SEED TREATMENT WITH TRICHODERMA AND CHEMICALS TO IMPROVE PHYSIOLOGICAL AND SANITARY QUALITY OF WHEAT CULTIVARS1

ABSTRACT Seed treatment with fungi of the genus Trichoderma spp. provides several benefits, including plant growth promotion, stress tolerance, and pathogenic fungi control. Moreover, to avoid inadequate doses and unnecessary costs, these treatments must be applied in proper amounts. However, no study has evaluated their applicability in wheat seeds. This study aimed to determine the most efficient dose of Trichoderma-based products applied as a seed treatment for improving the physiological and sanitary quality of the wheat cultivars TBIO ‘Toruk’ and TBIO ‘Sossego’, besides comparing the performance of biological and chemical agents. Two biological treatments (Trichoderma asperellum SF 04 and Trichoderma harzianum IBLF006) were applied at 0 (control), 5 × 10 11 , 1 × 10 12 , 1.5 × 10 12 , and 2 × 10 12 colony-forming units (CFU) 100 kg–1 seed. Two chemical treatments (carboxin + thiram and pyraclostrobin + thiophanate-methyl + fipronil) were applied at the manufacturers’ recommended doses. Seed germination, shoot and root lengths, seedling dry matter, and sanitary quality were analyzed under laboratory conditions, while seedling emergence, shoot length, and shoot dry matter were analyzed under greenhouse conditions. The optimal dose for wheat seed treatment with T. asperellum SF 04 and T. harzianum IBLF006 was 2 × 10 12 CFU 100 kg–1 seed. When comparing biological and chemical products, our findings indicate that both options are adequate for managing wheat diseases and providing seedling growth via seed treatment. RESUMO O tratamento de sementes com fungos do gênero Trichoderma spp. proporciona diversos benefícios, incluindo promoção de crescimento das plantas, tolerância a estresses e controle de fungos patogênicos. Entretanto, para evitar o uso de doses inadequadas e custos desnecessários, é fundamental a utilização destes na quantidade correta, todavia não há estudos que avaliem a sua aplicabilidade em sementes de trigo. Objetivou-se encontrar a dose mais eficiente de produtos a base de Trichoderma no tratamento de sementes para melhorar a qualidade fisiológica e sanitária das cultivares de trigo TBIO 'Toruk' e TBIO 'Sossego', além de comparar o desempenho de agentes biológicos e químicos. Os tratamentos biológicos utilizados foram: Trichoderma asperellum SF 04 e Trichoderma harzianum IBLF006, aplicados nas doses de zero (testemunha); 5x1011; 1x1012; 1,5x1012 e 2x1012 UFC (unidades formadoras de colônias) 100 kg-1 de sementes, e os químicos foram: car