Hot Water Treatment Project


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Adoption Evaluation Form: Propagative Material (PDF)

FINAL REPORT DUE: January 2000

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Project Title: Hot Water Treatment for Cut Flowers and Propagative Materials

Project Investigators: A. Hara, R. Yamakawa, E. Mersino, N. Nagata, K. Sewake, and R. Hamasaki

Project Goal: Demonstrate to growers the effectiveness and practicality of the hot water treatment and implement the treatment at commercial shipping facilities.

Designed and tested by the University of Hawaii (UH), College of Tropical Agriculture and Human Resources (CTAHR) and UH Hilo, College of Agriculture. Research results have demonstrated that hot water treatment can effectively disinfest flowers, foliage, and propagative materials (taro huli, banana corms, ginger roots, etc.) of insects, mites, and nematodes without significant effects on plant quality. Hot water treatment can also enhance propagative and vase life qualities. Adoption of hot water treatment by growers and shippers will significantly reduce the use of toxic pesticides.  The hot water treatment system was developed by Dr. Arnold Hara, UH Hilo Entomology. A "Hands -On" hot water treatment demonstration will be conducted on the all major cut flower and foliage producing islands.

The Hot Water Treatment project received funding from the UH IPM Smith Lever 3 (d) Extension program funds in January 1998. Since then, eight organized educational demonstrations were conducted on the islands of Oahu, Kauai, Maui, and Hawaii. In addition, demonstrations were also held at various county 'agricultural festivals' throughout the year. A total of 124 growers attended the eight organized demonstrations conducted by project investigators. Additional demonstrations will be conducted in 1999. Thus far, surveys indicate 41 growers are interested in adopting the HWT system. Interested growers represent 22% of the cut flower and foliage industry and 29% of the export industry. Project members will continue to demonstrate to interested growers the benefits of the HWT system.

Preliminary surveys conducted on three growers who have adopted the HWT system show a reduction in pesticide use by 80-90%, a reduction in labor requirements, and a reduction in export rejection rates. The HWT system also increases the vase life of certain products.  Growers who have adopted the HWT system represent 14% of the cut flower and foliage industry and 8% of the export industry. Two additional commercial distributors have made commitments to adopt the complete system. After adoption, project members will work with growers in obtaining impact figures.

In addition, hot water treatment demonstrations have sparked interest in other crops. Banana corm, taro huli, ginger root, and other propagative material susceptible to insect and root pest have discovered the benefits of hot water treatment. Several growers have reported hot water treatment of propagative material disinfest pest without damaging plant quality and also increases propagation and uniformity of planting material.

Anticipated Outcomes:

1) Adoption of non-chemical hot water treatment by shippers will eliminate the use of postharvest insecticidal dips, and promote the efficient and sustainable agricultural practices that protect, sustain, and enhance water and soil resources and ultimately achieve greater harmony between agriculture and environment.

2) Rate of quarantine rejections of flower shipments will be reduced because hot water is more effective than insecticidal dips.

3) Major shippers of tropical flowers and foliage responsible for 90% of the state export floriculture products will be aware of the benefits of hot water treatment.

4) Thirty percent of these major shippers will adopt the hot water treatment by the end of this one-year project.

5) Hot water treatment installed at shipping houses will be certified and incorporated into the California-Hawaii Origin Inspection Program.

Schematic diagram of hot water treatment tank

Current Impacts:

1) Environmental Impact: With the implementation of the HWT, disposal of pesticide solutions have been reduced by 175 gallons per week.

2) Educational Impact: HWT presentations and demonstrations increased awareness to over 1,643 participants statewide in 1998. Growers responsible for 90% of the states export floriculture industry are now aware of the benefits of the HWT. As a result, the HWT system has been recognized and approved as a quarantine treatment by the USDA, APHIS (Animal and Plant Health Inspection Service), California Dept. of Food and Agriculture and the Hawaii Dept. of Agriculture. It is incorporated in the California-Hawaii Origin Inspection Program that allows cut flowers and foliage to enter California without quarantine inspection.

3) Economical Impact: Growers who adopted the system report increased benefits with lower labor cost and increased environmental protection. The adoption of hot water treatment systems by three commercial floriculture exporters (14% of industry) provides effective quarantine treatment for insect pest and reduces quarantine rejection rates from 50-100%. A conservative estimate of losses (value of sales, cost of fumigation at port of entry & damage to flowers by treatment) prior to HWT adoption (by the three growers) totals over $15,200.00. With the adoption of HWT, losses dropped to $5,140.00, a 34 percent drop in annual losses. Additional time is needed before final conclusions are drawn.