Identification of agronomic factors that influence the levels of T-2 and HT-2 toxins in barley grown in France

The European Commission has considered the appropriateness of setting a maximum level for T-2 and HT-2 toxins in cereals and cereal products in future. Occurrence studies show that oats, and to a lesser extent barley, seem to accumulate higher levels of these toxins than other cereals. Consequently, ARVALIS – Institut du vegetal has conducted a field survey in collaboration with different French partners (cooperatives and merchants, agro industries and research institutes). The agronomic factors identified to reduce the risk of T-2 and HT-2 toxins on barley are different from those identified for deoxynivalenol (DON). They are, in decreasing order of importance: sowing date, rotation (number of small grain cereals in the last 2 years), tillage (with a smaller impact than for DON), and possibly varietal susceptibility and fungicide protection. Finally, this field survey shows that DON, and T-2 and HT-2 toxins seem to be opposed, which probably means a different risk management for these different mycotoxins.