Progress 10/01/05 to 09/30/11
Outputs
OUTPUTS: The final of 6 years' collection of daily water use of Live oak, red maple and Nellie R. Stevens holly from weighing lysimeters was completed. Annual water use of each tree species from propagated liners to trunk calipers (at 6 in) from 5 (holly) to 7.5 inches (oak and maple) are posted at http://www.mrec.ifas.ufl.edu/rcb/TreeWater/default.asp. A similar study was initiated in 2006 using D.D. Blanchard magnolia, Allee Chinese elm and slash pine. Data collection from liners to trees in #300 containers was recorded during this project. Final data collection continues into the next project. A third series of 3 species, bald cypress, Natachez crape myrtle and Japanese ligustrum, was initiated in spring 2011. Data collection will be completed in 2017. Quadpod suspension lysimeters were used in joint study with Utah State Univ. to compare effects of vapor pressure deficits on tree physiology and water use of Morus alba. Tripod suspension lysimeters were used to quantify plant water use from rooted cutting to market size plants in #3 containers. Data was collected for a year's production time for both Viburnum odoratissimum and Rhaphiolepis indica. Irrigation models derived from lysimeter data and based on reference evapotranspiration and plant growth were evaluated. One examined effects of container spacing on the Japanese ligustrum during 14 months of production. Two other year-long experiments evaluated different algorithms based on these irrigation. One used Japanese ligustrum, the other V. odoratissimum. An alternative to pine bark in container substrates was evaluated. The first experiment evaluated different blends of materials consisting principally of half-inch screened pine tree chips in #1 containers using V. odoratissimum. Two bends were carried forward to a second year where they were evaluated in #3 containers using 9 species of landscape plants. Studies were conducted in a rainout shelter to establish deficit irrigation levels based on plant available water that maintained aesthetically pleasing canopies for D.D. Blanchard magnolia and V. odoratissimum shrubs in landscapes. Eighteen large drainage lysimeters (145 sq. ft surface area each) were retrofitted with new leachate quantification systems and a control algorithm. A magnolia, V. odoratissimum plants and turfgrass were installed in each. Water balances and growth were quantified during 9 months of establishment and 1.5 yrs post-establishment. Deficit irrigation levels that maintained aesthetically pleasing appearances were also established for Live oak, Chinese elm, magnolia and red maple. Irrigation was based on models derived from the large tree lysimeters and trunk calipers. Relationships between turgor pressure and shoot growth were established for Live oak and Chinese elm. Relationships between water stress and carbon allocations; and between free amino acids and carbohydrates levels, and shoot or root growth were ascertained. During this period, 1 PhD and 1 MSc were trained and graduated, with 1 PhD and 2 MSc students still in training. Results were disseminated through refereed publications and national and regional meetings. PARTICIPANTS: Individuals: P.I. - R. C. Beeson, Jr. - Wrote the project and oversees all aspects of experimental setup, data collection and analysis. Edward Tillman - Agricultural technician. Responsible for day to day maintenance of production systems and plant growth and maintenance. Steven Toothmoth - Biological Scientist. Responsible for day to day operation of the lab and data collection and entry Dr. Dilma Silva - Post-Doctorate student. Analyzing large tree lysimeter data. Ms. Emily Massey - MSc student who conducted the research on turgor pressure and shoot growth of trees. Graduated 8-6-2011. Mr. Scott Simpson - MSc student. Turfgrass maintenance of drainage system and student developing and analyzing water budgets for the mixed landscape project. Ms. Catherine Teuton - MSc student. Research on utilizing mushroom compost for nursery and greenhouse production. Partner organizations: Southwest Florida Water Management District Florida Potting Soils Lake Brantley Plant Corporation Jon=s Nursery Collaborators and contacts: Dr. R Kjelgren - Utah State University Dr. T. Yeager - University of Florida Training and professional development Graduate students Ms. Dilma Silva - Post-Doctorate student Mr. Brian Pearson - PhD. Candidate Ms. Nisa Leksungnoen - PhD. student Ms. Emily Massey - MSc graduate Mr. Scott Simpson - MSc student Ms. Catherine Teuton - MSc student TARGET AUDIENCES: Horticulture and plant physiology faculty and professionals Tree nurseries and landscape irrigation managers. Regional and municipal water managers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Maximum tree water use for 5-inch caliper holly was 18 gal per day (gpd), while that of 6.9 inch caliper red maple was 27 gph and for a 7.5 inch Live oak 49 gpd. Total water use from liners until final measurements were 5,400, 7,690, 13,933 gal for the holly, maple and Live oak respectively. Maximum water use of 6.5 inch caliper D.D. Blanchard magnolia was 30 gpd, while that for 8.2 inch caliper slash pine was 16 gpd, with 22 gpd for 5.5 inch caliper Chinese elm. Morus alba was insensitive to vapor pressure deficits, transpiring more in Utah than Florida in the summer months, but with less growth. Production of V. odoratissimum (viburnum) from liners to market size plants in #3 containers required and average of 41 gal of evapotranspiration (ETA), while that of Rhaphiolepis indica required 26.7 gal on average and a month longer production time. ETA of both species was modeled as functions of ETo and canopy size relative to the degree of canopy closure using an exponential or third-order inverse polynomial equations. Incorporating the exponential model into an algorithm derived from lysimeter data from Japanese ligustrum produced market-size plants with less irrigation and production time than manual irrigation targeting 70 inches annually. However when used to irrigate viburnum during production, irrigation volumes exceeded that applied by manually controlled irrigation. A viburnum-specific algorithm also exceeded manual irrigation volumes. Although the canopy closure model was derived with a three-quarter container diameter spacing, the algorithm was successful at container spacing from one half to a full container diameter apart. Composted pine tree chips adequately substituted for composted pine bark in #1 containers if supplemented with a 32-0-0 controlled release fertilizer. Both pine chip based-substrates produced market size plants of the 9 species in #3 containers in a time period comparable to pine bark-based substrates. However the 60% pine chip substrate produced market size plants a month sooner than the 70% blend. D.D. Blanchard magnolia was still aesthetically pleasing when irrigated after 75% of plant available water had been transpired. For viburnum, aesthetics were acceptable only at a 30% of available water. These were correlated with irrigation coefficients of 0.7 based on planar projected canopy widths and reference evapotranspiration (ETo). When these coefficients were used to determine irrigation frequency in mixed species (tree-shrub-turfgrass) landscapes in drainage lysimeters, all species maintained aesthetically pleasing landscapes after establishment. Lower percentages of turfgrass (=larger percentages of woody plants) required less irrigation frequency and volume. Irrigation based solely on turfgrass demand was successful with a coefficient 40% lower than ETo. Shoot elongation was strongly linked to turgor pressure and supports irrigation at sunset for maximum growth. Post-dormancy shoot bud break was triggered by amino acid accumulation in quiescent buds, while root grow was governed by carbohydrate availability. Severe water stress overrides normal episodical cycles to emphasize root growth.
