Head Blight of Wheat Caused by Fusarium Graminearum Group I in New South Wales in 1983

Head blight (scab) of wheat caused by Fusarium graminearum Group 1 was detected in some crops in the northern wheat belt of New South Wales in 1983. The pathogen was isolated from up to 38.2% of grains from crops affected by head blight. However, it was isolated only from a low proportion (max. 1.6%) of grains of various grades from silos of the Grain Handling Authority of New South Wales. The frequency of isolation of other Fusarium spp. was also quite low despite wet preharvest conditions. F. graminearum Group 1 was isolated from 38.2% of the grains of one sample harvested from a crop with approximately 50% of the heads affected by blight. The trichothecene mycotoxin, 4-deoxynivalenol, was detected (0.6 ppm) in this sample. This is the first record of the production of 4-deoxynivalenol by F. graminearum Group 1 in grain grown under field conditions. 4-Deoxynivalenol was not detected in grain samples from Grain Handling Authority silos.