Progress 11/01/10 to 10/31/15
Outputs
Target Audience:The primary target audience for this research is container nursery growers in Michigan and the Midwest. Research outputs are also applicable to field nursery producers and Christmas tree growers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?We have used the research plots for several field day training/discussion sessions including: Michigan Christmas Tree Association German Christmas grower field tour Michigan Nursery and Landscape Association How have the results been disseminated to communities of interest?Results of this research have been presented at professional and scientific conferences including International Christmas Tree Research and Extension Conference American Society for Horticultural Science Michigan Nursery and Landscape Association Ohio Nursery and Landscape Association Michigan Christmas Tree Association Pennsylvania Christmas Tree Growers Association National Christmas Tree Association Michigan Seedling Growers Association What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
We planted 100 conifers (50 Colorado blue spruce trees [Picea pungens]and 50 Fraser fir trees [Abies fraseri]) in 25-liter containers. All trees were planted in a standard container substrate of 80% pine bark and 20% peat moss (v:v) (Renewed Earth, Inc. Kalamazoo, MI, USA). Four rows of trees in each nursery section were assign at random to receive either a conventional controlled-release fertilizer (Osmocote Plus 15-9-12, 5-6 month release, Scotts, Inc., Marysville, OH USA) or an OMRI-certified organic fertilizer (NatureSafe 10-2-8 and NatureSafe 5-6-6, Griffin Industries, Cold Spring, KY, USA). The organic fertilizers were blended to provide approximately the same ratio of N-P2O5-K2O as the conventional source. We measured height and trunk caliper at the start of the study and at the end of each growing season. Foliar samples were collected for nutrient analysis in November. Net photosynthetic gas exchange of the conifers was measured on three dates using a portable photosynthesis system (Li-6400, Li-Cor, Inc. Lincoln, NE, USA) equipped with a 0.25-liter cylindrical conifer chamber. Gas exchange measurements were collected on all conifers in the study between 10:00 and 16:00 on clear days (photosynthetic ally active radiation (PAR) >1500 mmol m-2 s-1). Gas exchange measurements were expressed on a projected shoot area basis. Leachate from eight containers in each row of the nursery was collected via an automated leachate collection system. Container leachate from each row was collected and total run-off was measured by a series of tipping bucket rain gauges and an automated data logger. Trees were irrigated daily at 09:00 via spray stakes (Netafim, Inc) operated by an automated timer. Irrigation and rainfall in excess of daily plant water use leached through the containers and was collected by tipping buckets and recorded by the datalogger After an initial assessment and trouble-shooting period, irrigation rates were adjusted in order to achieve a target leaching fraction of 10-20% of irrigation applied. Samples of leachate water were collected weekly after irrigation. Leachate samples were subsequently analyzed for nitrate and ammonium at the Michigan State University Soils laboratory. Total amount of nitrogen leached during each season was estimated by multiplying the amount of water leached each week by the N concentration of the samples collected that week and summing the totals over the growing season. Fertilizer source did not affect height or caliper growth of Colorado blue spruce trees and did not affect caliper growth of Fraser fir trees. Conventional fertilizer increased foliar nitrogen of Fraser fir trees relative to trees receiving organic fertilizer, but not affect foliar N of Colorado blue spruce trees. Fertilizer source and species affected rates of net photosynthesis. Colorado blue trees had higher rates of net photosynthesis than Fraser fir trees. Conventional fertilizer increased net photosynthetic rates of trees compared to trees fertilizes with organic fertilizer. Nitrate and ammonium concentrations of leachate samples collected during the growing season were consistently higher for trees fertilized with conventional fertilizer than for trees receiving organic fertilizer or trees in an unfertilized check row (data not shown). As a result of the increased level of nitrate and ammonium, total nitrogen leaching was greatest for trees fertilized with the conventional fertilizer. It is important to note, however, that the total amount of nitrogen leached were very small relative to the amount of nitrogen applied as fertilizer. For example, a total of 129.3 mg of N leached per container in the conventional fertilizer plots. This presents less than 1% of the total N applied (25 g N per container). This suggests the container production system is very efficient in terms of nutrient utilization. This is likely related to full utilization of the container substrate by tree roots. Fertilizer source (conventional versus organic) had little effect of tree growth, except for height growth of Fraser fir trees. Conventional fertilizer increased foliar N of Fraser fir trees and resulted in higher over photosynthetic rates for trees of both species. Casual observation indicated that color and quality of trees was comparable regardless of fertilizer source. Therefore growers may be able toproduce acceptable quality trees regardless of fertilizer source. Nutrient utilization appeared to be high and relatively little applied fertilizer leached out of containers during the growing season.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Eksi, M., Rowe, D. B., Fern�ndez-Ca�ero, R., & Cregg, B. M. (2015). Effect of substrate compost percentage on green roof vegetable production. Urban Forestry & Urban Greening, 14(2), 315-322.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Whittinghill, L.J., D.B. Rowe, R. Schutzki, and B.M. Cregg. 2014. Quantifying carbon sequestration of various green roof and ornamental landscape systems Landscape and Urban Planning 123:41-48.
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Whittinghill, L. J., Rowe, D. B., Andresen, J. A., & Cregg, B. M. 2015. Comparison of stormwater runoff from sedum, native prairie, and vegetable producing green roofs. Urban Ecosystems, 18(1), 13-29.
