Título:	Epidemiologia comparativa de mancha alvo da soja no Cerrado brasileiro
Outros títulos:	Comparative epidemiology of soybean target spot in the Neotropical Savanna
Autor(es):	Costa, Érica de Castro
Orientador(es):	Café Filho, Adalberto Corrêa
Assunto:	Corynespora cassiicola Soja - doenças e pragas Mancha alvo - morfométrica Soja - produtividade agrícola
Data de publicação:	13-abr-2021
Data de defesa:	20-nov-2020
Referência:	COSTA, Érica de Castro. Epidemiologia comparativa de mancha alvo da soja no cerrado brasileiro. 2020. 68 f., il. Dissertação (Mestrado em Fitopatologia)—Universidade de Brasília, Brasília, 2020.
Abstract:	Brazil is the world's largest soybean (Glycine max) producer, with cultivated areas ranging from the Country's Northern region to its Southern border. The largest producing area is located in the Cerrado, the South American Neotropical Savanna. Yield limiting factors of this crop include abiotic components and biotic factors. In the past several growing seasons soybean target spot, caused by Corynespora cassiicola, formerly considered a secondary disease for many years, has increased in importance in the Cerrado region of the Brazilian Midwest. However, few epidemiological studies have been completed on this pathosystem. Therefore, the objectives of this study were: I) to compare the development of soybean target spot in the Cerrado regions of the Federal District (DF) and the state of Bahia (BA), relating the macro and microclimate parameters in each region with the disease; II) to examine the response patterns of soybean cultivars to target spot in both regions, and determine their respective disease latent periods under controlled conditions; III) to relate the severity of the disease to losses in productivity; IV) to verify the cross-reaction of soybean and cotton C. cassiicola isolates to each host species. Ten commercial soybean cultivars were tested in Planaltina, DF and Luís Eduardo Magalhães, BA, Brazil, during the 2019/2020 harvest season. The same cvs. were also tested in greenhouses with artificial inoculation with C. cassiicola in two trials, spring/summer and autumn/winter. The total precipitation recorded during the field experiments was much higher in DF (818.7 mm) than in BA (460 mm), while the temperature was about 5 oC cooler with less extremely hot days. The daytime range in relative humidity was larger in BA than in DF. Greater intensity of the disease was observed in the DF crop, reaching 48% disease incidence and 19% disease severity at season’s end. Treatments with fungicide applications reduced disease intensities only in the DF trial. The field experiments allowed the separation of the cultivars into four groups, according to the patterns of susceptibility to target spot: highly susceptible, susceptible, moderately resistant, and resistant. The cv. CD2827 was considered the most susceptible to the disease, while cvs. C2811, C2830, and C2834 were the most resistant. In the greenhouse there was a higher intensity of the disease in the spring/summer trial with an average severity of 17%, while in autumn/winter no cv. reached 5%. Duration of the cultivars ́ latent periods were generally correlated with the resistance response. The environmental differences recorded during the trials are the probable causes for the expressive lower disease levels recorded in the field in BA and in the greenhouse in the autumn/winter trial. A negative relationship was found between severity and yield. In the cross-inoculation studies isolates of soybean and cotton were able to infect both hosts, but differences in aggressiveness were detected.
Unidade Acadêmica:	Instituto de Ciências Biológicas (IB) Departamento de Fitopatologia (IB FIT)
Informações adicionais:	Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Fitopatologia, 2020.
Programa de pós-graduação:	Programa de Pós-Graduação em Fitopatologia
Licença:	A concessão da licença deste item refere-se ao termo de autorização impresso assinado pelo autor com as seguintes condições: Na qualidade de titular dos direitos de autor da publicação, autorizo a Universidade de Brasília e o IBICT a disponibilizar por meio dos sites www.bce.unb.br, www.ibict.br, http://hercules.vtls.com/cgi-bin/ndltd/chameleon?lng=pt&skin=ndltd sem ressarcimento dos direitos autorais, de acordo com a Lei nº 9610/98, o texto integral da obra disponibilizada, conforme permissões assinaladas, para fins de leitura, impressão e/ou download, a título de divulgação da produção científica brasileira, a partir desta data.
Agência financiadora:	Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).
Aparece nas coleções:	Teses, dissertações e produtos pós-doutorado

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