Lysimeters have been used extensively in the study of soil water and the movement of compounds in solution. In the management of landscape plantings where the use of various fertilizer application methods is common, loss of NO3-N from the fertilizer source may limit plant growth and be less cost-effective. During a study examining the influence of mulch type (cottonseed hulls, cypress wood, pine bark, and pine straw) and fertilizer application method (granular, liquid, and time-release), a simple lysimeter was constructed to examine NO3-N loss under normal irrigation and cultural practices in annual beds. Losses of large quantities of NO3-N were initially seen in all treatments during the 1st week followed by a gradual decline to the study's end. Liquid and time-release fertilization methods contained NO3-N as a partial source of N and limited plant growth due to early rapid N loss. Granular fertilizer contained no NO3-N source and demonstrated the greatest plant growth at the lowest cost per square meter.
R.A. Mirabello, A.E. Einert, G.L. Klinaaman, and G. L. Wheeler
68 WORKSHOP 9 (Abstr. 662–666) Ornamental Plant Breeding in the Midwest
Alexander X. Niemiera and Monika Goy
A study was conducted to determinethe feasibility of using crop water stress index (CWSI) to schedule irrigation of eight species of freeway landscape plants, Acacia redolens B.R. Maslin, Acacia salicina Lindl., Caesalpinia pulcherrima Sw., Cassia nemophila A. Cunn. ex Vogel, Cercidium floridum Benth., Eucalyptus microtheca F.J. Muell., Nerium oleander L., and Prosopis chilensis Mol. Nerium oleander and C. pulcherrima were suited to the use of the CWSI, tolerated repeated exposures to CWSI values of 0.6, and remained aesthetically acceptable. Irrigation of N. oleander via the CWSI resulted in a 19% reduction in water use, compared to the conventional method. CWSI data of other species were too variable, and, thus, irrigation could not be scheduled by CWSI values. Variability was attributed, in part, to lack of a dense canopy, which is necessary to fill the view of the infrared thermometer.
D.A. Devitt, R.L. Morris, L.K. Fenstermaker, M. Baghzouz, and D.S. Neuman
Nineteen flowering landscape species were sprinkle irrigated with either reuse water or fresh water, with an additional treatment of reuse water plus shade (solar radiation reduced by 24%), for 113 days during late summer and early fall in southern Nevada. The species selected were common to mixed landscape areas on golf courses in southern Nevada transitioning to reuse water. An index of visual damage (IVD) was assessed, along with an assessment of flower production, canopy temperature, tissue ion analysis and spectral reflectance. The IVD values separated based on species (p < 0.001), treatment (p < 0.001) and by a species by treatment interaction (p < 0.001). Irrigating with reuse water plus shade reduced the IVD compared to the reuse without shade in 7 of the 19 species (p < 0.05). When IVD values were included for all species, 40% of the variation in the IVD values could be accounted for if N, B, Ca, Mg, Na, and Zn were included in the regression equation. Higher r 2 values were obtained when individual species were isolated, with regression equations differing based on tissue ion combinations [e.g., ice plant (Mesembryanthemum crystallinum L.) r 2 = 0.81 IVD↑, Na↓, Mn↑]. Three vegetation indices chlorophyll index (CHL), red/far red (R/FR) and water band index/normalized difference vegetation index (WBI/NDVI)) accounted for 51% of the variation in the IVD values. As much as 72% of the variation in vegetation indices could be accounted for based on tissue ion concentrations when separated based on treatment, with Na being the only common ion in all of the highest correlations. Flower production was highest in the reuse plus shade treatment in all 13 species flowering during the experimental period, with as much as 86% of the flower production variation driven by different tissue ion concentrations [purple cup (Nierembergia hippomanica), r 2 = 0.86, flowers↑, Mn↑, Zn↓]. Nine of the nineteen species had acceptable levels of foliar damage (IVD < 2.0). We believe that if the spray irrigation can be minimized (bubblers/drip) and/or partial shade provided, through multi-story landscape designs, a more favorable response will be observed.
Zhanao Deng, Brent K. Harbaugh, and Natalia A. Peres
pot-plant producers, homeowners, and landscapers ( Evans et al., 1992 ; Harbaugh and Tjia, 1985 ). The majority of caladiums commercially produced in the world belong to the fancy leaf type, and the most popular color has been white (white center with
T.K. Broschat, D.R. Sandrock, M.L. Elliott, and E.F. Gilman
Fertilization of established ornamental plants within the landscape has been given little attention by researchers to date. This may be because of a number of factors. Soils and climatic characteristics vary considerably among regions, and optimum
W.C. Dunwell, D. Fare, M.A. Arnold, K. Tilt, G. Knox, W. Witte, P. Knight, M. Pooler, W. Klingeman, A. Niemiera, J. Ruter, T. Yeager, T. Ranney, R. Beeson, J. Lindstrom, E. Bush, A. Owings, and M. Schnelle
The Southern Extension and Research Activities/Information Exchange Group-27 (SERA/IEG-27) is sponsored by the Southern Association of Agricultural Experiment Station Directors. Thirteen universities and the U.S. National Arboretum cooperate with official representatives from extension and research programs. The objective of the group is to identify, evaluate, select, and disseminate information on superior, environmentally sustainable, landscape plants for nursery crop production and landscape systems in the southeastern U.S. Plants are distributed to members responding to a request from cooperators for plant evaluation. Those who agree to cooperate are expected to grow the selected liner to landscape size, then transplant it in a landscape setting. The plant is rated for insect, disease, and cold damage, heat stress, growth rate, ornamental flowering and fruiting, fall color, commercial production potential, landscape potential, invasiveness potential, and insect disease transmission potential. Growth rate is evaluated annually by recording plant height and width. Initial bloom date is reported followed by bloom duration in days. Following evaluation, the group collectively and individually disseminates information gained from the plant evaluation system to a wide variety of audiences.