Publications
- Beeson, Jr., R.C. 2011. Suspension lysimeter systems for quantifying water use and modulating water stress for crops grown in organic substrates. Agricultural Water Management. 98: 967-976.
- Silva, D.D., D. Cox and R.C. Beeson, Jr. 2011. Development and evaluation of a large rotary root separator. HortScience. 46:676-678.
- Beeson, Jr., R.C. 2011. Evapotranspiration of woody landscape plants. In Evapotranspiration - From Measurements to Agricultural amd Environmental Applications. Ed. G. Gerosa. InTech Open. ISBN: 978-953-307-512-9.
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Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: The project quantifying the water use of Magnolia grandifolia `D.D. Blanchard', Ulmus parvifolia `Aliee` and Pinus elliotii advanced into the fifth year. Trees in #200 containers were transplanted into #300 containers in February and returned to the weighing lysimeters. Actual evapotranspiration and ETo were recorded daily, while canopy measurements were recorded every 3 weeks. In May, after a 8 month establishment period for the woody plants and turfgrass, data collection began on a project to evaluate different methods for calculation of a coefficients for mixed-plant landscapes relative to ETo, for use in allocating water to residential neighborhoods. Programing the computer for the 18 existing drainage lysimeters (145 sq ft surface area each) was accomplished over 2 months while trouble shooting the complete system required an additional 2 months. Water balances were calculated for each lysimeter when a minimum of 2 days had passed since water input from rain or irrigation. Tree and shrub dimensions were recorded every 3 weeks along with qualitative evaluations of the turfgrass. Research eluding the relationships between free amino acids and nonstructural carbohydrates on episodic shoot and root growth of Ligustrum japonicum were concluded. This was the conclusion of a 4 year PhD student's thesis. New research was initiated testing the hypothesis that shoot growth of woody plants occurs at night due to higher turgor pressures. Shoot growth of two tree species was measured at 2200 hr and 500 hr along with shoot water potential. Turgor pressure was estimated based on pressure-volume curves generated for each tree. Turgor pressures were lowered for some trees by controlled imposition of water stress with shoot growth measured concurrently. Trees were transplanted in October 2009 inside a gutter connected rainout shelter measuring 60 x 80 ft. In March 2010, irrigation frequency became based on trunk cross sectional area measured at 6 inches and algorithms developed for Quercus virginiana and Ulmus parvifolia Aliee under production growth rates. Treatments consisting of 100% of the algorithm and 3 deficit irrigation levels of 85, 70 and 55% . In October, plants will be evaluated for acceptable aesthetic by the public. PARTICIPANTS: P.I. - R. C. Beeson, Jr. - Wrote the project and oversees all aspects of experimental setup, data collection and analysis. Edward Tillman - Agricultural technician. Responsible for day to day maintenance of production systems and plant growth and maintenance. Dr. Dilma Silva - PhD student who conducted the research on the free amino acids and non-structural carbohydrates related to root and shoot growth of Ligustrum japonica. Ms. Emily Massey - MSc student conducting the research on turgor pressure and shoot growth of trees. Partner organizations: Southwest Florida Water Management District Florida Potting Soils Lake Brantley Plant Corporation Jon's Nursery Collaborators and contacts: Dr. R Kjelgren - Utah State University Dr. T. Yeager - University of Florida Training and professional development Graduate students Ms. Dilma Silva - PhD. Candidate Mr. Brian Pearson - PhD. student Ms. Nisa Leksungnoen - PhD. student Ms. Emily Massey - MSc. student Mr. Scott Simpson - MSc. student Mr. Kurt Rashall - MSc. student TARGET AUDIENCES: Tree nurseries and landscape irrigation managers. Regional and municipal water managers. Results have been disseminated through the web site and oral presentations at the American Society for Horticultural Science Conference in 2010. Conversations with clientele-initiated phone calls and email also occurred. PROJECT MODIFICATIONS: This extension allow for a more complete summary of results in 2011. The tree water use project was began a year before the project was initiated and will end in late fall 2011. This extension will allow all but the last 4 months of that project to be included in the final report
Impacts
