ABSTRACT The objective of this work was to evaluate the ability of Trichoderma asperellum isolates and their culture filtrates to control Lasiodiplodia theobromae in vivo and to promote the growth of pecan seedlings. Two experiments were carried out, both in a greenhouse. In the first experiment, the aerial part of the plants was sprayed by biological control treatments and, 14 days later, the pathogen was inoculated into the stem, through injury. In the second experiment, the substrate was moistened with biological control treatments and 14 days later the pathogen was inoculated following the same methodology as the first experiment. The following parameters were evaluated: length of the aerial part, stem diameter, fresh mass of the aerial part and the root, dry mass of the aerial part and the root, incidence and severity of the disease. The comparison of means was performed using the Skott-Knott test at a 5% probability of error, using the SISVAR software. In both experiments, the greatest responses were obtained in the growth parameters evaluated in the treatments with the culture filtrates and with the spore suspension in relation to the treatment inoculated with the pathogen without the use of biological control treatments. These treatments also reduced the incidence and severity of stem canker in pecan seedlings, and the best treatment varied with the form of application. The isolates of T. asperellum and the culture filtrates stimulated the initial growth of the plants, decreasing the incidence and severity of stem canker in pecan plants, regardless of the form of application.

RESUMO O objetivo deste trabalho foi avaliar a ação de isolados de Trichoderma asperellum e de seus filtrados de cultura no controle de Lasiodiplodia theobromae in vivo e na promoção do crescimento de mudas de nogueira-pecã. Foram desenvolvidos dois experimentos, ambos em casa de vegetação. No primeiro experimento, a parte aérea das plantas foi aspergida pelos tratamentos de controle biológico e 14 dias após foi inoculado o patógeno no caule, por meio de ferimento. No segundo experimento, o substrato foi umedecido com os tratamentos de controle biológico e 14 dias após foi feita a inoculação do patógeno seguindo mesma metodologia do primeiro experimento. Foram avaliados os seguintes parâmetros: comprimento da parte aérea, diâmetro do caule, massa fresca da parte aérea e da raiz, massa seca da parte aérea e da raiz, incidência e severidade da doença. A comparação das médias foi realizada pelo teste de Skott-Knott a 5% de probabilidade de erro, com o software SISVAR. Nos dois experimentos, obtiveram-se as maiores respostas nos parâmetros de crescimento avaliados nos tratamentos com os filtrados de cultura e com a suspensão de esporos, em relação ao tratamento inoculado com o patógeno sem o uso dos tratamentos de controle biológico. Esses tratamentos também reduziram a incidência e a severidade do cancro do tronco em mudas de nogueira-pecã, sendo que o melhor tratamento variou com a forma de aplicação. Os isolados de T. asperellum e os filtrados de cultura estimularam o crescimento inicial das plantas, diminuíram a incidência e a severidade do cancro do tronco nas plantas de nogueira-pecã, independente da forma de aplicação.

RESUMO: O trabalho teve como objetivo avaliar se há influência do alagamento temporário do solo no desempenho agronômico e no rendimento de cultivares de trigo. O delineamento experimental foi em blocos ao acaso, em esquema fatorial 11x2 (onze cultivares e duas condições hídricas do solo), com quatro repetições. O estresse foi o imposto no estádio antecedente a antese das plantas. Foi realizada a avaliação por dois anos (2016/2017) do número de espigueta da espiga principal, número de sementes da espiga principal, massa de sementes da espiga principal, número de sementes da espiga do perfilho, massa de sementes da espiga do perfilho e rendimento da área útil. Os atributos físicos número de sementes, massa de sementes e o rendimento de sementes de trigo, conforme a cultivar e ano agrícola, são afetados negativamente pelo alagamento temporário (12 dias) do solo. Há influência do alagamento temporário do solo no desempenho agronômico e na produtividade das variedades de trigo. As variedades TBio Toruk, TBio Sinuelo, TBio Sintonia e CD151 são superiores na condição de alagamento do solo para o número de espiguetas, número de sementes e para o atributo massa de sementes. Na condição de capacidade de campo, as sementes produzidas apresentam maior rendimento, atingindo cerca de 309,2 Kg a mais para a cultivar TBio Sinuelo, 262 Kg para a TBio Toruk e 114 Kg na CD1303 em comparação àquelas produzidas sob o período de alagamento imposto.

