Exserohilum turcicum, Phaeosphaeria maydis, Bipolaris maydis, Puccinia polysora, Puccinia sorghi and maize streak virus were the most serious maize pathogens found in Kenya during a 1995/96 survey of 65 farms representing all the agro-ecological zones. Exserohilum turcicum - induced blight was observed in all maize producing areas with disease incidence reaching over 45%. Lesions were sometimes over 400 mm long by 25 mm in width. Southern leaf blight caused by Bipolaris maydis was most severe in the Kenyan maize granary located in the highlands west of the Rift Valley where it occurred alone or with Phaeosphaeria maydis leaf spot. Incidences of over 75% were recorded for southern leaf blight and Phaeosphaeria maydis leaf spot in western Kenya and over 85% for Phaeosphaeria maydis leaf spot in Thika, Nyeri, Muranga and Kirinyaga Districts of Central Province. Common rust caused by Puccinia sorghi was equally severe in the areas of Molo, Njoro and Bahati in Nakuru District with severity levels of over 65%. Lowland rust caused by Pucinia polysora was important in the coastal region with over 75% disease severity in Kwale District. Traces of lowland rust were observed in Kirinyaga District. Maize streak virus was severe in the Lake Victoria region of western Kenya, central areas of Kenya and in the Coast. This disease was severe where Napier grass (Pennisetum purpureum) with streak like symptoms was near the infected maize plots. Individual cultures of Exserohilum turcicum were not appreciably different in appearance but varied in growth rates at 22oC. A total of nineteen isolates of Exserohilum turcicum were classified into races using the Ht gene bearing maize differential inbred lines. Three isolates were race 0, three were race 1, one was race 2, one was race 3, two isolates were race 12, and eight did not fit in the known classification. These were named and grouped as k1, k2 and k3. The k3 race was virulent to HtN gene only. Four Kenyan and two American lines were inoculated with eight isolates of Exserohilum turcicum. All the Kenyan lines were susceptible to the isolates used. Tables of means comparisons and figures for disease occurrence and severity are provided. This is the first time disease prevalence and severity has been documented for maize in Kenya. / Ph. D.

Made available in DSpace on 2017-07-25T19:29:52Z (GMT). No. of bitstreams: 1 Lincom Koguishi.pdf: 1991536 bytes, checksum: 2ab0674dbbe3a078502f0ecb0a0b2a5b (MD5) Previous issue date: 2011-12-20 / The objective of this study was to evaluate the effects of application timing of fungicides epoxiconazole + pyraclostrobin and azoxystrobin + cyproconazole in corn in the control of Phaeosphaeria leaf spot (Phaeosphaeria maydis), rust (Puccinia sorghi), Cercospora leaf spot (Cercospora zea-maydis), stain Diplodia (Diplodia macrospora) and stem rot. Three experiments were installed in a randomized block design with four replications in plots measuring 3.2 x 5.0 meters. In experiment 1, we applied the fungicide epoxiconazole + pyraclostrobin at a dose of 99.75 + 37.5 g ai ha-1, more mineral oil (Assist) at a dose of 500 mL pc ha-1 and Experiments 2 and 3 was applied fungicide azoxystrobin + cyproconazole at a dose of 70 gy + 28 ha-1, more paraffinic mineral oil (Nimbus) at a dose of 600 mL pc ha-1. In experiment 1, applications were made at the phenological stages V8, V16, V8 and V16, V12, V15, VT and R2, and evaluated the severity of Phaeosphaeria leaf spot and Cercospora leaf spot in at R3, R4 and R5 and rot stalk the stage R6. With the data of severity, we calculated the area under the disease progress curve to Phaeosphaeria leaf spot. The lowest AUDPC occurred in treatments with a V16 application, with two applications in V8 and V16, with controls from 74 to 80%. In Experiments 2 and 3, applications of fungicides were made in V8, V16, R2, V8 and V16, V8 and R2, and R2 V16, V8, V16 and R2. Was evaluated in experiment 2 to Cercospora leaf spot, Phaeosphaeria leaf spot and