Data/hora: 24/06/2024 20:30:08

Biblioteca(s): | Embrapa Agropecuária Oeste; Embrapa Soja.
Data corrente: | 15/07/1998
Data da última atualização: | 16/09/2019
Autoria: | MACHADO, C. C.
Título: | Macrophomina phaseolina: biological behavior of isolates, spatial pattern of microsclerotia in the soil, and incidence on soybeans.
Ano de publicação: | 1987
Fonte/Imprenta: | Urbana: University of Illinois at Urbana-Champaign, 1987.
Páginas: | 195p.
Idioma: | Inglês
Notas: | Ph.D. Thesis.
Conteúdo: | Twelve isolates of Macrophomina phaseolina (Tassi) Goid. from different plants hosts and/or geographical locations were compared. All isolates were pathogenic to their original host and to soybean cultivar Corsoy 79. Only six isolates produced pycnidia on soybean meal agar. Production of pycnidium and size of conidia varied significantly (P-0.05) among sporulating isolates. Starch gel electrophoresis indicated similarities in isozyme production among isolates. The 12 isolates did not fit the three category classification of Pearson, et al. based on characteristics on potassio chlorate medium. A clustered pattern of microsclerotia of M. phaseolina in soil was found within 96 3 x 3 m quadrats located in an area grown in continuous soybeans for over 20 years. Results over 3 years indicated variation in the microscletial numbers as well as patterns in the soil among years. Evaluation of 12 soybean cultivars from maturity groups II, III, and IV grown in these quadrats indicated lower incidence of M. phaseolina on late-maturing cultivars than on early-maturing ones. There was no correlation between the number of microsclerotia in the soil and disease incidence on the cultivars. Two methods were used to evaluate incidence of M. phaseolina on two soybean cultivars grown under two cropping sequences, six tillage systems, and two row spacings in the 1983, 1984, 1985, and 1986 growing seasons. Field evaluation was not accurate in determining incidence of M.phaseolina. The incidence of the fungus was significantly higher on stem pieces after treatment with paraquat than on those not treated in the field. Tillage did not affect the incidence of M. phaseolina in continuous soybeans and had little effect in maize-soybean rotation plots. A higher incidence was found on soybean cultivar Corsoy 79 than Cumberland. The effect of row spacing on incidence of the fungus was significant in maize-soybean rotation plots but not in continuous soybeans. The overal incidence of M. phaseolina in the maize-soybean rotation plots did not differ significantly from that in continuous soybeans. Differences in the incidence between years were due to variation in rainfall and temperature during the growing seasons.
Palavras-Chave: | Biological behavior; Comportamento biologico; Disease; Doenca, Fitopatologia; EUA; Fitopatologia; Phytopathology; Soybean; USA.
Thesagro: | Doença; Fungo; Macrophomina Phaseolina; Soja.
Thesaurus Nal: | fungi.
Categoria do assunto: | --
Registro original: | Embrapa Soja (CNPSO)

Exemplares:

CNPSO - (1104-1) - UPC - TS - PP - 2/87 -  - 2/87 - DIS
CPAO - (32585-1) - ADD - TS - PP - T 11/87 -  - 89.00033 - DIS