The tree water use project is a 6 year project, which was in its fifth year this year. Outcomes from this project will not be available until 2012. Evaluation of a general coefficient for residential landscapes will be completed in the 2011 and described in the final report. Preliminary results from the summer to early fall of 2010 suggest irrigation frequency based solely on St. Augustine turfgrass with a moderate coefficient of 0.75 may be sufficient to maintain aesthetically pleasing lawns with moderate growth of woody plants. Addition of woody trees and shrubs to a landscape appears to reduce the volume of irrigation required. Determining the threshold of irrigation for aesthetically pleasing landscape appearance should lead to reduced irrigation of residential and commercial landscapes. Roughly 40% of water consumption in Florida is thought to be applied to landscapes. Reducing irrigation to aesthetically pleasing levels will have minimum impact on visual appeal, but will reduce inputs of labor for maintenance and fertilizer applications. It would also reduce demands on water resources and the volume of green waste generated from landscape maintenance. Development of accurate models to predict mixed plant landscapes should reduce water consumption in landscapes and provide a model for other regions of the US. Similarly, calibrating algorithms developed for trees under production to produce acceptable aesthetic quality and growth in landscapes after establishment should lead to more judicial use of irrigation in residential landscapes and proper irrigation of trees in urban planting. Most cities have urban forest, with some of this in street side plantings with highly constricted soil volumes. Often these trees either drown from too much water or slowly decline and die from too little. Studies have shown that greenery in urban areas have a very positive effect on people, crime and the environment. Control of episodic shoot and root growth were highly associated with free amino acids (FAA) in buds and the FAA to nonstructural carbohydrate (NSC) ratio in quiescent root tips. High concentrations of FAA in buds were associated with initiated of episodic bud elongation in Ligustrum japonicum. Shoot growth was arrested when FAA concentrations declined to low levels. This decline in buds was a result of with reduced translocation of FAA in the xylem sap associated with increased root growth. Root growth was triggered by high NSC to FAA ratios at quiescent root tips. Water stress, such as that normally experienced by transplanted woody plants, reduces leaf area and shifts NSC to roots for osmoticum and maintains root growth at the expense of shoot growth. These results provide justification for not fertilizing woody trees and shrubs at transplanting. They also begin to explain why root growth predominates over shoot growth after transplanting of woody plants into landscapes. Evaluation of the hypothesis of turgor pressure on shoot growth awaits further data collection during the spring of 2011.
Publications
- Beeson, Jr., R.C. 2010. Response of Evapotranspiration of Viburnum odoratissimum to Canopy Closure and the Implications for Water Conservation During Production and in Landscapes. HortScience. 45(3): 359-364.
- Beeson, Jr., R.C. 2010. Modeling actual evapotranspiration of Viburnum odoratissimum during production from rooted cuttings to market size plants in 11.4 L containers. HortScience. 45(8):1260-1264.
- Beeson, Jr., R.C. 2010. Are you underwatering your trees Proc. Intl. Plant Propagation Society. 59:516-523.
- Beeson, Jr., R.C. 2010. Modeling actual evapotranspiration of Viburnum odoratissimum during production from rooted cuttings to market-size plants in 11.4-Liter containers. ASHS 2010 Annual Conference Oral Abstracts p. 30.
- Pearson, B. and R.C. Beeson, Jr. 2010. Influence of soil texture, precipitation intensity, and soil moisture on stormwater runoff and leachate. ASHS 2010 Annual Conference Oral Abstracts p. 47.
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: Results from the experiment to quantity tree water use for red maple, live oak and Nellie R. Stevens' holly initiated in 2001 were complied and finally analyzed. A method to expand individual tree water use to estimate annual irrigation requirements per acre was developed. Results from this project were posted at www.mrec.ifas.ufl.edu/rcbeeson/treewateruse.edu. In March 2006 a followup experiment using similar methodology was initiated. In 2009 trees of Magnolia grandifolia `D.D. Blanchard', Ulmus parvifolia `Aliee` and Pinus elliotii were transplanted from #95 black polyethylene containers to similar #200 containers in January and returned to the weighing lysimeters. Actual evapotranspiration and ETo were recorded daily, while canopy measurements were recorded every 3 weeks. Additional studies were also continued with Morus alba in collaboration with Utah State University to compare ETa and stomata conductance between humid and dry climates. A preliminary study evaluating container substrates in which composted clean pine tree chips replaced composted pine was completed. Growth in 2 of the new mixtures was better than the pine bark-based control. A larger trial of the 2 top substrates and similar control utilizing 9 species as began in April with rooted cuttings transplanted into #3 containers. Correlations were developed between aesthetic quality and deficit irrigations as a percentage of plant available water for D.D. Blanchard magnolia and Viburnum odoratissimum in simulated landscapes. Plants were transplanted into an open-sided, polyethylene-covered rainout structure in Sept. 2008. Daily ETA was measured on some plants using weighing lysimeters, other plants were inground and irrigated based on volumetric water content. Magnolia maintained acceptable aesthetic quality at greater soil water deficits than viburnum. Aesthetic value will be matched to