La hernie est une maladie racinaire affectant les Brassica, causée par Plasmodiophora brassicae. Le déploiement de variétés présentant des facteurs génétiques de résistances est le moyen de lutte principal contre cette maladie. Toutefois, l’efficacité de ces variétés résistantes dans les nouveaux systèmes d’agriculture durable, à bas intrant azoté, est encore à évaluer. Dans ce contexte, les questions de recherche posées dans cette thèse sont les suivantes : i) La modulation de la résistance à la hernie par la réduction de l’apport azoté est-elle génotype/isolat dépendante ? ii) Y-a-t-il un effet de la réduction des apports azotés sur l’architecture génétique de la résistance à la hernie chez le colza ? iii) Quels sont les réponses transcriptomiques et métabolomiques impliquées dans la réduction du développement des symptômes en condition de carence azotée ? Le criblage de la réponse de nombreux génotypes de colza vis-à-vis de plusieurs isolats de P. brassicae a été réalisé dans deux conditions de fertilisation azotée (8 mM et 1 mM de nitrate). Basé sur ces expériences, le contrôle génétique du développement des symptômes et de la production des spores de repos lors de l’infection par deux isolats (eH et K92-16) a été étudié par génétique de liaison chez une population biparentale et par génétique d’association chez un panel de colza d’hiver. Enfin, les réponses moléculaires impliquées dans la réduction du développement des symptômes observée chez le génotype ‘Yudal’ en condition 1mM ont été étudiées par des méthodes de RNA-seq et de métabolomique. L’impact de la fertilisation azotée sur la quantité de symptômes et la production de spores de repos est variable selon la combinaison génotype/isolat. Les modulations observées entraînent une augmentation de la résistance en condition 1mM. La fertilisation azotée module également l’effet (R2) de certains des Quantitative Trait Loci (QTL) impliqués dans la résistance. Dans le cas de l’isolat eH, elle affecte principalement l’effet des QTL C09 et C02. L’augmentation de résistance observée chez le génotype ‘Yudal’ en condition 1mM, vis-à-vis de l’isolat eH, semble liée à la surexpression de gènes impliqués dans l’assimilation des nitrates (famille NRT2) et dans le transport de l’auxine. / Clubroot is a Brassica root disease caused by Plasmodiophora brassicae. The use of varieties including genetic resistance factors is the most efficient strategy to manage clubroot disease. However, efficiency of these resistant varieties newly integrated in low-input agricultural systems (especially low nitrogen input) needs to be evaluated. In this context, the research questions investigated in this thesis are: i) Is clubroot resistance modulation by nitrogen fertilization genotype/isolate dependent? ii) Is there an effect of nitrogen fertilization reduction on the genetic architecture of clubroot resistance in rapeseed? iii) What are the transcriptomic and metabolomic responses implicated in symptom reduction under low nitrogen fertilization? To answer these questions, clubroot responses of several rapeseed genotypes were screened using different P. brassicae isolates under two nitrogen fertilizations (8mM and 1mM of nitrate). Based on this experiment, genetic control of symptom development and resting spore production during inoculation using two isolates (eH and K92-16) was studied by linkage analyses using a bi-parental population and by genome wide association using a winter rapeseed diversity set. Last, molecular responses implicated in symptom development, observed in ‘Yudal’ genotype under 1mM condition, were studied using RNA-seq and metabolomic methods. We revealed that impact of nitrogen fertilization on symptom quantity and resting spore production are dependent to genotype/isolate combination. Modulations observed were characterized by an increase of resistance under 1mM condition. Additionally, nitrogen fertilization modulates also the effect (R²) of some Quantitative Trait Loci implicated in clubroot resistance (QTL). Using eH isolate, nitrogen fertilization principally impacts C09 QTL and C02 QTL effects. Ultimately, increase of resistance observed on ‘Yudal’ genotype under 1mM condition, using eH isolate, seems to be related with overexpression of genes implicated in nitrate assimilation (NRT2 family) and auxin transport.