Data/hora: 05/06/2024 13:02:49

Biblioteca(s): | Embrapa Soja.
Data corrente: | 16/10/1992
Data da última atualização: | 27/10/2004
Autoria: | YORINORI, J. T.
Afiliação: | Embrapa Soja, Londrina, PR.
Título: | Frogeye leaf spot of soybean (Cercospora sojina Hara).
Ano de publicação: | 1989
Fonte/Imprenta: | In: CONFERENCIA MUNDIAL DE INVESTIGACION EN SOJA, 4., 1989, Buenos Aires. Actas... Buenos Aires: AASOJA, 1989.
Volume: | t.3
Páginas: | p.1275-1283.
Idioma: | Inglês
Conteúdo: | Frogeye leaf spot caused by Cercospora sojina, is one of the most traditional and conspicuous soybean diseases. Its wind and seed-borne nature offer great advantage over most soybean pathogens for quick dispersal. Once introduced, the fungus can survive on crop residues or on stored seed. For an outbreak to occur, the fungus require high temperature (25-35oC) and humidity, and susceptible cultivars. Currently, it is the most destructive disease in Central Brazil. In 1987/88 crop season an estimated half million tons of soybeans were lost due to the disease in the area. Temperatures below 20oC restrict germination and sporulation, resulting in slow disease development. Races of the pathogen (more than 20 in Brazil and 12 in the U.S.A.) have been identified and their number seems to depend on the intensity of sampling. Several races may be present in a region on commonly grown susceptible cultivars and a race may occur in a wide geographical area. Resistance to C. sojina is controlled by single dominant genes but reaction among genotypes have ranged from field immunity (ex. cv. Davis) to high susceptibility (ex. cv. Bragg). Resistance has been quite stable with occasional breakdown (cv. Santa Rosa was resistant for more than 20 years). Expansion of soybean production in Tropical and subtropical countries, often with susceptible cultivars, may be subject to severe losses. Resistant cultivars and seed treatment with fungicides are the most efficient means to avoid losses and introduction of the pathogen to new areas...
Palavras-Chave: | Brasil; Disease; Fitopatologia; Fungus; Phytopathology; Resistance; Soybean.
Thesagro: | Cercospora Sojina; Doença; Fungo; Melhoramento; Resistência; Soja.
Thesaurus Nal: | Brazil; breeding.
Categoria do assunto: | --
Registro original: | Embrapa Soja (CNPSO)