As of mid-May, the state of Arizona and counties in Texas, New Mexico and California have been quarantined. Grain facilities that have dealt with any of the quarantined areas are being examined for spores. While this fungus is not particularly damaging in terms of yield loss, it can cause significant reductions in grain quality and is strictly regulated in international wheat markets. It is the potential for grain quality and market loss that has caused great concern in the United States wheat industry. We discuss the background, life cycle and potential for Karnal bunt problems in the Pacific Northwest in this article.
Karnal bunt is a fungal disease of wheats, triticales and rye.
Bread wheats are most susceptible, while durum wheats, triticales and rye show greater levels of resistance. However, individual cultivar reaction to this disease varies widely. Barley and oats are not susceptible. While generally unfavorable for Karnal bunt, some environments in the Pacific Northwest are quite favorable for development and survival of other smuts. Dwarf bunt is an on-going concern in areas with high snowfall.