Combined Effects of Biological and Chemical Treatment on Rice Seed Physiological and Sanitary Quality

This study aimed to evaluate the efficiency of integrated biological and chemical control of pathogens in rice seeds and their effects on seed quality. The experiment was conducted in a 2 × 5 factorial completely randomized design. Fungicide-treated (carboxin/thiram) and untreated rice seeds were inoculated with distilled water (control), Azospirillum brasilense, Bacillus subtilis, Pseudomonas fluorescens, or Trichoderma harzianum. Seed vigor and viability, shoot and root length, and seedling dry weight were determined. The blotter test was carried out to assess seed health. Fungicide treatment improved seed vigor and viability and reduced the incidence of fungi. Biological treatment did not enhance the physiological quality of seeds but was able to control fungi. A. brasilense, B. subtilis, P. fluorescens, and T. harzianum controlled Phoma sorghina; B. subtilis, P. fluorescens, and T. harzianum were effective against Aspergillus flavus; P. fluorescens and T. harzianum controlled Pyricularia oryzae; and T. harzianum was effective against Gerlachia oryzae.