Cultivar and crop management influences on fusarium head blight and mycotoxins in spring wheat (Triticum aestivum) in New Zealand

Cultivar and crop management influences on fusarium head blight (FHB) of wheat (Triticum aestivum L.) were investigated in cultivar field trials and commercial wheat crops in the North Island of New Zealand over two growing seasons. There were consistent differences between cultivars in their susceptibility to FHB. The Chinese wheat 'Nanjing' had the lowest level of FHB, mycotoxins, and Fusarium infection in grain. Although no New Zealand cultivars approached an equivalent level of resistance, FHB in some cultivars was low in most situations, and these cultivars had a useful level of resistance. FHB and mycotoxin levels varied widely between crops surveyed. Two Fusarium mycotoxins, deoxynivalenol (DON) and nivalenol (NIV), were detected in grain samples from crops and trials. Overall, DON levels were higher than NIV in crops in both years. FHB incidence and levels of Fusarium infection and mycotoxins in grain were closely related in samples from a particular crop, but the relationships were much less apparent between crops. F. graminearum predominated in grain samples, although F. avenaceum, F. culmorum, and F. poae were also common. Highest levels of F. graminearum were recorded in grain samples from crops that followed maize, whereas F. avenaceum and F. poae were more common in samples from crops that did not follow maize.