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Wang, X., Fernandez, R. T., Cregg, B. M., Auras, R., Fulcher, A., Cochran, D. R., ... & Geneve, R. L. 2015. Multistate evaluation of plant growth and water use in plastic and alternative nursery containers. HortTechnology, 25(1), 42-49.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Herms, D. A., Smitley, D. R., & Cregg, B. 2014. Interspecific patterns of ash decline and mortality in a common garden. In 2014 Emerald Ash Borer National Research and Technology Development Meeting p. 38.
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: Nursery growers, Christmas tree producers, landscapers and urban foresters. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Training workshop for Michigan Department of Agriculture and Rural Development (MDARD) Michigan Agricultural Environmental Assurance Program Certiifcation Technicans. How have the results been disseminated to communities of interest? Results related to this project have been dissemated through presentations to nursery growers, Christmas tree producers, landscapers and urban foresters. Audiences inlcude Michigan Nurseyr and Landscape Association, Michigan Christmas Tree Association, Pennsylvania Christmas Tree Growers Association, and the Intenrational Society of Arboriculture. What do you plan to do during the next reporting period to accomplish the goals? Paclobutrazol is considered long lasting and can provide growth control for several years. Growth measurements and cone counts will continue for the next three years on both field plots and container-grown trees. We will provide a summary of results from the current years’ data collection at the end of the next reporting period. Longer-term results of the project will be presented in peer reviewed publications and professional publications such as the Michigan Christmas Tree Association’s Great Lakes Christmas Tree Journal and American Nurseryman.
Impacts
What was accomplished under these goals?
Phase one: Field trials In May 2013 we installed field trials in Christmas tree plantations at five tree farms in Michigan (Fig. 1). At four of the farms we applied paclobutrazol (Cambistat) to 120 Fraser fir trees in each three size classes (Table 1). Paclobutrazol was applied as a soil injection using a pressurized backpack system . Treatments were applied via three soil injections distributed evenly around each tree. We applied two foliar PGR treatments; paclobutrazol (TrimTect) and uniconazole (Sumagic). Gibberellin A4A7 (ProVide) was applied as a positive control to compare against the PGR’s. In addition to the Fraser fir test, we applied paclobutrazol via soil injection to field-grown blue spruce and Norway spruce at two farms. Evaluation: We are currently evaluating 2014 leader growth and evidence of phyto-toxicity or unusual growth on trees in all plots. In addition, cone counts are being conducted on all Fraser fir plots. Phase two: Container trial In spring 2014 we applied paclobutrazol as a drench treatment to container grown conifers at Dutchman tree farm, Manton, MI. The container trial was installed as a set of six experiments. Treatments were applied to Norway spruce, eastern white pine and Serbian spruce in 3 gallon (#3) and 5 gallon (#5) containers. In each experiment, 75 trees were assigned at random to one of three treatments; high rate of paclobutrazol (200 ml), low rate of paclobutrazol (100 ml) or untreated control. The trees were grown in an operational block of container-grown trees in the pot-in-pot production area. Trees were grown in standard mix of pine bark and compost. Trees were fertilized with a controlled release fertilizer and irrigated daily via an overhead irrigation system. Evaluation Leader growth was measured on all trees on July 17, 2014, except #3 Serbian spruce trees, which had not yet completed shoot growth for the season. Application of paclobutrazol resulted in a small decrease in growth for Norway spruce but had no effect on white pine or Serbian spruce..
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Whittinghill, L.J., D.B. Rowe, J.A. Andresen and B.M. Cregg. 2014. Comparison of stormwater runoff from sedum, native prairie, and vegetable producing green roofs. Urban Ecosystems. Published on-line June 2014 DOI:10.1007/s11252-014-0386-8
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Wise J.C., A.H. VanWoerkom, S.G. A?imovi?, G.W. Sundin GW, B.M. Cregg BM, and C. Vandervoort. 2014. Trunk Injection: A Discriminating Delivering System for Horticulture Crop IPM. Entomol Ornithol Herpetol 3: 126. doi:10.4172/2161-0983.1000126
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2014
Citation:
Cregg, B. 2014. Urban tree selection in a changing climate. International Urban Tree Diversity Conference. Alnarp, Sweden. June 16-18, 2014.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Whittinghill, L.J., D.B. Rowe, R. Schutzki, and B.M. Cregg. 2014. Quantifying carbon sequestration of various green roof and ornamental landscape systems Landscape and Urban Planning 123:41-48.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2014
Citation:
Cregg, B. 2014. Research in Real Time: Integrating Social Media and Landscape Horticulture Research. National eXtension Conference. Sacramento, CA. March 24-27, 2014.
|
Progress 01/01/13 to 09/30/13
Outputs
Target Audience: Landscape nursery managers, Chrsitmas tree producers, Urban foresters, profesional arborists, extension educators Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? Results of this project were presented at professional trade association meetings; Michigna Christmas Tree Association, Michigan Seelding Growers Association, Indiana Christmas Tree Association. What do you plan to do during the next reporting period to accomplish the goals? During the next phase of the project we will focus on water management for pot-in-pot grown nursery tree crops. We will use a newly-installed sensor-based irrigation system to control irrigation for honeylocust (Gleditisa triacanthos) trees grown in #25 (105 L) containers and conifers [concolor fir (Abies concolor) , Fraser fir (Abies fraseri), and blue spruce (Picea pungens)] grown in #7 (25 L) containers. Container substrate water content (v:v) will be continuously monitored with TDR moisture sensors linked to an automated datalogger. For sensor-based irrigation levels, irrigation will be automatically via electronic solenoids when moisture levels reach pre-set thresholds Within each nursery section trees will be assigned to one of three irrigation levels: sensor-based HIGH (maintained at 25% volumetric substrate moisture); sensor-based LOW (maintained at 15% volumetric substrate moisture); and CONTROL (constant irrigation equivalent to 1 cm water depth /day). All trees will be supplied with an operational standard rate of controlled release fertilizer. We will measure stem caliper and height growth for the growing season. Nutrient leaching (total N and total P) will be estimated from continuous monitoring of container leaching via and automated leachate collection systems and periodic analysis of nutrient concentration is subsamples of leachate.
