| Title |
Investigators | Department | Objectives | Approach Keywords | Progress Reports | Impact Statements | Publications | |
Project * COL00640 | |
| Title | *Production Systems of Ornamental Landscape Plants in the Intermountain West of the United States |
| Investigator(s) | Rogoyski, MK; |
| Department | Horticulture and Landscape Architecture |
| Objectives | 1) Compare, develop, and evaluate the production systems and components of these systems for ornamental landscape plants and their adaptation to Western Colorado climate with emphasis on container systems. 2) Identify and evaluate ornamental plants adapted to Western Colorado growing conditions, including the Plant Select material. 3) Identify and develop management strategies for pests, diseases, mycorrhizal relationships in ornamental landscape plants production and utilization. 4) Develop and adapt flower and fruit thinning procedures for fruit bearing ornamental plants during their production cycle and in the landscape. |
| Approach | Several experiments involving development, evaluation, and adaptation of production systems for containerized, ornamental landscape plants will be initiated. These are generally multi-year studies and results will guide subsequent approaches, for example experiments related to management strategies for pests, diseases, and mycorrhizal relationships. An experiment will evaluate and compare plant performance in the following three open production systems. 1) An above-ground container system, 2) a pot-in-pot system, and 3) a modified pot-in-pot system, optimized to Colorado environmental conditions, will be tested. Two native tree species will be used in these exeriments. In another experiment two open production systems and two covered, greenhouse-like systems will be compared. Because of high expenses involved in this trial, the treatments will be repeated in time (over several production cycles) rather than replicated during one production cycle. In another experiment, funded by the SARE (USDA) program, economics of drought-adapted plant production in a modified pot-in-pot system will be examined. This work will be conducted both at Utah State University in Logan, Utah and at a commercial nursery in Western Colorado. |
| Keywords | container grown, nursery production systems, best management practices, pot in pot production system, retractable roof greenhouses, woody ornamentals, drought adapted plants, water conservation, native plants/landscape use, pest diseases/mycorrhizal relationships, landscape performance, bloom & fruit thinning, fruit elimination, crabapple |
| Progress Reports | |
| 2001 | A first growing season evaluation of the Pot-In-Pot (PIP) system has been completed. Multi-stem trees of Alnus tenufolia and Betula occidentalis were grown in a pair of #20 commercial containers designed for the PIP system. Two main experiments were conducted. The first experiment compared two above-ground and two below-ground PIP systems. The second experiment evaluated the effect of doubling the recommended rate of slow release fertilizer and doubling the amount of irrigation water on tree growth. Trees in the second experiment were grown in a conventional, below-ground PIP system. Tree growth data from the first experiment indicate that plants of both species, when grown in below-ground containers, outperformed those grown in above-ground containers. The data from the second experiment, the fertilizer and irrigation water trial, indicate that water was a limiting factor for growth, as trees that received double the amount of water had the largest increase in the diameter of their trunks. The temperature of the growing medium, an artificial mix containing 1/3 soil by volume, was monitored during the later part of the growing season. The median temperature in the above-ground pots fluctuated; in contrast, the temperature of the in-ground containers was stable and followed closely soil temperature. Salinity-like symptoms were observed on mature leaves of both tree species tested; the symptoms were more severe on alder than on birch trees . The differences in growing medium infiltration rates among containers were observed and measured. These infiltration rate differences accounted for some variability in tree performance. The plants are over wintered in the field at the site of the experiment and the trial will continue during the 2002 growing season. |
