1. CATTS Quarantine Treatments for Tree Fruits
Time
Temperature
Atmosphere CA
CATTS Quarantine Treatments for Tree Fruits
Lisa G. Neven
USDA-ARS
Yakima Agricultural Research Laboratory

2. CATTS CA Controlled Atmosphere Temperature Treatment System
Time
Temperature
Atmosphere CA
Controls & Monitors:
O2, CO2, Air Speed,
Humidity, Dew Point, Air
Temperatures, Heat Rate,
Fruit Temperatures
(surface & core)

3. Time
Temperature
Atmosphere CA
What CATTS Does
Oxygen is reduced to a level which will not support active metabolism in the insects.
High carbon dioxide levels prevents the insect from ‘down regulating’ metabolism and respiration.
High temperatures cause metabolic stress in the insect, and large scale systems break down occurs.
Combination CA & Heat causes mortality about 2X as fast as heat alone.

4. Zone of Opportunity
Host Tolerances
Pest Intolerances
Illustration of the ‘zone of opportunity’ for optimization of insect mortality and commodity quality using a heat treatment.

5. Zone of Opportunity
Pest Intolerances
Host Tolerances
Illustration of the ‘zone of opportunity’ for optimization of insect mortality and commodity quality using a CATTS treatment.

6. Considerations for CATTS Treatments
Fruit Physiology
Insect Physiology
CATTS Treatments
Engineering of Commercial Units

7. Fruit on the Tree
While fruit are on the tree, they experience fluctuating temperatures.
In response to these fluctuating temperatures, the fruit produce a number of ‘stress response’ proteins.
The fruit will produce these proteins even if the daily temperatures are not in the ‘stress’ range every day.

8. Apple Temperatures During a Typical Summers’ Day in Washington State
August 12
12.0
17.0
22.0
27.0
32.0
37.0
42.0
12:05
1:35
3:05
4:35
6:05
7:35
9:09
10:39
12:09
1:39
3:09
4:39
6:09
7:39
Time
Temperature °C
air
deep
shallow
41.5°C
41.3°C

9. Peach Fruit Temperatures
on the tree 60 70 80 90
100
120
Temperature °F
12:00:00 AM
Time C1 C2 C3 C4
110

10. Cherries on the Tree in Tasmania
Cherry core temperatures in Tasmania, Australia where daily high air temperatures are below 30°C.

11. Fruit after Harvest
After harvest, the fruit will continue to make the ‘stress response’ proteins for a number of days.
These proteins will help the fruit tolerate heat treatments.

12. Fruit and CATTS
There is no evidence that the high carbon dioxide and low oxygen levels during CATTS causes any additional phytotoxicity.
This may be due to the high capacity for anaerobic metabolism in the fruit.
We do know that heating rate is very important for preventing damage.
We also know that heat disrupts many of the enzymes involved in ripening.

13. Insects in the Fruit
Insects in the fruit will also produce ‘stress response’ proteins when fruit temperatures reach ‘stressful’ levels.
Insects will only produce these proteins when they experience stressful temperatures.
When the fruit is harvested, and the insects are no longer exposed to stressful temperatures, they do not produce stress proteins.

14. Stress Proteins and CA
Insects cannot produce ‘stress response’ proteins if there is not enough oxygen to support metabolism.
We are not EXACTLY sure about the fruit, but we do fruit have a high capacity for anaerobic metabolism.

15. Scanning Metabolic Heat Rate15 11 9 7
Heat Rate µW/mg FW 3 -1 -5

16. Isothermal Heat Rates Heat Rate µW/mg FW 8 7 6 5 4 3 2 1 5 10 15 20 255 10 15 20 25 30 35 40 45 50
Temperature C

17. Codling Moth Pupal Respiration
0.06
Whole Range
0.05
uL CO2/mg/min = X Temp
R2 =
0.04
ul CO2/mg/min
0.03
0.02
10-30°C Range
uL CO2/mg/min = X Temp
0.01
R2 = 5 10 15 20 25 30 35 40
Temperature °C

18. VAPOR 48°C MOIST 48°C 1 2 3 4 ul CO2/mg/min 20 25 30 35 40 45 50 1001 2 3 4
ul CO2/mg/min 20 25 30 35 40 45 50
TEMPERATURE °C
100
150
200
250
300
TIME (min)
VAPOR 48°C 1 2 3 4
ul CO2/mg/min 20 25 30 35 40 45 50
TEMPERATURE °C
100
150
200
250
300
TIME (min)
MOIST 48°C

19. Importance of Heating Rate
We know that the faster the rate of heating, the shorter the time the insects have to be held at the final treatment temperature to kill them.
For example, CATTS at 12°C/h to final temperature of 46°C the core average temps have to be at 45°C for 30 min, while CATTS at 24°C/h to the same temperatures, cores only have to be at 45°C for 15 min.

