Research Series, 1981 - 1986

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    Green Manure and Legume Covers in the Tropics
    (University of Hawaii, 1988-09) Yost, Russell ; Evans, Dale
    Growing leguminous plants for multiple uses has lately received renewed interest. Costs of fossil-based nitrogen fertilizer, after being unrealistically low for decades, have increased. Supplying nitrogen through biological fixation is attractive, but systems that accomplish this are needed in both temperate and tropical farming systems. Biological fixation as a source of nitrogen is natural for leguminous crops, yet the consumers of most nitrogen fertilizer are the major food cereals. One way these can obtain biological nitrogen is through the judicious use of green manures and legume covers. This report provides an overview of literature describing various legumes and the cropping systems in which they are used in the humid tropics. Systems described include rice and green manures, plantation crops and legume covers, root crops and green manures, and some upland crops and green manures. A survey of current use of green manures and legume covers was conducted in 1981 as a preliminary part of the study. Alternative sources of nitrogen are both more attractive for use in complex tropical farming systems and more in demand because of the scarcity of other nitrogen sources and of nitrogen ferHlizer in many tropical countries. It seems apparent that biological nitrogen should be viewed as a complement to fertilizer nitrogen. The appropriate mix of the two is hard to assess because of inadequate or expensive techniques for measuring the amounts of nitrogen contributed by the green manure or legume cover. We emphasize the need to assess the advisability of legume use in particular situations from a farming systems research and development perspective because of the biologic, economic, and social complexity of tropical farming systems. As a result of the study, we emphasize that knowledge gaps or research needs exist as follows: 1. Techniques to measure nitrogen contributed by the green manure or legume cover are inadequate. 2. Viable seeds for legume germplasm evaluation are hard to get. 3. There is not enough information on the characteristics of various candidate green manures and legume covers and on their climate and soil requirements. Such data could be used in screening candidate legumes.
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    Performance of Wood Products as Media for Culture of Anthuriums
    (University of Hawaii, 1985-09) Higaki, Tadashi ; Imamura, Joanne S.
    A study was conducted on Anthurium andraeanum Andre cv. Kozohara Red testing wood bark, wood chips, redwood bark, and bagasse media with fertilizer levels of 100, 200, and 400lb N-P205 -K20/A/year. Media ranking from best to poorest for flower production, flower stem length, and flower size were wood bark > wood chips > bagasse = redwood bark. Flower production and flower size increased linearly with increase in fertilizer rate. Flower stem length was not affected by fertilizer rate. Fertilizer response was similar on all media.
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    A study of Some Morphological and Anatomical Aspects of Anthurium andreanum Lind.
    (University of Hawaii, 1984-07) Higaki, T. ; Rasmussen, H.P. ; Carpenter, W.J.
    Anthurium andreanum Lind. is a perennial,. herbaceous monocotyledon in the family Araceae with cordate leaves and flowers. The commercial "flower" is an inflorescence consisting of conspicuous bract (spathe) and protruding rachis (spadix), on which minute perfect flowers are borne helically. The flowers are protogynous; the stigma is receptive before the pollen is shed. Anatomically, the spathe has a uniseriate upper and lower epidermis,one or two layers of hypodermal cells, and 10 to 12 layers of spongy parenchyma cells. Anthocyanin is localized in the hypodermal cells. The leaf blade is similar to the spathe, except for two layers of palisade parenchyma cells immediately below the upper epidermis. Venation is netted. Chloroplasts are dispersed throughout the mesophyll but are more concentrated in the palisade cells. The peduncle, petiole, and stem are typically monocotyledonous in structure. Epidermal cells cover the cortex, a layer of sclerified parenchyma cells, and the ground tissue. Vascular bundles are dispersed throughout the groundtissue. Roots are cylindrical, fleshy, epiphytic, and adventitious. The epidermis is developed as a velamen. Raphide and druse crystals are found throughout the plant. Above-ground parts have a thick, waxy cuticle.
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    Productive Efficiency of the Swine Industry in Hawaii
    (University of Hawaii, 1996-12) Sharma, Khem R. ; Leung, PingSun ; Zaleski, Halina M.
    This study examines the future potential of the swine industry by determining operational efficiency based on farm-level costs of and returns from swine production collected from 60 commercial swine producers in Hawaii during the fall of 1994.
