Seed inoculation with pathogenic fungi using the water restriction technique is relatively recent. This study aimed to verify the effect of osmotic potentials (-0.4, -0.6 and -0.8 MPa) of PDA substrate modified by the amendment of sucrose in interaction with the period of exposure (48, 72 and 96 h) of wheat seeds to colonies of Bipolaris sorokiniana. Infection efficiency and inhibition of seed germination during and after treatment were the variables analyzed. The results of this study show that an exposure period longer than 48 hours to the fungal colonies did not inhibit full germination of the seeds. The germination rate increased linearly as the exposure period to the fungal colony was increased. Infection efficiency was not affected by osmotic potential and exposure time, varying from 0.53 to 0.92. However, seed germination was significantly reduced after 48 hours of exposure to the fungal colonies.
osmotic potential; seed health; artificial inoculation
