Progress 01/01/04 to 12/31/06
Outputs
Progress Report 4d Progress report. This final report serves to document research conducted under a reimbursable agreement between ARS and the California Department of Food and Agriculture. Additional details of research can be found in the report for the parent CRIS 5320-43000-014-00D "Postharvest Treatment of Tropical Commodities for Quarantine Security, Quality Maintenance, and Value Enhancement." The controlled atmosphere temperature treatment system (CATTS) was used to apply heat and modified atmosphere (high CO2 and low O2) to fruit as a quarantine treatment to control fruit flies. We developed treatments against fruit flies for fruits of interest to California with commercial plantings in Hawaii, including guava, longan, passion fruit, and persimmon. Previous research demonstrated that the most heat tolerant species and life stage is Mediterranean fruit fly eggs and all tests focused on this species and stage. We successfully developed a number of different
heat treatments without modified atmosphere to control fruit flies in the different fruits. Fruit flies were controlled in passion fruit, guava, and longan by raising the temperature of the fruit at the seed surface or fruit core to 46 degrees C or 47 degrees C during 2 h, and holding the temperature for 30-45 min. A total of 46,000, 33,000, and 24,000 Medfly eggs were treated with no survivors in passion fruit, longan, and guava, respectively. Fruit quality data are currently being organized and analyzed. Publications will be prepared later this year.
Impacts
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Progress 10/01/04 to 09/30/05
Outputs
4d Progress report. This report serves to document research conducted under a reimbursable agreement between ARS and California Department of Food and Agriculture. Additional details of research can be found in the report for the in- house associated project 5320-43000-014-00D, Postharvest Treatment of Tropical Commodities for Quarantine Security, Quality Maintenance, and Value Enhancement. The research investigates the use of a controlled atmosphere temperature treatment system (CATTS) to control Mediterranean fruit fly, oriental fruit fly, and melon fly eggs and larvae in avocados, guava, longan, passion fruit, and persimmons. Controlled atmosphere treatments modify levels of gases such as O2 and CO2 from ambient air, in combination with heat, to reduce the time necessary for 100% kill of fruit flies compared with heat treatment alone. Avocado fruit infested with Mediterranean fruit fly eggs were subjected to 44, 45, and 46DGC heat treatments with and without
preconditioning at 38DGC for 10 hours to develop heat tolerance in the avocados. Although insect mortality was 100% in the 46DGC treatment, the fruit quality was unacceptable. Quality improved but insect mortality decreased to 99.71% in the preconditioned fruit treated at 46oC. The 45DGC treatment without preconditioning still provided only 99.71% insect mortality although the quality was similar to control fruit. Therefore, use of controlled atmospheres to improve insect kill and fruit quality in avocado were unsuccessful.
Impacts
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Progress 10/01/03 to 09/30/04
Outputs
4. What were the most significant accomplishments this past year? D. Progress Report This report serves to document research conducted under a reimbursable agreement between ARS and the California Department of Food and Agriculture. Additional details of research can be found in the report for the parent CRIS 5320-43000-013-00D, Postharvest Treatments for Quarantine Security and Quality Maintenance of Tropical Commodities. We are investigating the use of a controlled atmosphere temperature treatment system (CATTS) to control Mediterranean fruit fly, oriental fruit fly, and melon fly in persimmons, avocados, guava, longan, and passion fruit. Controlled atmosphere treatments modify levels of gases such as O2 and CO2 from ambient air, in combination with heat, to reduce the time necessary for 100% kill of fruit flies compared with heat treatment alone. A treatment was developed for persimmons using heat alone. Ramping the internal fruit temperature from ambient to 47.2
during 4 h was effective in killing fruit flies and maintaining quality in mature firm persimmons. For avocados, treatment at 46 degrees C for 2.5 h with 1% O2 and 20% CO2 provided high kill but quality was variable. Modifications to this treatment regime to maintain fruit quality are currently being investigated.
Impacts
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