Didymella bryoniae resistance to fungicides in Brazil

O crestamento gomoso do caule (Didymella bryoniae) é uma das mais importantes doenças da melancia (Citrullus lanatus) no mundo. O controle químico, embora amplamente adotado, nem sempre pode impedir o progresso da doença no campo. A resistência do agente causal a alguns ingredientes ativos foi relatada na Europa, Japão e nos Estados Unidos, porém nenhum estudo foi feito no Brasil. Este trabalho descreve os resultados de três ensaios in vitro para resistência a fungicidas, medida pela taxa de crescimento micelial. No primeiro ensaio, sete isolados foram submetidos a nove fungicidas na metade da dose comercial recomendada. Evidência de resistência a Tiofanato metílico (TM), Carbendazim (CARB) (benzimidazóis) bem como a mistura Tiofanato metílico + Clorotalonil (TM + CHLO) foi detectada. Nenhuma resistência foi detectada contra Mancozebe, Difenoconazole, Tebuconazole e as misturas Mancozebe + Difenoconazole ou Trifloxistrobina + Propiconazole. O teste foi repetido com os mesmos sete isolados de D. bryoniae contra TM, CARB, TM + CHLO e Oxicloreto de Cobre a ¼, ½, 1 e 2 vezes a dose recomendada. Apenas Oxicloreto de cobre diminuiu consistentemente a taxa de crescimento micelial com o aumento da dose. TM não teve efeito na taxa de crescimento micelial em nenhuma concentração testada, e CARB e TM + CHLO mostraram mínimo efeito com o aumento da concentração do produto. Finalmente, 31 isolados de sete estados brasileiros foram testados para resistência a Tiofanato metílico na dose recomendada (490 ppm). Oitenta e um porcento dos isolados mostraram-se altamente resistentes. Isolados resistentes e sensíveis foram encontrados em uma mesma região geográfica. Considerando a prevalência de isolados resistentes a ambos TM e CARB, uma evidência de resistência cruzada, o uso de benzimidazoles não deve ser recomendado no controle do crestamento gomoso do caule. _________________________________________________________________________________ ABSTRACTGummy stem blight (Didymella bryoniae) is one of the most important diseases of watermelon (Citrullus lanatus) wordwide. Chemical control, although widely adopted, cannot always avoid disease progress in the field. Resistance of the causal agent to some active ingredients has been reported in Europe, Japan and in the United States, but no such study has been done in Brazil. This work reports results of three in vitro assays for fungicide resistance, as measured by the rate of mycelial growth. In the first test, seven isolates were evaluated against nine fungicides at half the recommended commercial doses. Evidence of resistance to Methyl Thiophanate (TM) and Carbendazim (CARB) (Benzimidazoles) as well as to the mixture of Methyl-Thiophanate and Chlorotalonil (TM+CHLO) was detected. No resistance was suggested to Mancozeb, Difenoconazole, Tebuconazole and the mixtures Mancozeb + Difenoconazole or Trifloxistrobine + Propiconazole. The test was repeated with the same seven isolates of D. bryoniae against TM, CARB, TM+CHLO and Copper Oxichlorate at ¼, ½, 1 and 2 times the recommended doses. Only Copper Oxichlorate consistently caused a decrease in the mycelial growth rates with increasing doses. TM had no effect on the mycelial growth rates at any of the concentrations tested, and CARB and TM+CHLO showed very minor effects with increasing product concentrations. Finally, a collection of 31 isolates from seven Brazilian states was tested for resistance against TM at the recommended dose (490 ppm). Eighty-one per cent of the isolates, from most Brazilian states, proved to be highly resistant. Resistant and sensitive isolates were found in the same geographic regions. Considering the prevalence of isolates resistant to both TM and CARB, an evidence of cross-resistance, the use of benzimidazoles should be avoided for gummy stem blight control

Search for sources of resistance to Fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) in okra germplasm

– Fusarium oxysporum f. sp. vasinfectum (FOV) is one the most destructive okra (Abelmoschus esculentus) pathogens in Brazil. Fifty-four okra accessions were evaluated for resistance to FOV. Greenhouse screening was initially carried out with one FOV isolate (‘Fus-194’). Inoculation (in all assays) was carried out with 21-day-old plantlets, using the root-dipping inoculation technique. Thirty-three accessions displaying differential responses in the first screening were re-evaluated in two additional assays, using two FOV isolates (‘Fus-194’ and ‘Fus-201’). Twelve accessions were rated as highly to intermediately resistant to ‘Fus-194’ during the dry/moderate temperature season, whereas nine accessions were classified as highly to intermediately resistant to ‘Fus-201’. In the assay carried out in the wet and warm season, 72% of the accessions were classified as having high and intermediate resistance to ‘Fus-194’, and 32% were resistant to ‘Fus-201’. The accessions ‘Santa Cruz-47’, ‘BR-2399’ and ‘BR-1449’ were the most promising resistance sources

