Bacterial spotTaking the focus off of the sprayer
Janice LeBoeuf
Vegetable Crop Specialist, Ontario Ministry of Agriculture, Food and Rural Affairs
Ridgetown, Ontario
Cheryl Trueman
Researcher, University of Guelph – Ridgetown Campus
Ridgetown, Ontario
• To collect grower views and knowledge on bacterial
spot
• Sent out at harvest time to processing tomato
growers, processor ag staff, agribusiness
• 32 surveys returned, 24 from growers1
Fall 2014 – grower survey
1There are about 85 growers and 8 processors
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not all all minor problem moderateproblem
severe problem
# R
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Q1. Was bacterial spot a problem this year?
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Q4. In the last 10 years, how many times has bacterial disease been a significant problem?
-Different perspectives on severity?-Location dependent?
15 responses 10 responses
Q3: How widespread are bacterial disease problems in your tomatoes this year?
• Where timing was mentioned, first seen:– Mid-June – 1 report– First half of July – 5 reports– End of July/early August – 1 report
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How much of your acreage was affected?
Q8: Do you think your bacterial disease spray program is helping to reduce losses to bacterial disease?
Total: 28 responses.
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80%
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100%
Yes No Unsure
per
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f re
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Kocide 2000 Kocide 2000 alt. Actigard 496/A + 497/B + Actigard
Kocide 2000 + Dithane Kasumin Taegro
Serenade Max Kocide 2000 + Kasumin Agral 90
Kocide 2000 + Serenade Max Kocide 2000 alt. Kasumin Surround
Kocide 2000 alt. Serenade Max Bravo Double Strength Trace Elements
Regalia Maxx Kocide 2000 + Bravo THIS Copper & Sulfur
Kocide 2000 + Regalia Maxx Quintec Cal-Mag-B alt. KP350DP
Kocide 2000 alt. Regalia Maxx Kocide 2000 + Quintec Cal-Mag-B alt. KP350OR
Actigard Kocide 2000 + Dithane +
Quintec
Cal-Mag-B alt. KP1000DP
Kocide 2000 + Actigard 496/A + 497/B
Efficacy trials
• > 5 years of trials, Trueman, University of Guelph
• Not all products tested each year
Trueman, University of Guelph, 2010-2014
Kocide 2000 Kocide 2000 alt. Actigard 496/A + 497/B + Actigard
Kocide 2000 + Dithane Kasumin Taegro
Serenade Max Kocide 2000 + Kasumin Agral 90
Kocide 2000 + Serenade Max Kocide 2000 alt. Kasumin Surround
Kocide 2000 alt. Serenade Max Bravo Double Strength Trace Elements
Regalia Maxx Kocide 2000 + Bravo THIS Copper & Sulfur
Kocide 2000 + Regalia Maxx Quintec Cal-Mag-B alt. KP350DP
Kocide 2000 alt. Regalia Maxx Kocide 2000 + Quintec Cal-Mag-B alt. KP350OR
Actigard Kocide 2000 + Dithane +
Quintec
Cal-Mag-B alt. KP1000DP
Kocide 2000 + Actigard 496/A + 497/B
Efficacy trials
• Only one treatment gave relatively consistent benefits
• Required 8 weekly applications
Trueman, University of Guelph, 2010-2014
Should we be spraying for bacterial
spot in field tomato?
There is little compelling evidence to suggest there is
a benefit• Little benefit (= yield, fruit quality) in small-plot field trials with 8
applications per season
• Research in other parts of North America also showing lack of
efficacy with copper
• Concern about Cu tolerant bacteria
Bacterial populations will continue to evolve tolerance
to any new highly effective products.
• Assumption:
• Overwintering of bacterial spot-causing Xanthomonads in Ontario is minimal
• Limitations:
• Economics
• Field is not a controlled environment
• Approach:
• Cheryl Trueman (University of Guelph – Ridgetown) and I worked with the Ontario processing tomato industry to develop draft best management practices focused on exclusion and limiting spread of bacterial spot pathogens.
• Will adapt based on experience, research data, input from others.
Can we do a better job of exclusion and
limiting spread of pathogen?