20. Time at Final Temperature versus Heating Rate
ln(LT95) = b0 + b1ln(heat rate) + b2 (treatment temperature) 10 20 30 40
Time at Final Temp. (Hr)
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
Heat Rate 42 44 46
Where...
b0 = SE
b1 = SE
b2 = SE
R2 = 0.972

22. DSC

29. Diapause CM Oxycaloric Ratio

48. Treatments against….. Codling moth Oriental fruit moth
Western Cherry fruit fly

49. Treatments developed for..
Sweet Cherries
Apples
Peaches
Nectarines

50. Sweet Cherry CATTS
Two treatments have been developed and efficacy tests (5,000 killed, 0 survivors) against both CM and WCFF have been performed.
25 min at 47°C with 1% O2, 15% CO2.
45 min at 45°C with 1% O2, 15% CO2.
Fruit quality better than Methyl Bromide fumigated.
No commercial application has meet with specifications.

51. Efficacy & Confirmation Tests
Western Cherry Fruit Fly
45°C—6315 treated with 100% Mortality.
47°C—5800 treated with 100% Mortality
Codling Moth
45°C—5076 treated with 100% mortality.
47°C: treated with 100% Mortality.

52. Apples CA Two treatments developed.
Time
Temperature
Atmosphere CA
Apples
Two treatments developed.
12°C/h, 3h, chamber at 46°C with 1% O2, 15% CO2
12°C/h, 4h, chamber at 44°C with 1% O2, 15% CO2
Efficacy tests on CM and OFM using #1.
Confirmatory tests on CM completed using #1.

53. CATTS Conditions for an Apple
Quarantine Treatment
Supply
Core
Sur O2
CO2 20 25 30 35 40 45 50
Temperature °C 5 10 15
% Atmosphere
100
150
200
Time (min)
12°C/hr
Time
Temperature
Atmosphere CA

54. Fruit quality CATTS before storage helps maintain quality by…
Maintaining firmness
Preventing storage scald
Delaying ripening
Delaying decay
Increases SS/TA ratio (sweeter)

55. CATTS treatment of apples using 12°C/h, 46°C final chamber temperature, 1% O2, 15% CO2, -2°C dew point, and 2 m/s air speed.
Efficacy Tests
CM: treated. 100% Mortality.
OFM: treated. 100% mortality
Confirmation Tests
CM: 31, 271 treated. 100% mortality

56. Treatments developed:
Stone Fruits
Treatments developed:
12°C/h, 3h, chamber at 46°C with 1% O2, 15% CO2
24°C/h, 2.5h, chamber at 46°C with 1% O2, 15% CO2
Efficacy tests on both CM and OFM.
Confirmatory tests on CM.

57. Stone Fruit CATTS Oriental Fruit Moth Codling Moth Efficacy Tests
24°C/hr—5453 treated. 100% mortality.
12°C/hr—5674 treated. 100% mortality
Confirmation Test
Codling Moth
24°C/hr—31,154 treated. 100% mortality.
12°C/hr—30,884 treated. 100% mortality

58. Fruit quality Helps maintain quality by… Delaying ripening
Increasing extractable juices
Increasing shelf life
Barely perceptible changes in quality as compared to untreated controls.

60. Status of Commercialization
There is a 2 ton CATTS unit in WA.
The two pallet unit in Parlier, CA.
Thermo Tech Inc. in CA is making a ‘CATTS ready’ unit that is a forced air cooling system.
ECO2 in the Netherlands is making commercial units for sale, lease, and treatment contract.
Time
Temperature
Atmosphere CA

61. Lab-Scale CATTS Air flow from bottom of unit to top.
Maintains 1-2 m/s air flow.
CA established within 15 min.
No water on fruit surface.
Heating rates up to 100°C/hr.

62. Bin Configured Commercial CATTS Chamber

63. Placing temperature probes in apples.
Technicians after placing a mixed load into the 2 ton CATTS unit.

64. Bin Unit Horizontal air flow. Flow of ~1 m/s
CA established in min using nitrogen flush.
Humidification with micromisters.
Different bin/container configurations possible.
Heating rates up to 50°C/hr.

65. Pallet Configured CATTS Unit in Parlier, CA

66. Pallet Configured CATTS
Horizontal air flow less than 1 m/s.
Humidification with micromisters.
CA established in 30 to 60 min.
Heating rates up to 100°C/hr.
Does not work well with packed boxes.

67. Critical Factors for Commercial Units
Air flow maintained throughout load.
No water on fruit surfaces.
Oxygen levels 1.0% or lower.
Carbon dioxide levels between 10 to 15%.
Treat freshly harvested fruit within 5 days of harvest.
Do not treat fruit with pulp temperatures below 15°C.

68. Thank You!