RESUMO Considerada uma das principais doenças do eucalipto, a ferrugem (Austropuccinia psidii) pode ocasionar sérios danos à cultura caso estratégias adequadas de manejo não sejam implantadas. De modo geral tem-se monocultura de eucalipto, com implicações epidemiológicas importantes. O objetivo desse estudo foi comparar o progresso da ferrugem do eucalipto consorciado com diferentes espécies em sistema agroflorestal, sob condições naturais de infecção. O experimento foi composto por três tratamentos (consórcios), dispostos de forma completamente aleatorizada no espaço. Em cada tratamento o eucalipto foi plantado com duas espécies diferentes, a saber: T1 - Cedro Australiano (Toona ciliata) + Eucalipto (Eucalyptus urograndis) + Banana (Musa acuminata); T2 - consórcio Amora (Morus celtidifolia) + Eucalipto + Pupunha (Bactris gasipaes), e T3 - Mogno Africano (Khaya ivorensis) + Eucalipto + Banana. Cada tratamento foi composto por seis repetições, totalizando 18 parcelas de 9m2 cada (2m x 4,5m), dispostos em linhas/aleia. Foram avaliadas altura, diâmetro da planta, incidência e severidade da doença, quinzenalmente. Os dados foram coletados em dois momentos distintos: pré-poda, compreendido de 17/08/2018 à 09/01/2019, e pós-poda, realizado de 17/04/2019 à 13/08/2019. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey (p<0,05). Verificou-se que o eucalipto apresentou maior desenvolvimento (altura e diâmetro) e menor intensidade da doença (incidência e severidade) no tratamento T2. Com base nos resultados, conclui-se que o plantio de eucalipto em consórcio com as espécies Amora + Eucalipto + Pupunha proporcionou menor intensidade da ferrugem e maior desenvolvimento das plantas.

ABSTRACT Fava bean is one of the major domesticated and the second most cultivated species of the genus Phaseolus. Anthracnose caused by Colletotrichum truncatum affects fava bean in several stages of its development, constituting an important disease for the crop; however, only few studies confirm genotypes as source of resistance. Thus, the present study aimed to select fava bean accessions resistant to C. truncatum and to verify whether there are morpho-agronomic traits associated with resistance source through track analysis. Twenty-two accessions of Phaseolus lunatus were evaluated for their resistance to C. truncatum and were morphologically and agronomically characterized in a distinct experiment. Resistance was evaluated by visual analysis, as well as by lesion measurement with Asses 2.0 program. The morpho-agronomic characterization of the accessions was performed based on fourteen quantitative descriptors. The obtained data were jointly analyzed by track analysis in order to identify related descriptors regarding resistance to anthracnose. The genotypes UFPI 842 and UFPI 832 were confirmed as sources of high resistance to the fungus C. truncatum and presented greater averages of bean pod width. Therefore, the positive direct effect of pod width on the infection level indicates that simultaneous benefits can be obtained through a combined selection of these traits. The present results will be useful to the fava bean breeding program for allowing the development of resistant C. truncatum cultivars with excellent agronomic characteristics.

RESUMO A podridão cinzenta do caule, causada por Macrophomina phaseolina, é uma importante doença do feijão-fava (Phaseolus lunatus L.) no Nordeste brasileiro. Considerando que no Brasil não existem relatos de resistência a esta doença, 37 acessos de feijão-fava foram avaliados pela reação de resistência e estabilidade da resistência contra isolados de M. phaseolina em duas épocas do ano (fevereiro-março e julho-agosto de 2016), visando selecionar genótipos com potencial de utilização no manejo da doença. As sementes foram inoculadas no momento da semeadura, com grãos de arroz com casca colonizados pelo patógeno. As avaliações dos genótipos foram realizadas a cada cinco dias, a partir do décimo dia após a semeadura, com auxílio de escala de notas, discriminando-os em seis classes de reação. De uma população de 37 acessos de P. lunatus não foi observada reação de imunidade a M. phaseolina, no entanto, treze acessos apresentaram os menores níveis de severidade e maior estabilidade nas duas épocas, dentre eles UFPI 892, UFPI 908 e UFPI 905, tendo sido considerados resistentes ao isolado COUFPI 06. A reação de resistência dos acessos considerados resistentes variou conforme o isolado de M. phaseolina. O acesso UFPI 908 expressou os resultados mais promissores de resistência e estabilidade da resistência contra os isolados COUFPI 06, COUFPI 08 e COUFPI 10. Portanto, o acesso UFPI 908 constitui uma fonte promissora de resistência a M. phaseolina, sendo possível a sua utilização em programas de melhoramento e no manejo integrado da podridão cinzenta do caule.

