Compatibilidade e eficiência de produtos biológicos no controle de fitopatógenos de solo e desempenho de sementes de soja

Abstract

The application of phytosanitary products aims to allow the germination of seeds infected with pathogens, to control pathogens transmitted by the seed and to protect the seeds from soil fungi. The objective of the work was to study thecompatibility and efficiency of biological products in the control of soil phytopathogens and soybean seed performance. The same was carried out in the Phytosanitary and Seed Analysis Laboratories and in a greenhouse at the Universidade Tecnológica Federal do Paraná (UTFPR), CampusDois Vizinhos –PR, using seeds from cultivar NS 6700 IPRO. For all studies, biological products based on Trichoderma harzianum were tested, following commercial recommendation; Paucilomyces lilacinus; Bacilus subtilis; Azospirillum brasiliense and Bradyrhizobium japonicum, also their combination. The first study was carried out by testing the compatibility of biological products with the main active ingredients used in seed treatments available on the market, this was carried out through the application of two methodologies the Minimum Inhibitory Concentration (MIC) and with the use of treated seeds and disposed in a medium of culture. The second study was to verify the efficiency of biocontrol agents, on the soil fungi Fusarium crassistipitatum, F. tucumaniae, Rizoctonia solani, Macrophomina phaseolina, Sclerotinia sclerotiorum and Phomopsis longicolla. For this, two methodologies were used both in vitro, the method being adapted from the circle and the methodology of direct confrontation. The third experiment was to verify the attributes of seed quality and development of soybean culture according to the treatment of seeds with these biologicals. The fourth experiment was carried out in a greenhouse, subjecting seeds treated withbiological products to soils contaminated with pathogens, in order to verify the efficiency of treatments in suppressing symptoms. The data were tabulated with some qualitative variables and the others submitted to the Lilliefors Normality Test and to ANOVA by the analysis of variance test (p = 0.05) and the Tukey or Scott-Knott test (p = 0.05).It was found that some chemicals used for seed treatment can interfere with the efficiency of biological agents and that they have potential to control phytopathogens. There are specificities that must be considered, regarding the association of biological agents and the phytopathological target. He also observed that there is no interference in the agronomic performance of soybean seeds treated with biological products