stem rot. In the control of Cercospora leaf spot were the best treatment applications in developmental stage V8, which coincided with the occurrence of disease in the crop. To Phaeosphaeria leaf spot, the lowest values were in AUDPC with two applications in V8 and V16, V16 and R2 and the three applications in V8, V16 and R2, with control ranging from 25 to 40%. In Experiment 3, we assessed the common rust, leaf spot Phaeosphaeria, stain and Diplodia stalk rot. To common rust treatments containing application in V8 were the most effective with the percentage of controls over 80%. In relation to Phaeosphaeria leaf spot, the best treatment for AUDPC was the three applications (V8, V17 and R2) with 27% control. The treatments did not control the stain of Diplodia. In three experiments, was also evaluated damaged kernels, weight of thousand seeds and productivity, there being only in experiment 2, significant difference in the number and developmental stage of application for the variables weight of thousand seeds and productivity, highlighting the three applications in V8, V16 (17), R2 and applications V16 (17), R2, V8, V17. Keywords: Phaeosphaeria maydis, Puccinia sorghi, Cercospora zea / O objetivo deste trabalho foi avaliar os efeitos da época de aplicação dos fungicidas piraclostrobin + epoxiconazole e azoxystrobin + ciproconazole na cultura do milho no controle da mancha foliar de phaeosphaeria (Phaeosphaeria maydis), ferrugem comum (Puccinia sorghi), mancha foliar de cercospora (Cercospora zea-maydis), mancha de diplodia (Diplodia macrospora) e a podridão de colmo. Foram instalados três experimentos, no delineamento de blocos ao acaso com 4 repetições, em parcelas medindo 3,2 x 5,0 metros. No experimento 1, foi aplicado o fungicida piraclostrobin + epoxiconazole na dose de 99,75 + 37,5 g i.a. ha-1, mais óleo mineral (Assist) na dose de 500 mL p.c. ha-1 e nos experimentos 2 e 3 foi aplicado o fungicida azoxystrobin + ciproconazole na dose de 70 + 28 g.i.a. ha-1, mais óleo mineral parafínico (Nimbus) na dose de 600 mL p.c. ha-1. No experimento 1, as aplicações foram realizadas nos estádios fenológicos V8; V16; V8 e V16; V12; V15; VT e R2, sendo avaliada a severidade da mancha foliar de phaeosphaeria e mancha foliar de cercospora nos estádios R3, R4 e R5 e a podridão de colmo no estádio R6. Com os dados de severidade calculou-se a área abaixo da curva de progresso da doença para a mancha foliar de phaeosphaeria. Os menores valores de AACPD ocorreram nos tratamentos com uma aplicação em V16, com duas aplicações em V8 e V16, com controles de 74 a 80%. Nos experimentos 2 e 3, as aplicações dos fungicidas foram realizadas em V8; V16; R2; V8 e V16; V8 e R2; V16 e R2; V8, V16 e R2. Avaliou-se no experimento 2 a mancha foliar de cercospora, mancha foliar de phaeosphaeria e a podridão de colmo. No controle da mancha foliar de cercospora os melhores tratamentos foram as aplicações no estádio fenológico V8, os quais coincidiram com a ocorrência da doença na cultura. Para mancha foliar de phaeosphaeria, os menores valores na AACPD foram os com duas aplicações em V8 e V16, V16 e R2 e as três aplicações em V8, V16 e R2, com controle variando de 25 a 40%. No experimento 3, foram avaliadas a ferrugem comum, mancha foliar de phaeosphaeria, mancha de diplodia e a podridão de colmo. Para ferrugem comum os tratamentos que continham aplicação em V8 foram os mais eficientes com porcentagem de controles acima de 80%. Em relação a mancha foliar de phaeosphaeria, o melhor tratamento para AACPD foi o com três aplicações (V8, V17 e R2) com 27% de controle. Os tratamentos não controlaram a mancha de diplodia. Nos três experimentos avaliou-se também grãos ardidos, peso de mil sementes e produtividade, constatando-se somente no experimento 2, diferença significativa quanto ao número e estádio fenológico de aplicação, para as variáveis peso de mil sementes e produtividade, destacando as 3 aplicações em V8, V16 (17), R2 e as 2 aplicações em V16 (17), R2 e V8, V17.