ABSTRACT: The aim of this work was to evaluate whether there is any influence of temporary soil flooding on the agronomic performance and yield of wheat varieties. The experimental design was completely random blocks, in an 11x2 factorial scheme (eleven varieties and two soil water conditions), with four replications. Stress was imposed in the stage prior to plant anthesis. The assessments were made in two seasons (2016/2017) in relation to the number of spikelets in the main ear, number of seeds in the main ear, mass of seeds in the main ear, number of seeds in the tiller ear, mass of seeds in the tiller ear and yield in the useful area. The physical attributes number of seeds, seed mass and wheat seed yield, according to variety and agricultural year, are negatively affected by the temporary flooding (12 days) of the soil. There is influence of temporary soil flooding on the agronomic performance and yield of wheat varieties. The varieties TBio Toruk, TBio Sinuelo, TBio Sintonia, and CD151 are superior in soil flooding condition for the number of spikelets, number of seeds end for the seed mass attribute. In the soil at field capacity, the seeds produced have higher yield compared to those produced under flooding period, reaching about 309.2 Kg more for the variety TBio Sinuelo, 262 Kg for TBio Toruk and 114 Kg in CD1303.

ABSTRACT One of the limiting factors for pecan production is the incidence of disease caused by Fusarium spp. which are a threat to orchards in the south of the country. Therefore, the study aimed to confirm the pathogenicity and evaluate the morphophysiological and molecular characteristics of Fusarium spp. associated with pecan in Rio Grande do Sul and Paraná. For this, samples of symptomatic plant material were collected, and potentially pathogenic isolates were evaluated for pathogenicity, by immersing the roots of the plants in a spore suspension of Fusarium spp. In addition, the severity of the disease was assessed using a rating scale according to the symptoms expressed by the plants. The isolates were also analyzed for morphophysiological variability, through evaluations of mycelial growth, colony and aerial mycelium pigmentation, and characteristics of reproductive structures. Molecular characterization was performed which amplify the region of the 1-alpha elongation factor and sequencing. Nineteen isolates were obtained, which were considered pathogenic, however, there was variability in their aggressiveness and morphophysiological characteristics. In addition, the sequencing was used to identify different species. Therefore, species of Fusarium are responsible for the occurrence of wilt in pecan in southern Brazil.

ABSTRACT This work aimed to evaluate the effect of nitrogen dose management on the growth responses and physiological performance of barley seeds. Two barley cultivars (BRS Brau and BRS Cauê) and four nitrogen doses were used. The experimental design consisted of randomized blocks in a 2 X 4 factorial scheme (cultivars BRS Brau and BRS Cauê x nitrogen doses 120, 150, 180, and 210 kg ha-1). Successive collections of primary data were performed every fourteen days for growth analysis. The analyzed variables were total dry matter, dry matter production and relative growth rate, assimilated partition, and seed electrical conductivity. Increasing nitrogen doses caused a temporal-quantitative difference in growth, partition, and the accelerated aging test of barley seeds. The 150 kg ha-1 N dose resulted in total dry matter over time (Wt) superiority for both evaluated cultivars. The variable dry matter production rate achieved an increase with the 150 kg ha-1 N dose at 70 days after emergence (DAE) for BRS Brau and at 56 DAE for BRS Cauê supporting Wt. The 180 and 150 kg ha-1 N doses increased the relative growth rate for BRS Brau and BRS Cauê.

RESUMEN Este trabajo tuvo como objetivo evaluar el efecto del manejo de las dosis de nitrógeno en las respuestas de crecimiento y el rendimiento fisiológico de las semillas de cebada. Se utilizaron dos cultivares de cebada (BRS Brau and BRS Cauê) y cuatro dosis de nitrógeno. El diseño experimental consistió en bloques al azar en un esquema factorial 2 X 4 (cultivares BRS Brau y BRS Cauê x dosis de nitrógeno 120, 150, 180 y 210 kg ha-1). Se realizaron recolecciones sucesivas de datos primarios cada catorce días para el análisis de crecimiento. Las variables analizadas fueron materia seca total, producción de materia seca y tasa de crecimiento relativa, partición asimilada y conductividad eléctrica de las semillas. El aumento de las dosis de nitrógeno causa una diferencia cuantitativa-temporal en el crecimiento, partición y la prueba de envejecimiento acelerado de las semillas de cebada. La dosis de 150 kg ha-1 N resultó en una superioridad total de la materia seca en el tiempo (Wt) para ambos cultivares evaluados. La tasa variable de producción de materia seca logró un aumento para la dosis de 150 kg ha-1 N a los 70 días después de la germinación (DAE) para BRS Brau y a 56 DAE para BRS Cauê apoyando Wt. Las dosis de 180 y 150 kg ha-1 N aumentaron la tasa de crecimiento relativo para BRS Brau y BRS Cauê.