• To ensure practicality and learn from each other,
worked in consultation with growers and processors.
• Transplant production:
• Updated an existing bacterial disease management
protocol
• Ontario Tomato Seedling Growers’ Marketing Board
• Processors
• Field production:
• Field growers
• Processors
Can we do a better job of exclusion and
limiting spread of pathogen?
Transplant Production BMPs (draft)
Goal: Exclusion & Limiting Spread
• Mostly standard practices, such as:
• Cleaning and disinfecting all surfaces pre-season.
• Written protocols, recordkeeping.
• Clearing greenhouse and perimeter of
other plant material (weeds, crop debris).
• New, clean trays and growing media.
Transplant Production BMPs (draft)
• More focus on avoiding cross-contamination
between trays, seed lots, crops.
• Clean the seeder and seed hopper when changing seed
lots, when changing crops, and at the end of each day.
Transplant Production BMPs (draft)
• More focus on avoiding cross-contamination
between trays, seed lots, crops.
• Sanitation when handling plants - between seed lots and
crops (or as often as between trays).
• Visitor biosecurity.
• When shipping plants, no entry by visitors.
Transplant Production BMPs (draft)
Visitor biosecurity
• More focus on avoiding cross-contamination
between trays, seed lots, crops.
• Sanitation of shipping and
loading equipment
Transplant Production BMPs (draft)
Field Production BMPs (draft)
Goal: Exclusion & Limiting Spread
• Strategy: adopt multiple practices to limit spread
and delay epidemic of bacterial spot as much as
possible.
• Four tiers, based on expected impact.
Field Production BMPs (draft)
Tier 1 – likely to have the biggest impact
Picking up plants
•One crop/plant lot per load.
•Plant trailer sanitation.
Holding plants
•Ventilation.
Transplanting
•Transplanter sanitation between fields and varieties.
•Transplanting crew - hands.
Tier 1 – likely to have the biggest impact
• Bacteria can be spread on workers’ hands. At a
transplanting rate
of 1.5 ac/hr,
with 6 workers
and 13,000 plants/ac,
3,250 plants are touched
per person per hour.
Tier 2 – some impact expected
In-season
•Avoid other host crops.
•Sanitation of field equipment.
•Avoid leaf damage. Stay out after rows start to fill.
Tier 2 – some impact expected
In-season
•Sanitation when working with plants.
•Biosecurity procedures for crop scouts and other visitors.
•8 applications of copper + Actigard, 7-day interval, starting within 7 days of transplanting.
Tier 3 – little impact expected (compared to tiers 1-2)
In-season
•Weed control.
•Fallowing weak areas.
• This tier includes practices mentioned by growers in the
survey, but not expected to help in bacterial disease
management, such as:
• Crop rotation
• Using other spray products/programs
• DSV-based spraying of bactericides (model for fungal disease)
• Disinfecting equipment, hands, surfaces without pre-cleaning to
remove films and organic matter.
• Initiating cleaning and disinfecting after disease is already
established.
Tier 4 – no impact expected on bacterial spot
• Research data
• Evaluation of suggested practices
Gaps
• Gather feedback from transplant and field growers
on their experiences implementing these practices.
• Validate components of the greenhouse and field
production BMPs to determine their impact on
management of bacterial spot.
• Explore and evaluate new techniques and
technologies for exclusion and limiting spread of
bacterial plant pathogens.
Future
Want to talk tomato bacterial disease?
Janice LeBoeuf, Vegetable Crop Specialist
OMAFRA
519-674-1699
[email protected] @ontariotomato
Cheryl Trueman, Researcher
Ridgetown Campus, University of Guelph
519-674-1500 ext. 63646
[email protected] @CherylTrueman
Extras
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)Q2. Observations on impact of bacterial disease in
different varieties. (note: growers didn't always indicate 'severe' 'moderate' 'light'
and in those cases a was assigned based on the description or estimated yield loss)
severe moderate light
Ontario processing tomato2: 336,202 tonnes produced with a farm value of $41.5 million(2014)
Ontario fresh market tomato1: 19,025 tonnes produced with a farm value of $16.7 million (2013)
1. Source: Statistics Canada 2. Ontario Processing Vegetable Growers
