The effects of inoculum concentration,leaf stages of host plant,and environmental factors on the infection of Exserohilum monoceras isolate X-27 to barnyardgrass were investigated.The results showed that the lesion was visibly appeared on the leaf when inoculum concentration above 1.00×105 conidia· mL-1,1-2 leaf stage of barnyardgrass was most sensitive for infection of E.monoceras.The data also indicated that dew period was the key factor for E.monoceras infection.Almost 90% of barnyardgrass plants were killed when dew period prolonged to 48 h.Temperature and illumination period did not significantly affect the infection of E.monoceras,25-28℃ and 12 h dark period after inoculation were enough for infection.