coefficients derived from similarly irrigated lysimeter trees to determine minimum acceptable coefficients. These results will be applied in the next phase of this project which started this fall. The objectives are to evaluate calculations of a coefficients (Kmp) for mixed-plant landscapes relative to ETo for use in allocating water for residential neighborhoods. Eighteen existing drainage lysimeters (145 sq ft surface area each) were upgraded to greater depth and more accurate measurements of leachate and irrigation input. These were planted in September with 1 magnolia tree, 0 to 5 Viburnum odoratissimum shrubs and St Augustine turfgrass in varying percentages of surface area. Water balances will be calculated in 2010 and 2011. Results have been disseminated through the web site (above) and oral and poster presentations at the American Society for Horticultural Science Conference in 2009. Conversations with clientele-initiated phone calls and email also occurred. PARTICIPANTS: Individuals: P.I. - R. C. Beeson, Jr. - Wrote the project and oversees all aspects of experimental setup, data collection and analysis. Jeff Kaesberg - Biological scientist. Responsible for data collection and entry. Oversaw general functioning of laboratory and assisted in production related activities. Edward Tillman - Agricultural technician. Responsible for day to day maintenance of production systems and plant growth and maintenance. Partner organizations: Southwest Florida Water Management District Florida Potting Soils Lake Brantley Plant Corporation Jon's Nursery Collaborators and contacts: Dr. R Kjelgren - Utah State University John Lea-Cox - University of Maryland Dr. T. Yeager - University of Florida Training and professional development Graduate students Ms. Dilma Silva - PhD. Candidate Mr. Brian Pearson - PhD. student Ms. Nisa Leksungnoen - PhD. student Ms. Emily Massey - MSc. student Mr. Scott Simpson - MSc. student Mr. Kurt Rashall - MSc. student TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Tree water use of the live oak, red maple and holly ranged from 5 oz to 49 gal per day over a 6 year production period as trees grew from 9 inches up to 26 ft tall. Water use varied substantially among species. Compared to measured actual evapotranspiration (ETA), daily water use could be predicted for all 3 species based on reference evapotranspiration (ETo), a species-specific coefficient and a measure of tree size. Tree size measurements of projected canopy area or trunk cross sectional areas (tcsa) resulted in correlation coefficients (r2) of 0.90 to 0.94. Best estimator for tree size across all species was tcsa measured at 12 inches above soil level for these relatively small trees. The results from the project are unique and stem from the one-of-a-kind weighing lysimeter system constructed for this project. Once published in a peer reviewed journal, simple linear equations relating tree size and microclimate conditions to tree water use will be posted to the existing web site for this project. This will provide a basis for precision irrigation of landscape trees in production and in landscapes in temperate humid regions in the US and world wide. The positive growth effect from clean pine chips offers another alternative substrate component for container-grown ornamental plants. The current experiment seeks to verify the response to clean pine chips is wide spread. Pine chips are a renewal and sustainability commodity that makes use of whole pine trees instead of just their bark. This can alleviate bark shortages for nurseries due to either reduced tree harvest due to low lumber demand or increased competition from landscape mulching. Determining the threshold of irrigation for aesthetically pleasing landscape appearance should lead to reduced irrigation of residential and commercial landscapes. Roughly 40% of water consumption in Florida is thought to be applied to landscapes. Reducing irrigation to aesthetically pleasing levels will have minimum impact on visual appeal, but will reduce inputs of labor for maintenance and fertilizer applications. It would also reduce demands on water resources and the volume of green waste generated from landscape maintenance. Development of accurate models to predict mixed plant landscapes should reduce water consumption in landscapes and provide a model for other regions of the US.
Publications
- Lea-Cox, J.D., Zhao, C., Ross, D.S., Bilderback, T.E., Harris, J.R., Chuanxue Hong, ., Yeager, T.H., Bauerle, W.L., Day, S.D., Ristvey, A.G., Beeson Jr., R.C. and Ruter, J. 2008. An on-line knowledge center for water and nutrient management for the nursery and greenhouse industry. Acta Hort. (ISHS) 801-693-700.
- Beeson, Jr., R.C. 2009. Relationship of transpiration, reference evapotranspiration and tree size during six years of growth for Ilex x Nellie R. Stevens. HortScience. 44(4): 1031.
- Pearson, B.J. and R.C. Beeson, Jr. 2009. Defining variability in residential landscape soils that influence nutrient runoff. HortScience . 44(4): 1032.
- Silva, D. and R. C. Beeson, Jr. 2009. Effect of soil moisture level on root and shoot growth of Ligustrum japonicum nad their relationship to free amino acid and nonstructural carbohydrate ratios. HortScience. 44(4): 1080.