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-09-06T18:21:23Z No. of bitstreams: 1 2017 - Carlos Ant?nio dos Santos.pdf: 1589290 bytes, checksum: fbf16019cb63898c65e615c045d17094 (MD5) / Made available in DSpace on 2018-09-06T18:21:23Z (GMT). No. of bitstreams: 1 2017 - Carlos Ant?nio dos Santos.pdf: 1589290 bytes, checksum: fbf16019cb63898c65e615c045d17094 (MD5) Previous issue date: 2017-02-17 / CAPES / CNPq / FAPERJ / The search for efficient strategies to reduce the losses caused by clubroot (Plasmodiophora brassicae) in cauliflower is essential due to the economic and social importance of this culture. Thus, the present study was developed with the objective of evaluating the effect of different treatments in the control of the disease, root development, biomass and inflorescences production under field and greenhouse conditions. The study consisted of three trials carried out in a family farmer's area in the municipality of Nova Friburgo, RJ, Brazil. In the first trial, it was tested the residual effect of four doses of calcined limestone (0, 1.0, 2.0 and 4.0 Mg.ha-1) associated to the application of Trichoderma harzianum biofungicide under field conditions. In the second trial, it was tested the effect of the liming associated to the application of T. harzianum and cyazofamid, under greenhouse conditions. In the third one, two ways of applying limestone were tested, in the planting pit, and applied by hand. The use of gypsum was evaluated in the field. The increase of the limestone doses promoted higher pH levels, and Ca+2 contents, and reduction of the toxic Al + 3 contents in the soil. There was also a reduction of root volume with galls, greater root development, and productivity in cauliflower. The use of T. harzianum was not effective to control the disease and did not favor the root development, either in field or in greenhouse conditions. The fungicide cyazofamid reduced the volume roots with galls, the severity, and the progression of the disease. The third rial revealed a discrete reduction in the severity of the disease when using limestone and gypsum combined. Although there was no effect of the treatments on the root system, limestone applied to the pit and by hand resulted in greater accumulations of fresh mass of inflorescence and productivity. The application of limestone by hand, in the pit, and combined with gypsum favored the accumulation of calcium in the plants. The application of limestone in the pit was equivalent to the hand application in terms of soil chemical attributes improvement, reduction of disease severity, and increase of productivity and accumulation of nutrients. / A busca por estrat?gias eficientes na redu??o das perdas causadas pela h?rnia das cruc?feras (Plasmodiophora brassicae) em couve-flor ? essencial devido ? import?ncia econ?mica e social dessa cultura. Com isso, desenvolveu-se o presente estudo com o objetivo de avaliar, em condi??es de campo e casa de vegeta??o, o efeito de diferentes tratamentos no controle da doen?a, desenvolvimento das ra?zes e produ??o de biomassa e infloresc?ncias em couve-flor. O trabalho foi constitu?do de tr?s ensaios realizados em ?rea de produtor familiar no munic?pio de Nova Friburgo, RJ. No primeiro ensaio, avaliou-se o efeito residual de quatro doses de calc?rio calcinado (0; 1,0; 2,0 e 4,0 Mg.ha-1), associado ? aplica??o de biofungicida a base de Trichoderma harzianum, em condi??es de campo. No segundo, avaliou-se o efeito da calagem associada ? aplica??o de T. harzianum e ciazofamida, em casa de vegeta??o. No terceiro, avaliou-se em campo duas formas de aplica??o de calc?rio, na cova e ? lan?o, e o uso de gesso agr?cola. O aumento das doses de calc?rio promoveu eleva??o do pH e dos teores de Ca+2 e redu??o do teor de Al+3 t?xico no solo. Ainda, houve redu??o do volume de ra?zes com h?rnias e maior desenvolvimento radicular e produtividade em couve-flor. O uso de T. harzianum n?o foi eficaz no controle da doen?a e n?o favoreceu o desenvolvimento radicular das plantas, seja nas condi??es de campo ou de casa de vegeta??o. O fungicida ciazofamida reduziu o volume de ra?zes doentes, a severidade e a progress?o da doen?a. Constatou-se no terceiro ensaio discreta redu??o da severidade da doen?a com o uso de calc?rio combinado com gesso. N?o houve efeito dos tratamentos sobre o sistema radicular, entretanto, calc?rio aplicado na cova e ? lan?o resultaram em maiores ac?mulos de massa fresca de infloresc?ncia e produtividade. A aplica??o de calc?rio ? lan?o, na cova, e calc?rio combinado com gesso favoreceram o ac?mulo de c?lcio nas plantas. O uso de calc?rio na cova foi equivalente ? sua aplica??o ? lan?o quanto a melhorias dos atributos qu?micos do solo, redu??o da severidade da doen?a, aumento da produtividade e ac?mulo de nutrientes.

