Why has the USA seen an increase in Fire Blight incidences this year?

Fire Blight, a disease caused by the bacterium Erwinia amylovora, which causes cankers and wilting in apples, pears and related ornamentals, is native to North America and has been an issue for many years, however, this year the USA has seen an increase in Fire Blight incidences.

Why the increase in Fire Blight incidences?

Ross Courtney put it well in his article on Good Fruit Grower by saying it has been a ‘Blightmare of a year’. In addition, one horticulturist Ross interviewed stated it’s the “worst blight I will have seen in my career”.

Fire Blight favours warmer temperatures and in the USA the first incidences of the pathogen appear in the spring, with rain, heavy dews and high humidity being the optimal conditions for the infection. And of course, this is exactly what happened this year in the USA.

These weather conditions resulted in growers engaging in an on-going battle to stem the increase in Fire Blight. The warm weather exasperated the presence of Erwinia amylovora still present from the previous year and the rain resulted in a greater number of infection incidences.

Washington,  Oregon, Idaho, Colorado and Ohio have all had a Fire Blight ‘punch in the face!’ in 2018.

Managing Fire Blight

In the USA Fire Blight incidences are common each year and if not treated quickly enough can lead to the bacteria causing significant problems. Fire blight management techniques include:

• Preventing the bacteria from spreading can be done by pruning (with sterilised shears) infected branches before the disease becomes more active.
• Any infected plant material should then be burned to kill the bacteria and prevent any further spreading.
• There are copper products available to control fire blight, which of course would require guidance on when and how to use them.

More detailed Fire Blight management techniques can be found here: http://ipm.ucanr.edu/PMG/PESTNOTES/pn7414.html

Detecting and monitoring Fire Blight

The symptoms of Fire Blight will be well known by many. However, if you’re an advisor or inspector you will need to prove to clients any presence or absence of Fire Blight.

One of the most cost-effective and time-efficient ways to test for Fire Blight is with an Erwinia amylovora rapid test. These portable rapid tests can detect Erwinia amylovora in the field within a matter of minutes.

In addition, the versatility of rapid tests means they are a handy tool carry with you for monitoring the success of your Erwinia amylovora (Fire Blight) management techniques.