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    Economic Implications of Import Barriers to Protect the U.S. Sugar Industry with Particular Reference to Hawaii
    (University of Hawaii, 1989-03) Leong, Jerrold K. ; Scott, Frank S Jr. ; Leung, PingSun
    This study analyzes consumer and producer costs and benefits of a modeled price support program for sugar superimposed on the 1974-1981 period, which was essentially free of effective price support programs and characterized by extreme variations in the U.S. price of domestic sugar. The study differs from previous studies in the sense that it models a with- and without-price support scenario. The modeled price support program is based on U. S. costs of production of raw cane sugar in 1981 and is imposed with appropriate deflation on the years 1974-1980 to permit comparison with the actual scenario without price supports. Research results indicate that an adequate price support program to maintain economic viability of the U. S. sugar industry during the 1974-1981 period would have cost consumers an additional $4.77 per capita annually for sugar. This compares to an annual average loss of $4.7 billion, or $21 per capita annually, during the research period if the U.S. sugar industry had become demised, assuming no alternative employment of production factors. The cost to the Hawaii economy would have been comparatively much more severe, amounting to $836 million annually in aggregate and $880 per capita. The program could be administered at no cost to the government through the imposition of import quotas. Per capita reduction in consumers' surplus would have averaged $1.76 annually based on the duty rate of $0.01875 per pound and $6.08 based on the 20 percent ad valorem rate in effect in 1981. The study is expected to provide valuable insight to policymakers for future sugar legislation.
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    Optimal Harvest Schedule for Maricultured Shrimp: a Stochiastic Sequential Decision Model
    (University of Hawaii, 1989-05) Leung, PingSun ; Hochman, Eithan ; Wanitprapha, Kulavit ; Shang, Yung C. ; Wang, Jaw-Kai
    Successful introduction of advanced intensive technology in shrimp mariculture requires the appropriate management tools. This report presents a management model for determining the optimal stocking and harvesting schedules for a shrimp pond of a mariculture shrimp operation. The developed model is an extension of the classical growing inventory model. It provides a set of simple intra- and interseasonal decision rules expressed as cutoff revenue when both price and weight are assumed random, and as cutoff price or cutoff weight when either price or weight is assumed random. If current realized revenue is less than the cutoff revenue, the decision is to keep the crop and delay the decision to sell for another period; otherwise, the decision is to sell. Application of this model to a hypothetical shrimp farm in Hawaii with 24 0.2-ha round ponds indicates that net return can be increased three times by applying the derived optimal policies, compared with a conventional fixed scheduling scheme. The economics of controlled environment is also evaluated using the model.
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    Use of Tropical Vegetables to Improve Diets in the Pacific Region
    (University of Hawaii, 1984-06) Evensen, Stacy K. ; Standal, Bluebell R.
    Eleven indigenous tropical vegetables studied included amaranth, pigeon pea, winged bean, Ceylon spinach, taro, edible hibiscus, breadfruit, swamp cabbage, sweetpotato, cassava, and Moringa. The findings suggested that these could supply more of the five essential nutrients than were available from the commonly eaten temperate-zone vegetables tested.
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    Sexual Development and Learning over the Life Span
    (University of Hawaii, 1994-03) Engel, John W. ; Kimmons, Lee C.
    Sexual development is a continual process that unfolds throughout one's life. Salient aspects of the psychosocial dimensions of sexual development are described for each of the following stages: prenatal, infancy, childhood, adolescence, and young to late adulthood. Common characteristics for each stage are given along with a discussion of potential problems that may occur during particular stages. This overview of background information will assist the educational efforts related to this important aspect of human development at every age level. A list of resources is provided.
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    Feasibility of Potato Production in Hawaii
    (University of Hawaii, 1984-01) Manrique, Luis A.
    Hawaii has a long history of unsuccessful potato production that is practically unknown to the agricultural community. Crop failure due to disease and insect attack, lack of available seed, improper crop and soil management, and overseas competition for the local market have reduced potato production in Hawaii to a backyard activity. However, Hawaii possesses extensive lands that are suitable for potato production. The report reviews the history, consumption, and production of potato in Hawaii and makes agronomic assessments of three soil categories: Ustic Humitropepts, Tropeptic Eutrustox, and Hydric Dystrandepts.
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    Effects of Nutritional Factors on Chemical and Soil Microbiostasis
    (University of Hawaii, 1982-03) Ko, Wen-hsiung
    Microorganisms including fungi, actinomycetes, and bacteria remain quiescent or decrease in number when they are introduced into natural soil. Such microbiostasis is a general phenomenon of natural soil. Tables list the nutritional factors that are capable of decreasing or increasing soil microbiostasis, and also the microorganisms tested. Those nutrients shown to be ineffective are also included. The majority of reports concerning the effects of nutritional factors on inhibition of microorganisms dealt with the inactivation of antimicrobial agents, and only a few cases of enhancement of antimicrobial activity of chemicals by nutrients were documented. The effects of nutritional factors on fungistasis was most extensively studied among the three types of soil microbiostasis, followed by bacteriostasis and antinostasis. Agar, sulfur-containing amino acids, vitamins, and mineral salts which are very effective in inactivating considerable numbers of antimicrobial agents are, in general, ineffective in annulment of soil microbiostasis. These differences suggest that soil microbiostasis is not due to chemical inhibition.
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