| 2002 | Two experiments evaluating several Pot-In-Pot (PIP) systems for production of container-grown woody plants were concluded during 2002. Two species, a thin leaf alder (Alnus tenuifolia) and a water birch (Betula occidentalis) were used to evaluate the PIP systems under the western Colorado climatic condition. The trial was conducted for two consecutive growing seasons. In the first experiment two above-ground and two below-ground PIP systems were compared. There was no significant difference between trunk cross-sectional areas between these four systems. This is a valuable finding as it is currently believed that below-ground and PIP systems are more beneficial to plant growth but the below-ground systems are much more expensive to install and implement. The differences of the growing medium temperature were recorded among above-ground and below-ground systems, but were not extreme enough to affect overall plant growth. As expected the growing medium temperature in below-ground PIP containers was similar to that of surrounding soil and the growing medium temperature of the above-ground PIP containers was highest on the exposed to sun side of the containers. The irrigation and fertilizer experiment indicated a beneficial effect of increasing water quantity when the total cross sectional area of trunks were compared. The symptoms of marginal leaf scorch were observed on alder and to a lesser extent on birch. It is possible that specific ion toxicity might have been involved, as indicated by leaf analysis results and visual observations of trees during the growing season. Some rooting-out (roots escaping from the growing pot) was observed in spite of inside of pots being coated with copper hydroxide. |
| 2003 | Five irrigation methods for production of container-grown cliffrose (Cowania mexicana, Rosaceae), grown under 3 environmental conditions, were evaluated. Irrigation methods included assessment of modified capillary mat technology. The experiment was replicated in 3 environments: each distinct site consisted of 30 plots with 5 irrigation treatments replicated 6 times. The growing environments were: (1) container yard (plants exposed to direct sunlight) , (2) peak-roof retractable roof greenhouse, and (3) flat-roof retractable roof greenhouse. An individual plot consisted of eight 12 liter(l) containers placed in an area of 1.5 m x 1.5 m. The irrigation methods tested can be categorized into 3 water delivery techniques: overhead irrigation, bottom irrigation, and direct application of water to individual pots. A volume of 4 l/pot/irrigation event was applied as needed. The need for irrigation was determined by water status of the growing medium, established visually, tactility, and with a Time Domain Reflectometry device. The experiment evaluated 5 irrigation treatments: (1) overhead irrigation, (2) overhead irrigation with a capillary mat to capture and redistribute water falling in between pots, (3) water applied to the capillary mat on which the pots were standing, (4) water added directly to the individual pots, (5) water added to individual pots with a capillary mat. When the impact of growing environments on water use is examined, plants grown in the container yard required more water (156 l/pot/season) than those grown in retractable greenhouses (134 l/pot/season). When various irrigation treatments are compared across the growing environments, the plants watered by overhead irrigation without capillary mat required the most water (177 l/pot/season), while plants bottom irrigated on capillary mats required the least water (113 l/pot/season). Plants watered by overhead irrigation with capillary mats & those watered by direct water application were similar (139 l/pot/season). Plant productivity, expressed as above ground plant dry weight (dw), differed considerably among irrigation treatments. Treatments 4 and 5 outperformed the other treatments with average dw/plant of 49 g. Plant productivity of the remaining 3 treatments was similar, 29g dw/plant. The dw of plants varied between the different growing environments from an average of 35 g for the container yard, to 40 g for the peak roof greenhouse, to 36 g for the flat roof greenhouse . The electrical conductivity (EC) of the growing medium was measured following the completion of the experiment. The EC, the medium salinity, ranged from 2.1 dS/m (deciSiemens per meter) for direct watered pots to 13.6 dS/m for the bottom irrigated plants. The medium from the overhead irrigated pots ranged from 5.1 dS/m for pots without capillary mats to 6.8 dS/m for pots on the capillary mat. The differences of medium EC likely explain differences in plant productivity. The pots that were directly irrigated had the lowest EC of the growing medium & outperformed plants from other treatments. This relationship was consistently observed across the 3 growing environments tested. |