No description available.

Orientador: Modesto Barreto / Banca: Margarete Camargo / Banca: Érika Auxiliadora Giacheto Scaloppi / Resumo: Representando cerca de 35,6% da safra de grãos do país, a cultura do milho tem sua produtividade ameaçada por um grande número de enfermidades. Diante do exposto o presente trabalho teve por objetivo analisar o progresso da Physopella zeae, Cercospora zeae-maydis e Phaeosphaeria maydis, sob diferentes tratamentos fungicidas na cultura do milho. Conduzido no delineamento de blocos casualizados com 6 tratamentos e 4 repetições em área do Departamento de Fitossanidade da FCAV-UNESP, utilizou-se os seguintes tratamentos de 1-6 (mL de p.c./ha), respectivamente: 1-testemunha; 2-epoxiconazole + pyraclostrobin 500; 3- epoxiconazole + pyraclostrobin 750; 4-azoxystrobin + cyproconazole 300 + óleo mineral parafínico 0,5%; 5-azoxystrobin + cyproconazole 300 + óleo mineral parafínico 0,5% e 6- azoxystrobin + cyproconazole 450 + óleo mineral parafínico 0,5%, todos aplicados com a planta no estádio V8, sendo que o Tratamento 5 foi repetido com a planta no início do pendoamento. Realizou-se 7 avaliações de severidade da doença com intervalos semanais. As curvas de progresso da doença foram analisadas através de 3 transformações (monomolecular, logístico e de Gompertz). Calculou-se a Área Abaixo da Curva de Progresso da Doença (AACPD) para cada doença, estas foram submetidas à análise de variância e as médias comparadas pelo teste de Tukey ao nível de 5% de probabilidade. Observou-se que o modelo monomolecular foi o que melhor se ajustou aos dados para a P. zeae e para a C. zeae-maydis. Em se tratando de P. maydis o modelo logístico proporcionou melhor ajuste...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The corn represents about 35,6% grain crop in Brazil and its productivity is threatened by a great number of pests and diseases. The objective of this study was to analyze the progress of the Physopella zeae, Cercospora zeae-maydis and Phaeosphaeria maydis, under different fungicides treatments in the corn crop. This work was carried out in experimental area of the Departamento de Fitossanidade of UNESP, Campus of Jaboticabal, São Paulo State, Brasil, in the period of January to May of 2006. Was evaluated in field plots arranged in complete randomized blocks, with 6 treatments and 4 replications. The used treatments were (mL of p.c. /ha): 1-check; 2-epoxiconazole + pyraclostrobin 500; 3-epoxiconazole + pyraclostrobin 750; 4-azoxystrobin + cyproconazole 300 + mineral oil 0,5%; 5-azoxystrobin + cyproconazole 300 + mineral oil 0,5% and 6 - azoxystrobin + cyproconazole 450 + mineral oil 0,5%. All the treatments fungicide spray was applied to maize at the stage V8, and the treatment 5 was replicated in the beginning of the tasseling. It was carried out 10 evaluations of the disease severity with a week interval among them. It was analyzed the curves of progress of the diseases through 3 transformations (monomolecular, logistic and Gompertz). There was calculated Area Under Progress Curve Disease (AUDPC), whose the variance analysis and the averages were compared by the Tukey test at 5% probability. It was observed that the monomolecular model had the best adjustment to the data for the P. zeae and C. zeae-maydis. For the P. maydis the logistic model had the best adjustment...(Complete abstract, click electronic address below) / Mestre

