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United States Department of Agriculture

Agricultural Research Service

Research Project: BIOLOGICAL, BEHAVIORAL, AND PHYSICAL CONTROL AS ALTERNATIVES FOR STORED PRODUCT AND QUARANTINE PESTS OF FRESH/DRIED FRUITS AND NUTS

Location: Commodity Protection and Quality

Title: Implementation of CATTS treatment using boxed/palletized peaches and nectarines

Authors
item Obenland, David
item Neven, Lisa

Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: November 10, 2009
Publication Date: November 10, 2008
Citation: Obenland, D.M., Neven, L.G. 2008. Implementation of CATTS treatment using boxed/palletized peaches and nectarines. International Conference on Methyl Bromide Alternatives and Emissions Reductions, November 10-13, 2009, San Diego, CA. 89:1-3.

Interpretive Summary: Forced hot air combined with a controlled atmosphere consisting of 1% oxygen and 15% carbon dioxide (CATTS) has been previously shown to be an effective quarantine treatment that does not adversely affect stone fruit quality. Although prior work with CATTS treatment has utilized bulk treatments in bins, the preferred treatment format that would best fit the practices of the California stone fruit industry would be using boxed fruit stacked on pallet. A large chamber capable of simultaneously treating two full pallets of boxed fruit was utilized to evaluate the effect on insect efficacy and fruit quality of CATTS treatment in this manner. Negative effects on quality due to treatment were noted for all three of the nectarine varieties tested with the percentage of marketable fruit being reduced substantially due to surface injury, decay and internal browning around the pit. Uneven heating among the boxes caused by poor air flow was a likely contributor to the negative effects on quality. Complete insect mortality was achieved in all of the boxes, but only using treatments of a greater severity than were used for the fruit quality portion of the testing. This research has helped define the problems associated with CATTS treatment of boxed/palletized fruit and will aid in developing the box and treatment chamber modifications that will be necessary for this to be a viable treatment.

Technical Abstract: Forced hot air combined with a controlled atmosphere consisting of 1% oxygen and 15% carbon dioxide (CATTS) has been previously shown to be an effective quarantine treatment that does not adversely affect stone fruit quality. Although prior work with CATTS treatment has utilized bulk treatments in bins, the preferred treatment format that would best fit the practices of the California stone fruit industry would be using boxed fruit stacked on pallet. A large chamber capable of simultaneously treating two full pallets of boxed fruit was utilized to evaluate the effect on insect efficacy and fruit quality of CATTS treatment in this manner. Three nectarine varieties in single-layer boxes were heated using forced hot air ramped from 23 °C to 46 °C at 18 °C/h. Heating was continued until the pit surface temperature of the coolest fruit was at 43 °C or higher for 30 min. Fruit quality in all three tested varieties was significantly reduced, primarily due to an increase in surface injury, decay and internal browning around the pit. Heating was very uneven among the boxes and was likely a major cause of the loss in fruit quality. Complete insect mortality was achieved in all of the boxes, but only using treatments of a greater severity than were used for the fruit quality portion of the testing. Changes in box and treatment chamber design will be needed to enhance airflow and heat transfer characteristics to reduce treatment time and lessen the negative effects on fruit quality.

Last Modified: 9/1/2014
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