ABSTRACT Charcoal rot, caused by Macrophomina phaseolina, is an important disease of lima bean (Phaseolus lunatus L.) in the Northeast of Brazil. Considering that there are no reports of resistance to this disease in Brazil, 37 lima bean accessions were evaluated for their resistance reaction and resistance stability against isolates of M. phaseolina in two periods of the year (February-March and July-August 2016), with the aim of selecting genotypes with the potential for use in the management of this disease. Seeds were inoculated at sowing, using rice grains with husk that were colonized by the pathogen. The evaluations of genotypes were carried out at every five days, from the tenth day after sowing, using a score scale and dividing them into six reaction classes. From a population of 37 accessions of P. lunatus, no immunity reaction to M. phaseolina was seen; however, thirteen accessions presented the lowest severity levels and greatest stability in the two seasons: UFPI 892, UFPI 908 and UFPI 905, which were considered resistant to the isolate COUFPI 06. The resistance reaction of accessions considered resistant varied depending on the isolate of M. phaseolina. Accession UFPI 908 expressed the most promising results for resistance and stability of resistance against the isolates COUFPI 06, COUFPI 08 and COUFPI 10. Therefore, accession UFPI 908 constitutes a promising source of resistance to M. phaseolina, making possible its use in breeding programs and in integrated management of charcoal rot.

RESUMO Os fungos Colletotrichum truncatum e Macrophomina phaseolina estão entre os principais patógenos associados a sementes de feijão-fava no Brasil, sendo os agentes causais da antracnose e da podridão de carvão, respectivamente. Este trabalho teve como objetivo verificar a transmissão semente-plântula de C. truncatum e M. phaseolina em sementes de feijão-fava inoculadas artificialmente. Meios de cultura batata-dextrose-agar (BDA) com diferentes potenciais hídricos foram obtidos após a adição de manitol. Isolados de C. truncatum e M. phaseolina foram repicados para esses meios. Quarenta gramas de sementes foram distribuídas sobre o micélio fúngico, permanecendo por diferentes períodos de exposição, em função do tratamento: T1: 0,0 MPa sem inóculo por 48 h; T2: 0,0 MPa por 48 h; T3: - 0,2 MPa por 48 h; T4: -0,4 MPa por 48 h; T5: -0,6 MPa por 72 h; T6: - 0,8 MPa por 96 h e T7: -1,0 MPa por 120 h. As sementes foram incubadas a 25 ºC, com fotoperíodo de 12 horas. Foram avaliadas a germinação em rolo de papel, a emergência de plântulas em areia e a sanidade de sementes em BDA. O T4 proporcionou melhores condições para impedir temporariamente a germinação das sementes, promovendo maior incidência de sementes infectadas por C. truncatum e maior porcentagem de plântulas doentes. M. phaseolina reduziu a germinação das sementes, independente do tratamento inoculado. Ambos os fungos foram transmitidos das sementes para as plântulas de feijão-fava, causando sintomas em diferentes órgãos aéreos. A taxa de transmissão de C. truncatum e M. phaseolina foi de 83,1% e 76.46%, respectivamente.

ABSTRACT The fungi Colletotrichum truncatum and Macrophomina phaseolina are among the main pathogens associated with lima bean seeds in Brazil, and they are the causal agents of anthracnose and charcoal rot, respectively. The aim of this study was to verify the seed-seedling transmission of C. truncatum and M. phaseolina in artificially inoculated lima bean seeds. Potato-dextrose-agar (PDA) media with different hydric potentials were obtained after the addition of mannitol. Isolates of C. truncatum and M. phaseolina were peaked to these media. Forty grams of seeds were distributed over the fungal mycelium, remaining there for different exposure periods, as a function of each treatment: T1: 0.0 MPa without inoculum for 48 h; T2: 0.0 MPa for 48 h; T3: -0.2 MPa for 48 h; T4: -0.4 MPa for 48 h; T5: -0.6 MPa for 72 h; T6: -0.8 MPa for 96 h and T7: -1.0 MPa for 120 h. The seeds were incubated at 25 ºC under a 12-hour photoperiod. Germination in a paper roll, emergence of seedlings in sand and seed health in PDA were evaluated. T4 provided the best conditions to temporarily prevent seed germination, promoting a greater incidence of seeds infected by C. truncatum and a greater percentage of diseased plants. M. phaseolina reduced seed germination, independently of the inoculated treatment. Both fungi were transmitted from the seeds to the seedlings of lima bean, causing symptoms in various aerial parts. C. truncatum and M. phaseolina transmission rate was 83.1% and 76.46%, respectively.