Yield, bolting and leaf blight in carrots grown under organic and conventional conditions

Quatro ensaios foram implantados no verão para avaliar a produtividade, o florescimento prematuro e a queima-das-folhas em genótipos de cenoura conduzidos em sistema orgânico e convencional. Os ensaios foram instalados em Brazlândia e na Embrapa Hortaliças. O delineamento experimental foi de blocos ao acaso, com oito tratamentos (genótipos Alvorada, Brasília RL, Brasília Bionatur, Kuronan, Nantes 3 Tip Top, Carandaí AG 106, Brazlândia e Pop. 0212246) e cinco repetições. Os nutrientes foram incorporados ao solo através de composto orgânico, no sistema orgânico e, fertilizantes químicos, no sistema convencional. Aos 70 dias da semeadura as plantas foram avaliadas no campo para incidência de doenças. Foi também identificada a prevalência de patógenos. A colheita foi realizada 95 dias após a semeadura. O florescimento prematuro foi mais freqüente no genótipo Brasília Bionatur, no sistema convencional, em Brazlândia. Foi observada diferença entre genótipos para queima-das-folhas nos dois sistemas. Nantes foi a mais suscetível, enquanto a Pop. 0212246 foi uma das mais resistentes nos dois sistemas de cultivo. Alternaria dauci prevaleceu em Brazlândia, enquanto Cercospora carotae foi observado em ambas as localidades, no sistema orgânico. Quanto à produção comercial e total os genótipos Pop. 0212246 e Brazlândia estiveram entre os mais produtivos, independente do sistema de cultivo. Para produtividade comercial e total, número e peso de raízes refugadas o sistema convencional apresentou resultados superiores ao orgânico. As cultivares Brasília RL, Brazlândia e a Pop. 0212246 podem ser recomendadas para plantio no período de verão, no DF, independente do sistema de cultivo. A Pop. 0212246 apresenta características agronômicas desejadas pelo mercado e poderá futuramente ser disponibilizada para produtores da região. ____________________________________________________________________________________ ABSTRACTFour experiments were carried out with carrots genotypes during summer season in Distrito Federal, Brazil, to evaluate yield, bolting and leaf blight under organic and conventional conditions. The experiments were carried out in two locations and in each one two experiments were established, considering both crop systems. The experimental design was a random block with eight treatments and five replicates. The treatments consisted of the cvs. Alvorada, Brasília RL, Brasília Bionatur, Kuronan, Nantes 3 Tip Top, Carandaí AG 106, Brazlândia and Pop. 0212246. The soil was fertilized with organic compost for the organic trial and with chemical fertilizer for the conventional trial. Plants were evaluated for leaf blight incidence, 70 days after sowing date, through visual observation. Roots were harvested 95 days after sowing, washed, classified and weighted. Bolting was more frequent in Brasília Bionatur, under conventional condition, in Brazlândia. A difference of susceptibility to leaf blight among genotypes was observed in plants cultivated in the organic system. Nantes was the most susceptible while Pop. 0212246 was the most resistant. Alternaria dauci was observed more frequently at Brazlândia, while Cercospora carotae was observed at both locations, similarly, under organic conditions. For commercial and total yield, commercial and total root number, Pop. 0212246 and Brazlândia were the best materials in both crop systems. Total and commercial yield, total and commercial root number, number and weight of refused roots were higher in the conventional area, compared to the organic area. Brasília and Brazlândia can be recommended for Distrito Federal, independently of crop system, during summer season. Pop. 0212246 showed desirable agronomical characteristics and can be, in the future, available for farmers in Distrito Federal

Identification of sources of seedling resistance to Phytophthora capsici in Cucumis melo

