EVALUATION OF THE BIOPROTECTANT AGRODALPIVA COMPARED TO MANCOZEB IN THE MANAGEMENT OF PHAKOPSORA PACHYRHIZI IN SOYBEAN CULTIVATION

Abstract

Soybean is the main agricultural crop in Brazil, cultivated in all regions of the country, and its productivity is strongly influenced by biotic and abiotic factors. Among the biotic problems, fungal diseases stand out, with Asian soybean rust, caused by *Phakopsora pachyrhizi*, being the most severe. Control of this disease is based on integrated management, with the use of chemical fungicides associated with sanitary breaks and the use of resistant cultivars. However, the high adaptive capacity of the pathogen has driven the development of new control strategies. This work aimed to evaluate the agronomic performance of "Bioprotetor da Agrodalpiva" as an alternative to mancozeb in the management of *P. pachyrhizi* in soybeans. Three doses (0.5, 1.0, and 2.0) of Bioprotector were tested, applied in mixture with the systemic fungicides Score Flexi, Mitrion, and Cypres, at three distinct times: 21, 35, and 49 days after emergence (DAE). The positive control consisted of the use of mancozeb associated with the same fungicides, and the negative control consisted of unsprayed plants. The efficiency of the management treatments was evaluated based on rust severity (diagrammatic scale), area under the disease progress curve (AUDPC), plant height, chlorophyll content, and dry matter accumulation. The results demonstrated a significant reduction in the severity and sporulation of the fungus in plants treated with Bioprotector + systemic fungicides and with mancozeb + systemic fungicides, compared to the negative control. However, plants treated with mancozeb showed greater dry matter accumulation in the aerial part and pods. The highest doses of Bioprotector did not match the performance of mancozeb in terms of biomass, although all were effective in reducing the disease.