The current high moisture and humidity conditions are conducive for disease development in wheat heads. One of the early wheat head diseases developing is loose smut. Loose smut is a fungal disease caused by Ustilago tritici. This fungus survives as dormant mycelium within the embryo of the seed. When infected seeds are planted, the fungus germinates and grows systemically within the seedling until heading. At heading, the fungus then differentiates into a dry, dark mass of teliospores. These spores are blown by wind and rain to neighboring plants that are heading or flowering. The fungus then germinates and infects the developing embryo and survives as dormant mycelia on the seed.

The loose smut pathogen infection is favored by high humidity and low to moderate temperatures (61-72 degrees Fahrenheit) at flowering time. The ovary is resistant to infection by the loose smut pathogen 7 days after flowering. Loose smut is best managed through cultivar resistance. If a cultivar being grown is having a high incidence of loose smut, then changing the cultivar is recommended. Usually a few heads with loose smut in a field are not unusual but high incidence of loose smut may mean that the cultivar is susceptible. Systemic fungicide seed treatments like carboxin, tebuconazole, and difeconazole are very effective against loose smut. If several heads with loose smut are seen in the field and the seed is to be saved for planting, a fungicide seed treatment with a systemic fungicide is recommended.

The current weather conditions have also been perfect for Fusarium head blight (FHB) development. Rainy and humid weather at flowering promotes FHB development. FHB symptoms can be confused with those of stem maggot damaged heads. It is very easy to diagnose stem maggot damaged heads by simply pulling out the bleached head slowly. If it pulls out easily, this would mean that there is stem maggot injury.

Wheat damaged by hail or common root rot may also show white heads. FHB infected heads may have a few spikelets or the entire head bleached and should be pink to salmon in color (the sign of the fungus) on the damaged spikelets.

Source - http://www.tristateneighbor.com/