The University of Hawaii at Manoa campus offers a rich diversity of plants for students, university personnel, and the public. Although providing botanical facts, a current university web site and an arboretum brochure about campus plants lack horticulturally related information. By highlighting the unique horticultural plants on campus, a web site would provide valuable information on the uses, care, and propagation of these plants. The purpose of this project was to develop a web site featuring horticulturally important plants on campus. The home page explains why plants are beneficial in interior spaces. Other sections of the web site include basic plant care, plant selection, plant names, and plant pictures. Basic plant care covers planting media, containers, watering, lighting, fertilizing, pruning, propagation, and pest control. Users can select plants using two criteria—lighting in the plant's desired location (low, medium, and high) and low plant maintenance. Information on a specific plant is accessed by common name, scientific name, or a plant's picture. Each plant's web page provides details on its background, care, and propagation. By emphasizing the important horticultural plants on campus, this web site helps students, university personnel, and the public select and grow plants for their dormitories, apartments, offices, and homes. In addition, users gain knowledge about the lush landscape environment on campus. Lastly, the web site enhances the learning experience of students in horticulture and botany courses, serves as a resource for K–12 students for their visits to the campus to learn about tropical plants, and aids tourists in planning a more informative visit to campus to see the plants they learned about on the web site.
Kent D. Kobayashi, Andrew J. Kaufman and Allison A. Ohama
Nichole F. Edelman, Bethany A. Kaufman and Michelle L. Jones
Ethylene gas can cause extensive damage to bedding plants during production, shipping, and retailing. Seedlings exposed to ethylene exhibit the triple response, which includes an exaggerated apical hook, thickened hypocotyl, and reduced hypocotyl elongation. Our objective was to determine if the hypocotyl elongation component of the seedling triple response could be used to predict the sensitivity of mature plants at the marketable stage. Eighteen common bedding plants were evaluated. For the seedling hypocotyl elongation screen, seeds were germinated and grown in the dark on filter paper saturated with various concentrations of 1-aminocyclopropane-1-carboxylic acid (ACC; the immediate precursor to ethylene). The relative hypocotyl length at each ACC concentration was compared with untreated control (0 μM) seedlings. Mature plants, with at least four open flowers, were treated with ethylene (0, 0.01, 0.1, 1, or 10 μL·L−1) in the dark for 24 hours. Phenotypic responses to ethylene, including flower abscission, flower senescence, leaf abscission, leaf chlorosis, and epinasty, were rated on a scale of 0 to 5. Five species exhibited very little reduction in hypocotyl elongation when grown on ACC (low sensitivity). The remaining species were classified as medium or high ethylene sensitivity at the seedling stage. The most common symptoms of ethylene damage observed in mature plants were leaf epinasty, flower abscission, and flower senescence. The severity of these responses was used to identify plants with high, medium, or low sensitivity to ethylene. For six of the bedding plant species that were equally responsive at both developmental stages, the seedling hypocotyl elongation screen would provide a reliable means of predicting the ethylene sensitivity of mature plants.
A. Naor, I. Klein, H. Hupert, Y. Grinblat, M. Peres and A. Kaufman
The interactions between irrigation and crop level with respect to fruit size distribution and soil and stem water potentials were investigated in a nectarine (Prunus persica (L.) Batsch. `Fairlane') orchard located in a semiarid zone. Irrigation treatments during stage III of fruit growth ranged from 0.62 to 1.29 of potential evapotranspiration (ETp). Fruit were hand thinned to a wide range of fruit levels (200 to 1200 fruit/tree in the 555-tree/ha orchard). Total yield did not increase with increasing irrigation rate above 0.92 ETp in 1996 and maximum yield was found at 1.06 ETp in 1997. Fruit size distribution was shifted towards larger fruit with increasing irrigation level and with decreasing crop level. The two highest irrigation treatments had similar midday stem water potentials. Our findings indicate that highest yields and highest water use efficiency (yield/water consumption) are not always related to minimum water stress. Total yield and large fruit yield were highly and better correlated with midday stem water potential than with soil water potential. This confirms other reports that midday stem water potential is an accurate indicator of tree water stress and may have utility in irrigation scheduling.
A. Naor, H. Hupert, Y. Greenblat, M. Peres, A. Kaufman and I. Klein
The interactions between irrigation and crop level with respect to fruit size distribution and midday stem water potential were investigated for 3 years in a nectarine (Prunus persica L. `Fairlane') orchard located in a semi-arid zone. Wide ranges of crop loads and irrigation rates in stage III were employed, extending from practically nonlimiting to severely limiting levels. Irrigation during stage III of fruit growth ranged from 0.63 to 1.29 of potential evapotranspiration (ETp). Fruit were hand thinned to a wide range of fruit levels (300 to 2000) fruit/tree in the 555-tree/ha orchard. The yields and stem water potentials from 1996, 1997 and 1998 were combined together and the interrelations among yield, crop load and stem water potential were examined. Fruit <55 mm in diameter growing at 400 fruit per tree were the only ones not affected by irrigation level. The yield of fruit of 60 to 75 mm in diameter increased with irrigation level, but only a slight increase was observed when the irrigation rate rose above 1.01 ETp. A significant decrease in the yields of 60 to 65, 65 to 70, and 70 to 75-mm size grades occurred at crop levels greater than 1000, 800, and 400 fruit per tree, respectively. Midday stem water potential decreased with increasing crop level, and it is suggested that midday stem water potential responds to crop load rather than crop level. Relative yields of the various size grades were highly correlated with midday stem water potential. It was suggested that the midday stem water potential integrates the combined effects of water stress and crop load on nectarine fruit size.