No description available.

Composting trials were undertaken to study the feasibility of using crucifer or carrot residues with straw or sawdust for composting. Compost temperature and moisture were monitored regularly, and compost samples were analyzed for physico-chemical characteristics at the beginning in the fall, before turning in spring, and at the end of each composting cycle. A geotextile cover was tested. Compost leachate volumes were measured throughout the two composting cycles. In addition, the leachate was submitted to phytotoxicity tests and physico-chemical analyses. Selected phytopathogens were introduced in the compost in order to assess their potential for survival during the composting process. Three pathogens having resistant survival structures were included: Plasmodiophora brassicae, Fusarium oxysporum f.sp. cucumerinum , and Sclerotinia sclerotiorum. Greenhouse growth trials were performed with compost-enriched media and a commercial mix. (Abstract shortened by UMI.)

Relationships between two taxonomic kingdoms; plants and herbivorous insects, are hypothesized to be a major zone of interaction for generating current day biodiversity; and coevolutionary processes between these intricately linked organisms are hypothesized to maintain diversity in plant secondary chemistry. These metabolites play a key role in plant defence against herbivory and a high degree of intraspecific variation is observed at multiple ecological scales. However, the nature of selection maintaining variation in plant defence profiles is still a major question in evolutionary biology and ecology, and progress towards a deeper understanding is hampered by a lack of studies that take into account ecological context and the multivariate nature of plant defence phenotypes. In this thesis, I employ sophisticated chemical analysis techniques to identify a suite of glucosinolate secondary chemicals, representing different biosynthetic pathways, in the wild cabbage, Brassica oleracea, in natural populations in the UK. I used model-based cluster analysis to explore patterns of association between individual glucosinolates, predicting that as simultaneous resource allocation to multiple defences is likely to be constrained; negative associations between defensive traits should be observed. However, results revealed positive associations between glucosinolates. Therefore co-expression of multiple defences may not be costly for this species. Using this information in conjunction with herbivore surveys and experiments, I show that this mixture has the potential to shape patterns of herbivore abundance and host plant utilization: species-specific responses to variation in glucosinolate phenotypes are discovered at various ecological scales. Thus there is the potential for differential selection on plant chemotypes though species-specific attractions and aversions. By conducting fine scale experiments with herbivore species, I also found that glucosinolate variation has an impact on the counter-adaptations that some brassica specialists have evolved: in order to optimally defend against their own natural enemies, Brevicoryne brassicae aphids sequestering glucosinolates from their host plants must do so selectively, and must choose plants whose chemical profile best matches this behaviour. These findings show that glucosinolate profiles may be under natural selection by herbivores in wild populations, and that reciprocal evolution between these plants and their specialists may continue to promote diversity in secondary metabolites. Together these results highlight the complexity inherent in plant-insect interactions, the importance of field studies and generate a wealth of testable hypotheses for future work.

No description available.