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: An experiment initiated in March 2001to measure daily actual evapotranspiration (ETa) of red maple, live oak and `Nellie R. Stevens' holly, and to relate these to tree size and reference evapotranspiration (ETo) was completed. ETa data was collected on the hollies through the end of December 2007, with leaf area and shoot dry mass determined in January to February 2007. Data analysis is continuing. A similar experiment with identical goals, initiated in March 2006 was also continued. In this experiment, ETa and daily ETo were recorded for Magnolia grandifolia `D.D. Blanchard', Ulmus parvifolia `Aliee` and Pinus elliotii growing in 95 L containers in large tree lysimeters was continued until February 2008. In February 2008, these trees were then transplanted into 360 L containers and returned to the large tree lysimeters. Additional trees were also transplanted into 360 L containers and placed around the lysimeters as border trees. ETa and ETo were recorded daily through the end of September, with canopy measurements recorded every 3 weeks. Additional studies were also continued with Morus alba in collaboration with Utah State University to compare ETa and stomata conductance between humid and dry climates. A study began in early April 2007 with rooted cuttings of Viburnum odoratissimum was completed. These plants were transplanted into 11.4 L containers and placed on 16 independently irrigated production pads. Plants were irrigated using 3 regimes based on ETo, canopy dimensions and container spacing. A fourth control treatment had irrigation adjusted manually every 3 weeks. ETo-based irrigation was applied as needed and in amounts based on algorithms derived from the best L. japonica regime from 2005, a similar algorithm from the V. odoratissimum data completed in March 2006, and an algorithm derived from the combined data set of these 2 species. In June 2008, 3 substrates based on clean pine chips screened to one-half inch were blended with composted yardwaste, hardwood bark, sedge peat, sand and/or coconut coir and amended with 0, 1, or 2 lbs of a controlled release nitrogen (34-0-0). The clean pine chips were composted 6 months prior to use. Rooted cuttings of V. odoratissimum were transplanted were transplanted in each and a control substrate based on pine bark, compost and sand (60:40:10). PARTICIPANTS: Individuals: P.I. - R. C. Beeson, Jr. - Wrote the project and oversees all aspects of experimental setup, data collection and analysis. Directs University-employed technicians who maintain experiments and assist in data collection and preparation for analysis. Partner organizations: Southwest Florida Water Management District Florida Potting Soils Cherry Lake Tree Farm Lake Brantley Plant Corporation Jon's Nursery Collaborators and contacts: Dr. R Kjelgren - Utah State University Dr. T. Yeager - University of Florida Training and professional development: Dilma Silva - PhD. candidate TARGET AUDIENCES: Southeastern Spontaneous Nursery Water Management Group web site: http://www.waternut.org/moodle/ . A website developed to collect the knowledge of nursery water management from several land grant universities across the Southeastern US and make it available to professionals, the nursery industry and the general public. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The lysimeter data for the trees is unique in North America, especially trees in the Southeastern US. A complete data set now exist for 3 tree species up to 8 m in height. Tree water use ranged up to 122 L per day for red maples 19 cm in trunk diameter (at 15 cm), up to 190 L per day for similar size Live oak. Preliminary analysis suggest landscape tree water use can be adequately modeled for irrigation control based on ETo and trunk diameter below the first major branch. A second set of 3 landscape trees species is nearing completion of a third year's growth. Tree water use for trees of 5 to 8 cm in caliper (at 15 cm) ranged from 7.6 L for magnolia to 15 L for Chinese elm. Correspondingly, water use of woody evergreen shrubs is even rarer in the literature. By associating woody plant transpiration, or alternatively plant irrigation needs, to canopy size and reference evapotranspiration (ETo), more precise amounts of water required for production or landscape establishment can be prescribed. Viburnum in the algorithm evaluation reached marketable size earliest when irrigated under the viburnum algorithm, followed by the combined then ligustrum algorithms. Despite differences in production time to achieve 90% marketable size, there were no differences in total irrigation applied among ETo-based algorithms. All finished sooner and with less irrigation volumes than the manually controlled treatment. This research has shown that transpiration of woody shrubs and large shade trees corresponds to ETo in a similar manner to agronomic crops. In production, this revelation provides an avenue for precise irrigation will reduce nutrient leaching, thereby lowering fertilizer applications and nutrient runoff to surface or ground water. Results of viburnum production using ETo and the canopy closure model verify last year's results with ligustrum and demonstrate that irrigation water can be conserved during the first three-quarters of production to be used during the final quarter push to marketable size. Irrigation control based on ETo is rainfall sensitive and more representative of a crop than soil based moisture sensors. Similarly for trees, irrigation needs are much lower than previously thought for smaller trees, requiring less than 16 L per summer day for trees up to 6.6 cm in trunk caliper measured 15 cm above the soil line. Applying irrigation more precisely speeds establishment of both trees and shrubs into a landscape site. With adequate water of even tertiary quality, woody shrubs and trees can sequester large amounts of carbon dioxide annually. Measurements of shoot biomass are recorded annually for trees and at the end of an experiment for shrubs. Healthy landscape plantings not only would sequester carbon locally where it is produced, they also are credited with providing a positive psychological effect on people. Joint research into the sometimes quenching effects of low relative humidity will aid in adapting the ETo-based models to more arid regions of the US and the world.
Publications
- Beeson, Jr., R.C. and J. Brooks. 2008. Modeling Actual Evapotranspiration of Acer rubrum from a rooted cutting to an 8 m tall tree. Acta Hort. 792: 91-97.
- Beeson, Jr., R.C. and J. Brooks. 2008. Evaluation of a model based on ETo for precision irrigation using overhead sprinklers during nursery production of Ligustrum japonica grown in 11L containers. Acta Hort. 792:85-90.
- Alvarez, E., S.M. Scheiber, D.R. Sandrock, and R. C. Beeson, Jr. 2007. Drought tolerance responses of purple lovegrass and Adagio maiden grass. HortScience 42(7): 1695-1699.
- Scheiber, S.M., Beeson, Jr., R.C. and Vyapari, S. 2007. Pentas water use requirements and growth in the landscape affected by municipal compost and mined field clay soil amendments. HortScience. 42 (7):1744-1747.
- R.C. Beeson, Jr. 2007. Determining Plant Available Water of Woody Ornamentals in Containers During Production. HortScience. 42(7): 1700-1704.
- Desbiens, M.-.C., Bussieres, P., Caron, J., Beeson, R., Haydu, J., Boudreau, J. and Elrick, D. 2008. Improved water saving in nursery production using spaghum peat. Acta Hort. 70:407-414.
- Scheiber,S.M., R.C. Beeson, Jr, J. Chen, Q. Wang, and B. Pearson. 2008. Evaluation of Irrigation Frequency and Quantity on Leaf Gas Exchange, Growth, and Nitrate Leaching of Coleus in a Simulated Landscape. HortScience. 43: 881 - 884.
- Beeson, Jr., R. C. and J. Brooks. 2007. Container spacing influences canopy dimensions of Ligustrum japonica. Proc. South. Nursery Assoc. Res. Conf. 53: 473-475.
