What is it? Fusarium Head Blight is a fungal disease that affects the head of small grain crops. Also referred to as Scab, it can affect wheat, barley, oats, rye, corn, and triticale. Wheat and barley are generally the most affected. It is mainly caused by the species Fusarium graminearum, and can cause loss of […]
What is it?
Gibberella Ear Rot, or Red Ear Rot, is caused by the fungus, Gibberella zeae (Fusarium graminearum). This disease can occur throughout the U.S. Mid-West and Southern Ontario. The pathogen overwinters on corn, wheat and barley debris. Spores produced on the debris lead to infection during silking. Red Ear Rot is more prevalent when cool, wet weather occurs during the first 21 days after silking. Extended periods of rain in the fall, which delay dry down, increase the severity of the disease. Red Ear Rot will be most severe in fields where corn follows corn, or corn follows wheat that was affected by Fusarium head blight (scab), which is caused by the same pathogen. Read more
Ear rots can be difficult to control since weather conditions are critical to the disease development. Rots can establish any time after pollination in wounds created by insects, birds, machinery, and even hail. Rainy weather or heavy, prolonged dews often lead to ear rots in these wounded cobs.
Why are rots a concern?
The direct concern for ear rot disease is yield loss due to poor quality grain. In years when conditions favour development, large portions of fields can be affected. Once fields are infected, other management practices should be followed which can increase cost of harvesting, drying, and storing the grain.
The distribution and prevalence of stalk rot diseases vary from year to year. However, the diseases are present in most years even though it may be at low levels. The majority of stalk rot damage in Ontario is caused by three fungi, Anthracnose, Gibberella and Fusarium. However, Diplodia and Pythium have also been observed.
Although these fungi cause different symptoms, their ultimate effect on the corn plant is the same. They reduce grain fill, stalk integrity, and accelerate senescence. The severity of this damage increases when the crop is under stress.
What increases the risk of infection?
- Cool temperatures.
- Prolonged periods of wet weather.
- Rust problems in the southern US states and Mexico could mean the same for Ontario as storm systems carry the spores north.
- Planting susceptible varieties.Planting after another cereal or corn crop.
How do I know when to apply a fungicide?
The higher the price of wheat, the more economical treatment is. In general, if trace amounts of rust, powdery mildew, or leaf spot are Read more