Droplet spectrum and fungicide efficiency in the control of Asian soybean rust (Phakopsora pachyrhizi Syd. & P. Syd.)

Acta Agronomica

Garcés-Fiallos, Felipe Rafael¹  Durante Danelli, Anderson Luiz²  Baldiga Tonin, Rosane³  Boller, Walter⁴ 

[1] National Secretariat for Higher Education, Science, Technology and Innovation, Ecuador;Technical University of Manabí, Manabí, Ecuador;University of Guayaquil, Guayaquil, Ecuador;University of Passo Fundo, Passo Fundo, Brazil

关键词: Application technology;    chemical control;    controlled conditions;    inoculation;    Phakopsora pachyrhizi;    Glycine max.;   

DOI  :  10.15446/acag.v67n2.62865

学科分类：农业科学（综合）

来源: Universidad Nacional de Colombia * Facultad de Ciencias Agropecuarias Palmira

【 摘 要 】

The aim of this study was to evaluate the chemical control of Asian soybean rust (Phakopsora pachyrhizi Syd. & P. Syd.) using different tips and spray nozzles under controlled conditions. Rooted trifolia placed inside an acrylic box containing macronutrients, micronutrients and vitamins were treated with epoxiconazol + pyraclostrobin, ciproconazol + azoxystrobin and tebuconazol fungicides. These fungicides were sprayed at a height of 0.5 m with two knapsack sprayers pressurized with CO2 gas (drop generator in four spray tips spaced by 0.5 m from each other) and another rotating nozzle (drop generator through a rotating nozzle). Untreated trifolia were controls. Water sensitive paper was placed next to each acrylic box to obtain median volume diameter (VMD), number of droplets.cm2 and coverage (%). Trifolia were inoculated 24 hours after that these were treated with fungicide, using a spore concentration adjusted to 2 x 104 uredospores.mL1. Then, the number of lesions and uredia.cm-2 in central leaflets were quantified. Lower number of lesions and uredia.cm2 were observed in leaflets treated with two fungicide mixtures using an AIRMIX 11001 tip. A lower VMD was found in leaflets sprayed with the fungicides azoxystrobin + epoxiconazol and tebuconazol, when compared to the leaflets treated with another mixture. The Asian rust control, as well as the number of droplets.cm2 and coverage, seems to be dependent on the interactions among fungicides and tips or nozzles.

【 授权许可】

CC BY-NC-SA