Fungicides Application against Fusarium Head Blight in Wheat and Barley for Ensuring Food Safety

Abstract

Fusarium head blight (FHB), or scab, caused by several Fusarium species, especially Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schweinitz) Petch], is a widespread and destructive disease of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and other small-grain cereals (Liddell 2003; Parry et al. 1995; Pirgozilev et al. 2003). These pathogens infect spikes and reduce grain yield and quality. Moreover, Fusarium species that cause FHB produce trichothecene mycotoxins such as deoxynivalenol (DON) and nivalenol (NIV), which are toxic to humans and other animals. The Joint WHO/FAO Expert Committee on Food Additives evaluated the risk of DON and set a provisional maximum tolerable daily intake of DON as 1 μg/kg body weight in 2001. Accordingly, the Japanese government determined provisional guidelines for DON content in unpolished wheat grains as 1.1 mg kg–1 in 2002. Many other countries have also established maximum allowed levels for DON in cereals and cereal products. There is currently no robust single control measure by which to manage either FHB or mycotoxin contamination in barley and wheat. Fungicide application is one measure available to reduce the risk; however, results have not been highly effective or consistent (Horsley et al. 2006; Jones 2000; McMullen et al. 1997; Mesterhazy 2003). To obtain increased chemical control of FHB, the timing of fungicide application is an important factor, as well as fungicide selection, application rate, and good coverage of the spike (Mesterhazy 2003). This chapter introduces FHB disease and its related mycotoxins, and summarizes our research on the chemical control of mycotoxin contamination.