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-17T14:46:49Z No. of bitstreams: 1 Cicero Nicolini.pdf: 204101 bytes, checksum: 7157eb0dfbcf608b64b0ae9bbbaf5c05 (MD5) / Made available in DSpace on 2017-02-17T14:46:49Z (GMT). No. of bitstreams: 1 Cicero Nicolini.pdf: 204101 bytes, checksum: 7157eb0dfbcf608b64b0ae9bbbaf5c05 (MD5) Previous issue date: 2008-03-03 / The Alternaria black spot is one of the most common and destructive diseases of brassica species. This disease can be caused by several species of Alternaria, although A. brassicicola is predominant species in both conventional and organic crops in Brazil. Since commercial cultivars of brassica with acceptable levels of disease resistance are not available, the disease control in conventional production system is based on the fungicide applications, while in the organic production system the disease control on relays on cultural methods. The objective of this study is to assess the sensitivity of 112 isolates of A. brassicicola to fungicide groups: benzimidazoles (carbendazim), dicarboximides (iprodione), triazoles (tebuconazole) and strobilurines (azoxystrobin). The isolates were evaluated in vitro to obtain the concentration capable of inhibiting 50% of the mycelial growth (CL50) and separated in four classes depending on the sensibility to the tested fungicides. All the isolated of A. brassicicola were sensitive the iprodione, with CL50 values below to 0.1 mg i.a./L. Most of the isolates originating from conventional (92.9%) and organic (96.4%) were middling resistant the azoxystrobin, while an isolated (CFM-576) was highly resistant. In relation to tebuconazole, only isolated sensitive (42.9%) and lightly resistant (57.1%) were observed. There was nosignificant difference between the isolates of A. brassicicola originated either from conventional or organic systems and brassica types regarding the levels of sensitivity to the fungicides. / A alternariose é uma das doenças foliares mais comuns e destrutivas das brássicas, podendo ser causada por várias espécies de Alternaria, embora A. brassicicola seja a espécie predominante em plantios convencionais e orgânicos no Brasil. Como inexistem cultivares comerciais de brássicas com níveis aceitáveis de resistência à doença, no sistema de produção convencional o controle da doença se baseia na aplicação de fungicidas, enquanto no sistema orgânico em métodos culturais. O presente trabalho teve como objetivo avaliar a sensibilidade de 112 isolados de A. brassicicola oriundos de cultivos convencionais e orgânicos de brássicas a fungicidas dos grupos dicarboximidas (iprodione), triazóis (tebuconazole) e estrobilurinas (azoxystrobin). Os isolados foram avaliados in vitro visando obter a concentração capaz de inibir 50% do crescimento micelial (CL50) e separados em quatro classes dependendo da sua sensibilidade aos fungicidas testados. Todos os isolados de A. brassicicola foram sensíveis a iprodione, com valores de CL50 inferiores a 0,1 mg i.a./L. A maioria dos isolados oriundos de cultivos convencionais (92,9%) e orgânicos (96,4%) se comportou como medianamente resistente a azoxystrobin, enquanto um isolado (CFM-576) foi altamente resistente. Em relação a tebuconazole, foram constatados somente isolados sensíveis (42,9%) e ligeiramente resistentes (57,1%). Não foi encontrada diferença significativa quanto à sensibilidade aos fungicidas testados entre os isolados de A. brassicicola oriundos de cultivos convencionais e orgânicos, bem como, coletados de diferentes tipos de brássicas.

