Location: Tropical Crop and Commodity Protection Research
2016 Annual Report
Objectives
The long-term goals of our research program are to develop and protect U.S. export markets for fresh tropical commodities. An emphasis is placed on expanding and diversifying agriculture and agricultural exports in Hawaii and other states by providing environmentally sound, economically viable systems, treatments, or processes that control quarantine pests, ensure product quality, and increase product value while safeguarding the agriculture of other states. Our research will address four broad objectives over the next 5 years:
Objective 1: Develop new or improved postharvest treatments or technologies for fresh tropical commodities to ensure security against quarantine pests, including new irradiation treatments for western flower thrips, and various ants on fresh fruits.
Sub-objective 1A. Develop quarantine irradiation treatments for western flower thrips, coffee berry borer, rough sweetpotato weevil, and red imported fire ant.
Sub-objective 1B. Develop a quarantine cold treatment for melon fly in citrus.
Sub-objective 1C. Determine the effectiveness of hypobaric treatments against surface pests.
Objective 2: Develop new or improved postharvest treatments or systems (such as hypobaric storage and modified atmospheres) to improve quality and extend shelf life of tropical horticultural crops subjected to quarantine treatment.
Sub-objective 2A. Determine hypobaric storage conditions that retain quality and extend storage life of fresh tropical fruit.
Sub-objective 2B. Develop combination treatments of modified atmosphere packaging and irradiation to retain quality of exported fresh papaya.
Objective 3: Develop or improve preharvest methods for surveillance, detection, and control of invasive tropical plant pests of quarantine significance, such as coffee berry borer.
Sub-objective 3A. Study the ecology of Cathartus quadricollis and other predatory flat bark beetles and explore ways to increase their role in suppressing coffee berry borer populations in coffee.
Objective 4: Develop multiple-component systems approaches to decrease the severity of or need for commodity treatments.
Sub-objective 4A. Quantify systems approaches for quarantine security of melon fly.
Approach
The approach is to develop quarantine treatments, such as low dose irradiation and hypobaric treatments, and other mitigation techniques for fresh tropical commodities and ornamental crops. Quarantine irradiation treatment will be developed for rough sweetpotato weevil, in sweet potato, western flower thrips, red imported fire ant, and coffee berry borer. Optimum hypobaric treatment parameters for maritime shipment of tropical fruits to preserve quality and extend shelf life will be determined. We will establish the tolerance of tropical fruits to any new or modified quarantine treatments.To expand markets for high-value tropical specialty fruit, we will develop postharvest disease and packaging strategies to extend shelf life. Integrated pest management strategies for coffee berry borer will focus on understanding the population dynamics and ecology of predatory flat bark beetles and improving rear-and-release systems. A cold treatment will be developed for melon fly in citrus. Also, a systems approach will be developed for melon fly control in covered tomatoes using mass trapping, protein baits and sanitation.
Progress Report
This research project develops preharvest and postharvest treatments or systems to control quarantine pests, while retaining the quality and shelf-file of tropical crops. The project supports the expansion and diversification of U.S. exports of fresh tropical crops, while protecting U.S. agriculture from pest incursions. Proposed irradiation quarantine treatments are under review by the Animal and Plant Health Inspection Service (APHIS) for spotted wing drosophila (80 Gy), light brown apple moth (150 Gy, eggs and larvae), and moths in the family Tortricidae (250 Gy, eggs and larvae).
Irradiation in combination with basil essential oil was shown to provide synergistic control of rice weevil, and Aspergillus and Penicillium molds in packaged rice. Red imported fire ant queens can be sterilized by irradiation treatment at 100 Gy which may be useful to prevent movement of this ant in certain agricultural products. The predatory beetles Leptopholoeus sp. and Cathartus quadricollis are being promoted as a component of an integrated pest management program against coffee berry borer, an important new pest of Hawaii coffee. Coffee growers were provided with starter kits and are now independently raising and releasing the predatory beetles on their farms. Rough sweet potato weevil (RSPW) is a new filed pest of Hawaii sweet potatoes and a potential regulatory pest in exported roots, which totaled 14 million pounds in 2015. The 150 Gy irradiation treatment developed for three other regulatory pests was shown to be effective in controlling RSPW as well. Hypobaric treatment (low oxygen partial pressure) may allow refrigerated tropical fresh fruits to be maintained for months without loss of edible quality. Cherimoya fruit stored at 2.7 kilopascal (kPa) pressure, 100% radiation hardened (RH), and 12 degrees Celsius (C) had 10 to 12 days extended storage life when compared to control fruit stored under ambient pressure (100 kPa). In contrast, rambutans stored at 2.7 kPa pressure, 100% RH, and 10 degrees C had minimal storage life extension (3 days) when compared to control fruit. For papaya, modified atmosphere packaging (MAP) using polymer-blend films with high moisture vapor transmission rates produced 1-3 percent carbon dioxide (CO2) steady state levels within packages during storage at 10 degrees C, and 5-10 percent CO2 at 22 degrees C. Shelf-life (15.5 days) and quality were similar for control (box only) and packaged (MAP) fruit, however MAP reduced fruit weight loss from 5.3 percent to 2.3 percent.