ABSTRACT The objective of this study was to evaluate the performance of wheat plant grown from seeds with different vigor levels. The experimental design was randomized blocks in a 3 x 3 factorial design (cultivar x vigor level) with four replications. The wheat cultivars were Tbio Toruk, Tbio Mestre and Tbio Iguaçu. The classification of vigor levels was high, medium and low, determined by several vigor procedures. The following evaluations were performed: plant height, number of spikelets in the main tiller, number of seeds in the main tiller, seed mass in the main tiller, number of fertile tillers, number of seeds in tillers, seed mass in tillers, number of plants.m-2, number of spikes.m-2, and grain yield per hectare. The use of high vigor seeds provides a greater number of wheat plants and spikes per area. Grain yield is affected significantly by seed vigor level: there is an increase of up to 11% by using high vigor seeds compared to low vigor seeds.

RESUMO A nogueira-pecã [Carya illinoinensis (Wangenh.) K. Koch] é uma espécie arbórea amplamente difundida na região sul do Brasil e comercialmente importante devido à produção de nozes e madeira. Cancros do tronco em árvores de noz-pecã impactam negativamente o pomar, mas as causas bióticas dos cancros geralmente não são identificadas. Sintomas de cancro do caule foram observados em cerca de 60% das nogueiras de pomares em municípios do Rio Grande do Sul e Paraná. Assim, este estudo teve como objetivo analisar as características moleculares e morfofisiológicas de fungos isolados de cancros em nogueira-pecã em pomares do sul do Brasil e confirmar sua patogenicidade na planta. Amostras de caules sintomáticos foram coletadas e possíveis agentes causais foram isolados. A identificação molecular foi realizada pela técnica de Reação em Cadeia da Polimerase para amplificação da região EF-1α e posterior sequenciamento. O sequenciamento, seguido de aspectos morfofisiológicos do crescimento micelial e pigmentação da colônia, permitiu a identificação de um complexo de espécies incluído na família Botryosphaeriaceae. Os isolados foram classificados como Lasiodiplodia theobromae, Pseudofusicoccum kimberleyense e Neofusicoccum parvum. A patogenicidade foi testada inoculando os isolados em mudas de nogueira-pecã para avaliar os sintomas. Todos os isolados causaram cancro no caule, mas houve variação na severidade. Portanto, diferentes espécies da família Botryosphaeriaceae são responsáveis pela ocorrência de cancro em tronco de nogueira-pecã na região sul do Brasil, mas em diferentes níveis de dano. Assim, é crucial identificar e compreender o comportamento dos isolados fúngicos para melhor controlar os cancros nos pomares.

ABSTRACT Pecan tree [Carya illinoinensis (Wangenh.) K. Koch] is a widespread species in the southern region of Brazil and commercially important for nut and wood production. Stem cankers in pecan trees negatively impact the orchard, but the biotic causes of cankers are usually not identified. Symptoms of stem canker were observed in about 60% of pecan trees from orchards in the states of Rio Grande do Sul and Paraná. Therefore, this study aimed to analyze the molecular and morphophysiological characteristics of fungi associated with pecan canker in orchards in southern Brazil and to confirm their pathogenicity in pecan seedlings. Samples from symptomatic stems were collected in different municipalities and possible causal agents were isolated. Molecular identification was performed by the Polymerase Chain Reaction technique for amplification of the EF-1α region and subsequent sequencing. The sequencing, followed by morphophysiological aspects of mycelial growth and colony pigmentation, allowed the identification of a species complex included in the Botryosphaeriaceae family. The isolates were classified as Lasiodiplodia theobromae, Pseudofusicoccum kimberleyense and Neofusicoccum parvum. Pathogenicity was tested by inoculating the isolates into pecan seedlings to evaluate the symptoms. All isolates caused canker in the stem, but there was variation in the severity. Therefore, different species of the Botryosphaeriaceae family are responsible for stem canker occurrence in pecan trees in the southern region of Brazil, but at different levels of injury. Thus, it is crucial to identify and understand the behavior of the fungal isolates to best control cankers in pecan orchards.