Made available in DSpace on 2014-06-11T19:28:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-07Bitstream added on 2014-06-13T20:18:16Z : No. of bitstreams: 1 koshikumo_esm_me_jabo.pdf: 514654 bytes, checksum: c6c89f1bd2aafce34a1da5563e125019 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Com objetivo de analisar aspectos epidemiológicos da Mancha de Phaeosphaeria (Phaeosphaeria maydis) e da Cercosporiose (Cercospora zeae - maydis) do milho (Zea mays) no município de Capão Bonito/SP de março a agosto de 2002 a 2006, sendo que a primeira ocorreu em todo período de estudo, enquanto a Cercosporiose (Cercospora zeae-maydis) ocorreu em dois anos (2002 e 2004), foram feitos ensaios em Blocos Casualizados com 3 repetições com 42 a 54 cultivares dependendo do ano. Quatro avaliações em todos os ensaios em intervalos semanais utilizando-se escala diagramática proposta pela Agroceres em 1993. Foi calculada a Curva de Progresso da Doença e a Área abaixo da mesma (AACPD), a qual foi analisada pelo teste F e as médias comparadas pelo teste de Scott-Knott. Com base neste teste os cultivares foram divididos em 4 grupos: Resistentes, Moderadamente Resistentes, Moderadamente Suscetíveis e Suscetíveis. Dados climáticos foram correlacionados com a doença. Foram testados os modelos matemáticos: Logístico, Exponencial, de Gompertz e Monomolecular. Sendo que este último foi o que melhor se ajustou aos dados em todos os anos para as duas doenças, tomando por base o R*2 (coeficiente de determinação entre os valores previstos e os observados). O ano de maior severidade para a Mancha de Phaeosphaeria foi o de 2005, enquanto para a Cercosporiose foi de 2002; isto provavelmente é devido às condições climáticas. A maioria dos cultivares se comportou como moderadamente resistente e resistente à Mancha de Phaeosphaeria e a Cercosporiose. Nota-se que nos anos onde a Mancha de Phaeosphaeria e Cercosporiose ocorreram concomitantemente (2002 e 2004), a primeira apresentou em todos os grupos (R, MR, MS e S) maiores severidades e inicio da epidemia mais tardia que a Cercosporiose. Em ambas a diferença de severidade deve-se principalmente à taxa de progresso de doença (r). / With the aim to analyze epidemiological aspects the Phaeosphaeria spot (Phaeosphaeria maydis) and gray leaf spot (Cercospora zeae-maydis) of maize (Zea mays) at Capão Bonito city, from march to august of 2002 to 2006, were studied, as the first occurred in all the period of study, while the gray leaf spot occurred in 2 years (2002 and 2004). The experimental design was casualized blocks with 3 repetitions each and 42 to 54 treatments, depending on the year. Four evaluations were made in weekly intervals using Agroceres diagrammatic scale. The disease progress curve (AUDPC) and its area under it was calculated and submitted to variance analysis (ANAVA) by F test, which averages were compared by Scott-Knott. Based on the results, the cultivars were grouped in resistant, moderately resistant, moderately susceptible and susceptible. Climate data were related to the disease. The logistic, exponential, Gompertz and monomolecular mathematic models were tested, being the monolecular model which better suited the data in all years, for both diseases, based in R*2. The year with higher Phaeosphaeria spot severity was 2005, while for Cercospora leaf spot was 2002, probably caused by climatic conditions. Most varieties were moderately resistant or resistant for Phaeosphaeria spot and Cercospora leaf spot. It was observed that on the years where Phaeosphaeria spot and Cercospora leaf spot occurred concomitantly (2002 and 2004); the first presented in all groups (R, MR, MS and S) higher levels of severity and the delay on the begining of the epidemy compared to Cercospora leaf spot. For both diseases, the difference on the disease progress occured mainly beause of the disease progress rate (r).