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-03-23T12:15:14Z No. of bitstreams: 1 Priscilla Anunciada Alves Moreira.pdf: 1192520 bytes, checksum: f783ff4175972095251ac5f078d7fe19 (MD5) / Made available in DSpace on 2017-03-23T12:15:14Z (GMT). No. of bitstreams: 1 Priscilla Anunciada Alves Moreira.pdf: 1192520 bytes, checksum: f783ff4175972095251ac5f078d7fe19 (MD5) Previous issue date: 2008-08-06 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The Alternaria black spot is considered one of the most common and destructive diseases of brassica, and although it may be caused by several species, Alternaria brassicicola is the predominant pathogen in both conventional and organic brassica crops in State of Pernambuco, Brazil. To assess the pathogenic variability of 120 isolates of A. brassicicola, was analyzed the virulence to brassica species, physiology aspects of the pathogen and sensitivity to fungicides. The isolates obtained from conventional and organic crops were inoculated under greenhouse conditions in 40 days old plants of broccoli, cabbage, cauliflower and Chinese cabbage and disease severity was assessed 10 days after the inoculation. Under laboratory conditions the following parameters were evaluated for all isolates: rate of growth mycelial, sporulation, and sensitivity to fungicides iprodione and tebuconazole. Based on the variables analyzed, it was found variability among isolates of A. brassicicola, but there were no significant (P>0.05) correlation among the analyzed variables, regardless of the cultivation system and the original host of each isolate. The variables were useful in distinguishing individual groups of isolated with similarity in virulence to the host, physiological characteristics and sensitivity to fungicides. The cross inoculations and the development of symptoms in brassica highlighted the absence of host specificity. All isolates weresensitive to the fungicides iprodione and tebuconazole. Based on the components of variance analysis, there was no significant effect of the cultivation system on the variables, except for disease severity on Chinese cabbage (P = 0.0391). Most of the variance results from the difference among isolates of A. brassicicola within the cropping systems and the host of origin. In the context multivariate, no effect was found regarding the host of origin of the isolates (P = 0.4993), however, there was great variability (P <0.0001) among isolates within the cropping systems and the host of origin. / A alternariose é considerada uma das doenças mais comuns e destrutivas das brássicas, e embora possa ser causada por várias espécies, Alternaria brassicicola é o agente patogênico predominante nos plantios convencionais e orgânicos de brássicas no Estado de Pernambuco, Brasil. Para avaliar a variabilidade patogênica de 120 isolados de A. brassicicola, foi analisada a virulência a espécies de brássicas, aspectos relacionados à fisiologia do patógeno e sensibilidade a fungicidas. Os isolados obtidos de cultivos convencionais e orgânicos foram inoculados em plantas de brócolis, couve-chinesa, couve-comum e couve-flor com 40 dias de idade, em casa de vegetação, onde a severidade da doença foi avaliada 10 dias após a inoculação. Em condições de laboratório, os isolados foram avaliados quanto a taxa de crescimento micelial, esporulação e sensibilidade aos fungicidas iprodione e tebuconazole. Com base nas variáveis analisadas, foi constatada a existência de variabilidade entre os isolados de A. brassicicola, mas não foram observadas correlações significativas (P=0,05) entre as variáveis avaliadas, independentemente do sistema de cultivo e do hospedeiro de origem dos isolados. As variáveis individuais foram úteis na distinção de grupos de isolados do patógeno com similaridade na virulência às hospedeiras, características fisiológicas e sensibilidade aos fungicidas. As inoculações cruzadas e o desenvolvimento de sintomas nas brássicas evidenciou a inexistência de especificidade por hospedeiro entre os isolados do patógeno. Todos os isolados foram sensíveis aos fungicidas iprodione e tebuconazole. Pela análise dos componentes de variância, não houve efeito significativo do sistema de cultivo sobre as variáveis analisadas, com exceção para severidade em couve-chinesa (P=0,0391). A maior parte da variância foi resultante da diferença entre os isolados de A. brassicicola dentro dos sistemas de cultivo e dos hospedeiros de origem. No contexto multivariado, não se constatou efeito do hospedeiro de origem dos isolados (P=0,4993), porém, houve grande variabilidade (P<0,0001) entre os isolados dentro dos sistemas de cultivo e dos hospedeiros de origem.