- Lea-Cox,, J.; D.S. Ross, C. Zhao, T.E. Bilderback, M. Lorscheider,T.H. Yeager, J. R. Harris, S.D. Day, C. Hong, W.L. Bauerle, R.C. Beeson, Jr., A.G. Ristvey and J.M. Ruter. 2007. Proc. South. Nursery Assoc. Research Conference. 52:115-121.
- Beeson, Jr., R.C. 2008. Evaluation of an ETo-based operational irrigation algorithm using two genera of container-grown woody ornamentals. HortScience - 43(4): 1104.
- Silva, D, R.C. Beeson, Jr. and F. Irizarry. 2008. Using ECH2O probes to maintain differential substrate moisture levels did no produce differences in plant growth in large soil volumes. HortScience - 43: 1192.
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Progress 10/01/06 to 09/30/07
Outputs
OUTPUTS: An experiment initiated in March 2001to measure daily actual evapotranspiration (ETa) of red maple, live oak and `Nellie R. Stevens' holly, and to relate these to tree size and reference evapotranspiration (ETo) was continued. Leaf areas and shoot dry mass of the 2 remaining live oaks was determined. ETa data was collected on the hollies through the end of December 2006, with leaf area and shoot dry mass determined in January/February 2007. Data analysis is continuing. A similar experiment with identical goals, initiated in March 2006 was also continued. In this experiment, ETa and daily ETo were recorded for Magnolia grandifolia `D.D. Blanchard', Ulmus parvifolia `Aliee` and Pinus elliotii growing in 26 L containers and suspended from tripod lysimeters through until late March 2007. Lysimeter trees were then transplanted into 95 L containers and placed in the large tree lysimeters. Additional trees were also transplanted into 95 L containers and placed around the lysimeters
as border trees. ETa and ETo were recorded daily through the end of September, with canopy measurements recorded every 3 weeks. Initial studies were also began with Morus alba in collaboration with Utah State University to compare ETa and stomata conductance between humid and dry climates. ETa and canopy measurements of Rhaphiolepis indica which began in April 2006 were completed in early May 2007 when 90% of the measured plant obtained marketable size. ETa normalized by projected 2-dimensional canopy area is being modeled as a function of canopy closure as was been done for the previously for Ligustrum japonica and Viburnum odoratissimum. In early April 2007, rooted cuttings of V. odoratissimum were transplanted into 11.4 L containers and placed on 16 independently irrigated production pads. Plants were irrigated 6.3 mm daily for 3 weeks, then 4 irrigation regimes were imposed. These were a manually adjusted control with a goal of 1.8 m applied depth annually, and 3 regimes based on
ETo, canopy dimensions and container spacing. ETo-based irrigation was applied as needed and in amounts based on algorithms derived from the best L. japonica regime from 2005, a similar algorithm from the V. odoratissimum data completed in March 2006, and an algorithm derived from the combined data set of these 2 species. By September 2007, visual differences were becoming evident among the algorithm regimes.
PARTICIPANTS: Individuals: P.I. - R. C. Beeson, Jr. - Wrote the project and oversees all aspects of experimental setup, data collection and analysis. Directs University-employed technicians who maintain experiments and assist in data collection and preparation for analysis. Partner organizations: Southwest Florida Water Management District Florida Potting Soils Cherry Lake Tree Farm Lake Brantley Plant Corporation Jon's Nursery Collaborators and contacts: Dr. R Kjelgren - Utah State University Dr. T. Yeager - University of Florida
TARGET AUDIENCES: Target audiences: Pinellas County Master Gardners Palm Beach Florida Nursery, Landscape and Grower Association Chapter Florida Environmental Horticulture Landscape Extension Agents - In service training
Impacts
The lysimeter data for the trees is unique in North America, especially trees in the Southeastern US. A complete data set now exist for 3 tree species up to 8 m in height. Data analysis is continuing. A second set of 3 trees species is nearing completion of a second year's growth. Correspondingly, water use of woody evergreen shrubs is even rarer in the literature. By associating woody plant transpiration, or alternatively plant irrigation needs, to canopy size and reference evapotranspiration (ETo), more precise amounts of water required for production or landscape establishment can be prescribed. This research has shown that transpiration of woody shrubs and large shade trees corresponds to ETo in a similar manner agronomic crops. This has not been shown to this extend before. In production, precise irrigation will reduce nutrient leaching, thereby lowering fertilizer applications and nutrient runoff to surface or ground water. For woody evergreen shrubs, data
indicates that only 6.3 mm of irrigation daily are needed the first third or more of a production cycle. This is in contrast the 8.4 to 12.3 mm this is thought should be or is applied. Results of ligustrum production using ETo and the canopy closure model, if verified by the current viburnum experiment, will demonstrate that irrigation water can be conserved during the first three-quarters of production to be used during the final quarter push to marketable size, while using less total water than currently applied. During drought conditions, precise irrigation will result in more marketable inventory at the end of drought conditions. Irrigation control based on ETo is rainfall sensitive and more representative of a crop than soil based moisture sensors. Similarly for trees, irrigation needs are much lower than previously thought for smaller trees, requiring less than 3.8 L per summer day for trees up to an inch in trunk caliper measured 15 cm above the soil line. Whereas for the
largest trees, highest daily transpiration was over 220 L per day for Live oak. Commercial developments are increasingly installing larger trees, which require longer establishment times and care than smaller trees. Applying irrigation more precisely speeds establishment of both trees and shrubs into a landscape site. With adequate water of even tertiary quality, woody shrubs and trees can sequester large amounts of carbon dioxide annually. Healthy landscape planting not only would sequester carbon locally where it is produced, they also are credited with providing a positive psychological effect on people. Joint research into the sometimes quenching effects of low relative humidity will aid in adapting the ETo-based models to more arid regions of the US and the world.