Made available in DSpace on 2014-06-11T19:28:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-03-05Bitstream added on 2014-06-13T20:37:27Z : No. of bitstreams: 1 costa_fm_me_jabo.pdf: 412278 bytes, checksum: b137b47f1e7a98ef2356e7beda9b1bee (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Representando cerca de 35,6% da safra de grãos do país, a cultura do milho tem sua produtividade ameaçada por um grande número de enfermidades. Diante do exposto o presente trabalho teve por objetivo analisar o progresso da Physopella zeae, Cercospora zeae-maydis e Phaeosphaeria maydis, sob diferentes tratamentos fungicidas na cultura do milho. Conduzido no delineamento de blocos casualizados com 6 tratamentos e 4 repetições em área do Departamento de Fitossanidade da FCAV-UNESP, utilizou-se os seguintes tratamentos de 1-6 (mL de p.c./ha), respectivamente: 1-testemunha; 2-epoxiconazole + pyraclostrobin 500; 3- epoxiconazole + pyraclostrobin 750; 4-azoxystrobin + cyproconazole 300 + óleo mineral parafínico 0,5%; 5-azoxystrobin + cyproconazole 300 + óleo mineral parafínico 0,5% e 6- azoxystrobin + cyproconazole 450 + óleo mineral parafínico 0,5%, todos aplicados com a planta no estádio V8, sendo que o Tratamento 5 foi repetido com a planta no início do pendoamento. Realizou-se 7 avaliações de severidade da doença com intervalos semanais. As curvas de progresso da doença foram analisadas através de 3 transformações (monomolecular, logístico e de Gompertz). Calculou-se a Área Abaixo da Curva de Progresso da Doença (AACPD) para cada doença, estas foram submetidas à análise de variância e as médias comparadas pelo teste de Tukey ao nível de 5% de probabilidade. Observou-se que o modelo monomolecular foi o que melhor se ajustou aos dados para a P. zeae e para a C. zeae-maydis. Em se tratando de P. maydis o modelo logístico proporcionou melhor ajuste... / The corn represents about 35,6% grain crop in Brazil and its productivity is threatened by a great number of pests and diseases. The objective of this study was to analyze the progress of the Physopella zeae, Cercospora zeae-maydis and Phaeosphaeria maydis, under different fungicides treatments in the corn crop. This work was carried out in experimental area of the Departamento de Fitossanidade of UNESP, Campus of Jaboticabal, São Paulo State, Brasil, in the period of January to May of 2006. Was evaluated in field plots arranged in complete randomized blocks, with 6 treatments and 4 replications. The used treatments were (mL of p.c. /ha): 1-check; 2-epoxiconazole + pyraclostrobin 500; 3-epoxiconazole + pyraclostrobin 750; 4-azoxystrobin + cyproconazole 300 + mineral oil 0,5%; 5-azoxystrobin + cyproconazole 300 + mineral oil 0,5% and 6 - azoxystrobin + cyproconazole 450 + mineral oil 0,5%. All the treatments fungicide spray was applied to maize at the stage V8, and the treatment 5 was replicated in the beginning of the tasseling. It was carried out 10 evaluations of the disease severity with a week interval among them. It was analyzed the curves of progress of the diseases through 3 transformations (monomolecular, logistic and Gompertz). There was calculated Area Under Progress Curve Disease (AUDPC), whose the variance analysis and the averages were compared by the Tukey test at 5% probability. It was observed that the monomolecular model had the best adjustment to the data for the P. zeae and C. zeae-maydis. For the P. maydis the logistic model had the best adjustment...(Complete abstract, click electronic address below)

