The role of cooperative extension in providing information to amateur and professional horticulturists is being profoundly altered by the availability of vast amounts of horticultural resources on the World Wide Web and other electronic media. Advances in computer-related instructional technologies including the Internet, have coincided with, and to some extent triggered, a burgeoning demand for non-traditional continuing education in practically all fields of knowledge, including landscape horticulture. Although there are numerous Web sites offering a wide range of gardening and related information, there are relatively few opportunities for structured learning in the form of on-line distance learning courses or instructional modules. In Fall 1999, we conducted a survey of the membership of the New York State Nursery/Landscape Association to determine priority-training needs that might be met by computer-mediated distance learning. One-hundred-seven companies, representing horticulture-based businesses throughout New York State, completed the surveys. Results from the survey indicated that 83% of those responding were interested in taking one or more computer-based distance learning course(s), that 67% were willing to provide financial support for continuing education of their employees, and that 95% have access to a personal computer. We have also collected data indicating subject matter preferences, interest in full-course and short-course offerings, levels of computer and Internet experience, and more. It is apparent from the findings in this study that the cooperative extension has a great opportunity to use the World Wide Web as a component of its role as an information provider. This research will contribute to designing effective approaches for teaching hands-on horticultural skills at a distance, thereby expanding the cooperative extension's ability to reach its intended audiences.
Kenneth W. Mudge and Kelly Hennigan
Jinwook Lee and Kenneth W. Mudge
Variation in ginsenoside content was investigated as a function of population/genotype, plant organ, and age using four geographically isolated wild populations and one landrace population of american ginseng (Panax quinquefolius L.). The contents of individual and total ginsenosides were affected by the main and two-way interactions between population, organ, and age. Ginsenoside Re was not detected in roots of the wild population plants but was found in leaves and in both organs of the landrace population. A positive relationship between root age and total root ginsenosides was detected in two wild populations. Individual root ginsenosides were highly correlated with certain leaf ginsenosides in wild populations rather than in landrace populations. Therefore, the results suggest that certain leaf ginsenosides would be applied for potential biomarkers to estimate individual root ginsenosides. Principal component analysis (PCA) scores plot indicates that all wild populations were segregated from the single landrace population. However, cluster analysis indicates that differences existed between organs, and between the wild and landrace populations. Overall, the result suggests that the variation of individual and total ginsenoside contents would be influenced by a combination of population, plant organ, and root age.
Chin-Chang Chu and Kenneth W. Mudge
Rockwool plugs were placed in Magenta G-7 boxes (Sigma) and then autoclaved at 121°C for 20 min. Fifty milliliters of cool autoclaved liquid medium was poured into Magenta G-7 boxes in aseptic conditions before microcuttings of Amelanchier, Cercis canadensis, cherry, and apple were transferred. Murashige and Skoog medium (MS, M-5519, Sigma) containing 30 g·L–1 sucrose, and with/out 1 ppm of NAA, pH 5.5 were used in all experiments. All cultures were incubated at 23 ± 1°C under a 16-hour lighting period with a light intensity of about 4000 lux of white fluorescent light. Microcuttings of Amelanchier, Cercis, Apple, and cherry rooted in rockwool plugs in 3 weeks after transfer and were ready to be out-planted in 6 weeks. Out-planted plantlets were leached with tap water and potted in 4-inch pots with Metrolite mix, then, placed in mist bench under 50% shade for 2 weeks before taking to bench with full sun light. The survival was 100%. Conditions and growth rate of rockwool-plug-rooted plantlets were much better than those plantlets rooted in agar medium. Rockwool plug plantlets had 2–3 flushes of growth before dormancy in greenhouse and were ready to be planted in the field or garden in 8 months after out-planting. Using a rockwool plug system simplifies out-planting procedure, produces better plantlets, increases out-planting survival, and greatly shorten time needed from out-planting to field-plantable size. This system is a very useful system for difficult-to-root woody ornamentals.
Jin Wook Lee and Kenneth W. Mudge
In the Northeast, wild American ginseng (Panax quinquefolium L.) is typically found growing in the dense shade provided by deciduous hardwood tree species such as a sugar maple, in slightly acidic soils with relatively high calcium content. Woods cultivated ginseng is often grown in forest farming agroforestry systems under similar conditions. Supplemental calcium by soil incorporation of gypsum (CaSO4·2H2O) is often recommended for woods cultivated ginseng. The objective of this study was to investigate the effects of this practice on soil chemical properties, plant growth and quality of American ginseng. In a greenhouse pot culture experiment, 2-year-old seedlings were treated with 0, 2, 4, 8, or 16 Mt·ha–1 gypsum and grown for 12 weeks. Gypsum application decreased soil pH slightly, elevated soil electrical conductivity and increased available soil Ca and sulfate concentrations. Tissue calcium concentration was increased with by gypsum treatment, but shoot and root growth was reduced. HPLC analysis of root ginsenosides revealed that Re, Rb1, Rc, and Rb2, PT ginsenoside (sum of ginsenoside Rb1, Rc, Rb2, and Rd) and total ginsenoside concentration increased by gypsum soil amendment.
Chin-Chang Chu and Kenneth W. Mudge
Seeds from mature seed pods of Cypripedium calceolus var. parviflorum were germinated on 1/4 MSMO (Sigma) + 100ml/l coconut water + 1% sucrose +/- 8g/l agar (pH 6.0), and with or without prechilling at 5C for 8 weeks. Protocorm with apex (stage 3) was use as an index of germination. Seeds sown on agar medium withou chilling treatment resulted in a 40% germination rate in 120 days but the germination was very uneven. Seeds germinated on agar medium with prechilling developed more synchronously with 92% germination in 60 days (ie. about 120 days after sowing). Suspension culture of seeds without prechilling resulted in 85% germination after 90 days. The synchronization of seed germination in suspension culture was intermediate between that on agar with and without prechilling. Protocorms germinated in suspension culture appeared morphologically identical to those germinated on agar medium. All stage 3 protocorms developed further on the same agar medium in darkness.