Publications
- Scheiber, S.M. & Beeson, Jr., R.C. 2006. Establishment and growth of begonias in the landscape as affected by root ball condition at transplant. J. Environ. Hort. 24(4):213-217.
- Scheiber, S. M. & Beeson, R. C. 2007. "Landscape growth and water use efficiency of coleus managed with irrigation deficits." HortTechnology -17(4): 561-566.
- Beeson, Jr., R.C. and J. Brooks. 2006. How Much Water Does it Take to Grow a Ligustrum? Proc. South. Nursery Assoc. Res. Conf. 51: 525-527.
- Beeson Jr., R. C. 2007. ETo-based Operational Model for Irrigation of Container-grown Woody Ornamentals. HortScience - 42(4): 862.
- Neal, C. and R.C. Beeson, Jr. 2007. Viburnum root mass and fall carbohydrate levels as affected by container type. HortScience - 42(4): 862.
- Lea-Cox, J., D. Ross, T. Bilderback, T. Yeager, J.R. Harris, C. Hong, W. Bauerle, S. Day, A. Ristvey, J. Ruter, R. Beeson and C. Zhao. 2007. Developing a knowledge center for water and nutrient management for the nursery and greenhouse industry. HortScience - 42(4): 898.
- R.C. Beeson, Jr. 2007. Heavy Lifting. Ornamental Outlook. 16(5): 21-22.
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Progress 10/01/05 to 09/30/06
Outputs
An experiment initiated in March 2001to measure daily actual evapotranspiration (ETa) of red maple, live oak and `Nellie R. Stevens' holly, and to relate these to tree size and reference evapotranspiration (ETo) was continued. Beginning 1 Nov. each of the 3 maples were harvested for leaf area and shoot biomass. Maples were around 20 cm in caliper (at 15 cm.) at harvest and contained around 104 sq. m of leaf area. A model calculated from reference evapotranspiration (ETo) and ETa data of a maple normalized by projected canopy area (pca) predicted measured ETa with a 12% error, but was skewed as trees increased in height. Normalizing by trunk cross sectional area before the first major branch increased the error to 15%, but relationships remained linear and 1:1. In June the largest of 3 live oaks was similarly harvested. In early Sept. the 2 remaining oaks were harvested ahead of damage from Hurricane Ernesto. Oaks were around 10 cm in caliper at harvest and frequently
had ETa near 190 L daily. Hollies, due to their smaller statue, are being continued through December 2006 before harvested. Shrub experiments initiated March 2005 were completed. Ligustrum japonica transplanted into #3 containers were irrigated based on daily ETo and 3 algorithms based on the canopy closure model and canopy size, or manually. Two of the algorithms produced marketable size plants in 14 months with less than 1.65 m of overhead irrigation. This occurred during climatic drought conditions. Other irrigation regimes required greater than 20% more water and 2 to 4 additional weeks of growth. L. japonica grown in #3 containers at 0.5, 1.0 and 1.5 container diameter spacings exhibited comparable responses to the canopy closure algorithm used in the concurrent experiment. In a third experiment, Viburnum odoratissimum were grown in individual suspension lysimeters, with canopy measurement recorded tri-weekly. When ETa was normalized by pca and ETo, the relationship between the
resulting water needs index and percent canopy closure almost exactly matched that derived from L. japonica in 2001-2002. In April, the V. odoratissimum were replaced with Raphalis indica and similar data collection resumed. By the end of Sept., R. indica canopies covered roughly 70% of the container substrate surface. In March, propagated material of Magnolia grandifolia `D.D. Blancher', Ulmus parvarfolia `Aliee` and Pinus elliotii were transplanted into #7 containers to begin another set of trees to determine irrigation requirements to 15 cm caliper or large. ETa has been recorded daily along with tri-weekly measurements of canopy size and trunk diameter.
Impacts
This project is establishing water requirements for commercially acceptable plant growth. These would be same for both production nurseries and in landscapes; although in landscapes adequate quality would likely be maintained with lower amounts. Result from this project provides information for guidelines for efficient water use for commercial nurseries and maximum amounts for landscapes. Establishing these amounts based on reference evapotranspiration (ETo) and plant size allows their application throughout the US and other countries where similar calculations of ETo are available. Understanding the mechanics of canopy closure and ETa, from direct measurement and modeling, will impact all nurseries both during early production when plants are small and later as plants are removed for sale. The comparable responses to the canopy closure model at the different spacings indicates the robustness of this procedure for shrubs and its independence of container spacing
within the range commonly used in the nursery industry. Comparable responses between the V. odoratissimum and L. japonica suggest algorithms may be derived that can control irrigation for several different species of plants rather than the need of species specific models.
Publications
- Beeson, Jr., R.C. and J. Kahoun. 2005. Seasonal water use of large trees. Proc. South. Nursery Assoc. Res. Conf. 50: 596-601.
- Beeson, Jr., R.C. 2006. Relationship of plant growth and actual evapotranspiration to irrigation frequency based on managed allowable deficits for container nursery stock. J. Am. Soc. Hort. Sci. 131(1):140-148.
- Scheiber, S.M. and Richard C. Beeson, Jr. 2006. Petunia growth and maintenance in the landscape as influenced by alternative irrigation strategies. HortScience. 41:235-238.