RESUMO Objetivou-se verificar o potencial de folhas de girassol mexicano (Tithonia diversifolia) como alternativa de manejo ao nematoide Pratylenchus brachyurus em quiabeiro. Foram conduzidos dois ensaios em casa de vegetação, em delineamento inteiramente casualizado, com sete repetições, sendo cada parcela composta por um vaso contendo uma planta. Utilizou-se o quiabeiro como planta indicadora e o sorgo como testemunha suscetível. Os tratamentos foram cinco níveis de fitomassa verde e seca (0, 5, 10, 15 e 20 g kg-1 de solo) de T. diversifolia, incorporada ou na forma de cobertura do solo, para avaliar o efeito sobre a população de P. brachyurus. A incorporação de folhas frescas de T. diversifolia no solo, como adubo verde, reduziu a população de P. brachyurus 60 dias após a inoculação, com destaque para o nível de 20 g kg-1 de solo que possibilitou reduzir a população do nematoide (FR=0,00). Com 5 g de fitomassa seca, em cobertura, de T. diversifolia foi possível reduzir 2,96 % a população do nematoide, enquanto que os níveis de fitomassa seca de 10, 15 e 20 g kg-1 de solo eliminou o patógeno. Conclui-se que a incorporação ao solo de folhas frescas de T. diversifolia, e a cobertura morta com folhas de T. diversifolia sobre o solo, na forma de fitomassa seca, proporcionaram redução na população de P. brachyurus no solo e nas raízes de quiabeiro, sendo uma alternativa importante para o manejo de P. brachyurus

ABSTRACT The objective of this study was to verify the potential of Mexican sunflower leaves (Tithonia diversifolia) as an alternative for the management of the nematode Pratylenchus brachyurus in okra. Two trials were conducted in a greenhouse, in a completely randomized design, with seven replicates, and each plot consisting of one pot containing one plant. Okra was used as an indicator plant and sorghum as a susceptible control. Treatments were five levels of green and dry phytomass (0, 5, 10, 15 and 20 g kg-1 soil) of T. diversifolia, incorporated in the soil or as soil cover, to evaluate their effect on P. brachyurus population. The incorporation of fresh leaves of T. diversifolia in the soil as green manure reduced P. brachyurus population 60 days after inoculation, especially the level of 20 g kg-1 soil, which allowed complete reduction in the nematode population (FR = 0.00). At 5 g dry phytomass of T. diversifolia, as soil cover, nematode population could be reduced by 2.96%, while the dry phytomass levels of 10, 15 and 20 g kg-1 soil eliminated the pathogen. In conclusion, the incorporation of fresh leaves of T. diversifolia in the soil and mulching with T. diversifolia leaves on the soil, in the form of dry phytomass, provided a reduction in the population of P. brachyurus in the soil and in the roots of okra, constituting an important alternative for the management of P. brachyurus.

ABSTRACT The fungal genus Curvularia is associated with a number of diseases in plants, commonly producing foliar spots in forage grasses. The objective of this study was to characterize the morphological and molecular diversity of the isolates of Curvularia sp. associated with Andropogon seeds, and to assess both their capacity to transmit disease and the pathogenicity of this fungus to crop. Ten isolates of Curvularia sp. were sourced from Andropogon seeds from agricultural producing regions in the Brazilian states Tocantins and Pará. Morphological characterization was achieved by observing fungus colonies and conidia and molecular characterization by DNA extraction and amplification with sequence-specific primers. The disease transmission was evaluated from seed sowing, in which after 40 days typical symptoms of Curvularia sp. were observed. Pathogenicity was evaluated by inoculating conidial suspension into the leaves of healthy plants, and after ten days, inspecting for pathogenic symptoms. Based on morphological and molecular features, the pathogen associated with Andropogon seeds was identified as Curvularia lunata, which, as such, is transmitted through the Andropogon plants via its seeds and is pathogenic to this species of forage grass.

Pitch canker is one of the most important diseases of pine trees worldwide, including South America. The causal agent of this disease is Fusarium circinatum, a member of the Gibberella fujikuroi complex (GFC). In South America, the species is reported from Colombia, Uruguay and Chile, but is considered a quarantine organism in Brazil. In this study we characterized isolates obtained from symptomatic pine seedlings intercepted in a nursery in Santa Catarina State using phylogenetic analyses, crossings and morphological markers. The Brazilian isolates grouped with reference material in an unique clade and formed fertile perithecia when crossed with reference tester strains. The detailed characterization given here and the availability of tester strains will allow for reliable identification and support monitoring of this important plant pathogen.