Despite epidemics in recent years in the neighboring countries of Lithuania, Latvia and Belarus, Estonia has reportedly been fire blight-free until this year. Estonia’s Viljandi County is experiencing its first outbreak of fire blight in pear trees.
According to the UK Department for Environment, Food, and Rural Affairs, the disease is native to North America, and was introduced in Europe in the 1950s. It is relatively widespread in many EU nations. Those who do not have fire blight are granted a special Protected Zone status.
Fire blight is a plant disease affecting fruit trees, caused by the bacterium Erwinia amylovora.
Fire blight bacteria can be transmitted between plant blossoms by wind, hail, and insect movements. Once on a plant’s pollen receptors, the bacteria multiply. They multiply best in higher temperatures (above 65 F), causing farmers and orchard owners to be wary of the early spring and summer days. The bacteria kill the blossoms, and then move down to other parts of the plant.
Signs of fire blight infection begin with a light tan “bacterial ooze” that is secreted from cankers on the bark. After being exposed to the air, the ooze turns dark. Infected plants often look like they have been scorched.
Some plants are more susceptible than others. For example, pear and quince plants are particularly susceptible. Some apple varieties, such as Fuji, Gala, Paulared and Rome Beauty are also very susceptible. To avoid and control flight outbreaks, Cornell University’s Integrated Pest Management Program recommends avoiding these plant varieties and pruning shoots and limbs with blight as soon as they appear. The limbs should be cut approximately one foot below the invisible infection and the shears should be sterilized after use. It is also recommended to control the insect population, as it is integral to blight transmission.
Estonia’s Department of Agriculture is requesting that anyone who finds evidence of the disease contact their local agriculture department office.
Fire blight poses no risk to human health.