Impacts
What was accomplished under these goals?
Objective 1. Comparison of growth and physiology of container-grown trees grown under conventional and organic nutrition management. We planted 100 conifers (50 Colorado blue spruce trees [Picea pungens]and 50 Fraser fir trees [Abies fraseri]) in 25-liter containers. All trees were planted in a standard container substrate of 80% pine bark and 20% peat moss (v:v) (Renewed Earth, Inc. Kalamazoo, MI, USA). Four rows of trees in each nursery section were assign at random to receive either a conventional controlled-release fertilizer (Osmocote Plus 15-9-12, 5-6 month release, Scotts, Inc., Marysville, OH USA) or an OMRI-certified organic fertilizer (NatureSafe 10-2-8 and NatureSafe 5-6-6, Griffin Industries, Cold Spring, KY, USA). The organic fertilizers were blended to provide approximately the same ratio of N-P2O5-K2O as the conventional source. We measured height and trunk caliper at the start of the study and at the end of each growing season. Foliar samples were collected for nutrient analysis in November. Net photosynthetic gas exchange of the conifers was measured on three dates (Aug. 8, Aug. 31 and Oct. 7) using a portable photosynthesis system (Li-6400, Li-Cor, Inc. Lincoln, NE, USA) equipped with a 0.25-liter cylindrical conifer chamber. Gas exchange measurements were collected on all conifers in the study between 10:00 and 16:00 on clear days (photosynthetic ally active radiation (PAR) >1500 mmol m-2 s-1). Gas exchange measurements were expressed on a projected shoot area basis. Objective 2. Nutrient leaching Leachate from eight containers in each row of the nursery was collected via an automated leachate collection system.. Container leachate from each row was collected and total run-off was measured by a series of tipping bucket rain gauges and an automated data logger (Zhu et al. 2005). Trees were irrigated daily at 09:00 via spray stakes (Netafim, Inc) operated by an automated timer. Irrigation and rainfall in excess of daily plant water use leached through the containers and was collected by tipping buckets and recorded by the datalogger. After an initial assessment and trouble-shooting period, irrigation rates were adjusted in order to achieve a target leaching fraction of 10-20% of irrigation applied. Samples of leachate water were collected weekly after irrigation. Leachate samples were subsequently analyzed for nitrate and ammonium at the Michigan State University Soils laboratory. Total amount of nitrogen leached during each season was estimated by multiplying the amount of water leached each week by the N concentration of the samples collected that week and summing the totals over the growing season. Results Objective 1. Comparison of growth and physiology of container-grown trees grown under conventional and organic nutrition management. Conventional fertilizer increased (p<0.05) height growth of Fraser fir trees compared to trees receiving organic fertilizer. Fertilizer source did not affect height or caliper growth of Colorado blue spruce trees and did not affect caliper growth of Fraser fir trees. Conventional fertilizer increased foliar nitrogen of Fraser fir trees relative to trees receiving organic fertilizer, but not affect foliar N of Colorado blue spruce trees. Fertilizer source and species affected rates of net photosynthesis. Colorado blue trees had higher rates of net photosynthesis than Fraser fir trees. Conventional fertilizer increased net photosynthetic rates of trees compared to trees fertilizes with organic fertilizer. Objective 2. Nutrient leaching Nitrate and ammonium concentrations of leachate samples collected during the growing season were consistently higher for trees fertilized with conventional fertilizer than for trees receiving organic fertilizer or trees in an unfertilized check row (data not shown). As a result of the increased level of nitrate and ammonium, total nitrogen leaching was greatest for trees fertilized with the conventional fertilizer (Table 3). It is important to note, however, that the total amount of nitrogen leached were very small relative to the amount of nitrogen applied as fertilizer. For example, through August 2011 a total of 129.3 mg of N leached per container in the conventional fertilizer plots. This presents less than 1% of the total N applied (25 g N per container). This suggests the container production system is very efficient in terms of nutrient utilization. This is likely related to full utilization of the container substrate by tree roots.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Taylor, J.T., R.T. Fernandez, P. Nzokou, and B.M. Cregg. 2013. Carbon isotope discrimination, gas exchange, and growth of container-grown conifers under cyclic irrigation. HortScience 48:848-854.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Whittinghill, L.J., D.B. Rowe, and B.M. Cregg. 2013. Evaluation of vegetable production on extensive green roofs. Agroecology and Sustainable Food Systems 37:465-484.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2014
Citation:
Acimovic, S. A. VanWoerkom, P. Reeb, C. VanderVoort, T. Garavaglia, B. Cregg, and J. Wise. (in review) Spatial and temporal distribution of trunk-injected Imidacloprid in apple tree canopies. Pest Management Science.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Cregg, B. 2013. Weather 2012: One for the record books. The Michigan Landscape 56(1):29-31.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Stelzer, H. and B. Cregg. 2013. FAQ's for helping your tree survive during a drought. Extension Disaster Education Network (EDEN) 6 pp.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Cregg. B. and D. Ellison. 2013. Is all N created equal? Great Lake Christmas Tree Journal. 8(2):4-9.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Cregg, B, and D. Ellison. 2013. Urban tree selection in a changing climate. Presented at ASHS-2013, Annual Conference, July 22-25, Palm Desert, CA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Cregg, B. 2013. Research in Real Time: Integrating Social Media and Landscape Research. Presented at ASHS-2013, Annual Conference, July 22-25, Palm Desert, CA.