The employment of genetic resistance to minimize yield losses induced by Phytophthora capsici remains unexplored in melon (Cucumis melo). A diverse collection of melon accessions was evaluated against P. capsici isolates at the seedling stage. In the frst screening assay, 105 accessions were evaluated using isolate PCpe-04 obtained from cucumber (Cucumis sativus). In a second assay, 31 accessions displaying high levels of resistance in the frst assay were challenged with a distinct isolate (PCpe-09 also from cucumber). In a third assay, a subset of 14 selected accessions was re-evaluated using isolates PCpe-09 and PCmo-07 (from strawberry). In the last screening, seven accessions with high levels of resistance across all assays were challenged with fve isolates from representative host species [PC-Vagem (snap bean), PCp-129 (Capsicum chinense), PCp-155 (C. annuum), PCpe-09 and PCmo-07] to assess their reaction against a varied sample of P. capsici isolates. For two accessions (CNPH-093 and L040), all plants remained free of symptoms after inoculation with all fve isolates. Accessions WMR-29, CNPH 084, CNPH 088 and CNPH 092 were also free of symptoms to all isolates, except PCmo-07. These large-spectrum resistance sources might be useful for breeding programs aiming to incorporate resistance against P. capsici in elite melon lines

FREQUENCY OF HEPATIC STEATOSIS IN A RADIOLOGY CLINIC IN PALMAS

ABSTRACT Introduction: Recent studies suggest that hepatic steatosis is a worldwide distribution pathology that can progress to chronic liver disease with a highly unfavorable outcome resulting in the need for liver transplantation. That’s why early diagnosis is important. The liver biopsy’s considered a "gold standard" in its diagnosis, but the use of ultrasonography helps to detect steatosis in a non-invasive manner and is a very accessible method for the population. Objectives: To evaluate the frequency of steatosis in patients treated at a radiological clinic in Palmas using abdominal ultrasonography; observing its distribution in genders and age groups and its difference between 2010 and 2016. Methods: It was used ultrasound reports of abdomen of 3.222 patients made in 2010 and of 2.346 patients made in 2016. A longitudinal analysis was performed, between these two years, regarding the frequency of hepatic steatosis at the people and also between the genders and the age groups. Results: In 2010, 25,67% of people had hepatic steatosis in the ultrasound report, while in 2016 were 31,67%. In 2010, of the total number of people with steatosis, 52,48% were women and 47,52% were men; however in 2016, 51,94% were women and 48,06% were men. Regarding the age groups, in both periods, as in men and in women, steatosis was lower at the extremes of age and more frequent around the 5th to 7th decades of life. Discussion: The frequency of hepatic steatosis has increased in the period from 2010 to 2016. It was, as seen in the literature, quite high in the 5th and 6th decades of life, besides being more frequent in females. Unlike 2010, in 2016 begins to have children under 20 with signs of steatosis. Conclusion: In the year 2010 the frequency of hepatic steatosis was 25,67%, whereas in 2016 it was 31,84%.   Keywords: Steatosis; ultrasonography; liver.Introduction: Recent studies suggest that hepatic steatosis is a worldwide distribution pathology that can progress to chronic liver disease with a highly unfavorable outcome resulting in the need for liver transplantation. That’s why early diagnosis is important. The liver biopsy’s considered a "gold standard" in its diagnosis, but the use of ultrasonography helps to detect steatosis in a non-invasive manner and is a very accessible method for the population. Objectives: To evaluate the frequency of steatosis in patients treated at a radiological clinic in Palmas using abdominal ultrasonography; observing its distribution in genders and age groups and its difference between 2010 and 2016. Methods: It was used ultrasound reports of abdomen of 3.222 patients made in 2010 and of 2.346 patients made in 2016. A longitudinal analysis was performed, between these two years, regarding the frequency of hepatic steatosis at the people and also between the genders and the age groups. Results: In 2010, 25,67% of people had hepatic steatosis in the ultrasound report, while in 2016 were 31,67%. In 2010, of the total number of people with steatosis, 52,48% were women and 47,52% were men; however in 2016, 51,94% were women and 48,06% were men. Regarding the age groups, in both periods, as in men and in women, steatosis was lower at the extremes of age and more frequent around the 5th to 7th decades of life. Discussion: The frequency of hepatic steatosis has increased in the period from 2010 to 2016. It was, as seen in the literature, quite high in the 5th and 6th decades of life, besides being more frequent in females. Unlike 2010, in 2016 begins to have children under 20 with signs of steatosis. Conclusion: In the year 2010 the frequency of hepatic steatosis was 25,67%, whereas in 2016 it was 31,84%

