Made available in DSpace on 2016-12-08T16:44:42Z (GMT). No. of bitstreams: 1 PGPV11MA101.pdf: 1302742 bytes, checksum: b7efc06d336ca4a49c0225d1d0b03cfb (MD5) Previous issue date: 2011-02-08 / The objectives of the work were: a) to obtain the damage function equations for multiple pathosystem to calculate the EDT to time fungicides application; b) to quantify the control and damage of the yield components, and c) To relate the brown spot incidence and severity in different growth stages. The experiments were carry out at the NBN Seeds Company during the 2009 and 2010 crop seasons, located in Muitos Capões county, Rio Grande do Sul state, Brazil and in the Agro science Center at Santa Catarina State University only in 2010. The cultivar BRS Cauê was used as susceptible cultivar to brown spot and powdery mildew. The experiments design was in randomized block with four replications. The nine treatments consisting of different rates (half and recommended rates) and fungicide applications number (one, two, three and four) of mixture strobilurin and triazole fungicides, generating the disease gradients intensity. The total area of 5.0 x 2.5 m was the experimental unit in both experiments. The fungicide applications and incidence and severity assessment were done at EC 22, EC 31, EC 39, EC 45 and EC 56 plant development stages. Plants from central rows of each plot were manually harvested and grain yield (GY), one-thousand grain weight (TGW) and granulometry (G) were evaluated. In the first chapter, the damage function equations between disease intensity and GY for each plant development stages, obtained by regression analysis, in both 2009-10 crop growing seasons were significant and negative indicative that increasing disease severity lead into decreasing grain yield. The damage coefficients of these equations can be used to calculate the economic damage threshold. In the second chapter, the values of disease intensity were used to calculate the area under disease progress curve (AUDPC). The GY, TGW, G and AUDPC values were tested using the mean comparison between treatments and the percentage of damage and disease control were determinated. The largest 2009 crop damage was 45.87%, 15.47% and 25.84% for GY, G and TGW, respectively. The ultimate control was 68.11% when considered the severity and four foliar applications, independent of the used dose. In 2010, the greatest damage were 31.16%, 14.02% and 10.76% in Muitos Capões and 39.44%, 23.59% and 45.88%, in Lages, for GY, 10 TGW and G, respectively. The highest percentage of control, based on the leaf severity were 71.63% and 73.96% for Muitos Capões and Lages, respectively. The greater control, independent of used dose were obtained with three and four applications in Muitos Capões and four applications in Lages. In the third chapter, brown spot incidence and severity data were subjected to regression analysis and correlation and the obtained values were significant and positive. The brown spot and powdery mildew diseases incidence and severity recommended by the Technique Indication of crop (TIC) to initiate fungicide applications is 20% and 5% respectively. The severity average values for initiating chemical control are 0.77% and 0.34% respectively for 2009 and 2010 crop seasons when the incidence diseases were substituted in the equations. These values are lower than TIC recommended values / Os objetivos do trabalho foram: a) obter equações de função de dano para patossistema múltiplo para calcular o LDE servindo como critério indicador de aplicação de fungicidas; b) quantificar controle e dano nos componentes de rendimento; e c) relacionar incidência e severidade foliar da mancha marrom em diferentes estádios fenológicos. Os experimentos foram conduzidos nas safras agrícolas 2009 e 2010 na NBN Sementes no município de Muitos Capões, RS; e, na safra de 2010 no Centro de Ciências Agroveterinárias no município de Lages, SC. Em todos os experimentos foi utilizada a cultivar BRS Cauê suscetível à mancha marrom e oídio. O delineamento foi blocos casualisados, com quatro repetições e nove tratamentos constituídos de diferentes doses (meia dose e dose indicada) e número (uma, duas, três e quatro) de aplicações de fungicidas triazóis e estrobilurinas para gerar os gradientes de intensidade das doenças. A área de cada unidade experimental correspondeu a 5,0 x 2,5 m. As aplicações e as avaliações da incidência e severidade foliar ocorreram nos estádios de crescimento (EC) EC 22, EC 31, EC 39, EC 45 e EC 56. A colheita foi manual cortando as plantas das linhas centrais de cada parcela. Foram avaliados rendimento de grãos (RG), massa de mil grãos (MMG) e granulometria (G). No primeiro capítulo, as equações de função de dano entre intensidade de doença e RG para cada EC, obtidas por análise de regressão, em ambas as safras agrícolas, foram significativas e negativas, ou seja, à medida que aumentou a intensidade de doença, diminuiu o RG. Os coeficientes de dano obtidos podem ser utilizados no cálculo do limiar de dano econômico. No segundo capítulo, os valores de intensidade das doenças foram usados para o cálculo da área abaixo da curva de progresso da doença (AACPD). Os valores de RG, MMG, G e AACPD foram submetidos ao teste de comparação de médias. Foram determinados o percentual de dano e de controle das doenças. Na safra 2009, os maiores danos foram 45,87%, 15,47% e 25,84% para RG, MMG e G, respectivamente. O controle máximo foi 68,11% considerando a severidade foliar e quatro aplicações, independente da dose usada. Em 2010, os maiores danos foram 31,16%, 14,02% e 10,76% em Muitos Capões e 39,44%, 23,59% e 8 45,88% em Lages, respectivamente para R, MMG e G. Com base na severidade obteve-se controle de 71,63% e 73,96% em Muitos Capões e Lages, respectivamente. Em Muitos Capões três e quatro aplicações e em Lages quatro aplicações, independente da dose, apresentaram maior percentual de controle. No terceiro capítulo, os dados de incidência e severidade foliar de mancha marrom foram submetidos à análise de regressão e correlação. As equações obtidas foram significativas e positivas. A incidência e a severidade foliar recomendado pela Indicação Técnica da cultura (ITC) para iniciar as aplicações de fungicidas é de 20% e 5%, respectivamente. Substituindo esse valor de incidência nas equações obtidas têm-se valores médios de severidade para iniciar o controle químico de 0,77% e 0,34% respectivamente para 2009 e 2010, inferior ao recomendado pela ITC

Blumeria graiminis f. sp. hordei (powdery mildew) is an obligate biotroph infecting hordeum vulgare (barley). It is one of the most devastating pathogens of barley, decreasing barley yield in great extent. In order to decrease barley loss, numerous studies are being conducted for overcoming the disease from the sides of both pathogen and host. However the pathogen is evolving very rapidly preventing the effective use of pesticides such as fungisides or development of resistant barley varieties by crossing race-specific resistance varieties, varieties having R genes, with susceptible but high yield producing varieties. In order to understand the mechanism of pathogen-host interactions, and producing enduring solutions for the problem of yield loss in barley molecular tools need to be used. In this thesis study, Amplified Fragment Length Polymorphism (AFLP) molecular marker method is used in order to reveal the molecular characterization of Turkish Blumeria graminis f. sp. hordei varieties collected from &Ccedil / ukurova region in Turkey. Thirty-nine samples were analyzed with eigth universal races, of which virulence genes are studied. AFLP studies were conducted on LI-COR 4300 DNA Analyzer system. Bioinformatics analysis was performed with NTSYS program. By the help of this Numerical Taxonomic System, similarity, dissimilarity, clustering, dendograms, two-dimensional scatter plots, and three-dimensional perspective plots were obtained. By the light of these analyses Turkish Blumeria graminis f. sp. hordei varieties together with universal races are grouped into three clusteres. In conclusion, studying Turkish Blumeria graminis f. sp. hordei isolates and comparing them with universal races is a unique study in terms of characterizing the Turkish Bgh isolates for the first time, and can be used as a frontier study for studying Resistance genes, by reverse genetic tools.