| 2004 | Conservation of irrigation water has been the goal of an experiment on production of container-grown ornamental plants in western Colorado. A novel water harvesting system, based on stretch wrap film and integrated with the overhead irrigation, has been developed. This system has been compared with another water-harvesting system, the capillary mat, and with the system for conventionally irrigated container-grown plants. Water conservation has been achieved both in the case of the capillary mat and stretch wrap film treatments. An excessive increase in electrical conductivity (EC) of the growing medium has been observed both in the case of capillary mat and stretch wrap film plots when compared to EC of the growing medium from control plots. In spite of the higher EC of the growing medium, the plants grown on capillary mat and stretch film plots performed as well or better than those from control plots . The plants utilized in the experiment, grown in 2.5 liter (l) containers, were ornamental herbaceous perennials, Delosperma floribundum, Viola corsica, and Gazania linearis. The plots were located in three growing environments: an outside environment (a container yard) and in two protected environments: a peak retractable roof and a flat retractable roof greenhouse. The overall irrigation consisted of two stages. During the first ten days all the plots received uniform amount of water, 0.5 l per plant, per irrigation event. It was observed that the plants from stretch wrap film and capillary mat plots were being over-watered. The volume of water applied to various treatments was modified following ten first days: the control treatment (plots without any water harvesting) received 1.6 l per plant per irrigation event, the capillary mat treatment received 0.6 l per irrigation event, and the stretch film treatment received 0.3 l per plant per irrigation event until harvest. The total amount of water applied for the duration of the experiment for the plots located in the container yard was: 53.4 l per plant for the control plots (no water harvesting), 35.0 l per plant for the capillary mat plots, 24.0 l per plant for the stretch film plots. Total amount of water applied to the plots located in peak roof retractable roof greenhouse was: 38.2 l per plant for the control plots, 25.4 l per plant for the capillary mat plots, 16.6 l per plant for the stretch film plots. The total amount of water to plots located in a flat roof retractable roof greenhouse was: 37.6 l per plant for the control plots, 24.0 l per plant for the capillary mat plots, 16.0 l per plant for the stretch film plots. The electrical conductivity (EC) of growing medium from plots where water harvesting was implemented, the capillary mat and stretch film, ranged from 7.1 to 9.3 dS/m. The EC of growing medium from control plots ranged from 4.2 to 4.9 dS/m. |
| 2005 | Three irrigation systems for production of container-grown ornamental herbaceous perennials have been evaluated during the 2005 growing season. This trial was a continuation of experiments conducted during the previous growing season. The goal of this work is to evaluate technologies for conservation of irrigation water in commercial production of container-grown crops that utilizes the conventional overhead irrigation system. The water conserving technology evaluated here is based on integration of water harvesting, redistribution, and capillary uptake processes. The majority of producers of container-grown crops choose the overhead irrigation system because of its low labor requirements and modest capital costs. Overhead irrigation is a water-wasteful system because about 75% of irrigation water falls between pots. The amount of water not reaching the growing medium can be even higher as a crop matures and foliage directs water away from the pots. The over-watering is responsible for runoff and leaching of fertilizers and pesticides into ground water. The conventional overhead irrigation system was compared with two hybrid overhead irrigation systems. The first hybrid system is based on integration of a modified capillary mat; the second system integrates stretch film mulch. The experiments were conducted in three growing environments: a container yard, peak and flat roof retractable roof greenhouses. Plant growth and appearance results were comparable for plants from the three irrigation systems tested. The amount of irrigation water used per irrigation event differed between systems but the watering frequency was the same across three irrigation systems tested. The plots irrigated with conventional overhead system received 1.7 l (liter) per plant per irrigation event. The plots irrigated with overhead system combined with a modified capillary mat received 0.9 l per plant per irrigation event. The plots irrigated with overhead system and a stretch film mulch received 0.5 l per plant per irrigation event. Few typical phytotoxicity symptoms, due to salinity, were observed at harvest, as was the case for the 2004 growing season trial. The electrical conductivity (EC) of the extract from the saturated paste of the growing medium was determined. The growing medium column was divided into three layers along vertical axis. The average EC reading of 7.4 dS/m was observed in the upper layer in two treatments that included sub irrigation components: capillary mat or stretch film mulch. The EC level of comparable layer of growing medium from conventionally overhead irrigated plots was 3.3 dS/m. The EC reading of the middle layer of the growing medium was 3.2 dS/m from plots with sub irrigation component and 2.6 dS/m from conventionally overhead-irrigated plots. The EC reading of the bottom layer was 2.2 dS/m and 2.8 dS/m respectively. This salinity gradient within growing medium column explains why plants grew relatively well in spite of superficially high salinity levels for plots with sub irrigation components. |
