With this measure, the Alberta government and the cereal industry may be able to minimize the possible impact of this disease until there is a better understanding of its potential and more resistant varieties become available. Disease cycle and symptoms Fusarium graminearum overwinters mainly on infected crop residue, but can also be seed-borne. Infections in wheat occurs during flowering, via wind-borne spores produced from infested crop residue. About 2 weeks later symptoms become visible on infected heads. Moist conditions resulting from high humidity, dew and rainfall and moderate temperatures during flowering are critical for infection to occur.
Symptoms initially appear as dead, prematurely ripened portions of the cereal head.
With severe infections, the entire head may prematurely ripen and there will be a brownish discolouration of the stem directly below the head. An orange or pinkish discolouration on affected portions of the head may also be apparent. Head and kernel symptoms in barley are much less distinct and can be easily confused with diseases such as spot blotch, kernel smudge, or perhaps even hail damage. Typical symptoms in barley are premature ripening and a brownish discolouration of the affected portions of the head. As in wheat, orangish or pinkish discolouration may be produced on affected spikelets.