In Brazil, the rapid expansion of the soybean crop during the past three decades, frequently
done without the necessary phytossanitary care, allowed the dissemination of major pathogens to all soybean
producing areas, through the seed, its main vehicle of introduction and spread into new areas. Besides the
seed transmission of pathogens and the epidemiological implications, some seedborne pathogens may reduce
germination, vigor, storability, field emergence and sometimes, the yield. Seed treatment with fungicides is
mainly used to improve germination of infected seeds, to control important seedborne pathogens and to
protect the seed from soilborne fungi. The objective of this research was to evaluate the efficiency of
thiabendazol used in different formulations, doses and in mixture with thiram, for the control of important
seedborne pathogens. In this research, ?BR-16? soybean seeds with 66% of vigor, 78% germination potential
(tetrazolium test) and naturally infected with Phomopsis spp. (60%), Fusarium semitectum (23%), Cercospora
kikuchii (16%) and Colletotrichum truncatum (3%) were treated with thiabendazol, thiabendazol + thiram
(four doses in liquid formulation), thiram. After the treatment the control of these pathogens and seed
quality were evaluated in laboratory (blotter test) and in greenhouse (emergence in sand), respectively.
Thiabendazol was very efficient in the control of Phomopsis spp., Fusarium semitectum and Cercospora
kikuchii, in the seeds in all doses, formulations and mixture with thiram. For Colletotrichum truncatum,
thiram was more efficient.