The increased frequency and severity of head scab during the past 10 years are attributed to the increase in reduced and no-till acres. The Fusarium species of fungi, which causes stalk rot in corn, also causes scab or head blight in wheat. The fungus flourishes under wet, warm conditions such as crop residues left on the soil surface. Wind and rain droplets at flowering time can carry the fungi spores from the crop residue to the wheat heads. And warm, humid conditions during flowering favor spreading the fungus in the wheat head.
Symptoms are initially visible a couple of weeks after infection.
The individual spikelets of the wheat head begin to discolor and turn white. Infected heads are very visible among the uninfected, green heads. The first scab-resistant wheat variety from Pioneer will be available in limited supply for fall planting. For more information on product availability, contact your local provider of Pioneer products.