- Type:
Other
Status:
Published
Year Published:
2013
Citation:
Cregg, B. 2013. Effect of nitrogen source on growth and nutrition of Fraser fir and Colorado blue spruce Christmas trees. International Christmas Tree Research and Extension Conference. Truro, Nova Scotia Canada. Aug. 11-14, 2013.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Wang, X., R.T. Fernandez, B. Cregg, M. Ngouajio, R. Auras, and J. P. Albano. 2013. Sensor Integrated Automatic Irrigation System to Reduce Runoff and Nutrient Loss without Affecting Plant Growth. Presented at ASHS-2013, Annual Conference, July 22-25, Palm Desert, CA
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: In this project we developed water and nutrient budgets for two nursery tree crops; shade trees (Platanus x acerifolia `Bloodgood') grown in #25 containers and conifers (Picea pungens and Abies fraseri) grown in #7 containers. All trees were grown in a soilless substrate consisting of 80% composted pine bark and 20% peat moss. Trees were irrigated once daily with an automated miscrosprinkler system. Irrigation was adjusted periodically to provide 10-20% leaching fraction. Within each nursery section, trees were fertilized with either controlled release fertilizer (Osmocote 15-9-12, N-P2O5-K2O, Everris, Inc.) or an OMRI-listed organic source (blend of NatureSafe 8-5-5 and NatureSafe 10-2-8). A third group of trees in each section was not fertilized. We measured height and caliper on all trees at the beginning and end of the season. A subsample of trees was destructive sampled at the end of the season to develop allometric equations of stem, foliage and root biomass as a function of trunk caliper and height. Nutrient concentrations were also determined for stems, foliage, roots, and remaining substrate of subsampled trees. Biomass accumulation of stems, roots, and foliage was estimated for all trees based on the allometric equations. Total nitrogen accumulation was calculated from biomass estimates and stem, foliage and root nutrient concentrations. Results from this research were presented at the American Society for Horticultural Science annual meeting in August 2012. PARTICIPANTS: Dana Ellison, Graduate assistant, and Arianna Wilcom, Undergraduate assistant, particpated in study installation and data collection. Tom Dudek, MSU Extension Educator, organized meetings with nursery growers in which results and implications of the project were discussed. Everris, Inc., Griffin Industries,LLC, Renewed Earth, Inc, and J Frank Schmidt and Sons Nursery provided direct and in-kind support. TARGET AUDIENCES: Primary target audiences for this project are nursery and Christmas tree producers. Additional audiences include extension personnel and other researchers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
For shade trees and conifers, biomass accumulation was similar between fertilizer sources and greater for fertilized trees than unfertilized trees. Nutrient accumulation in trees and nitrogen leaching were lower with the organic fertilizer source than with the controlled release fertilizer. Our results indicate that organic fertilizer can produce acceptable growth and quality but understanding nutrient release will be critical to ensure adequate nutrition in container culture.
Publications
- Klooster, W.S., B.M. Cregg, R.T. Fernandez, and P. Nzokou. 2012. Growth and physiology of deciduous shade trees in response to controlled-release fertilizer. Scientia Horticulturae 135:71-79.
- Warsaw, A.L., R.T. Fernandez, D.R. Kort, B.M. Cregg, B. Rowe, and C. Vandervoort. 2012. Remediation of metalaxyl, trifluralin, and nitrate from nursery runoff using container-grown woody ornamentals and phytoremediation areas. Ecol Engineering 47:254-263.
