on laboratory and greenhouse trials. However, under commercial field conditions, the less affected one was GT04-9180. The highest amount of airborne spore collected (Burkard spore trap) was in January and February 2007 (~100-600/day) and 2008 (~50-500/day), from 11 a.m (~65-80/h) to 7 p.m. (~35-80/h). There was positive correlation between collected airborne spores and to the climate factors. The inoculum concentration of 1x105 spores/ml allowed an ideal amount of disease for genotype reaction comparisons

Phytophthora infestans: Sobrevivência em restos culturais, hospedeiros alternativos e dinâmica temporal de esporângios no ar

A requeima, causada por Phytophthora infestans, é uma doença destrutiva da batateira e do tomateiro. Há poucas informações quanto a potenciais fontes de inóculo primário do patógeno no Brasil. Os objetivos deste trabalho foram: determinar o tempo de sobrevivência do patógeno em hastes, folíolos e frutos de tomateiro em solo; verificar a especificidade de P. infestans por meio de teste centrífugo-filogenético com a inclusão de espécies nativas do Brasil e estudar a dinâmica temporal do inóculo de P. infestans no ar. Avaliou-se a sobrevivência em restos culturais de tomateiro, tanto em casa de vegetação como no campo. A sobrevivência do patógeno em restos culturais foi inferior a 100 e 35 dias em casa de vegetação e no campo, respectivamente. Em casa de vegetação, a quantidade de estruturas do patógeno visualizadas em microscópio estereoscópico foi maior em tratamentos mantidos em solo seco, que aqueles mantidos em solo úmido. Dois isolados de P. infestans, da linhagem clonal US-1, obtidos de tomateiro, e dois de BR-1, obtidos de batateira, foram inoculados em plantas de 43 espécies. Além das plantas de batata e tomate, apenas plantas de Petunia hybrida e Nicotiana benthamiana foram suscetíveis ao patógeno. A ocorrência de esporângios de P. infestans foi monitorada em condições de campo com armadilhas Rotorod, Burkard e plantas de tomate e batata. Esporângios foram observados ao longo de todo o ano de 2004 e início de 2005. A captura de esporângios de P. infestans realizada pela Burkard foi maior no período das 6:00 às 18:00 h. Conclui-se que o inóculo advindo do ar é mais importante para o início de epidemias de requeima, que aquele em restos de cultura.Tomato and potato late blight, caused by Phytophthora infestans, is one of the most important diseases of these crops in Brazil. Despite its importance, little is known about inoculum dynamics in tropical/subtropical areas, particularly in Brazil. The objectives of this study were: to determine survival period of P. infestans on stems, leaflets, and tomato fruits buried or not in soil; to assess the specificity of P. infestans to different hosts, mainly towards solanaceous species commonly found in Brazil and to study aerial inoculum (sporangia) temporal dynamics. Survival of P. infestans associated with tomato plant parts under greenhouse and field conditions was less than 100 and 35 days, respectively. Under greenhouse, pathogen structures were more promptly identified on crop debris kept on dry than on wet soil conditions. Isolates of two clonal lineages of P. infestans, US-1 and BR-1, isolated from tomato or potato, respectively, were inoculated on 43 plant species. Only two species, Petunia hybrida and Nicotiana benthamiana, were susceptible to P. infestans. Sporangia were monitored by Rotorod and Burkard spore traps and also by tomato and potato trap plants. Sporangia were captured in most weeks throughout 2004 and in the first two weeks of 2005. Most airborne inoculum captured with the Burkard trap was between 6:00 and 18:00 h. Airborne inoculum is abundant and is more important to late blight outbreaks than inoculum produced in crop debris

Validation of decision support systems for tomato early blight and potato late blight, under Brazilian conditions

Early and late blight are the most important foliar diseases of tomato and potato crops in Brazil. Decision support systems (DSS) are important tools in reducing the large amount of fungicides applied to suppress disease intensity. Systems developed for early or late blight were validated in two cropping seasons under Brazilian conditions. For tomato early blight, FAST, CUFAST, and TOMCAST systems were compared in the spring–summer (September–December) (SS) 2002 and summer–autumn (January–April) (SA) 2003. In both seasons, area under disease progress curve (AUDPC) values for FAST (123.2 and 340.3, respectively) and CUFAST (64.0 and 359.2, respectively) did not differ from calendar-based treated plots (82.5 and 225.7, respectively). Plots treated according to TOMCAST were sprayed once and AUDPC values (369.9 and 697.8) in SS and SA seasons, respectively, did not differ from the control plots (397.5 and 836.0, respectively). In SS, four fungicide sprays were recommended by CUFAST and FAST, whereas five were set by fixed calendar treatment; there were no differences in yield loss among treatments. In SA, FAST, CUFAST and calendar, recommended 4, 9, and 11 sprays, respectively. Higher yields were recorded in plots sprayed according to the calendar system compared to control plots, but there were no significant differences between the DSS and the calendar system. For potato late blight, BLITECAST, SIMCAST, NegFry, and Wallin systems were compared in the summer (December–March) and in the autumn (March–June). Despite no late blight developing in the summer, all systems recommended fungicide sprays. In the autumn–winter, late blight was severe but was reduced by fungicide applications according to all DSS, but the number of sprays was similar to the calendar. The AUDPC values in control plots (1193.5) were higher than BLITECAST (19.5), SIMCAST (97.7), NegFry (193.1), Wallin (69.7), and calendar (63.5) but there were no differences among AUDPC values in plots treated according to DSS. The NegFry and Wallin systems recommended five and the calendar six sprays. All DSS were as effective as the calendar treatment in reducing AUDPC. FAST and Wallin were the most effective systems in forecasting tomato early blight and potato late blight, respectively. Decision support systems are potentially useful tools for integrated management of both diseases in Brazil

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data