Both agar and suspension culture in media containing coconut water provided reliable seed germination methods for this orchid species.
Kenneth W. Mudge, Kelly Hennigan, and Peter Podaras
An instructional system involving tropical hibiscus (Hibiscus rosa-sinensis) was developed for teaching hands-on grafting skills as part of a traditional comprehensive course in plant propagation and also as part of an online grafting course. The advantages of using tropical hibiscus include the following: the absence of phenological constraints associated with seasonal changes in temperate woody species; the comparative ease of grafting hibiscus, assuring positive reinforcement of the student's learning experience; and the ease of propagating and growing hibiscus in the greenhouse for use at any time of year. The three methods included in these laboratory exercises are top wedge grafting—selected for its ease and high rate of success—T-budding, and chip budding. In addition to development of hands-on skills, the exercises are designed to teach students three of the most important requirements for successful grafting of any species, regardless of method. These requirements include cambial alignment, application of pressure between stock and scion, and avoidance of desiccation. An online rating tutorial and lab report form was developed for students to self-evaluate their grafted plants.
Kenneth W. Mudge and Chin-Chang Chu
In vitro asymbiotic seed germination, subculture, and outplanting of orchids is presented as a laboratory exercise suitable for students of plant propagation or tissue culture. Dendrobium antennatum (Lindley), Phalaenopsis (Blume) white hybrid, or both, are used in this exercise because they flower predictably in the greenhouse, are reliable for seed production, and germinate and grow rapidly in vitro. The exercises can be used to instruct students in the skills involved in orchid seed sterilization, sowing, and culture, as well as instruct students in the unique features of orchid reproductive biology and symbiosis. A schedule is suggested for stock plant flower pollination, capsule harvest, seed sowing, and seedling subculture so that the necessary plant material is available for students to sow, subculture, and outplant seedlings during a single laboratory session.
Kenneth W. Mudge, Joseph P. Lardner, and Katherine L. Eckenrode
The objective of this study was to determine the feasibility of CO2 enrichment and optimal radiation level for accelerating the rooting and growth of micropropagated Kalmia latifolia cuttings during the Stage IV acclimation period. Inch long microcuttings of the Kalmia cultivars `Elf' and `Carousel' shipped from a commercial micropropagation laboratory, were stuck in flats of peat, and place in a fogging chamber constructed to allow for the simultaneous experimental variation of CO2 level and either radiation level or photoperiod. Treatments consisted of a complete factorial arrangement of 2 levels of CO2 (ambient and 1200 ppm) and 3 levels of radiation (30, 98, and 158 μmoles/m2/sec). The experiment was repeated 6 times. For `Carousel' CO2 enrichment stimulated both shoot and root growth and either the high or medium light level was optimal depending on the experiment. CO2 enrichment also stimulated growth of `Elf' but results were less consistent from experiment to experiment. Similar experiments are in progress with Amelanchier and Lilac microcuttings.
Henry E. DeVries II, Joseph P. Lardner, and Kenneth W. Mudge
To test the hypothesis that phytohormone production is related to mycorrhizae formation 29 isolates of ectomycorrhizal fungi have been evaluated for production of ethylene and auxin in pure culture and for their ability to form ectomycorrhizae with Pinus mugo. The fungi tested included a series of monokaryotic isolates of Laccaria bicolor and dikaryotic isolates of Amanita muscaria, Hebeloma crustuliniforme, L. laccata, L. proxima, Pisolithus tinctorius, Rhizopogon ellenae, and R. vinicolor. Inoculated root systems were rated for mycorrhizae formation, root/shoot ratio and root morphology. P. tinctorius isolates which formed abundant mycorrhizae produce no ethylene in vitro, but did produce the auxin IAA. L. bicolor isolates produced ethylene as well as auxins putatively identified as IAA, and IBA. Correlations between phytohormone production and mycorrhizogenicity will be presented.
Jin Wook Lee, Kenneth W. Mudge, and Joseph Lardner
American ginseng (Panax quinquefolium L.) contains pharmacologically active secondary compounds known as ginsenosides, which have been shown to be affected by both genetic and environmental factors. In this greenhouse experiment, we tested the hypothesis that ginsenosides would behave as “stress metabolites” and be associated with osmoregulation in response to drought stress. Two year-old seedlings, grown in 5-inch pots, were well watered for 40 days prior to the initiation of treatments. Plants in the drought stress treatment were watered every 20 days while the controls were watered every 10 days, and the experiment was terminated after 4 and 8 dry down cycles (80 days), respectively. Predawn leaf water potential and relative water content (RWC) of drought-stressed plants during a typical dry down cycle were lower than control plants. The diameter and weight of primary storage roots were decreased in the stressed treatment. The length of the main storage root and the longest secondary (fibrous) root were significantly increased by the drought stress treatment. Leaf chlorophyll content of drought-stressed plants was lower than controls. The osmotic potential of the drought-stressed ginseng was not lower than the control, indicating that ginsenoside is not involved in osmoregulation in response to drought stress. Furthermore, ginsenosides Rb1 and Rd, and total ginsenosides were significantly lower in primary roots of drought-stressed plants compared to control plants.