- Kulac, S., P. Nzokou, D. Guney, B.M. Cregg, and I. Turna. 2012.Growth and Physiological Response of Fraser Fir [Abies fraseri (Pursh) Poir.] Seedlings to Water Stress: Seasonal and Diurnal Variations in Photosynthetic Pigments and Carbohydrate Concentration. HortScience 47:1512-1519.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: We completed the second year of two trials to compare growth, physiology, and nutrient leaching of container-grown landscape trees fertilized with conventional controlled-release fertilizer (Osmocote Plus 15-9-12, 5-6 month release, Scotts, Inc., Marysville, OH USA) or an OMRI-certified organic fertilizer (NatureSafe 10-2-8 and NatureSafe 5-6-6, Griffin Industries, Cold Spring, KY, USA). Responses were compared for conifers (Colorado blue spruce [Picea pungens] trees and Fraser fir [Abies fraseri] trees) grown in 25-liter containers and for `Bloodgood' planetrees (Platanus x acerifolia `Bloodgood' grown in 105-liter containers. We measured gas exchange on trees on three dates during the growing season. Foliar nutrient samples were collected at mid-summer (Planetrees) and fall (conifers). Container leachate from 8 rows in each nursery section (conifers and planetrees) was collected and total run-off was measured by a series of tipping bucket rain gauges and an automated data logger. Irrigation rates were adjusted in order to achieve a target leaching fraction of 10-20% of irrigation applied. Samples of leachate water were collected weekly after irrigation. Total amount of nitrogen leached during each season was estimated by multiplying the amount of water leached each week by the N concentration of the samples collected that week and summing the totals over the growing season. Growth and photosynthetic gas exchange of planetrees was unaffected by fertilizer source. In the conifer trial; conventional fertilizer increased net photosynthesis, foliar N and caliper growth of Fraser fir trees compared to the organic fertilizer, whereas responses of Colorado blue spruce were unaffected. In both trials nitrogen leaching was greater conventional fertilizer than with organic fertilizer. Regardless of fertilizer source, however, total nitrogen lost to leaching represented a small fraction (<2%) of total fertilizer applied. PARTICIPANTS: Dana Ellison, Graduate Student Brent Crain, Graduate Student Arianna Wilcox, Undergraduate Student Jill O'Donnell, MSU Extension Statewide Christmas tree educator Tom Dudek, MSU Extension District Extension Educator Dutchman Tree Farms Michigan Nursery and Landscape Association Michigan Christmas Tree Association J Frank Schmidt and Son Nursery TARGET AUDIENCES: The primary target audience for this research are container nursery producers in the Midwest. Results are also applicable to field producers and growers in other parts of the country as well. PROJECT MODIFICATIONS: This spring we will install a controller and solenoid valves in the irrigation system at our research nursery at MSU. This will allow irrigation to be controlled based on soil moisture sensors that are already installed in the system. We will compare growth, physiology, and nutrient leaching of nursery crops at irrigation rates based on different volumetric water contents.
Impacts
Research results and activities related to this project presented at grower meetings and in publication have increased awareness among growers of the impacts of nursery water and nutrient practices on crop growth and quality. In June 2011 we conducted an irrigation workshop for nursery and Christmas tree growers in northern Michigan. In the workshop participants engaged in `hands-on' training in soil moisture measurements and irrigation system uniformity checks. As a direct result of the workshop, one of the largest growers in the state (Dutchman's tree farms) installed soil moisture sensors to help schedule irrigation and began a program of irrigation system uniformity checks.
Publications
- Cregg, B.M., D. Ellison, R.T. Fernandez, and P. Nzokou. 2011. MSU Research Update: Water and nutrient management for container tree production. The Michigan Landscape 54(5): 39-43.
- Cregg, B.M., R.T. Fernandez, D. Ellison, and P. Nzokou. 2011. Growth, Foliar Nutrition, Photosynthesis, and Nutrient Leaching of Container-Grown Landscape Trees Produced with Conventional and Organic Fertilizer. HortScience 46(9): S165-S166. Presented at ASHS-2011, Annual Conference, September 25-28, Waikoloa, HI.
- Ellison, D., B.M. Cregg, R. Schutzki, and P. Nzokou. 2011. Pre-Plant Storage and Handling of Difficult to Transplant Ash Alternatives. HortScience 46(9): S166. Presented at ASHS-2011, Annual Conference, September 25-28, Waikoloa, HI.
- Pershey, N.A., R.T. Fernandez, B.M. Cregg, J.A. Andresen, and W. Northcutt. 2011. Nursery Runoff Water Nutrient Content and Volume and Plant Growth of Four Conifer Taxa Subjected to Four Irrigation Treatments. HortScience 46(9): S323. Presented at ASHS-2011, Annual Conference, September 25-28, Waikoloa, HI.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: In the spring of 2010 we installed a new two-year nursery trial at the MSU Pot-in-Pot research nursery at the Michigan State University Horticulture Teaching and Research Center to compare growth, physiology, and nutrient leaching of common nursery trees under conventional and organic fertilization. The 25-gallon container section and the 7-gallon container section of the nursery were retro-fit with a leachate collection system under the containers. The leachate collection system was designed to collect leachate from each of 8 rows of containers in each production area. Container leachate from each row was collected and total run-off was measured by a tipping bucket rain gauge and an automated data logger. The system was completed in early July 2010. After the system was installed we planted 200 35 mm caliper London planetree (Plantanus x acerifolia "Bloodgood") liners in 25 gallon containers and 100 conifers (50 Colorado blue spruce (Picea pungens) and 50 Fraser fir (Abies fraseri) in 7 gallon containers. All trees were planted in a standard container substrate of 80% pine bark and 20% peat moss (v:v). Trees were irrigated daily via on automated spray stake system. Irrigation was adjusted to provide approximately 10% leaching fraction. Trees were fertilized with either a conventional controlled release fertilizer (Osmocote Plus 15-9-12 5-6 month release, Scotts, Inc., Marysville, OH) or an OMRI-certified organic fertilizer (NatureSafe 10-2-8 and NatureSafe 5-6-6, Griffin Industries, Cold Spring, KY). The organic fertilizers were blended to provide approximately the same ratio of N-P-K as the conventional source. Fertilizers were applied at a rate of 30 grams N per container for trees in the 25 gallon containers and 12 grams of N per container for trees in the 7 gallon containers. Application of the organic fertilizer was split into two applications, once in early July and once in mid-August. We measured height and trunk caliper at the start of the study and at the end of the growing season. Foliar samples were collected for nutrient analysis in September (planetrees) and November (conifers). Subsamples of leachate were collected every two weeks throughout the growing season. The experiment will be continued in 2011 to complete a typical 2-year production cycle. We conducted several preseations related to this project including: Cregg, B.M. 2010. Pot-in-Pot production for living Christmas trees. National Christmas Tree Association. Winston-Salem, NC. Aug. 12, 2010. Cregg, B.M. and D. Ellison. 2010. Pre-plant storage and handling of difficult to transplant ash alternatives. Michigan Seedling Growers Association. Lake City, MI. Aug. 20, 2010. Cregg, B.M. 2010. Container production for conifers. Michigan Christmas tree Association Summer meeting. Paw Paw, MI, July 24, 2010. Cregg, B.M. 2010. ABC's of tree nutrition. Michigan Nursery and Landscape Association Great Lakes Trade Expo, Grand Rapids, MI, Jan. 4, 2010. Cregg, B.M. 2010. Pot-in-Pot production for living Christmas trees. Wisconsin Christmas Tree Producers Association, Waukesha, WI, Jan. 22, 2010. PARTICIPANTS: Individuals: Bert Cregg (PI) Aaron Warsaw Dana Ellison Partner Organizations: USDA Specialty Crop Block Grant Program Michigan Nursery and Landscape Association Collaborators and contacts: Fred Hulme, Scotts, Inc. Keith Warren, J. Frank Schmidt and Sons Nursery, Inc. Training or professional development: Dana Ellison, Graduate student Description of research project featured on video for Michigan Christmas Tree Association TARGET AUDIENCES: Nursery growers Christmas tree producers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Initial results from the first year of the trial indicate that fertilizer source (conventional versus organic) affected (p<0.05) stem caliper growth of conifers but not planetrees. Conifers fertilized with conventional controlled release fertilizer grew an average of 25% larger in caliper than trees fertilized with the same amount of nitrogen in the organic form. Planetrees grew an average of 4.8 mm in caliper with conventional fertilizer and grew an average of 4.5 mm with the organic product. Foliar nutrient levels in planetree leaves did not differ (p>0.05) between conventional and organic fertilizer treatments for most elements including N (conventional: 21.4 g/kg vs. organic:19.1 g/kg), P (1.5 g/kg vs. 1.3 g/kg), K (6.8 g/kg vs. 6.4 g/kg), and Mg (5.6 g/kg vs. 5.4 g/kg). Conventional fertilization increased (p<0.05) foliar manganese compared to trees receiving the organic fertilizer (291 mg/kg vs. 239 mg/kg). Foliar manganese levels of trees from both treatments were above sufficiency standards. Through the first year of the study, growth and foliar nutrition of planetrees was similar with either conventional or organic fertilization. This suggests that growers may use either fertilizer source. Caliper growth of conifers was greater with conventional rather than organic fertilization. We are currently processing conifer foliar samples for nutrient concentration.
Publications
- Klooster, W.S., B.M. Cregg, R.T. Fernandez, and P. Nzokou. 2010. Growth and photosynthetic response of Pot-in-pot-grown conifers to substrate and controlled-release fertilizer. HortScience 45:36-42.
- Nzokou, P. and B.M. Cregg. 2010. Morphology and foliar chemistry of containerized Abies fraseri seedlings as affected by water availability and nutrition. Ann. For. Sci. 67:602-611.
- Cregg, B.M.. A. Taylor, W. Klooster, R.T. Fernandez and P. Nzokou. 2010. Growth and physiology of living Christmas tree in container production. IN: Hart, J. Landgren, C. and Chastagner, G. (Eds.) Proceedings of the 9th International Christmas Tree Research and Extension Conference, Corvallis, OR and Puyallup, WA. p. 28-33.
- Nzokou, P. and B.M. Cregg. 2010. The effect of watering and nitrogen fertilization on growth, nutrient use, and leaching in containerized Fraser fir (Abies fraseri). Proceedings of the 9th International Christmas Tree Research and Extension Conference, Corvallis, OR and Puyallup, WA. p. 37-44.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: The objective of this project is to determine the effect of common landscape mulches (pine bark, hardwood fines, cypress mulch, color enhanced ground pallets) on soil moisture, soil pH, weed control, and physiology and growth of landscape shrubs. Two additional treatments were not mulched; no mulch + no weed control and no mulch + weed control. Growth was measured on 8 taxa (Euonymus alatus Compactus, Spiraea x bumalda Goldflame, Weigela florida Java red, Taxus x media Runyan, Thuja occidentalis Golden Globe, Hydrangea paniculata Tardiva, Viburnum dentatum Synnestvedt, Viburnum trilobum Compactum). Leaf gas exchange (net photosynthesis and stomatal conductance) were measured on Hydrangea paniculata and V. dentatum and V. trilobum only. All mulches increased soil moisture compared to no mulch + weed control. We evaluated height growth, diameter growth and survival of newly-planted Fraser fir and Colorado blue spruce Christmas trees in southwest Michigan in response to mulch, weed control and irrigation. Mulches included black polyethylene, white polyethylene, VisPore mulch mats, and wood chips. Seedlings were also established with or without raised