- Additional Plants: ginger
- Crop Production: crop rotation, cover crops, multiple cropping
- Education and Training: demonstration, extension, farmer to farmer, focus group, on-farm/ranch research, participatory research, workshop
- Farm Business Management: whole farm planning, budgets/cost and returns, feasibility study, agricultural finance
- Natural Resources/Environment: biodiversity
- Pest Management: compost extracts, cultural control, field monitoring/scouting, integrated pest management, mulches - killed
- Production Systems: holistic management, integrated crop and livestock systems
- Soil Management: earthworms, green manures, soil microbiology
- Sustainable Communities: local and regional food systems, new business opportunities, employment opportunities, sustainability measures
Edible ginger (Zingiber officinale) is a high-value crop in Hawaii. Bacterial wilt of ginger (caused by Ralstonia solanacearum race 4) has caused a precipitous decline in production since 1992-93. The bacteria persist for years in soil and much of the available land in Hawaii Island is now unsuitable for ginger production after 15 years of outbreaks. The overall objective is to develop and demonstrate sustainable farming practices that will help control bacterial wilt. Specific objectives are to: 1) demonstrate importance of clean planting materials; 2) demonstrate procedures to test fields for R. solanacearum; 3) conduct field studies to determine the effectiveness of green manure crops or rotational crops for pathogen control; 4) conduct greenhouse studies to determine effectiveness of vermicomposts to control R. solanacearum; 5) conduct economic analysis of farming practices; and 6) disseminate information and enhance farmer adoption of practices through a video and a web site.
Project objectives from proposal:
The overall goal of this project is to develop and demonstrate sustainable farming practices that control bacterial wilt in edible ginger. Specific objectives are to: 1) demonstrate the importance of clean planting materials; 2) demonstrate procedures to test fields for R. solanacearum; 3) conduct field studies to determine the effectiveness of green manure crops or rotational crops for pathogen control; 4) conduct greenhouse studies to determine effectiveness of vermicomposts to control R. solanacearum; 5) conduct economic analysis of sustainable, farming practices; and 6) disseminate information and enhance farmer adoption of practices through a video and a web site.
Objective 1. Pathogen-free planting material is a basic requirement of any disease management program. It is particularly difficult for crops such as ginger that are grown from vegetative propagules or rhizomes. Most growers perform a pre-plant hot-water dip to reduce or eliminate pathogenic nematode populations, and to break shoot dormancy. We have developed a decontamination procedure for R. solanacearum using hot water to raise the core temperature of ginger propagules to 50C for 10 minutes (12). Alternatively, our team has used hydroponic culture to multiply disease-free planting materials (6). There is a need to demonstrate the use of these two techniques to farmers so that they can plant disease-free ginger propagules. Performance target: Adoption of these new technologies by 25 percent of farmers.
Objective 2. In Hawaii, almost all ginger production is located on Hawaii Island, due to the presence of volcanic ash soil and abundance of rainfall. Ralstonia solanacearum can survive for years in soil, and most of the fields on Hawaii Island are now contaminated. Our team has developed bioassays (7, 8) and PCR-based tests (10, 11) to allow for sensitive, rapid, and repeatable evaluation of soils for the presence of the pathogen. We will test fields of farmer-cooperators for the presence of the pathogen prior to planting to demonstrate the importance of planting disease-free ginger propagules into clean fields. Performance target: Adoption of these new technologies by 25 percent of farmers.
Objective 3. For fields that are infested with the pathogen, a cropping system needs to be developed that will allow for sustainable ginger production. We will establish two on-farm trials to study the effectiveness of deep-plowing and various green manures or rotational crops on reduction of pathogen populations. Performance target: Increased knowledge of these new cropping systems will be gained by 50 percent of farmers.
Objective 4. Vermicomposting is a term adopted for a commercially-developed process that uses organic waste-consuming species of earthworms to process agricultural, industrial and domestic organic wastes into cast materials. We will conduct two greenhouse studies on the effectiveness of vermicomposts to suppress R. solanacearum. Performance target: Increased knowledge of vermicomposts will be gained by 50 percent of farmers.
Objective 5. This project will focus on adoption of new technologies by ginger farmers. Diffusion theory suggests that five characteristics that influence how quickly an innovation will be adopted include: a) relative advantage, b) compatibility, c) complexity, d) trialability (degree to which an innovation can be tried), and e) observability. We will form focus group(s) to examine each of these factors for each new practice. Performance target: Adoption of proven technologies by 25 percent of farmers.
Objective 6. We will produce a video and a web site that will illustrate the use of these new technologies. This video and web site will help farmers learn about the relative advantages, observe the new technology (i.e. observibility) and encourage them to try the new technology (i.e. trialability). Performance target: Adoption of new technologies by 25 percent of farmers.