| 2006 | Data from experiments on weed control in container-grown ornamental crops has been evaluated as a part of ongoing effort. The experiments were initiated in two geographically distant and climatically distinct locations in Colorado during the 2002 growing season. Effectiveness of five preemergent herbicides, Barricade (prodiamine); Broadstar (flumioxazin); Gallery (isoxaben); Scotts Ornamental Weedgrass Control (pendimethalin); and Treflan (trifluralin) was determined. All herbicides tested were effective in controlling weeds at both sites. Four herbaceous plant species were utilized in this trial: Guizho sage (Artemisia lactiflora Guizho); hopflower oregano (Origanum libanoticum); Daghestan sage (Salvia daghestanica); skullcap (Scutellaria resinosa). Seven weed species were utilized in this trial: annual bluegrass (Poa annua); barnyard grass (Echinochloa crus-galli); yellow foxtail grass (Setaria glauca); purslane (Portulaca oleracea); common groundsel (Senecio vulgaris); redroot pigweed (Amaranthus retroflexus); and annual sowthistle (Sonchus oleraceus). The level of weed control varied across a range of herbicide treatments. When differences among herbicides were observed Barricade, Broadstar, and Treflan were more effective than the other herbicides while Gallery and Scotts Ornamental Weedgrass Control were less effective. No visual phytotoxicity symptoms were observed with any herbicide treatments. However, plants treated with Gallery often resulted in smaller plant size (dry mass) although no signs of phytotoxicity were observed. These experiments have been conducted each year utilizing various perennial ornamentals. |
| Impact | |
| 2001 | The adoption of the Pot-In-Pot system will lower the cost of production of container-grown ornamental trees in Colorado. The need to store trees in a protected environment during the winter, such as storage in poly houses, will be eliminated. Trees produced using the Pot-In-Pot system will be less susceptible to diseases, especially to root-born diseases because of moderate temperatures of the growing medium during the growing and dormant seasons. These physiologically stronger trees will require fewer applications of fungicides and other pesticides. |
| 2002 | The impact of these trials is three fold. Lowering of production costs for container-grown woody plants is likely the most important finding of this work. The finding that the growth of trees in above-ground Pot-In-Pot systems is comparable to below-ground system indicates that this lower cost system can be utilized instead of costly below-ground systems at least for the species tested in this trial. Also, a simple modification to the above-ground PIP system can be made to accommodate plants with more winter tender root systems. The outcome of irrigation and fertilizer trial clearly indicates that productivity gains can be achieved by modification to currently practiced water management regime and indicate that more work needs to be conducted in this area. The identification of possible chloride toxicity indicates that expression of marginal leaf scorch symptoms can be readily minimized as many commercial fertilizers use the potassium chloride as a source of potassium and a sulfate salt of potassium can be readily substituted for the chloride salt. This finding has indirect impact of the water usage as when chloride toxicity is eliminated, irrigation water does not need to be used to mitigate the chloride toxicity and symptoms of marginal leaf scorch. |
| 2003 | The focus of this trial has been on water conservation. The plots utilizing the bottom irrigation and capillary mat technology required the least water and have potential to provide considerable water savings for the nursery industry, reduce run-off of water, and minimize pesticide and fertilizer pollution of ground water. The work described here indicates that this technology needs further enhancement to control elevated electrical conductivity levels of growing media especially in areas such as Western Colorado where quality of irrigation water is sometimes inadequate. The retractable roof greenhouses, utilized in this trial, also provided considerable water savings. The uniqueness of the retractable roof greenhouse technology is its minimal energy usage as these structures do not require energy and water-intensive cooling systems that are necessary for conventional greenhouses. |
