Sunn-hemp, Crotalaria juncea L. cv. Tropic Sun was developed in Hawaii in 1982 and recently introduced to the island of Guam by USDA Soil Conservation Service as a potential green manure crop. An evaluation of various legumes at three different soil regimes revealed that sunn-hemp produced greater biomass than other plants. In the study of the effects of sunn-hemp in subsequent vegetable production, slightly greater canopy was observed for potato, Solanum tuberosum cv. Kennebec, with green manuring with sunn-hemp than without. Yield of head cabbage, Brassica oleracea var. capita cv. KK Cross, was higher with green manuring (1085.5g/head) than without (725.4g/plant). Competition between indigenous rhizobia and introduced inoculant seems to exist at some locations. Major constraints in using sunn-hemp as green manure on the island are its limited seed sources and requirements of additional labor. Education and promotion of using this legume in a long term soil-improving system is needed.
Glenn Takai* and Mari Marutani
Hot peppers (Capsicum sp.) were introduced to Guam and other Mariana Islands and became a “necessary” ingredient of local cuisine. Seven hot pepper accessions, including four local cultivars, were grown in calcareous soils on Guam and evaluated for total yield, marketable yield, the number of fruit, and weight of fruit. `Hot Beauty', a Taiwan cultivar, produced the highest total and marketable yields. `Group Zest', another Taiwan cultivar, was the earliest maturing cultivar and produced the largest fruits. `Guafi', a local cultivar, was the latest maturing cultivar. Consumer preference for hot pepper is being studied as fresh market and as processed hot sauce.
Mari Marutani and Veronica Endirveersingham
The effect of shade covers on degradation of insecticide, carbaryl on field-grown pakchoi (Brassica rapa subsp. chinensis) was examined by a commercial enzyme-linked immunosorbent assay (ELISA) kit. Carbaryl at a.i. 10.6 g·L-1 (1.42 oz/gal) was applied to the plants grown under five different shade treatments including control without any coverings. The experiment was arranged in a randomized complete block design with three replications. Pesticide residue on leaf tissues was examined on dates of 1, 3, 5, and 7 days after pesticide application. On all sampling dates, pesticide residue was greater with treatments with higher shade percentage. Both linear and quadratic relationship of shade (independent variable) and the concentration of remained carbaryl (dependent variable) were significant (P < 0.05). The half-life of carbaryl on pakchoi leaves ranged from 2 days for control to 9 days for the heaviest shade (75%) treatment with rain protection.
James McConnell and Mari Marutani
A Print-On-Demand (POD) System was developed for the rapid production of educational and extension materials such as fact-sheets. Information is stored in a final format on the computer and the number of copies of a specific publication can be printed as needed. The system greatly reduces the time to having the finished product and allows any number of publications to be printed. The printing cost ranges from $.43 to $.80 per page with a 300dpi color thermal wax printer.
Photo CDs and video capture images are the most common sources of color images used in the POD system. Photo CDs produce higher quality images but require time to process a film before images are used in the system. In live video capture, an image can be captured by a video camera, and sent to a computer for immediate production of a fact-sheet. Tape playback reduces the image quality compared to live video. Live video also gives the best feedback in determining whether the image shows the desired information. In general, the image is video captured at twice the needed size and reduced while increasing the resolution from 72 dpi to 130 dpi. This produces a better quality image. Other sources of pictures are flatbed scanners and slide scanners.
Rozalyn Pama*, Jay Doronila and Mari Marutani
Fifteen sweetpotato [Ipomoea batatas (L.) Lam] accessions grown on Guam were studied for morphological and genetic characteristics. Accessions, obtained from AVRDC (Asian Vegetable Research and Development Center) in Taiwan, Saipan, Rota, and Guam, were investigated for marketable yield, growth habit and characteristics of tuberous roots (color, shape, sugar content and moisture content). Results of this study were used to determine the morphological relationship of the accessions of sweetpotato. Phenetic analysis revealed four major clusters according to tuberous root characteristics. The genetic relationship of these sweetpotato accessions was also evaluated for genetic differences among accessions. DNA was extracted and went through polymerase chain reaction (PCR). PCR products were analyzed by random amplified polymorphic DNA (RAPD) fingerprinting. Result of the genetic relationship among the sweetpotatoes was compared with the morphology of accessions using UPGMA cluster analysis and principal compounds analysis.