Submitted by BELISA CRISTINA SAITO null (belisasaito@gmail.com) on 2017-04-20T18:20:53Z No. of bitstreams: 1 Tese Belisa Saito.pdf: 1868613 bytes, checksum: 40d639682537f01c2cc01e7a92791445 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-25T17:59:26Z (GMT) No. of bitstreams: 1 saito_bc_dr_ilha.pdf: 1868613 bytes, checksum: 40d639682537f01c2cc01e7a92791445 (MD5) / Made available in DSpace on 2017-04-25T17:59:26Z (GMT). No. of bitstreams: 1 saito_bc_dr_ilha.pdf: 1868613 bytes, checksum: 40d639682537f01c2cc01e7a92791445 (MD5) Previous issue date: 2017-03-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O milho é uma das culturas mais extensamente cultivadas em todo mundo. A incidência e a severidade de doenças têm aumentado significativamente nos últimos anos acarretando perdas no rendimento e afetando a qualidade dos grãos. Muitos trabalhos têm sido desenvolvidos na tentativa de identificar híbridos resistentes às principais doenças que acometem a cultura do milho, mas poucos são os relatos de estudos com linhagens. Dessa forma, o objetivo deste estudo foi: 1) identificar linhagens resistentes e susceptíveis com base na área abaixo da curva de progresso de doenças (AACPD) para os sintomas de ferrugem tropical (TR), ferrugem polissora (SR), cercosporiose (GLS), helmintosporiose (NLB), mancha marrom (PBS) e mancha branca (PLS); 2) identificar linhagens resistentes e suscetíveis com base nos parâmetros de adaptabilidade e estabilidade fenotípica para os sintomas de cercosporiose, helmintosporiose, mancha marrom e mancha branca; 3) identificar as melhores datas de semeadura, com a maior ocorrência das doenças, para fins de avaliação de linhagens e outros genótipos para resistência. Cinquenta linhagens, derivadas de populações com grãos flint e dent, foram avaliadas em blocos casualizados com três repetições, aos 45, 60, 75 e 90 dias após a semeadura em duas épocas, para medição da AACPD. Para a análise de adaptabilidade e estabilidade, 41 linhagens foram avaliadas em blocos casualizados com três repetições, 30 dias após o florescimento feminino, em onze épocas de semeadura, usando o método de análise de regressão. Foram atribuídas notas de 1, 2, 3, 4, 5, 6, 7, 8 e 9 correspondendo a 0, 1, 10, 20, 30, 40, 60, 80 e > 80% de área foliar com sintomas de doença. Para a AACPD, a análise de variância conjunta foi significativa para TR, SR, GLS e PLS e a interação linhagens x épocas foi significativa para ferrugem tropical e polissora. Para GLS e NLB as 41 linhagens foram classificadas como resistentes, sendo que as maiores severidades de doenças ocorreram nas semeaduras entre Junho e Setembro. As linhagens IVF1-3, IVF1-7, IVF1 -9, IVF1-10, IVF1 -11, IVF1 -25, IVF1-230, IVD1-2, IVD1 -2-1, IVD1-3, IVD1-9, IVD1 -12, 2F, 3F, 6F, 9F, 10F, 4C, 2D e 7D foram classificadas como resistentes para as doenças estudadas, sendo indicadas para o desenvolvimento de sintéticos. Para a mancha marrom e mancha branca, as semeaduras de Abril, Junho, Julho e Agosto apresentaram maiores severidades de doenças. As linhagens IVD1-9, IVD1-10, 7D, 10D e 2F podem ser indicadas no desenvolvimento de sintéticos resistentes. / Corn is one of the most widely cultivated crops in the worldwide. The incidence and severity of diseases affecting crops have increased significantly in the past years, leading to yield losses and affecting grain quality. Many studies have been carried out with the attempt to identify hybrids that are resistant to the main diseases, but few reports have studied inbred lines. Therefore, the objectives of this study were: 1) identify resistant and susceptible inbred lines based on the area under disease progress curve (AUDPC) for tropical rust, southern rust, gray leaf spot, northern leaf blight, physoderma brown spot and phaeosphaeria leaf spot; 2) identify resistant and susceptible inbred lines based on adaptability and stability parameters for symptoms of gray leaf spot (GLS), northern leaf blight (NLB), physoderma brown spot (PBS) and phaeosphaeria leaf spot (PLS); 3) identify the best planting dates, with the highest occurrence of diseases, for the purpose of evaluating inbred lines and other genotypes for resistance. For AUDPC, fifty