FONTE DE ALIMENTAÇÃO SIMÉTRICA SEM TRANSFORMADOR

O presente artigo aborda o projeto de uma fonte de alimentação elétrica simétrica, que fornece tensões de +12 V e -12 V e corrente em torno de 2 mA em sua saída, onde o transformador de redução da tensão é substituído por uma reatância capacitiva, fazendo com que ela gere um mínimo de campo eletromagnético, bem como seu peso e tamanho possam ser reduzidos de forma significativa. Tal projeto é um subprojeto do projeto de medição elétrica utilizando placa de captura, pois havia a necessidade de se obter uma fonte de alimentação sem emissão eletromagnética, que possui níveis elevados quando se utiliza um transformador comum em sua construção. O seu princípio construtivo é baseado na propriedade da reatância capacitiva, propriedade esta que surge quando um capacitor se encontra em um circuito de corrente alternada, permitindo uma queda de tensão sem absorção de corrente. Cabe citar que tal tipo de fonte não é algo inédito, mas o objetivo foi de mostrar os passos de sua construção

AS INFLUÊNCIAS DAS DIFERENTES CORRENTES HISTORIOGRÁFICAS E DO LIVRO DIDÁTICO NAS PRÁTICAS DE ENSINO DE HISTÓRIA – UMA AMOSTRAGEM DA HISTÓRIA ENSINADA NO COTIDIANO ESCOLAR

A presente pesquisa tem como objetivo evidenciar a produção de saber histórico escolar, analisando como os docentes trazem para a sua prática as diferentes correntes historiográficas. Realizamos uma investigação no cotidiano do trabalho dos docentes de História em três unidades de ensino, e, a partir da análise dessas amostragens, concluímos que os professores utilizam de determinadas astúcias e táticas individuais para apropriação apenas parcial de teorias curriculares e historiográficas. Se não há uma completa recusa de tais teorias, a pesquisa demonstra, entretanto, ocorre a apropriação somente daquilo que lhes interessa na realização de sua prática educativa

NITROGEN FERTILIZERS AND OCCURRENCE OF Leucoptera coffeella (Guérin-Mèneville & Perrottet) IN TRANSPLANTED COFFEE SEEDLINGS

The coffee leaf-miner (CLM) Leucoptera coffeella (Lepidoptera: Lyonetiidae) is one of the main pests of coffee plants in Brazil. Its occurrence in the crop is directly related to the physiological state and growth characteristics of coffee plants, in turn related to plant nutrition. The present work, therefore, aimed to evaluate the effect of nitrogen sources on the occurrence of CLM in coffee seedlings. The fertilizers used were ammonium sulfate, urea, and organomineral. The number of leaves mined by CLM and the relative contents of chlorophyll and crude protein in the leaves were recorded. Ammonium sulfate and urea favored higher occurrence of leaves mined and organomineral fertilizer provided the lowest incidence of leaves mined by CLM. The three sources of nitrogen increased the chlorophyll content, but only ammonium sulfate caused an increased percentage of crude protein in the leaves of coffee seedlings. For the improvement of management strategies for L. coffeella it is fundamental to understand favorable conditions, nutritional management it is one of the pest control mechanisms, thus making it possible to control the insect and prevent the population of CLM from reaching an economic damage threshold

Characterization of isolates of Phytophthora infestans from southern and southeastern Brazil from 1998 to 2000

The population of Phytophthora infestans in Brazil was first characterized 12 years ago. In this research, isolates of P. infestans from potato (n = 184) and tomato (n = 267) collected in southern and southeastern Brazil were characterized to provide more detailed analysis of the current structure of the population. All 451 isolates were analyzed for mating type, and subsets of the isolates were analyzed for allozymes, restriction fragment length polymorphism fingerprint, mtDNA haplotypes, and metalaxyl resistance. Tomato isolates were all of A1 mating type, mtDNA Ib, and US-1 genotype or some variant within this clonal lineage. Of the potato isolates, 82% were A2 mating type, mtDNA IIa, BR-1 genotype, which is a new lineage of P. infestans. All A2 isolates were found on potato, whereas 91% of the A1 isolates were from tomato. A1 and A2 isolates were never found in the same field. The frequency of resistance to metalaxyl was higher in isolates from tomato (55%) than in isolates from potato (38%). After more than a decade of coexistence of isolates of the A1 and A2 mating types, the population was highly clonal, dominated by the BR-1 and US-1 clonal lineages