Adjuvant concentrations and uredospore densities on Phakopsora pachyrhizi infection efficiency in soybean

Summa Phytopathologica

Tiago Zanatta¹  Erlei Melo Reis¹  Mateus Zanatta¹ 

[1] ,Universidade de Passo Fundo Faculdade de Agronomia e Medicina Veterinária Passo Fundo RS

关键词: Leaflet incidence;    lesion density;    Asian soybean rust;    Glycine max;    Folíolos;    densidade de lesões;    ferrugem asiática da soja;    Glycine max;   

DOI  :  10.1590/S0100-54052012000200007

来源: SciELO

【 摘 要 】

Experiments were carried out in a growth chamber to evaluate the effect of spreader and uredospore concentrations on the efficiency of infection by Phakopsora pachyrhizi, the causal agent of Asian soybean rust. CD 214 RR soybean cultivar was inoculated with the following polyoxyethylene sorbitane monolaurate concentrations: 0, 30, 60, 120, 240, 480 and 960 µL.L-1 water, as well as a fixed uredospore concentration of 2 x 10(4) spores.mL-1. In a second phase, the inoculum concentrations of 0, 5 x 10³, 1 x 10(4), 2 x 10(4), 4 x 10(4), 8 x 10(4) and 16 x 10(4) uredospores.mL-1 were evaluated, and the spreader concentration of 240 µL.L-1, selected in the previous experiment, was fixed. The spreader concentration of 240 µL.L-1 can be used in artificial inoculation studies, as well as up to 4 x 10(4) uredospores.mL-1. In this work, there was a correlation between uredia and lesion density. Thus, the use of lesion density is recommended to assess disease intensity for its accuracy and less time consuming. There was also a positive correlation between uredia and lesion density.

【 授权许可】

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