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-03-20T15:01:07Z No. of bitstreams: 1 Luiz Augusto Martins Peruch.pdf: 694087 bytes, checksum: 27f67eb702a71e64c5b03780e75fe68e (MD5) / Made available in DSpace on 2017-03-20T15:01:07Z (GMT). No. of bitstreams: 1 Luiz Augusto Martins Peruch.pdf: 694087 bytes, checksum: 27f67eb702a71e64c5b03780e75fe68e (MD5) Previous issue date: 2004-02-18 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The brassica cultivation has been of high importance in Brazil. However, the profitable crop production can be limited by occurrence of diseases such as Alternaria black spot, caused by Alternaria brassicicola and/or Alternaria brassicae, and black rot, caused by Xanthomonas campestris pv. campestris. In that context, the present study had as objectives to evaluate the intensity of Alternaria black spot and of black rot diseases on brassica under organic cultivation in the states of Pernambuco and Santa Catarina, and the spore production longevity of A. brassicicola in leaf debris of broccolis. The intensity of the diseases was evaluated from November 2001 to February 2002, in 103 fields under organic farming systems, including broccoli, Chinese cabbage, cauliflower, kale and cabbage. High prevalence of the diseases was registered in both states, except on Chinese cabbage in Santa Catarina. Prevalence of Alternaria black spot was 100% on broccoli fields in Pernambuco, as well as on cauliflower in the two states, while the black rot reached that level on broccoli and cauliflower fields in Santa Catarina. In the average of the different brassica species, the diseases were more prevalent in Pernambuco than in Santa Catarina. However, when considered severity averages of each disease, no significant differences were verified between the two states, although the climatic conditions have been sharply different. The levels ofdisease severity were low, considering that 98% of the fields presented severity lower than 5%. The Alternaria black spot severity varied among the brassica species in Pernambuco, being higher on Chinese cabbage and lower on kale. In Santa Catarina no significant differences were verified among the brássicas species. In relation to the black rot, only in Santa Catarina there was difference in the disease severity among the brassicas, being registered the lowest level on Chinese cabbage. No significant correlations were verified between severity levels of Alternaria black spot and black rot, neither between disease severity and total number of plants or plant age. The spore production longevity of A. brassicicola was investigated in leaves debris of broccoli, considering different depths of debris incorporation, periods of the year, and systems of soil handling, in two experiments carried out in Urussanga city, State of Santa Catarina, Brazil. Infected leaves debris of broccoli were conditioned in bags of polyethylene and distributed in portions in the field, on the soil surface and at depths of 5 and 10 cm. Periodically, the debris in the bags were collected and conidia concentrations were quantified for longevity of spore production andextinction rate. In both experiments there was higher spore production longevity in leaves debris in the period I, characterized by lighter temperatures, higher air relative humidity and lower pluvial precipitation than in the period II. Depth of debris incorporation influenced directly on A. brassicicola spores production, being lower when incorporation was made at 10 cm depth. In relation to soil handling systems, when the inoculum source was deposited on the soil surface there was not difference in the rate of spore production extinction between the soils under conventional and organic handling. However, at depths of 5 and 10 cm, the rate was significantly higher in the soil under conventional handling. The management of Alternaria black spot on broccoli at the area under study can be accomplished by integrated control, including the incorporation of infected leaves debris in the soil, at least 10 cm depth, along with crop rotation, for no less than a 60-day interval in subsequent brassica plantings. / O cultivo de brássicas tem destacada importância na olericultura brasileira. No entanto, a produção dessas olerícolas pode ser limitada pela ocorrência de doenças, dentre as quais se destacam a alternariose, causada por Alternaria brassicicola e/ou Alternaria brassicae, e a podridão negra, causada por Xanthomonas campestris pv. campestris. Nesse contexto, o presente estudo teve como objetivos realizar o levantamento da intensidade da alternariose e da podridão negra em cultivos orgânicos de brássicas nos Estados de Pernambuco e Santa Catarina, bem como avaliar a longevidade da esporulação de A. brassicicola em restos foliares de brócolis. Os levantamentos foram realizados