Condições meteorológicas associadas a coleta das primeiras estruturas de reprodução da Phakopsora pachyrhizi na cultura da soja

Abstract

The aiming evaluate the meteorological conditions, associated with the appearance of uredospores of Phakopsora pachyrhizi, the experiment was conducted with the Glycine max and uredospore collector, Laranjeiras do Sul-Pr in two different places. The experiment start October 19, 2021 when the collectors were sown and installed. The meteorological elements were obtained by the Vantage Pro 2 model station. The collection of uredospores was performed using a microscope slide. The first microscope slide was changed on October 26, 2021, adopting a weekly change schedule. Thus, the identification of uredospores was made with the aid of a binocular microscope. Thus, the data records of meteorological elements, Graph 5, exposes the relationship between weather conditions and the number of spores present in the atmosphere from December 1, 2021 to January 31, 2022. The date of capture of the first uredospores of Phakopsora pachyrhizi was on 12/28/2021, the uredospore was captured only in the university collector, in the collectors installed on the farm, no presence of spores was identified during the entire crop cycle. The atypical meteorological conditions of the 21/22 season caused a reduced concentration of Phakopsora pachyrhizi uredospores in the atmosphere. Thus, when there are no favorable meteorological conditions for the fungus cycle, the disease does not manifest itself. In view of this, the importance of monitoring meteorological conditions and the capture of uredospores, in order to use fungicides only when necessary.