Resumo Juglans regia e Carya illinoinensis, ambas da família Juglandaceae, são espécies de nogueiras conhecidas mundialmente pela produção das chamadas nozes, com crescente expansão da área cultivada na América do Sul. Entretanto, nos últimos anos houve aumento da incidência de doenças nessas espécies, o que compromete a rentabilidade dos cultivos e a qualidade do produto. Colletotrichum nymphaeae foi recentemente identificado no Brasil causando danos em frutos de Juglans regia. Este estudo teve como objetivo avaliar o potencial de infecção cruzada de C. nymphaeae, isolado de frutos sintomáticos de Juglans regia, em folíolos e frutos de cultivares de Carya illinoinensis. Para isso, discos de meio de cultura contendo estruturas do patógeno foram depositados sobre folíolos e frutos de seis e três cultivares de Carya illinoinensis, respectivamente. Colletotrichum nymphaeae mostrou-se patogênico tanto em folíolos como em frutos de todas as cultivares avaliadas, sendo que as maiores lesões em folíolos foram observadas nas cultivares ‘Barton’, ‘Melhorada’ e ‘Imperial’, enquanto que a cultivar ‘Shawnee’ demonstrou menor suscetibilidade ao patógeno. Nos frutos, a cultivar ‘Imperial’ mostrou-se mais suscetível ao patógeno, já que apresentou as maiores lesões.

Abstract Juglans regia and Carya illinoinensis, both from the Juglandaceae family, are species known worldwide for the production of edible nuts, with an increasing expansion of the cultivated area in South America. However, in recent years there was an increase in the incidence of diseases in the species, which compromises the profitability of crops and the nut quality. Colletotrichum nymphaeae was recently identified in Brazil causing damage to fruits of Juglans regia. This study aimed to evaluate the potential for cross-infection of Colletotrichum nymphaeae, isolated from symptomatic fruits of Juglans regia, on leaves and fruits of Carya. illinoinensis cultivars. Disks of culture medium containing structures of the pathogen were deposited on leaflets and fruits of six and three cultivars of Carya illinoinensis, respectively. Colletotrichum nymphaeae was found to be pathogenic both in leaflets and in fruits of all the cultivars evaluated, with the largest lesions in leaflets observed in the cultivars ‘Barton’, ‘Melhorada’ and ‘Imperial’, while the cultivar ‘Shawnee’ demonstrated less susceptibility to the pathogen. In the fruits, ‘Imperial’cultivar was more susceptible to the pathogen, since it presented the largest lesions.

Resumo Nas regiões Centro-Oeste e Sul do Brasil, a cultura da erva-mate (Ilex paraguariensis) constitui-se uma importante fonte de extrativismo florestal, além de diversificar a renda, principalmente na agricultura familiar. A erva-mate, como outras espécies florestais, é infectada por diversos patógenos, como o gênero Fusarium, causador da podridão-de-raízes. Os patógenos possuem ampla variabilidade genética, mesmo dentro de um único gênero e dentro de uma única espécie, resultado de adaptações ao meio em que vivem. Este estudo teve como objetivo avaliar o sequenciamento das regiões do genoma ITS e β-tubulina na identificação em nível de espécie dos isolados de Fusarium spp. patogênicos à erva-mate, e identificar a formação de grupos de compatibilidade vegetativa (VCG) entre os isolados de Fusarium spp. patogênicos à erva-mate. O sequenciamento das regiões ITS e β-tubulina consolidou a separação entre os sete isolados patogênicos em F. solani e F. oxysporum. Para esses isolados, a técnica para obtenção de mutantes nit foi adequada para a classificação fenotípica, fundamentais nos testes de VCG para espécies de Fusarium, sendo obtidos cinco VCG.