beds and with or without complete weed control. PARTICIPANTS: Individuals who worked on project; Bert Cregg (PI) Provided overall direction and supervision. Analyzed data, prepared reports for funding organizations and partners. R.T. Fernandez, Pascal Nzokou. D. Rothstein (co-PI's) Provided support on proposal development, study design, data interpretation, and report preparation. Amanda Taylor (Graduate research assistant) Collected and analyzed data. Prepared research summaries, presented results to grower groups and at scientific meetings. James Baguley and Jake Hamilton (Undergraduate research assistants) installed and maintained plots, collected data. Partner organizations Michigan Nursery and Landscape Association, Michigan Christmas Tree Association, Michigan Department of Agriculture, Scotts Inc., J Frank Schmidt and Sons Nursery, Inc., Peterson's Riverview Nursery Training and professional development. Pot-in-Pot research site was featured on Michigan Christmas Tree Association summer 2009 field tour. Research site was also subject of an on-line video feature by the MSU State News. In addition, we have toured several individual growers on the site. Conducted a field tour for research colleagues from North Carolina State University (Dr. John Frampton), Oregon State University (Chal Landgren) and Czech Republic (Dr Jaroslav Klobliha). TARGET AUDIENCES: Target Audiences: Primary audiences are landscape nurseries and Christmas tree producers. In addition, landscapers and urban and community foresters are secondary audiences that benefit from improved diversity of planting stock and improved planting stock quality. Additional audiences include extension educators and homeowners. Efforts: Research technology transfer has been accomplished through a variety of means including grower field days and on-site tours, presentations at MCTA and MNLA association meetings and articles in trade publications including the Michigan Landscape, Great Lake Christmas Tree Journal, and American Christmas Tree Journal. Additional technology transfer has occurred through MSU Landscape and Nursery CAT Alert articles and popular press including Midwest Living magazine, the Garden Professors blog and newspaper articles. PROJECT MODIFICATIONS: In response to grower interest and funding opportunity through the USDA's SCRI Block Grant program, we will initiate an investigation of use of organic nutrient sources for production of container-grown landscape shade trees and conifers beginning in spring of 2010.
Impacts
There was no difference in soil pH or foliar nitrogen among treatments. All mulches, except cypress mulch, increased plant growth of most shrub taxa compared to no mulch without weed control. Mulches increased stomatal conductance relative to no mulch without weed control. Photosynthetic rates of plants mulched with cypress mulch were less than the other mulches and not different from no mulch. Overall, the result suggests that, except for cypress mulch, the organic mulches tested are equally effective in improving growth of landscape plants. Reduced photosynthetic efficiency and growth of shrubs with cypress mulch suggest potential allelopathic effects. Weed control (mulches or combination of chemical weed control and hand weeding) improved survival and growth of both species after two years. Growth was similar for trees in irrigated plots or with wood chip mulch without irrigation. Polyethylene mulch increased growth compared to similar production systems with raised beds and bare-ground. Among production systems, variation in growth and survival reflected patterns of pre-dawn water potential and mid-day shoot gas exchange, suggesting that differences were largely related to plant moisture stress. White mulch improved growth relative to similar production systems with black mulch and wood chip mulch improved growth compared to similar production systems without irrigation. Overall, the ranking of magnitude of growth response effects were weed control > irrigation > mulch. These results underscore the importance of weed control for establishment and maintenance of high quality Christmas tree plantations.
Publications
- Mota-Sanchez, D., B.M. Cregg, D,G,. McCullough, T,M. Poland, R.M. Hollingworth. 2009. Distribution of trunk-injected 14 C-imidacloprid in ash trees and effects on emerald ash borer (Coleoptera: Buprestidae) adults. Crop Protection 28:655-661.
- Cregg, B.M. P. Nzokou, and R. Goldy. 2009. Growth and physiology of newly planted Fraser fir (Abies fraseri) and Colorado blue spruce (Picea pungens) Christmas trees in response to mulch and irrigation. HortScience 44:660-665.
- Cregg, B.M. and R. Schutzki. 2009. Weed control and organic mulches affect physiology and growth of landscape shrubs. HortScience 44:1419-1424.
- Gooch, N.J., P. Nzokou, and B.M. Cregg. 2009. Effect of indoor exposure on the cold hardiness and physiology of containerized Christmas trees. HortTechnology 19:72-77.
- Warsaw, A.L., R.T. Fernandez, B.M. Cregg and J.A. Andresen. 2009. Water conservation, growth, and water use efficiency of container grown woody ornamentals irrigated based on daily water use. HortScience 44:1308-1318.
- Warsaw, A.L., R.T. Fernandez, B.M. Cregg and J.A. Andresen. 2009. Container-grown ornamental plant growth and water runoff nutrient content and volume under four irrigation treatments. HortScience 44:1573-1580.
- Taylor, A., B.M. Cregg, R.T. Fernandez, J. Andresen and P. Nzokou. 2009. Growth and physiology of living Christmas trees under cyclic irrigation HortScience 44:1189-1189. Presented at ASHS-2009 Annual Conference, July 25-28, 2009, St. Louis, MO.
- Nzokou, P. and B.M. Cregg. 2009. Effect of irrigation and nitrogen fertilization on growth and foliar chemistry of Abies fraseri grown in containers. HortScience 44:1038-1039. Presented at ASHS-2009 Annual Conference, July 25-28, 2009, St. Louis, MO.
- Nzokou, P., N. Gooch, and B.M. Cregg. 2009. Effects of soil matric potential on Fraser fir (Abies fraseri) growth and water stress un drip irrigation in Michigan.. HortScience 44:1039-1039. Presented at ASHS-2009 Annual Conference, July 25-28, 2009, St. Louis, MO.
