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Larry A. Rupp and Larry Sagers

The fabled “wide open spaces” of the west make travel an integral, though expensive, part of most extension programs. As an alternative, Utah State Univ. has been successful in targeting a major extension audience for service via satellite teleconferences. The audience we have worked with consists primarily of landscape managers at institutional facilities, such as schools, cities, churches, hospitals, and parks, who do not have formal training in horticulture. The primary impetus and key to the success of this program is a collaboration between the university (provides content material and production) and an outside institution (provides satellite broadcasting and receives employee training). As a result, the program simultaneously reaches three main audiences: employees of the partnering institution, county extension audiences throughout the state, and any private party with a satellite who watches. Keys to the success of this program include a statewide system of satellite dishes at all county extension offices, close collaboration between content and distance-learning specialists, marketing assistance to county agents, endorsement of the program for employee training by employers, a workbook to supplement broadcast material, administrative support, and careful identification of the target audience. Concepts we are struggling with include bridging regional to national audiences and improved marketing.

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Larry A. Rupp

The Plants, Soils, and Biometeorology Department at Utah State University was formed in 1989 as the result of a merger between the Soil Science and Biometeorology Department and the Plant Science Department. While constant vigilance is required to keep the department balanced and functioning as a single unit, overall the combined department seems to be stronger than the previous units.

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Roger Kjelgren and Larry A. Rupp

We investigated water use and potential drought avoidance of Norway maple (Acer platanoides L.) and green ash (Fraxinus pennsylvanica Marsh) seedlings grown in protective plastic shelters. Gravimetric tree water use and reference evapotranspiration for fescue turf (ETo) were monitored for 1 to 3 days during the growing season. Water use of trees was 8% to 14% of ETo in shelters vs. 29% to 40% for trees not in shelters. Trunk diameter was affected more than whole-tree water relations by lack of irrigation, suggesting that the nonirrigated trees were subjected to only mild water stress. Shelters did not improve drought avoidance, as water potentials were generally more negative and trunk diameter increment was lower for nonirrigated trees in shelters. Maples in shelters were affected more adversely by lack of water than were ash. Higher temperatures in shelters also may have reduced trunk growth. Air temperatures were 13 °C warmer than ambient in nonirrigated shelters, but only 5 °C warmer in irrigated shelters. Tree shelters can reduce transpiration rates by over half, but benefits from reduced water loss may be offset by negative effects of higher air temperatures. Shelters reduced cold hardiness of both species, but maple was affected more than ash.

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Melody Reed Richards and Larry A. Rupp

Bigtooth maple (Acer grandidentatum) has potential as a small, water conserving landscape tree in western landscapes. This potential has been hindered in part by the difficulty in asexually propagating superior accessions. The ability of etiolation to enhance rooting of softwood cuttings of selected wild accessions was determined by grafting six accessions onto seedling rootstocks to use as stock plants. Etiolation was applied to stock plants by placing open-ended, black, velour, drawstring bags over the end of pruned shoots at bud swell allowing new shoots to develop and grow out the end of the bag while leaving the base of the shoot covered. In 2009 and 2010, cuttings from etiolated and nonetiolated shoots were treated with 4000 ppm indole-3-butyric acid (IBA) + 2000 ppm naphthaleneacetic acid (NAA), stuck in a premoistened 3 perlite:1 peat (by volume) rooting substrate and placed under intermittent mist. After 4 weeks, 89% (2009) and 85% (2010) of the etiolated cuttings rooted and only 47% (2009) and 17% (2010) of the nonetiolated cuttings rooted. Etiolated cuttings produced on average 11.3 (2009) and 7.2 (2010) roots per cutting and nonetiolated 2.1 (2009) and 0.5 (2010) roots per cutting. Etiolation, and its application through the use of black cloth bags, can be an effective way to increase the rooting of bigtooth maple cuttings and the availability of these plants for use in water conserving landscaping.

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Larry A. Rupp, William A. Varga, and Roger Kjelgren

Bigtoothmaple(Acer grandidentatum Nutt.) is of interest for its fall color and potential use in water-conserving landscapes. Clonal propagation of desirable selections would be beneficial. Since bigtooth maple commonly self-propagates by layering, we explored mound layering as a means of vegetative propagation. A stool bed was established in 1999 with seedlings grown from northern Utah seed. Beginning in 2001, seedlings were dormant pruned to their base and shoots allowed to grow until early July, when treatments were applied. At the time of treatment application for the reported experiments, shoot bases were girdled with 24-gauge copper wire, covered with conifer wood shavings, and kept moist during the growing season. The effects of rooting hormones and enclosure of the rooting environment on rooting were examined. On 7 July 2002, 32 trees were randomly selected and the four tallest shoots within each tree were treated with either 0, 1:5, 1:10, or 1:20 (v/v) solutions of Dip-N-Gro© rooting hormone (1% IBA, 0.5% NAA, boron). There was no significant difference in rooted shoots between treatments and 81% of the trees had at least one rooted shoot. On 9 July 2004, 39 trees were selected and two shoots per tree were girdled. One-half of the stool bed area was treated by underlaying the shavings with BioBarrier© (17.5% trifluralin a.i.). Measurements on 12 Nov. 2004 showed no apparent treatment effect on rooting and 90% of the trees had at least one rooted shoot. This research demonstrates that mound layering is an effective means of rooting shoots of juvenile bigtooth maples. Further research will examine the effectiveness of the technique in propagating mature clones.