| 2004 | Water harvesting utilizing stretch film is a promising technology for water conservation in container-grown crops production systems. This effective technique is simple to implement and integrate with existing irrigation systems utilized by commercial nurseries. Water conservation in container-grown nurseries has multiple benefits through direct and indirect effects. As the irrigation water falling in between pots, and water draining from pots and plants is being recovered through water harvesting, the amount of water saved this way is the most obvious and an important impact of this technology. Water harvesting has a major impact on environmental pollution through reduction of leaching of pesticides and fertilizers carried by water away from production site. The water harvesting could become a key component of a closed system where little or no water leaves the site of container-grown crops production. The key to the practical impact of water harvesting technology based on implementation of stretch film is that it can be readily integrated with the existing irrigation systems used in production of container-grown crops. |
| 2005 | The conventional overhead water irrigation system, widely used in commercial production for container-grown crops, is water-wasteful and is responsible for runoff and leaching of fertilizers and pesticides into ground water. The hybrid systems tested in this trial address the limitations of conventional overhead irrigation systems. The 2005 growing season trial confirmed previous year findings that irrigation systems that combine overhead irrigation, water harvesting, and sub irrigation, is a promising technology for water conservation in production of container-grown crops. Such hybrid irrigation systems combine high labor efficiency and low capital requirements of overhead irrigation systems with water conserving attributes of a stretch mulch system or capillary mat. Results from this year's trial indicates that a previously reported concern, i.e. elevated salinity levels in the growing medium from hybrid systems, was overstated. The most important environmental impact of this work is on reduction of leaching of pesticides and fertilizers away from production site of container-grown crops through irrigation water conservation. |
| 2006 | This work will reduce environmental impact of production container-grown ornamental crops and will decrease labor expenses associated with growing of these crops. Choice of effective herbicide applied at the appropriate rate will decrease likelihood of leaching of these pesticides from the production containers. Reduction in manual weeding will greatly reduce labor costs and will improve plant quality by decreasing disturbance of crop plants. Knowledge of potential herbicidal phytotoxicity to wide ranging selection of ornamental crop plants will allow growers and regulatory agencies to confidently utilize and recommend these herbicides. |
| Publications | |
| 2001 |
Rogoyski, M. 2001. Pot-In-Pot production system looks promising. Western Phytoworks, Fall 2001 , Western Colorado Research Center, Colorado State University, Grand Junction, Colorado. |
| 2002 |
Cummins, A., Klett, J., Rogoyski, M. 2002. Tree production utilizing Pot-In-Pot techniques. Program XXVIth International Horticultural Congress (IHC2002). Abstract# S18-P-39 p.464 http://www.ihc2002.org Pearson, C., Rogoyski, M, Godin, R. 2002. Performance of hybrid poplars in Western Colorado. Proceedings of the Plain and Prairie Forestry Association Annual Meeting, Grand Junction, Colorado, July 2002, 7p. Rogoyski, M., Klett J., Cummins, A. 2002 Evaluation of the Pot-In-Pot system for production of Rocky Mountain native trees. Fifteen Biennial High Altitude Revegetation Workshop, Fort Collins Colorado, March 2002. (abstract) http://www.highaltitudereveg.com/har/abstracts.htm |
| 2003 |
Cummins, A. 2003. Tree Production Utilizing Pot-In-Pot Techniques. M. S. Thesis, Department of Horticulture and Landscape Architecture, Colo. State Univ., Fort Collins, CO Klett, J., Staats, D., Rogyski, M. 2003. Preemergence weed control in container-grown herbaceous perennials and woody plants. HortScience 38(5):700. Pearson, C., Rogoyski,M., Godin,R., Hammon, B. 2003. Performance of hybrid poplar in Western Colorado, 2000-2002. Western Colo Research Center Report 2002. Colo Ag. Expt. Sta. Tech. Report TR03-7. Colo. State Univ. Fort Collins, CO p.7-18. |
| 2004 |
KLETT, J.E., STAATS, D. and ROGOYSKI, M. 2004. Preemergence Weed Control in Container Grown Herbaceous Perennials. HortScience 39 (4):745-46. (abstract). ROGOYSKI, M.K. 2004. Production of container-grown cliffrose plants in three environments using several irrigation methods. Western Phytoworks Spring 2004 p.3 http://www.colostate .edu/programs/wcrc/infopages/Spring pct 2004-web.pdf ROGOYSKI, M.K., PEARSON, C.H., KELSEY, F., WILHELM, J. 2004. A production system for high value crops, retractable roof greenhouses in western Colorado. Agricultural Experiment Station , Colorado State University, Technical Report TR04-05:7-12. |
| 2005 |
Klett, J.E., Staats, D., and Rogoyski, M. 2005. Pre-emergence Weed Control in Container-grown Herbaceous Perennials. HortScience 40(4) 1024. (abstract) Pearson, C.H., Rogoyski, M., and Kelsey, F. 2005. Using native and adapted plants in disturbed landscapes. Agricultural Experiment Station, Colorado State University, Technical Report TR05-08:7-18. http://colostate.edu/programs/wcrc/annrpt/05/pearsonnative.pdf |