Disease progress of soybean bud blight and spatial pattern of diseased plants.

• Autor(a) principal: ALMEIDA, A. M. R.
• Data de Publicação: 1994
• Outros Autores: BERGAMIN FILHO, A., AMORIM, L.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/458775
• topic: Fitopatologia; Distribuicao espacial; Desenvolvimento temporal; Brasil; Soybean; Phytopathology; Disease; Bud blight; Spatial pattern; Temporal development; Doença; Epidemiologia; Queima do Broto; Soja; Vírus; Brazil; epidemiology

Fourteen epidemics of soybean bud blight, caused by the tobacco streak virus, were monitored in two soybean cultivars ('IAC-4' and 'FT-10') for two years (1987 and 1988) at Arapoti County, state of Parana, southern Brazil. Disease incidence, based on different sowing dates, were analyzed for statistical fitness in several growth models. Ten epidemics were better described by the monomolecular model, while four epidemics were better described by the Gompertz model. The highest final level of disease incidence was y((f))= 0.6 in 1987 and 0.9 in 1988. There were no significant differences between the cultivars in relation to susceptibility. Early-crops always presented more disease than late-crops. The spatial patterns of diseased plants also changed according to sowing dates as determined by ordinary runs analysis. Diseased plants in early sowings had a random pattern, at first, later becoming clustered (Z below -1.64). In late sowings, diseased plants always had a random pattern.