James McConnell, Louise Q. Naholowaa and Mari Marutani
A survey was conducted in Guam to determine the preferred uses and preferred flowers and foliage for leis and mwarmwars. Mwarmwars are a form of lei that is worn on the head. Mwarmwars were introduce to Guam by Carolinians. Lei giving is popular for special occasions to signify honored guests, as a token to loved ones, or given to travelers. In Guam, it is popular to give mwarmwars and leis as gifts to middle school, high school and college students. Preferred characteristics of flowers and foliage are wilt resistance and those that are not fragile. The most popular flowers are orchids, plumeria, mini carnations, baby's breath, bougainvillea, alstromeria, crown flowers, mini daisies, red ginger, spray roses, and sweetheart roses. The most popular foliage are leather leaf fern, polyscias, ti leaf, asparagus fern, and lemon leaves. The majority of the flowers and foliage are imported.
Mari Marutani, Joseph Tuquero, Robert Schlub and James McConnell
The effects of a vesicular–arbuscular mycorrhizal fungus, Glomus aggregatum inoculation were examined on growth of vegetable crops in pot culture and field experiments with Guam cobbly clay loam soil (clayey, gibbsitic, nonacid, isohyperthermic Lithic Ustorthents). In pot experiments, the growth response of yard-long beans (Vigna unguiculata subs. sesquipendalis), sweet corn (Zea mays), watermelon (Citrullus lanatus), cucumber (Cucumis sativus), okra (Abelmoschus esculentus), green onion (Allium fistulosum), eggplant (Solanum melongena), and papaya (Carica papaya) were significantly improved with mycorrhizal inoculation. A pot experiment was also conducted to evaluate effects of G. aggregatum inoculation on the growth of corn seedlings at four different water regimes. Seedlings inoculated with G. aggregatum significantly improved the plant growth and the mineral uptake at all levels of water treatments. In the first field trial, prior to seed sowing the media in seedling trays were either inoculated or not inoculated with G. aggregatum. Treated watermelon and eggplant seedlings were transplanted in field. It was found that inoculating seedlings did not improve the harvest yield of two fruit-bearing crops. The second field experiment was conducted to study G. aggregatum inoculation and different levels of inorganic fertilizer application on growth of corn. Mycorrhizal colonization had positive effects on corn development and uptake of some minerals such as Fe. Experiments in the study suggested potential uses of a mycorrhizal fungus in an alkaline soil in the tropics.
James McConnell, Mari Marutani, Robert Schlub, Lynn Raulerson, Lauren Gutierrez and Gregoiro Perez
This publication was produced with the goal of printing the booklet on demand. The photographs were from multiple sources: scanned film, digital photographs (camera), and digital photographs (flatbed scanner). Fifty-six plants were included. Each plant was allocated four half-letter-size pages (one double-sided letter). These four pages include text descriptions of the plants and about nine images to give the user information on habit, seed, fruit, inflorescence, flower, stem characteristics, leaf pattern, pest damage, and other unique characteristics. Magnified images were used as necessary. The original digital images were in either TIFF or RAW format. The final images were in either TIFF or PSD format. Images were edited in Adobe Photoshop and various plug-ins used to enhance the images to optimize color and information that could be obtained from the printed image.
Mari Marutani, John Brown, Mark Acosta, Joseph Sablan, Sheeka Afaisen and James McConnell
A grant to construct a “Model Farm” on Guam and the Virgin Islands was approved in 2000 by the USDA/CSREES/Initiative for Future Agriculture and Food Systems Program. The main goal was to establish an integrated model farm that had potential benefits for small agricultural enterprises operated by Asian-Pacific and Caribbean Islanders. University of Guam Triton Farm was established on 3.75 acres (1.5 ha) of the Agricultural Experiment Station. Initially we conducted a soil survey, and established windbreaks/hedgerows. We also built the foundation for aquaculture/aquaponic system, field irrigation systems, and animal production facilities. Then, we planted long-term fruit and ornamental plants while growing short-term vegetable crops for quick returns. Currently we raise tilapia (Oreochromis niloticus), goats (Capra hercus) and layer-chickens (Gallus gallus). We grow banana (Musa spp.), calamansi (X Citrofortunello mitis, hot peppers (Capsicum spp.), cucumbers (Cucumis sativus), lettuce (Lactuca sativa), eggplants (Solanum melongena), and Ti-leaf (Cordyline terminalis). We also try to develop value-added products using local produce. Occasionally we investigate other potential commodities and operational schemes for the farm. These must be suitable for Guam's agro-climate and social and economic structure. We focus on conservation of natural materials, composting, and sustainable agriculture. Education and outreach activity is also an important component of the farm to disseminate technologies and to educate young children about farming.