Shoot and root growth were measured on Chinese juniper (Juniperus chinensis L. `Torulosa', `Sylvestris', `Pfitzeriana', and `Hetzii') 1, 2, and 3 years after planting from 1l-liter black plastic containers. Mean diameter of the root system expanded quadratically, whereas mean branch spread increased linearly. Three years after planting, root spread was 2.75 times branch spread, and roots covered an area 5.5 times that covered by the branches. Percentage of total root length located within the dripline of the plants remained fairly constant for each cultivar during the 3 years following planting. Root length density increased over time but decreased with distance from the trunk. During the first 2 years after planting, shoot mass increased faster than root mass. In the 3rd year, the root system increased in mass at a faster rate than the shoots. Root length was correlated with root weight. Root spread and root area were correlated with trunk cross-sectional area, branch spread, and crown area.
Edward F. Gilman and Michael E. Kane
Gary W. Knox, Edward F. Gilman, and Sydney Park Brown
Environmental Landscape Management (ELM) is an extension education program developed to promote resource conservation and environmental protection through appropriate landscape design and maintenance practices. Use of ELM practices by Florida home owners and landscape professionals will conserve energy and water, recycle yard wastes, and reduce inputs of fertilizers and pesticides. Site analysis and appropriate landscape design and plant selection are inherent components of ELM. Guidelines for ELM integrate irrigation, fertilization, pest control, recycling of yard wastes and other cultural practices to result in a holistic approach to landscape management.
Five videos, 3 slide sets, 20 newspaper releases, and a 45-page booklet, The Florida Environmental Landscape Guide, have been produced to support ELM. This information also will be available on CD-ROM in each county extension office.
Edward F. Gilman, Thomas H. Yeager, and Diane Weigle
Dwarf burford holly (Ilex cornuta `Burfordii Nana') fertilized with N at 22.1 g per container yearly during production in the nursery generated more new shoot weight but less root weight after transplanting to a landscape than those receiving N at 14.8 g per container yearly. Slicing the root ball at planting, compared to not slicing, resulted in comparable regenerated root weight but reduced new shoot number, new shoot dry weight, and new shoot:regenerated root dry-weight ratio when irrigation was not applied daily after transplanting. Although irrigation frequency did not impact total weight of regenerated roots into landscape soil, more roots grew from the bottom half of the root ball when plants were irrigated periodically after planting than when plants received daily irrigation. Plants irrigated other than daily produced fewer shoots and less shoot weight than those receiving irrigation daily after transplanting. When plants were without irrigation for 4 or 6 days in the first week after transplanting, those planted without the nursery container on the root ball were more stressed (more negative xylem potential) than those planted with the container still on the root ball. However, 2 weeks later, plants without the nursery container were less stressed due to root growth into landscape soil.
Edward F. Gilman, Thomas H. Yeager, and Diane Weigle
Columns (4 × 15 cm) of incubated (25C, 7% volumetric moisture) milled cypress [Taxodium distichum (L.) L. Rich] wood chips received 180 mg of each ionic form of N applied to the surface from dry NH4NO3, KNO3, or (NH4)2SO4 and were leached daily with 16 ml deionized water (pH 5.5). After 10 days, >85% of applied N leached from the columns in all treatments. After 25 days, all N leached from the NH4NO3 and KNO3 treatments, and 93% leached from the (NH4)2SO4 treatment. In subsequent experiments, columns received 360 mg N from NH4NO3 and were leached daily with either 16, 32, 48, or 64 ml of deionized water for 50 days. The rate of N leaching increased with increasing water application rate, although total N leached per column was similar for all water rates after 25 days. Columns that received 45, 90, 180, or 360 mg N/column were leached daily with 16 ml of deionized water. Nitrogen concentrations in the leachate ranged from 3406 ppm
G.L. Davis, Edward F. Gilman, and Howard W. Beck
A large horticultural database and an electronic retrieval system for extension education programs were developed using compact disk-read only memory (CD-ROM) and World Wide Web (WWW) as the medium for information delivery. Object-oriented database techniques were used to organize the information. Conventional retrieval techniques including hypertext, full text searching, and expert systems were integrated into a complete package for accessing information stored in the database. A multimedia user interface was developed to provide a variety of capabilities including computer graphics and high resolution digitized images. Information for the CD-ROM was gathered from extension publications that were tagged using the standard generalized markup language (SGML)-based document markup language (International Standards Organization, 1986). Combining funds from the state legislator with grants from the USDA and other institutions, the CD-ROM system has been implemented in all 67 county extension offices in Florida and is available to the public as a for-sale CD-ROM. Public access is also available to most of the database through the WWW.
Michael E. Kane, Edward F. Gilman, Matthew A. Jenks, and Thomas J. Sheehan
Procedures for in vitro establishment, rapid shoot proliferation, and ex vitro plantlet acclimatization of Cryptocoryne lucens de Witt were determined. Shoot cultures were established from surface-sterilized shoot tips cultured on Linsmaier and Skoog salts and vitamins medium (LS) solidified with 0.8% (w/v) agar and supplemented with 2.0 μm BA and 0.5 μm NAA. The effect of BA (0 to 20 μm) and 0.5 μm NAA on shoot multiplication from single-node and clustered triple-node shoot explants was determined after 35 days. The most efficient shoot proliferation (7.7 shoots/explant) occurred from single-node shoot explants cultured on LS + 20 μm BA and 0.5 μm NAA. Maximum plantlet establishment was achieved by direct sticking of triple-node (cluster) microcuttings in either soilless planting medium or polyurethane foam cubes. Production of highly branched salable plants from microcuttings was possible within 18 weeks. Chemical names used: N-(phenylmethyl) -1H-purin-6-amine (BA); 1-naphthaleneacetic acid (NAA).