inbred lines, derived from populations with flint and dent grains, were evaluated in randomized block designs with three replications, at 45, 60, 75 and 90 days after planting in two seasons. For the analysis of adaptability and stability, forty-one inbred lines were evaluated in randomized blocks with three replications, 30 days after silking, in eleven planting dates, using regression analysis method. The scale of scores from 1, 2, 3, 4, 5, 6, 7, 8 and 9 corresponding to 0, 1, 10, 20, 30, 40, 60, 80 and > 80% of leaf area with disease symptoms was used. For AUDPC, the joint analysis of variance was significant for TR, SR, GLS and PLS, while the interaction inbred lines x environments, was significant for TR and SR. For GLS and NLB, forty-one inbred lines were classified as resistant and the highest severities of diseases occurred in planting dates between June and September. The inbred lines IVF1-3, IVF1-7, IVF1 -9, IVF1-10, IVF1 -11, IVF1 -25, IVF1-230, IVD1-2, IVD1 -2-1, IVD1-3, IVD1-9, IVD1 -12, 2F, 3F, 6F, 9F, 10F, 4C, 2D and 7D were classified as resistant to the diseases studied and are indicated to produce synthetics. For PBS and PLS, the plating dates of April, June, July and August showed higher disease severity. The inbred lines IVD1-9, IVD1-10, 7D,10D and 2F may be indicated to produce synthetics.

Orientador: João Antonio da Costa Andrade / Resumo: O milho é uma das culturas mais extensamente cultivadas em todo mundo. A incidência e a severidade de doenças têm aumentado significativamente nos últimos anos acarretando perdas no rendimento e afetando a qualidade dos grãos. Muitos trabalhos têm sido desenvolvidos na tentativa de identificar híbridos resistentes às principais doenças que acometem a cultura do milho, mas poucos são os relatos de estudos com linhagens. Dessa forma, o objetivo deste estudo foi: 1) identificar linhagens resistentes e susceptíveis com base na área abaixo da curva de progresso de doenças (AACPD) para os sintomas de ferrugem tropical (TR), ferrugem polissora (SR), cercosporiose (GLS), helmintosporiose (NLB), mancha marrom (PBS) e mancha branca (PLS); 2) identificar linhagens resistentes e suscetíveis com base nos parâmetros de adaptabilidade e estabilidade fenotípica para os sintomas de cercosporiose, helmintosporiose, mancha marrom e mancha branca; 3) identificar as melhores datas de semeadura, com a maior ocorrência das doenças, para fins de avaliação de linhagens e outros genótipos para resistência. Cinquenta linhagens, derivadas de populações com grãos flint e dent, foram avaliadas em blocos casualizados com três repetições, aos 45, 60, 75 e 90 dias após a semeadura em duas épocas, para medição da AACPD. Para a análise de adaptabilidade e estabilidade, 41 linhagens foram avaliadas em blocos casualizados com três repetições, 30 dias após o florescimento feminino, em onze épocas de semeadura, us... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

The thesis deals with important pathogens affecting winter wheat, in particular the speckled glume and leaf blotch on wheat(Phaeosphaeria nodorum), septoria leaf blotch on wheat(Mycosphaerella graminicola)and tan spot on wheat(Pyrenophora trtici-repentis. It outlines the biology, symptoms that appear on wheat plants, and economic importance of these diseases and emphasizes the climatic conditions needed for their development and spread .The conclusion sumarizes the occurence data of the above-mentioned 3 diseases from 3 production(corn, beetroot and potato) areas and 4 districts (2 Moravian and 2 Bohemian districts per each production area) in the period of 1971 to 2010 and compares their frequency of occurrence. That work also includes the occurrence data of the diseases from 2012 when their occurrence on winter wheat was monitored at the training experimental station of the Mendel University in Brno in Žabčice.