Abstract In the central-western and southern regions of Brazil, the cultivation of yerba mate (Ilex paraguariensis) is considered an important source of forest extraction, besides providing an alternative income, especially for families. The yerba mate, like other forest species, is infected by several pathogens, such as fungi of the genus Fusarium, causing root rot. Pathogens have wide genetic variability, even within a single genus and species, resulting from adaptations to their environments. This study aimed at characterizing molecularly isolated Fusarium spp. through the sequencing of the ITS and β-tubulin genome regions, identifying the species level as well as the formation of vegetative compatibility groups (VCG) among these isolates of the root rot pathogen in yerba mate. The sequencing of the ITS and β-tubulin regions, defined the separation between the seven pathogenic isolates of F. solani and F. oxysporum. For the same isolates, the technique to obtain nit mutants was suitable for the phenotypic classification, obtaining five VCGs for species of Fusarium, root rot in yerba mate.

Resumo: A qualidade das sementes e a ocorrência de estresses são determinantes para o crescimento e desenvolvimento das culturas. Assim, o trabalho teve como objetivo verificar o efeito do vigor das sementes no crescimento e na partição de massa seca de plantas de trigo submetidas a condições de estresse hídrico. Para avaliação do crescimento o delineamento experimental foi inteiramente casualizado, em esquema fatorial 2 x 2 x 8 (nível de vigor x regime hídrico x época de coleta), com quatro repetições. Para avaliação do rendimento de grãos, o delineamento foi inteiramente casualizado, em esquema fatorial 2 x 2 (nível de vigor x regime hídrico), com quatro repetições. Foram avaliadas massa seca total, taxa de produção de massa seca, taxa de crescimento relativo, razão de área foliar, área foliar, eficiência de conversão da energia solar, partição de massa seca e índice de colheita. A produção de massa seca total, a taxa de produção de massa seca, taxa assimilatória líquida, área foliar, razão de massa foliar, eficiência de conversão da energia solar e rendimento foram superiores para plantas provenientes de sementes de alto vigor sob capacidade de campo. O rendimento foi superior para plantas de alto vigor em relação àquelas de baixo vigor na capacidade de campo.

Abstract: The quality of the seeds and the occurrence of stresses are decisive for the development of the crops. Thus, the work aimed to verify the effect of seed vigor on growth and dry weight partition of wheat plants subjected to water stress. For growth evaluation, the experimental design was completely randomized, in a 2 x 2 x 8 factorial scheme (vigor level x water regime x collection time), with four replications. To evaluate the yield of the seeds, the design was completely randomized, in a 2 x 2 factorial scheme (level of vigor x water regime), with four replications. Total dry weight, dry weight production rate, relative growth rate, leaf area ratio, leaf area, solar energy conversion efficiency, dry weight partition and harvest index were evaluated. Total dry weight production, dry weight production rate, leaf area, leaf weight ratio, solar energy conversion efficiency and yield were higher for plants from highly vigorous seeds under field capacity. The yield was higher for plants with high vigor compared to those with low vigor in field capacity.

Abstract Pecan cultivation in Brazil has gained increasingly economic importance in the southern part of the country. The objective of this work was to identify the pathogen that causes root rot in Carya illinoinensis seedlings in the nursery, through morphological, molecular and pathogenicity tests. Fungi from the genus Fusarium found in symptomatic roots of pecan seedlings were isolated in potato dextrose agar (PDA) culture medium and purified. Morphological characterization was performed in PDA and carnation leaf agar (CLA) media. For the molecular characterization, the genomic segments ITS (internal transcribed spaces), β-tub (beta-tubulin), and tef1-α (elongation fact 1-alpha) were sequenced. The pathogenicity test was performed on healthy seedlings in the greenhouse. The combination of morphological and molecular characters was fundamental for identification of the species, showing that the most suitable genes for identification were ITS and tef1-α. The causative agent of root rot in C. illinoinensis seedlings in the nursery was identified as Fusarium oxysporum.