- Brooks, J., R. C. Beeson, Jr. and S.M. Schieber. 2005. Slab Production of Asiatic Jasmine for Instant Landscape Appeal. Proc. South. Nursery Assoc. Res. Conf. 50: 535-536.
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Progress 10/01/04 to 09/30/05
Outputs
Work accomplished during this period occurred while this new project was in the evaluation and approval stage. An experiment initiated in March 2001to measure daily actual evapotranspiration (ETa) of red maple, live oak and `East Paltaka holly and relate these to tree size and reference evapotranspiration (ETo) was continued. Maples and oaks were about 4.5 inches in caliper at 6 inches above soil level in September 2004. Hurricane winds from 3 different storms stripped most leaves from the maples in September and October 2004. In contrast leaf loss from live oak trees was much less and they flushed new leaves in October, while hollies were unscathed. In February maple and oak trees were transplanted into #300 containers, with hollies transplanted into #200 containers. By September 2005, maples were around 7 inches in caliper and oaks 6 inches. Daily maximum water use was up to 43 gal for live oak in September 2005. Live oak and holly trees will be continued through
2006, while maples will be harvested before leaf senescence. `Cathedral' live oaks grown for 2 years in 5 porous bottom container types and 2 solid bottom systems, including a control #25 pot-in-pot, were harvested in December 2004. Through to the first hurricane in mid-August 2004, solid bottom systems required up to twice as much water as the best porous bottom system, yet produced significantly smaller trees. Trees in some porous bottom systems remained upright through the hurricanes, but were difficult to harvest. Porous sides reduced root circling in the outer inch of a root ball in all cases, but there was still some circling roots in the interior for all systems. Other experiments initiated in Spring 2004 were terminated due to excessive damage after the third hurricane in October. In March 2005, three experiments were established, two being repeats of those lost in 2004. Liners of Ligustrum japonica were transplanted into #3 containers and placed on 16 independently irrigated
areas. Irrigation frequency and amount was controlled by 3 different algorithms or manually. Algorithm-controlled irrigation was based on ETo, canopy size, and container spacing. Through the end of September, two algorithms and the manual control treatments were of similar size with plants about one-third grown. The same species and container size were used in a second experiment to evaluate effects of container spacing on ETa and plant size, as a test of the rigor of a canopy closure model for estimating plant ETa from ETo and canopy size. Two plants were placed in suspension lysimeters on 9 independently irrigated areas with surrounding plants spaced at 0.5, 1 or 1.5 container diameters between them in March. Plant growth has varied based on spacing, although actual ETa appear similar to date. The third experiment placed Viburnum odoratissimum plants in suspension lysimeters in #3 containers at a 0.75 container diameter spacing. Resulting measurements of daily ETa and triweekly
measurements of canopy size will be used to evaluate the canopy closure model with a second species.
Impacts
Water for irrigation is becoming an issue for landscape nurseries for a larger portion of the US then ever before. Additionally drought, and urban irrigation restrictions aimed at conserving potable and even tertiary water sources, have no sound basis for how much irrigation is required for woody plant growth or survival. This project is establishing water requirements for plant growth. These would be same for both production nurseries and in landscapes; although in landscapes adequate quality would be maintained with lower amounts. Result from this project provides information for guidelines for efficient water use for commercial nurseries and maximum amounts for landscapes. Establishing these amounts based on reference evapotranspiration (ETo) and plant size allows their application throughout the US and other countries where similar calculations of ETo are available. Understanding the mechanics of canopy closure and ETa, from direct measurement and modeling, will
impact all nurseries both during early production when plants are small and later as plants are removed for sale. The research evaluating new production systems provide information that give nurseries options for improving the efficiency of their irrigation, with or with the addition of collection basins.
Publications
- Caron, J., R. C. Beeson Jr., J. J. Haydu. J. Boudearu. 2004. Saving water with Sphagnum peat in nursery growing media. Acta Horticulturae. 664: 119-124.
- Haydu, J. J., R. C. Beeson, Jr., J. Caron. 2004. Economics of five irrigation technologies for container-grown Viburnum odoratissimum. Acta Horticulturae. 664: 309-315.
- Beeson, Jr., R. C. 2004. Modeling Actual Evapotranspiration of Ligustrum japonicum from rooted cuttings to commercially marketable plants in 12 liter black polyethylene containers. Acta Horticulturae 664: 71-77.
- Chen, J. and R. C. Beeson, Jr. 2004. Production of quality aroid foliage plants using captured rainwater and irrigation runoff as an irrigation source. Acta Horticulturae. 664: 139-145.
- Kjelgren, R., R. C. Beeson, Jr., T. Montague. 2004. Water use and stomatal behavior of sweetgum (Liquidambar styraciflua) relative to reference evapotranspiration in three contrasting regions. Acta Horticulturae. 664: 353-360.
- Caron, J., Elrick, D.E., Beeson, R.and J. Boudreau. 2004. Defining critical capillary rise properties for growing media used with subirrigation devices in nurseries and greenhouses. Soil Science of America Journal. 69: 794-806.
- Beeson, Jr. R. C. 2005. Modeling irrigation requirements for landscape ornamentals. HortTechnology. 15(1) 18-22 .
- Kahoun, J. and R. C. Beeson, Jr. 2004. Slab production of asiatic jasmine for instant landscape appeal. Proc. South. Nursery Assoc. Res. Conf. 49: 40-42.
- Beeson, Jr. R.C. , T.H. Yeager and J. Kahoun. 2004. Irrigation volumes and tree growth of Quercus virginiana in porous bottom containers and #25 pot-in-pot. Proc. South. Nursery Assoc. Res. Conf. 49: 535-537.
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