no período de novembro de 2001 a fevereiro de 2002, num total de 103 cultivos orgânicos, incluindo brócolis, couve-chinesa, couve-flor, couve-manteiga e repolho. Foram registradas elevadas prevalências das doenças nos dois Estados, com exceção em couve-chinesa em Santa Catarina. A prevalência da alternariose foi de 100% nos cultivos de brócolis em Pernambuco, bem como em couve-flor nos dois Estados, enquanto a podridão negra atingiu esse nível nos cultivos de brócolis e couve-flor em Santa Catarina. Na média das diferentes espécies de brássicas, as doenças foram mais prevalentes em Pernambuco que Santa Catarina. Entretanto,quando consideradas as médias de severidade de cada doença no conjunto das brássicas, não foram constatadas diferenças significativas entre os dois Estados, embora as condições climáticas tenham sido nitidamente distintas. Os níveis de severidade das doenças foram baixos, tendo em vista que 98% dos cultivos apresentaram severidade inferior a 5%. A severidade da alternariose variou entre as espécies de brássicas em Pernambuco, com maior severidade registrada em couve-chinesa e menor em couve-manteiga, enquanto em Santa Catarina não foram constatadas diferenças significativas entre as brássicas. Em relação à podridão negra, somente em Santa Catarina houve diferença na severidade entre as brássicas, sendo registrados os menores níveis em couve-chinesa. Não foram constatadas correlações significativas entre os níveis de severidade da alternariose e da podridão negra, bem como da severidade destas com o número total de plantas e a idade das plantas nos cultivos. Foi também investigada a longevidade da esporulação de A. brassicicola em restos foliares de brócolis, considerando diferentes profundidades de incorporação dos restos, períodos do ano e sistemas de manejo do solo, em dois experimentos realizados em Urussanga - SC. Restosfoliares de brócolis infectados pelo patógeno foram acondicionadas em sacolas de polietilenoperfuradas e distribuídos em parcelas no campo, na superfície do solo e nas profundidades de 5 e 10 cm. Nos dois experimentos foi verificada uma maior longevidade da esporulação nos restos foliares no período I, caracterizado por temperaturas mais amenas, maior umidade relativa do ar e menor precipitação pluvial que no período II. A profundidade de incorporação dos restos influiu diretamente na esporulação de A. brassicicola, que foi inferior quando a incorporação foi efetuada a 10 cm de profundidade. Em relação aos sistemas de manejo, quando a fonte de inóculo foi depositada na superfície do solo não houve diferença na taxa de extinção da esporulação entre os solos sob manejo convencional e orgânico. No entanto, nas profundidades de 5 e 10 cm, essa taxa foi significativamente superior no solo sob manejo convencional. O manejo da alternariose em brócolis na região do estudo pode ser realizado pela combinação de vários métodos de controle, inclusive pela incorporação dos restos foliares infectados no solo, à profundidade mínima de 10 cm, combinado com rotação de culturas, visando um intervalo mínimo de 60 dias entre cultivos de brássicas.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2018-09-11T12:50:42Z No. of bitstreams: 1 2016 - Eduardo Spitz de Carvalho.pdf: 2778180 bytes, checksum: 34e805f58061af534403ec60b6659541 (MD5) / Made available in DSpace on 2018-09-11T12:50:42Z (GMT). No. of bitstreams: 1 2016 - Eduardo Spitz de Carvalho.pdf: 2778180 bytes, checksum: 34e805f58061af534403ec60b6659541 (MD5) Previous issue date: 2016-03-31 / The municipality of Nova Friburgo is an important producer of brassica, in the Alto Rio Grande region, mainly cauliflower. This culture of great economic value has suffered with the incidence of clubroot causing huge losses, reaching 100% loss. For the prevention of the disease, it is necessary to understand that there is imbalance on the environment and that a change in the soil and crop management is crucial. In the region, young people have great importance in the production process and many of them study in technical courses offered by CEFFA (Centro Familiar de Forma??o por Altern?ncia) Col?gio Estadual Agr?cola (CEA) Rei Alberto I. The courses offered at the school work with the Pedagogy of Alternation. The aim of this study was to build with farmers and their children brassica crop management opportunities for minimizing impact of clubroot disease, with the association of local and academic knowledge. Therefore, we applied two questionnaires, one with 123 students from CEFFA CEA Rei Alberto I to the selection of the Production Units who grow brassicas and present incidence of clubroot, the other one, with 48 students, seeking to characterize the production systems, as for the topography, the main crops, and management strategies used to control the disease. At the end we selected eight