RESUMO A erva-mate (Ilex paraguariensis) tem grande importância socioeconômica na agricultura familiar do Sul do Brasil. A principal doença da erva-mate é a podridão-de-raízes causada por Fusarium spp. Pouco se sabe a respeito da fisiologia deste patógeno, principalmente quanto à agressividade associada à produção de enzimas extracelulares. Neste trabalho, avaliou-se a agressividade de isolados de F. oxysporum e F. solani patogênicos à erva-mate e determinou-se as atividades das enzimas extracelulares catalase, lacase, celulase, caseinase, amilase, protease, lipase e pectinases produzidas por Fusarium spp. em meio de cultura. Foram utilizados seis isolados de F. solani e um isolado de F. oxysporum patogênicos à erva-mate. O isolado de F. oxysporum mostrou-se menos agressivo em relação aos demais isolados de F. solani. Todos os isolados de Fusarium spp. produziram, de maneira semiquantitativa, as enzimas extracelulares catalase, lacase, celulase, caseinase, amilase, protease, lipase e pectinases (poligalacturonase e pectato liase). Entretanto, a quantidade produzida de cada enzima foi significativamente diferente entre os isolados. Com exceção das enzimas lacase e poligalacturonase o isolado M7C1 de F. solani exibiu as maiores médias do índice enzimático e foi também o responsável pelo maior percentual de morte de mudas de erva-mate.

ABSTRACT The yerba-mate (Ilex paraguariensis) has great socioeconomic importance on family farming in Southerm Brazil. One of the main yerba-mate disease is root rotting, caused by Fusarium spp. Little is known about the pathogen physiology, especially regarding the aggressiveness associated with the production of extracellular enzymes. On this work, the aggressiveness of isolates of F. oxysporum and F. solani pathogenic to yerba-mate was evaluated and it was determined the activities of extracellular enzymes catalase, laccase, cellulase, caseinase, amylase, protease, lipase and pectinases produced by Fusarium spp. in culture medium. Six isolates of F. solani and one isolate of F. oxysporum pathogenic to yerba-mate were used. The F. oxysporum isolate proved to be less aggressive in relation to the other F. solani isolates. All isolates of Fusarium spp. produced, on a semiquantitative manner, the extracellular enzymes catalase, laccase, cellulase, caseinase, amylase, protease, lipase and pectinases (polygalacturonase and pectate lyase). However, the quantity produced for each enzyme was significantly different among the isolates. With the exception of the laccase and polygalacturonase enzymes, the M7C1 isolate showed the highest enzymatic index and was also responsible for the highest percentage of yerba-mate seedlings death.

ABSTRACT Pecan is susceptible to the occurrence of diseases capable of harming its development, and leaf spot caused by Cladosporium spp is among them. Therefore, the objective of this work was to analyze the potential antagonist and in vitro effect of volatile metabolites of Trichodermaspp. On Cladosporium spp. isolated from pecan leaf spots. Three Cladosporium spp. isolates and two commercial products based on Trichodermaspp. were used, as well as an isolate of the same genus provided by the 'ElocyMinussi' Laboratory of Phytopathology at UFSM. Cladosporium spp. mycelial growth was monitored in order to evaluate the morphological characteristics of the pathogen. The use of Trichoderma spp. as biocontrol was assessed through dual culture tests and production of volatile metabolites. Trichoderma spp. showed positive results in inhibiting the growth of Cladosporium spp., thereby presenting potential to be used as a biocontrol agent.

ABSTRACT The cultivation of yerba-mate (Ilex paraguariensis) has been intensified in the State of Rio Grande do Sul, as result of the valuation of the price paid to the producer. However, studies related to Fusarium pathosystem vs. yerba-mate are still insufficient, so that many producers have faced significant losses in herbal production due to the occurrence of the roots rotting. Considering the above, the objectives of this study were: a) morphologically characterize the Fusarium spp. isolates collected in sick plants of yerba-mate; b) select efficient morphological characters on separating the Fusarium spp. isolates in similarity groups; c) identify the Fusarium spp. isolates to species level through the sequencing of the genomic region of elongation factor 1-α (TEF-1α); and d) testing the pathogenicity of the Fusarium spp. isolates selected based on the morphological characterization. For such, collections for the pathogen isolates were made in five cities and the collection points were georeferenced. Thirty-nine isolates were morphologically characterized by variables as mycelial growth, sporulation, macroconidia length and width, microconid format, colonies pigmentation and formation of chlamydospore, and tested for pathogenicity by substrate inoculation. The variables used in the morphological characterization were efficient in discriminating the isolates in seven groups, especially length of macronidia associated to sporulation. Seven pathogenic isolates of Fusarium spp. were identified, also through molecular sequencing of the TEF-1α gene region. The sequencing of the TEF-1α region consolidated the identification of pathogenic isolates as F. solani and F. oxysporum.