Benjamin D. Anderson, Gary W. Knox, Ann R. Blount, Cheryl L. Mackowiak, and Edward F. Gilman
Rhizoma peanut has the potential for use as an ecologically friendly groundcover or turf alternative. Little is known about height and cover characteristics of this plant, which are important ornamental considerations. The objectives of this field study were to characterize maximum average canopy height, height variability, the time to reach full canopy cover, and the time at full canopy cover of seven released and nine experimental selections of rhizoma peanut grown in full sun or under 30% shade at two North Florida locations. Greater height and a less uniform canopy were observed for shaded plants. Establishment, as measured by full canopy cover, did not occur until the second year after planting. Shade treatment had little effect on the time to reach full canopy cover or the duration of full canopy cover, indicating that rhizoma peanut will perform equally in full sun or under 30% shade. Recommended selections for ornamental use based on these variables include ‘Brooksville 67’, ‘Brooksville 68’, EX3, and EX8.
Shawna Loper, Amy L. Shober, Christine Wiese, Geoffrey C. Denny, Craig D. Stanley, and Edward F. Gilman
The urban soil environment is usually not conducive to healthy root growth and function, leading to problems with plant establishment, growth, and aesthetic quality. The objective of this study was to determine if the addition of compost with or without the application of shallow tillage or aeration will improve soil physical and chemical properties and plant growth compared with an unamended control in simulated new residential landscapes. Twenty-four mixed landscape plots were established in a randomized complete block design to simulate new residential landscapes. Each plot was constructed using 10 cm of subsoil fill material over a compacted field soil and planted with Stenotaphrum secundatum and mixed ornamental plant species. Composted dairy manure solids were applied as an organic soil amendment at a depth of 5 cm (≈256 Mg·ha−1) in combination with two mechanical soil treatments (tillage to 15 cm and plug aeration) for a total of five soil management treatments plus an untreated control. Soil physical and chemical properties, plant growth, and quality and plant tissue nutrient concentrations were assessed periodically to determine the effect of soil treatment on soil and plant quality. Applications of compost to soils significantly reduced soil bulk density and pH and increased soil organic matter, electrical conductivity, and Mehlich-1 phosphorus and potassium concentrations. All ornamental plant species, with the exception of Raphiolepis indica (L.) Lindl. ex Ker Gawl., exhibited more growth when grown in soils amended with composted dairy manure solids. In most instances, plant tissue nitrogen and phosphorus concentrations were higher for plants grown in soils receiving compost. Results of our study suggested that the addition of composted dairy manure solids to soils can improve soil properties and enhance plant growth in residential landscapes when sandy fill soils are used. In contrast, shallow tillage and aeration had little effect on soil properties or plant growth.
Edward F. Gilman, Gary W. Knox, Catherine A. Neal, and Uday Yadav
Lagertroemia indica L. × fauriei Koehne (`Natchez' crape myrtle) crown width increased after 13 months as irrigation frequency increased from every 3 days to every day, and the irrigated area around the fabric container increased from 20% to 100% of the circular area within 20 cm beyond the container. Restricting irrigation to within the fabric container plus 20% of the area 20 cm beyond the container edge resulted in less height and width for crape myrtle, but had no effect on root growth, compared to irrigating 100% of area 20 cm beyond the container. Restricting the pattern of irrigation to the container plus 20% of the area 20 cm beyond the container resulted in greater free-root weight (roots < 5 mm in diameter) within the container for laurel oak (Quercus laurifolia Michx.) compared to irrigating the container plus 100% of the area 20 cm beyond the container. Height, width, and caliper of oak were not different among treatments.
Sloane M. Scheiber, Maria Paz, Edward F. Gilman, Kimberly A. Moore, Sudeep Vyapari, and Richard C. Beeson Jr.
Landscape water consumption has become a prime target for water conservation and regulation. Imposing water restrictions during landscape establishment is detrimental to plants that have not developed sufficient root systems to compensate for transpirational water losses. Generally, municipalities regulate irrigation frequency but not application rate. Application frequency affects establishment rates of shade trees, but the effects on shrub establishment are not well documented. This study evaluated three irrigation frequencies during establishment of Ilex cornuta `Burfordii Nana' and Viburnum odoratissimumin a landscape. To simulate maximum stress, both species were transplanted into field plots in an open-sided, clear polyethylene covered shelter. Each species was irrigated either every 2, 4, or 7 days, and received 9 L of water per plant per event. Predawn, midday, and dusk water potentials were recorded at 28-day intervals and cumulative stress intervals calculated. Water potentials were taken the day prior to irrigation (maximum stress day) and the day of irrigation (minimum stress). Growth indices were also recorded. As days after transplant (DAT) increased, significant declines in cumulative water stress of Ilexwere found among treatments on the day of maximum stress. The 7-day treatment declined at a faster rate than the other treatments tested. No differences were found for Viburnum. No significant differences were found on the day of irrigation as DAT increased. Differences in canopy size were not significant among treatments for either species.