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Heidi A. Kratsch, Ruby Ward, Margaret Shao, and Larry A. Rupp

The green industry in Utah is a large and diverse group that ranges from nursery/greenhouse growers and retailers to landscape maintenance and design professionals to irrigation and turf industry professionals. Because of the size and diverse membership of the Utah green industry, extension faculty are challenged to gauge the needs and attitudes of the industry as a clientele group. In 2007, we conducted a mail survey of the Utah green industry to identify the learning preferences of industry members, to better understand the structure and extent of Utah green industry businesses, and to elicit industry perceptions about present and future challenges to success. We found that the service sector is a significant component of Utah's green industry, and that extension-based short courses can be used to provide more advanced and targeted education to specific industry groups. Drought/water issues and labor shortages were viewed as significant challenges to the future of the green industry, and these could be used as a foundation for building strategic alliances between extension and the green industry in Utah. Results of our survey will be useful to green industry professionals and extension educators that deal with green industry education, particularly in states with service- rather than production-oriented businesses.

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Roger Kjelgren, David T. Montague, and Larry A. Rupp

We investigated the microclimate, gas exchange, and growth of field-grown Norway maple (Acer platanoides L.) and green ash (Fraxinus pennsylvanica Marsh) trees nonsheltered, and in brown and white shelters. Shelter microclimate—air temperature (Ta), vapor pressure deficit (VPD), and radiation—and tree leaf area, growth in diameter, stomatal conductance (gs), and photosynthesis were measured during the first growing season after bare-root transplanting. Bark temperatures in midwinter were also measured. Treeshelter microclimate was greenhouse-like compared to ambient conditions, as shortwave radiation was lower, and midday Ta and relative humidity were higher. Although trees in shelters had greater shoot elongation and higher gs than trees grown without shelters, photosynthesis was not different. White shelters allowed 25% more shortwave radiation penetration and increased Ta by 2 to 4 °C and VPD by 0.5-1 kPa over brown shelters. However, tree growth and gas exchange generally were not affected by shelter color. Winter injury was increased for trees in shelters and varied with species and shelter color. Both species exhibited shoot dieback in shelters the spring following a winter where bark temperatures varied 40 to 50 °C diurnally. More new growth died on maple, particularly in white shelters where several trees were killed. These data suggest that supraoptimal summer and winter temperatures may reduce vigor and interfere with cold tolerance of some species grown in shelters.

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Kirsten M. Judd, Larry A. Rupp, and Richard F. Fisher

Fertilization effects on mycorrhizal formation by Tricholoma virgatum with three pine species were studied. Inoculum was mixed into a 1 peat: 1 vermiculite media (1:9, v/v), prior to seeding in 160-cm3 “Leach Containers”. Four nutritional regimens were used: Full-strength Ingestad solution with 10% P, 10% Ingestad solution, modified-exponential Ingestad, and a slow-release fertilizer (Sierra TM, 17N-6P-1OK). Seedlings were harvested at 3, 4, and 5 months after sowing. Tricholoma inoculation resulted in 11% of the short roots of all species forming ectomycorrhizae (ECM) and 40% of the seedlings being colonized. P. sylvestris and P. nigra had significantly more ECM than did P. ponderosa, The number of ECM increased from the 3rd to the 4th month, but no increase occurred after the 4th month. Treatment with full-strength Ingestad/10% P yielded the largest seedlings and the least ECM, while exponential and 10% Ingestad produced smaller seedlings with the most ECM. The slow-release fertilizer treatment resulted in trees with intermediate growth and ECM formation. No differences in growth were found between inoculated and uninoculated trees.

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Asmita Paudel, Youping Sun, Larry A. Rupp, and Richard Anderson

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Melody Reed Richards, Larry A. Rupp, Roger Kjelgren, and V. Philip Rasmussen

The potential of bigtooth maple (Acer grandidentatum) as a small, water-conserving landscape tree for the western United States is limited by the selection of superior accessions from a morphologically diverse gene pool and the ability to propagate wild plants in a nursery environment. Superior accessions were selected based primarily on red fall color. Aerial digital images taken during peak fall color in 2007 and 2008 were synchronized with flight global positioning system (GPS) track files using digital image editor software and visually compared with corresponding satellite images to determine the exact latitude and longitude of selected trees on the ground. Trees were physically located using GPS technology then visually evaluated for initial selection. Criteria included fall color, habitat, relative disease and insect resistance, bud quality, and plant form. From 56 observed trees of interest, six were selected for propagation. Through time-course experiments using multistemmed, bigtooth maple seedling rootstocks in a coppiced stoolbed, the optimum time for chip budding scions of wild accessions in northern Utah was determined to be July through mid-August. Further evaluation of accessions for use in the landscape industry is required.