Location: Tropical Crop and Commodity Protection Research
Project Number: 2040-30400-001-000-D
Project Type: In-House Appropriated
Start Date: Jul 8, 2025
End Date: Jul 7, 2030
Objective:
Objective 1: Develop new or improved postharvest treatments or technologies for fresh tropical commodities to ensure security against quarantine pests and to improve quality and shelf-life.
Sub-objective 1A: Evaluate co-fumigation of low-dose ethyl formate and phosphine fumigation for mealybug control in ornamental exports.
Sub-objective 1B: Develop accurate, real-time, and non-destructive methods to determine the maturity of Hawaii ‘Sharwil’ and ‘Malama’ avocado for export markets.
Sub-objective 1C: Develop improved processing methods to produce consistent quality breadfruit flour for local and export markets.
Objective 2: Develop or improve new preharvest methods for the surveillance, detection, and control of invasive tropical plant pests of quarantine significance.
Sub-objective 2A: Determine the season-long flight phenology of macadamia nut borer and tropical nut borer in macadamia using semiochemical-based monitoring.
Sub-objective 2B: Manage macadamia nut borer in macadamia orchards using pheromone-based mating disruption.
Objective 3: Develop multiple-component systems approaches to control tropical plant pests and decrease the severity of or need for commodity treatments.
Sub-objective 3A: Develop a push-pull-kill system as a management strategy for the tropical nut borer in macadamia.
Sub-objective 3B: Develop a systems approach for export of Persian limes and Lisbon lemons from Hawaii to the continental United States.
Approach:
Objective 1A: To develop co-fumigation of low-dose ethyl formate and phosphine treatment, dose response tests will be performed with citrus mealybug life stages and different concentrations and exposure durations of ethyl formate and phosphine, tested alone and in combination, to determine lethal times (LC50 and LC99) and concentrations (LC50).
Objective 1B: To develop algorithms to determine avocado maturity, data will be taken for dry matter, oil content, and days to ripeness for avocado cultivars using non-destructive near infrared (NIR) detectors to build a predictive model and maturity index to help growers harvest and market high quality fruit.
Objective 1C: To develop infra-red blanching and drum drying processing methods for breadfruit flour with improved nutritional and sensory qualities, process factors that contribute to ‘ulu flour quality will be tested including no blanching (control) vs. IR blanching vs. steam blanching, hot air drying (control) vs. drum drying vs. dehydrator, by peeled and cored ‘ulu (control), vs. whole ‘ulu. For each processing combination, data will be collected on ascorbic acid levels and sensory properties, and specific energy consumption (cost/kg).
Objective 2A: To establish the phenology of key pests of macadamia, different trap types (delta, bottle, yellow sticky) and lures (pheromone, ethanol/methanol) will be compared to determine the best height and position in the tree and location in the orchard for capturing and monitoring tropical not borer and macadamia nut borer across six macadamia-growing areas on Hawaii Island throughout the year.
Objective 2B: To reduce infestation by macadamia nut borer using mating disruption, field trials will determine optimal dispenser rates (no. of dispensers per acre) and dispenser deployment strategies to reduce the numbers of MNB. Treatment effectiveness will be evaluated using delta traps baited with pheromone (checked bi-weekly) and regular sampling of macadamia nuts for eggs and injury.
Objective 3A: To reduce the damage caused by the tropical nut borer using a push-pull-kill management system, different chemicals will be used to manipulate the behavior and control tropical not borer in the field. Methanol (an attractant) will be used as the ‘pull’ component, verbenone and methyl salicylate (repellents) will be used as ‘push’ component, and cypermethrin will be used as the ‘kill’ component. Treatment effects on TNB numbers will be measured using methanol traps and nut damage estimates.
Objective 3B: To determine whether Persian limes and Lisbon lemons are conditional nonhosts for Oriental fruit fly and Mediterranean fruit fly, the host status of limes and lemons to Oriental fruit fly and Mediterranean fruit fly will be determined using small- and large-cage no-choice tests with punctured (damaged) or intact (no damage) fruit, followed by sleeve cage tests with punctured or intact fruit on the trees, and finally field collection of fruit to look for natural infestation. Fruits are held after fruit fly exposure for fly development and pupal and adult emergence.