2012 Annual Report
During the period 1 October 2011 to 30 September 2012, three primary sub-projects and three small secondary projects (also of importance to Hawaii’s agriculture) were conducted as follows:
Primary Sub-Projects: -Biofuel byproducts to supplement cattle grazing. -Use of algae for aquaculture feeds. -Marine agronomy for feed and biofuels.
Secondary Sub-Projects: -Vermicomposting. -Beekeeping. -Sustainable Technology for greenhouses.
Biofuel Byproducts to Supplement Cattle Grazing: Eight experimental paddocks have been developed at the University of Hawaii at Hilo farm in Panaewa to provide the capability for replicated supplemental feeding trials. The paddocks have electrical fencing to allow the paddocks to be subdivided to accomodate water troughs, and a chute area for weighing animals. Initial trials of mulato grass-glycine supplementation have been conducted to provide a baseline and to confirm that the livestock would readily graze the mulato grass. We plan to commence the full grazing trials in May 2013. Until then the pasture will be periodically grazed to maintain the site in good condition.
Use of Algae for Aquaculture Feeds: This sub-project had three major components: development of replicated facilities for feeding trials and pilot-scale microalgae culture facilities; and a feeding trial comparing a microalgae-based diet with a standard test diet. The new research capacity includes:
-A flexible fifteen 20 gallon aquaria system with filters allowing experiments with static water (fresh or saltwater), flowing freshwater, or recirculation (fresh or saltwater). -Dual 25 gallon tank systems (10 tank and 11 tank) with filters allowing experiments with static water (fresh or saltwater), flowing freshwater, or recirculation (fresh or saltwater). -Twelve 500 gallon tanks allowing experiments with static or flowing water (brack or salt). -A thirty six 300 liter bag system for microalgae culture.
One feeding experiment was done in which four diets were tested in tilapia fingerlings. Fish were fed to apparent satiation twice a day during12 weeks. Effects of diets on fish growth, survival, feed utilization and body composition were analyzed. Best results in terms of growth and feed utilization were obtained with the microalgae-based diet. A manuscript is under preparation.
Marine Agronomy for Biofuel and Fish Feed: A group of 20+ people from academia, industry, U.S. government, and financial institutions met in Las Vegas, NV in February 2012 to discuss the possibility of industrial-scale Marine Agronomy (mainly seaweeds farming) as a major source of food, animal feeds, and raw material for biofuels. Additionally, the group discussed how marine plants provide ecosystem services such as nutrient extraction, shelter and substrate that support fisheries. To act on the recommendations of the Las Vegas meeting, a Marine Agronomy web portal was created to facilitate communication within the group and to the public. This web portal’s basic structure is now operational at www.marineagronomy.org and is being populated with content.
Vermicomposting and their effects on plant growth and disease suppression: The effects of vermicomposts and their aqueous extracts ‘teas’ on the growth and productivity of crops and their efficacy in the managing the incidence of pests and diseases. Three experiments were conducted to evaluate the effect of vermaculture extracts on germination of tomato and lettuce seeds. Soaking seeds into vermicompost teas significantly (p<0.0001) increased germination percentage and seedling growth of tomato and lettuce compared to control. Another study examined the effect of vermicompost on ginger and ginger wilt disease. Results of this last study were inconclusive and will be examined again in field situations.
Beekeeping as an integral part of sustainable agriculture: Honey bees are an integral part of sustainable agriculture as pollinators of important agricultural crops and for the products that can be harvested from the hive. In Hawaii, honey bees play an even more crucial role in sustaining agriculture thereby lessening our dependency on imports. Presentations to the public were made and value added bee products were developed. Prototypes for hive design and other hive equipment were made and more land at the University of Hawaii at Hilo farm is being cleared for beehives to use for research.
Sustainable Technologies for Greenhouses: A treatment protocol consisting of hot water spray at 49 °C and neem oil with wettable sulfur as needed effectively managed common insect pests and diseases in container grown eggplants, tomatoes and bell peppers in an enclosed screened greenhouse. The hot water also enhanced crop growth with beneficial effects on yield. The screen mesh size (1 mm x 1.6 mm) aided with wall mounted solar-operated fans provided adequate ventilation and maintained conditions of temperature and RH inside the greenhouse favorable for crop growth. An experimental solar pasteurization unit provided the capacity to clean potting media of most soil insects, pathogens and some of the less heat resistant weed seeds.