Accomplishments
1. Proved the efficacy of irradiation quarantine treatments against ants. Ants can be problematic hitchhiker pests in exported fruits and vegetables that cause rejection or return shipment. Irradiation is a postharvest quarantine treatment option to control ants and other hitchhiker pests on fresh horticultural products traded between countries. ARS scientists in Hilo, Hawaii, and foreign collaborators conducted the first radiation tolerance studies with ants, including the big headed ant, little fire ant, Argentine ant and red imported fire ant to establish radiation doses to provide to regulatory officials at the Animal and Plant Health Inspection Service (APHIS) and California Department of Agriculture. Queens of all species were sterilized at doses less than 125 gray (Gy), suggesting that the commonly used generic dose for fruit flies (150 Gy) will also control any hitchhiking ants.
2. A systems approach developed to export Hawaii Sharwil avocados for the first time in 25 years. Sharwil avocados are known for their large size and buttery taste. Export of all Hawaii avocados to the mainland was banned in 1992 after a fruit fly species was found in an outbound shipment. Avocados could still be sent if they went through a fumigation process, but that can affect taste. ARS scientists in Hilo, Hawaii, conducted research to support the systems approach and wrote the technical report to the Animal and Plant Health Inspection Service (APHIS) requesting the export protocol. APHIS approved the systems approach for Hawaii avocado in 2013. A first shipment of Sharwil avocados was made three years later in 2016 (951 pounds to Minneapolis, Minnesota), and several growers are planting new avocado orchards to take advantage of the export program.
ARS scientists in Hilo, Hawaii, have participated in activities targeting small farmers and minority stakeholders including: 1) mentoring native Hawaiian and Asian undergraduate students; 2) determining optimal postharvest practices for specialty fruit grown on small farms, 3) developing irradiation and other quarantine treatments for new invasive pests that limit exports, 4) developing value-added products and delivering workshops for small, diversified growers; and 5) holding workshops and developing rear-and-release materials for flat bark beetle predators of coffee berry borer.
Review Publications
Lacroix, M., Follett, P.A. 2015. Combination irradiation treatments for food safety and phytosanitary uses. Stewart Postharvest Review. 11(3):1-10.
Hossain, F., Follett, P.A., Salmieri, S., Vu, K., Harich, M., Lacroix, M. 2015. Evidence for synergistic activity of plant-derived volatile essential oils against fungal pathogens of food. Food Control. 45:156-162.
Haff, R.P., Jackson, E.S., Gomez, J., Light, D.M., Follett, P.A., Simmons, G.S., Higbee, B.S. 2015. Building lab-scale x-ray tube based irradiators. Journal of Radiation Physics and Chemistry. 121:43-49.
Wall, M.M. 2015. Phytosanitary irradiation and fresh fruit quality: Cultivar and maturity effects. Stewart Postharvest Review. 11(3):1-6.
Madani, B., Wall, M.M., Mirshekari, A., Bah, A., Mohamed, M. 2015. Influence of calcium foliar fertilization on plant growth, nutrient concentrations, and fruit quality of papaya. HortTechnology. 25:496-504.
Youn, U., Park, E., Kondratyuk, T.P., Sang-Ngern, M., Wall, M.M., Wei, Y., Pezzuto, J.M., Chang, L. 2016. Anti-inflammatory and quinone reductase inducing compounds from fermented noni exudates. Journal of Natural Products. 79(6):1508-1513.
Sang-Ngern, M., Youn, Y., Park, E., Kondratyu, T.P., Simmons, C.J., Lorch, S.E., Wall, M.M., Pezzuto, J.M., Chang, L. 2016. Withanolides derived from Physalis peruviana (Poha) with potential anti-inflammatory activity. Bioorganic and Medicinal Chemistry Letters. 26(12):2755-2759.
Sim, S.A., Yoneishi, N., Brill, E., Geib, S.M., Follett, P.A. 2015. Molecular markers detect cryptic predation on coffee berry borer (Coleoptera: Curculionidae) by silvanid and laemophloeid flat bark beetles (Coleoptera: Silvanidae, Laemophloeidae) in coffee beans. Journal of Economic Entomology. 109(1):100-105.
Follett, P.A., Neumann, G., Hollingsworth, R.G., Swedman, A., Sibucao, R. 2016. Release and establishment of Encarsia diaspidicola (Hymenoptera: Aphelididae) against white peach scale in papaya. Hawaiian Entomological Society Proceedings. 47:51-54.
