This presentation will include an overview of the BC Decision Aid System and how it is being used by Okanagan and Similkameen Valley tree fruit growers and industry consultants to manage two of the most important diseases that affect pome fruit.
Managing Fire Blight & Scab with the BC Decision Aid System, Molly Thurston, Claremont Ranch Organics
1. Managing Fire blight and
Scab with the BC Decision
Molly Thurston, P.Ag
Claremont Ranch Organics
Presentation to BC ACARN Workshop
December 2, 2019
2. How did BC DAS come about?
• DAS is an online decision support system for Tree Fruit
Growers and Integrated Pest Management Consultants.
• DAS originated at WSU as a result of reduced extension
capacity and increasingly more complex IPM programs.
• BCDAS is collaboration between the SIR, WSU and BCTF.
3. What is the BC Decision Aid
• DAS is an online decision support system for
Tree Fruit Growers and Integrated Pest
• BCDAS collects daily weather data to run pest,
disease and horticultural models.
• Provides time-sensitive pest and horticultural
information with management
4. How does BCDAS work?
• DAS collects weather data from Growers Supply
and Environmental Canada stations to run 18
• Model forecasts are based on DarkSky weather
forecast data and on 10-year temperature
• Conventional and organic management
recommendations are included.
5. What does BCDAS recommend?
• DAS can recommend product options and
timing for when to spray.
• DAS cannot recommend IF a spray is
needed in a specific orchard.
• Management decisions are made by the
grower and the pest manager, based on
observed field conditions.
8. Life Cycle of Apple
9. Setting up the Scab
Model in BCDAS
Growers using the DAS system should go into
the Apple Scab model and set the date of
green tip when it occured in your orchard.
Use Gala or McIntosh to set the date if you
have them; they are usually the first varieties
to show green tip.
As soon as apple buds reach green tip
growers have to start monitoring the weather
for apple scab.
Growers with a scab problem last year should
keep trees PROTECTED by applying scab
protection products starting at green tip.
11. Apple Scab Management
• Protectants recommended from
Green Tip through Petal Fall in
areas with known inoculum.
• Eradicants are used in the case
of an infection period where
coverage needs to be enhanced.
• Scab coverage period in North
extends until end of ascospore
18. Case Study:
Located: Winfield South
2.5 acres Pears, 1.5 acres
No observed fire blight in
2017 or 2017.
Adjacent to Gala Apples, two
new plantings of Ambrosia
and Honeycrisp apples.
19. CRO 2019 Pear
April 25, 2019: Popcorn
Full Bloom: April 28 – 30,
FROST! April 29, -2ºC
Petal Fall: May 7, 2019
25. 2020 CRO Fire Blight Plan:
• Active Fire blight confirmed in
• Monitor BCDAS in 2020 during Pear
and Apple bloom.
• Follow BCDAS treatment
recommendations for Biologicals
• Monitor for shoot blight using BCDAS
data and field observations.
• Plan for shoot blight treatments, if