May Day, May Day – Look Out for Fire Blight

As fire blight season approaches, Tianna DuPont, Washington State University (WSU) Extension Tree Fruit Specialist, advises apple growers to watch WSU’s CougarBlight and check out their new updated Fire Blight page.

“With the cool weather this spring fire blight pressure is generally low,” she writes. “However, with warm temperatures risk could increase. Due to the high innocula from last year it is critical to be on top of things.”

It is crucial that growers are aware of fire blight risk from when primary bloom begins until the end of secondary (rat tail) flowering. Secondary bloom, typically 1 to 3 weeks after full bloom is generally a prime period for infection. Compared to non-dwarfing rootstocks, dwarfing rootstocks tend to promote secondary flowering. Many modern cultivars (e.g., Bartlett pear and Cripps Pink apple) also tend to produce secondary flowers.

At temperatures of 60°F -70°F, the fire blight pathogen grows slowly. When temperatures reach 70°F -75° F, it is important that growers watch the weather forecast and blight risk warning models, and prepare to apply preventative spray treatments. 75°F -90°F is fire blight weather. The bacteria will replicate quickly at these temperatures (Pusey and Curry 2004).

DuPont concludes her post by outlining examples of both organic and conventional spray programs.

Topics: , ,

Leave a Reply

3 comments on “May Day, May Day – Look Out for Fire Blight

Apples & Pears Stories
Apples & Pears
October 3, 2017
Mexican Fruit Grower Union Says U.S. Still Smuggling in Apples
Union seeks investigation into how 200 tons of U.S. ‘Golden Delicious’ apples were smuggled into the country. Read More
Apples & Pears
September 22, 2017
Media Reflects Modern Society [Opinion]
Little about fruit growing — or any agriculture — appears because too few of us are willing to illuminate the media. Read More
Apples & Pears
September 16, 2017
Researcher Finds Bacteria Can Stop Blue Mold on Apples
The natural bacterium found in soil can survive in cold storage; this promising biocontrol offers an alternative to chemical treatments. Read More
Apples & Pears
September 5, 2017
Pears Finding Home in Fermentation
Perry, a fermented beverage similar to hard apple cider, is gaining popularity in the U.S., and growers are learning about the production process from square one. Read More
Apples & Pears
August 26, 2017
‘EverCrisp’ Apple gets PLU Approval
Midwest Apple Improvement Association prepares for large harvest and larger distribution reach for first variety released. Read More
Apple Grower of the Year
August 22, 2017
U.S. Apple Association Hosts Annual Apple Outlook Conference in Chicago
American Fruit Grower® and Western Fruit Grower® magazine’s 2017 Apple Grower of the Year will be officially presented on Thursday, Aug. 24, during the first day of the conference. Read More
Apples & Pears
August 20, 2017
APHIS Seeks Comments on Risk Removal for Dormant Apple Cuttings
Dormant live cuttings from countries in the European Union must currently go through pest risk assessment. Read More
Apples & Pears
August 15, 2017
Wet Weather Breeds Phytophthora in Young Apple Plantings
Crown rot, root rot flourishing in very wet growing season. Read More
Apples & Pears
August 9, 2017
2017 Washington Apple Crop Down Slightly
Forecasted harvest predicted to be 131 million boxes, down 1.2% from 2016. Read More
Apples & Pears
August 5, 2017
Penn State University Develops Bitter Pit Prediction Model
Research team unlocks relationship between bitter pit, minerals, and shoot lengths. Read More
Apples & Pears
August 1, 2017
New York Growers’ Input Needed on Apple Tree Decline
Project has begun to identify rapid collapse and chronic decline being found in young Eastern apple orchards. Read More
Apples & Pears
July 25, 2017
Tips to Transition to an Apple Fruiting Wall System
Follow these suggestions to make the move from a 3-D spindle-shaped canopy to a 2-D system using mechanical pruning. Read More
Apples & Pears
June 30, 2017
Tackling the Challenges of Organic Apple Production Head-on
Researchers at Michigan State University test organic controls for fire blight. Read More
Apples & Pears
June 29, 2017
Integrating Control Methods to Tackle Fire Blight
Fire blight is a damaging disease, no matter the location. Most production areas of the Pacific Northwest and California experience Read More
The Latest
Apples & Pears
October 9, 2017
How to Transition to Multileader Product…
Use this guide to help you determine whether multileader production is a good fit for your farm. Read More
Apples & Pears
October 6, 2017
What You Need to Know About Multileader …
While multiple leaders shrink the tree canopy, experts warn there are places where missteps can be made. Read More
Apples & Pears
October 5, 2017
Apple Growers Moving to Multileaders
Growers shift from single leader to multiple leader systems to increase light interception and production. But this system isn’t without its risks and costs. Read More
Apples & Pears
October 3, 2017
Mexican Fruit Grower Union Says U.S. Sti…
Union seeks investigation into how 200 tons of U.S. ‘Golden Delicious’ apples were smuggled into the country. Read More
Apples & Pears
September 22, 2017
Media Reflects Modern Society [Opinion]
Little about fruit growing — or any agriculture — appears because too few of us are willing to illuminate the media. Read More
Apples & Pears
September 16, 2017
Researcher Finds Bacteria Can Stop Blue …
The natural bacterium found in soil can survive in cold storage; this promising biocontrol offers an alternative to chemical treatments. Read More
Apples & Pears
September 5, 2017
Pears Finding Home in Fermentation
Perry, a fermented beverage similar to hard apple cider, is gaining popularity in the U.S., and growers are learning about the production process from square one. Read More
Apples & Pears
August 26, 2017
‘EverCrisp’ Apple gets PLU Approval
Midwest Apple Improvement Association prepares for large harvest and larger distribution reach for first variety released. Read More
Apple Grower of the Year
August 22, 2017
U.S. Apple Association Hosts Annual Appl…
American Fruit Grower® and Western Fruit Grower® magazine’s 2017 Apple Grower of the Year will be officially presented on Thursday, Aug. 24, during the first day of the conference. Read More
Apples & Pears
August 20, 2017
APHIS Seeks Comments on Risk Removal for…
Dormant live cuttings from countries in the European Union must currently go through pest risk assessment. Read More
Apples & Pears
August 15, 2017
Wet Weather Breeds Phytophthora in Young…
Crown rot, root rot flourishing in very wet growing season. Read More
Apples & Pears
August 9, 2017
2017 Washington Apple Crop Down Slightly
Forecasted harvest predicted to be 131 million boxes, down 1.2% from 2016. Read More
Apples & Pears
August 5, 2017
Penn State University Develops Bitter Pi…
Research team unlocks relationship between bitter pit, minerals, and shoot lengths. Read More
Apples & Pears
August 1, 2017
New York Growers’ Input Needed on Apple …
Project has begun to identify rapid collapse and chronic decline being found in young Eastern apple orchards. Read More
Apples & Pears
July 25, 2017
Tips to Transition to an Apple Fruiting …
Follow these suggestions to make the move from a 3-D spindle-shaped canopy to a 2-D system using mechanical pruning. Read More
Apples & Pears
July 6, 2017
International Fruit Tree Association See…
Deadline for proposals is July 31. Read More
Apples & Pears
June 30, 2017
Tackling the Challenges of Organic Apple…
Researchers at Michigan State University test organic controls for fire blight. Read More
Apples & Pears
June 29, 2017
Integrating Control Methods to Tackle Fi…
Fire blight is a damaging disease, no matter the location. Most production areas of the Pacific Northwest and California experience Read More