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

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)

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.

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.

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.

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

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.

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

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

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

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.

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.

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.

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.

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

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

Codling Moth Pupal Respiration 0.06 Whole Range 0.05 uL CO2/mg/min = 0.001533 X Temp -0.00809 R2 = 0.977207 0.04 ul CO2/mg/min 0.03 0.02 10-30°C Range uL CO2/mg/min = 0.001942 X Temp -0.01618 0.01 R2 = 0.998422 5 10 15 20 25 30 35 40 Temperature °C

VAPOR 48°C MOIST 48°C 1 2 3 4 ul CO2/mg/min 20 25 30 35 40 45 50 100 1 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

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.

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 = 22.4462 + 1.0486 SE b1 = -1.5745 + 0.09844 SE b2 = -0.2970 + 0.02339 SE R2 = 0.972

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Diapause CM Oxycaloric Ratio

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

Treatments developed for.. Sweet Cherries Apples Peaches Nectarines

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.

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: 5759 treated with 100% Mortality.

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.

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

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

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: 5728 treated. 100% Mortality. OFM: 5497 treated. 100% mortality Confirmation Tests CM: 31, 271 treated. 100% mortality

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.

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

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

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

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.

Bin Configured Commercial CATTS Chamber

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

Bin Unit Horizontal air flow. Flow of ~1 m/s CA established in 20-30 min using nitrogen flush. Humidification with micromisters. Different bin/container configurations possible. Heating rates up to 50°C/hr.

Pallet Configured CATTS Unit in Parlier, CA

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.

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.

Thank You!