production units (PUs) in different watersheds, distributed in the territorial space of the 3rd district, which were characterized by the history of clubroot in the production area, the forms of tillage, acidity correction and fertilization, seedlings source, planting season, crop rotation strategies, source of irrigation water and established strategies for coexistence with clubroot. Later, there were quality assessments of the soil, the health of crops and the potential for clubroot with students and their parents in each of the UPs. Soil samples were collected for fertility analysis. Then, there was a return of the reviews for farmers so they exchanged their joining knowledge. The management practices identified in the production units (PUs) evaluated in the 3rd District of Nova Friburgo- RJ have contributed to the spread and incidence of the disease. To live with the disease a change in the local production system design is necessary, pointing to new strategies regarding the encouragement of biotic and nutritional balance of soil and crop over the pathogen. The use of indicators to assess the local impact of potential hernia of cruciferous was efficient to point out the bottlenecks in the production of brassica system against the disease. The highly acidic pH and low Ca++ content in the soil, associated with frequent mechanization without cleaning the equipment might explain the high incidence of clubroot in the production units. The PUs require monitoring over time through evaluations of agro-ecosystems, using the tools presented in this study, as well as actions aimed at promoting the indicators towards sustainability, thus leading to the balance of soil, crops and biota / O munic?pio de Nova Friburgo ? importante produtor de br?ssicas na regi?o do Alto Rio Grande, principalmente, couve-flor. Esta cultura de grande valor econ?mico para o munic?pio vem sofrendo com a incid?ncia da h?rnia das cruc?feras com preju?zos de at? 100% de perda. Para preven??o da doen?a ? necess?rio o entendimento de que h? desequil?brio no ambiente e que a mudan?a no manejo do solo e da cultura ? imprescind?vel. Na regi?o, os jovens t?m grande import?ncia no processo de produ??o e grande parte desses estuda em cursos t?cnicos no CEFFA (Centro Familiar de Forma??o por Altern?ncia) Col?gio Estadual Agr?cola (CEA) Rei Alberto I, que funcionam com a Pedagogia da Altern?ncia. O objetivo desse trabalho foi construir participativamente junto aos agricultores e seus filhos possibilidades de manejo de cultivo de br?ssicas para o conv?vio com a doen?a h?rnia das cruc?feras, a partir da associa??o de conhecimentos locais e acad?micos. Para tanto, aplicou-se dois question?rios, um com os 123 alunos do CEFFA CEA Rei Alberto I para a sele??o das Unidades Produtivas que cultivam br?ssicas e que apresentam incid?ncia de h?rnia, o outro com 48 desses alunos, buscando caracterizar os sistemas de produ??o, quanto ao relevo, principais cultivos, e estrat?gias de manejo utilizadas para o controle da h?rnia. Ao final foram selecionadas oito unidades de produ??o (UPs) em diferentes microbacias, distribu?das no espa?o territorial do 3? distrito, as quais foram caracterizadas, quanto ao hist?rico da h?rnia das cruc?feras na ?rea de produ??o, formas de preparo do solo, corre??o da acidez e aduba??o, origem das mudas, ?poca do ano de plantio, estrat?gias de rota??o de cultivos, a origem da ?gua de irriga??o e as estrat?gias estabelecidas para a conviv?ncia com a h?rnia das cruc?feras. Posteriormente, foram avaliadas a qualidade do solo, a sanidade dos cultivos e a potencialidade para a h?rnia das cruc?feras, com os alunos e seus pais em cada UP. Foi coletado solos para an?lise de fertilidade. Posteriormente, foram retornadas as avalia??es para que os agricultores trocassem seus saberes. As pr?ticas de manejo identificadas nas unidades de produ??o (UPs) avaliadas do 3? Distrito de Nova Friburgo contribuem para dissemina??o e incid?ncia da doen?a. Para conviv?ncia com a doen?a deve ser mudada a concep??o do sistema produtivo local, apontando para novas estrat?gias para favorecimento do equil?brio bi?tico e nutricional do solo e das culturas em detrimento ao pat?geno. O uso de indicadores para avaliar a potencialidade de incid?ncia local da h?rnia das cruc?feras apontou os gargalos no sistema produtivo de br?ssicas em rela??o a doen?a. Os valores de pH, fortemente ?cidos, e os baixos teores de Ca no solo, associados a mecaniza??o frequente e sem limpeza dos equipamentos explicam a alta incid?ncia da h?rnia das cruc?feras nas unidades produtivas. As UPs necessitam acompanhamento ao longo do tempo, com avalia??es dos agroecossistemas, usando ferramentas como as apresentadas neste estudo, assim como a??es para promo??o dos indicadores no sentido da sustentabilidade, logo o equil?brio do solo, dos cultivos e da biota