R.M. Mirabello, A.E. Einert, and G.L. Klingaman
The objective of this study was to examine the influence of mulch material and fertilizer application method on nutrient availability in a landscape situation. Beds containing four mulch materials (pine bark, cypress pulp, pine straw, and cottonseed hulls) and three fertilizer application methods (granule, liquid, and time release) were established. Fertilizer placement included application either above or below the mulch horizon. Beds with and without mulch cover and no fertilization were established as controls. Marigolds, Tagetes erecta `Hybrid Gold', were planted within the beds. Plants in unmulched or fertilized control beds had greater dry weights than plants in beds with mulch alone. Only plants grown in the cottonseed hull control demonstrated a slight improvement and cottonseed hulls demonstrated the best plant performance overall. The greater nitrogen content of cottonseed hulls may influence less immobilization of nitrogen in the soil solution during decomposition and reduce competition for nutrients between microorganisms and plants. Fertilization improved plant growth in all treatments except pine bark. Beds using pine bark showed significant reduction in plant dry matter accumulation. Potential toxicity or changes in soil chemistry by pine bark may have influenced these results and will be examined in further experiments. Fertilizer placement had no effect on plant growth.
Sudeep Vyapari, Robert Graves, and Edmund Thralls
Use of growth regulators in ornamental plant production is a common nursery practice. Research conducted in determining landscape establishment of herbaceous plants treated with various concentrations of growth regulators is limited. The first phase of this study was conducted to evaluate response of three herbaceous ornamental species to application of ethephon. Containerized plants of irish moss, scotch moss, and salvia were treated once with FLOREL® (ethephon) at 0, 250, 500, or 750 ppm 2 weeks after transplanting into #1 size containers. During the course of the 6-week production period, standard nursery practices of fertigation, pest control, and weed management were followed. Data were collected on growth indices and marketable quality ratings (scale of 1–5) every 2 weeks. Mean initial and final shoot and root dry weights were calculated at the start and end of this phase of the experiment. The experimental design was completely randomized and data analyses were made using the analysis of variance with SAS general linear model procedure. Growth indices (cm) were significantly affected by increasing concentrations of FLOREL®. At 750 ppm concentration the mean growth indices were low (2516 cm) whereas, control (0 ppm) produced the highest mean growth indices (4317 cm). Significant differences in marketable quality ratings were also observed among the treatments where control (0 ppm) plants had the best mean rating (4.3) as compared with 500 ppm (3.6) or 750 ppm (3.5) concentrations. Salvia produced mean growth indices and mean width of 9106 and 513 cm, respectively. However, irish moss had asignificantly higher mean quality rating (4.4) when compared with either salvia (3.7) or scotch moss (3.3).
James C. Sellmer, Kathleen M. Kelley, Susan Barton, and David J. Suchanic
Attendees at the 2001 Philadelphia Flower Show participated in an interactive-quiz-formatted survey on touch-screen computers to determine their knowledge and use of plant health care (PHC) and integrated pest management (IPM) practices. Participants answered 15 questions in three categories: 1) PHC practices (criteria for proper plant selection, correct planting practices, and reasons for mulching and pruning); 2) IPM practices (insect identification, plant and pest monitoring, and maintenance of records on pests found and treatments applied to their landscape plants); and 3) demographic and sociographic questions to aid in characterizing the survey population. Over half of the participants (58%) were interested in gardening and a majority (77%) were interested in protecting the environment. Most participants (66%) were between 36 and 60 years of age with a mean age of 47 years, 76% lived in and owned a single-family home, and greater than half (56%) had never purchased professional landscape services. Most recognized PHC criteria for proper site selection, although not all environmental site characteristics were recognized as being equally important. Nearly half (49%) identified the correct planting practice among the choices offered; while an equal number of participants chose among the several improper practices listed. Although reasons for mulching were properly identified by the respondents, excess mulching around trees was considered a proper planting practice by over 39% of the participants. When questioned about IPM practices, a majority reported that they identify pests prior to treating them (71%) and that they scouted their landscapes (82%). However, only 21% kept records of the pests that they had found and the treatments that they applied for those pests. Participants' responses were further examined using cluster analysis in order to characterize the participants and identify meaningful consumer knowledge segments for targeting future extension programming. Three distinct segments were identified: 1) horticulturally savvy (69% of the participants), 2) part-time gardener (25% of the participants), and 3) horticulturally challenged (6%). At least 47% of the horticulturally savvy and part-time gardeners correctly answered plant health care questions (44% of the total survey participants). These two segments included more individuals who were interested in gardening and protecting the environment and are potential targets for future PHC and IPM extension education programs. In contrast the horticulturally challenged recorded no interest in or opinion on gardening or protecting the environment. It is apparent that a majority of consumers are learning and employing PHC and IPM concepts. Proper site selection, planting practices, and mulching along with record keep- ing and pest identification proficiency remain key educational areas to be developed. Although not all gardeners are well versed in all subject matter, a basic knowledge of PHC and IPM is being demonstrated.