- Warsaw, A.L., R.T. Fernandez, B.M. Cregg and J.A. Andresen. 2009. Evapotranspiration and growth-based models to estimate irrigation of container-grown Korean spirea (Spirea fritshiana Wilma) under four irrigation regimes. HortScience 44:1038-1039. Presented at ASHS-2009 Annual Conference, July 25-28, 2009, St. Louis, MO.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: In the spring of 2006 we established a Pot-in-Pot nursery production area at the Michigan State University Horticulture Teaching and Research Center in cooperation with Green Industry Partners, including the Michigan Nursery and Landscape Association, the Michigan Christmas Tree Association and MDA. In 2006 and 2007 we conducted research to characterize the growth and physiological response of deciduous landscape trees and conifers to varying rates of fertilization and container substrate. Based on this research we are developing fertilization and nutrition guidelines for shade trees and landscape conifers. In 2008 we initiated a new set of trials to improve conservation of water in landscape nurseries through cyclic irrigation. The studies established were 3-gallon conifers (Fraser fir, Colorado blue spruce, Eastern white pine, and Black hills spruce), 7 gallon conifers and 25-gallon shade trees (Autumn blaze maple, Red sunset maple, red oak, Northern treasure honeylocust, Skyline honeylocust, Accolade elm, Triumph elm. 3-gallon containers Irrigation frequency had a greater effect on caliper growth of trees in the 3-gallon container than irrigation rate. . Trees receiving 4-cyclic pulses of irrigation per day grew more than trees that were given the same amount of irrigation but delivered only once per day. This trend was especially evident for the eastern white pine and Colorado blue spruce trees, which were also the fastest growing trees. Height growth was less effected by irrigation treatments than caliper growth. This is likely due to the fact that height growth is completed relatively early in the growing season when weather conditions are relatively mild and irrigation effects are less pronounced. Caliper growth of trees grown in the 7-gallon containers showed a strong interaction between daily irrigation rate and irrigation frequency. Trees receiving the low rate of irrigation grew more when watered once per day, whereas trees at the high level of irrigation grew more when irrigation applied on 4 cycles per day. The reduced growth associated with cyclic irrigation for the trees at the low irrigation level may be due to lack of complete wetting of the container media since this treatment requires irrigating in small amounts at each cycle. The reduced growth of the 1 x high compared to the 1 x low irrigation may be associated with increased leaching of nutrient due to the large single pulse of irrigation each day. Shade trees Increasing the rate of daily irrigation from 1 cm to 2 cm per day increased caliper growth of shade trees (Fig. 4 but number of cycles per day did not affect growth. Caliper growth varied by species but the interaction of species and daily irrigation rate was not significant. Preliminary analysis of gas exchange data indicated significant difference in photosynthesis among species but not irrigation programs. We have presented the results of research at grower field days, association meetings (Michigan Christmas Tree Association, Michigan Nursery and Landscape Association), trade publications and on-site visits with growers. PARTICIPANTS: Wendy Klooster, Graduate Student Amanda Taylor, Graduate Student Ron Goldy, MSU Extenion Educator Marsha Gray, Michigan Christmas Tree Assocaiton Mike Bryan, Michigan Dept. of Agriculture Dutchmann Tree Farms Chris Lufkin, Scotts, Inc. TARGET AUDIENCES: Primary target audiences are landscape nurseries and Christmas tree producers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The information developed in this project has been central to our efforts to educate nursery and Christmas tree growers on appropirate water and nutreient management during crop production. We have ideintified appropriate substrates for conifer production in containers. We have also identified a range of fertilzer additions that are suitbale for producing high quaility conifers and shade trees in container production systems.
Publications
- CREGG, B.M., P. NZOKOU, and R. GOLDY. 2008 Growth and physiology of newly planted Fraser fir (Abies fraseri) and Colorado blue spruce (Picea pungens) in response to mulch. IN: Thomsen, I.M., Rasmussen, H.N. & Sorensen, J.M. (Eds.): Proceedings of the 8th International Christmas Tree Research and Extension Conference. Forest & Landscape Working Papers No. 26-2008, Forest & Landscape Denmark, Horsholm, p.61-64.
- NZOKOU, P., N. GOOCH, and B.M. CREGG. 2008 Cold Hardiness and Morphological Characterization of Containerized Conifers Used as Live Christmas Trees. IN: Thomsen, I.M., Rasmussen, H.N. & Sorensen, J.M. (Eds.): Proceedings of the 8th International Christmas Tree Research and Extension Conference. Forest & Landscape Working Papers No. 26-2008, Forest & Landscape Denmark, Horsholm, p.38-40.
- Cregg, B.M. and R. Schutzki. 2008. Effect of organic mulches on soil properties, physiology, and growth of landscape shrubs. HortScience 43(4):1091-1092. Presented at ASHS-2008 Annual Conference, July 21-24, 2008, Orlando, FL.
- Cregg, B.M., P. Nzokou, and R. Goldy. 2008. Growth and physiology of Fraser fir and Colorado blue spruce in response to mulch. HortScience 43(4):1127-1128. Presented at ASHS-2008 Annual Conference, July 21-24, 2008, Orlando, FL.
- Klooster, W.S., B.M. Cregg, R.T. Fernandez, and P. Nzokou. 2008. Effect of nutrition on growth and physiology of landscape trees in Pot-in-Pot production. HortScience 43(4):1105. Presented at ASHS-2008 Annual Conference, July 21-24, 2008, Orlando, FL.
- Tanis, S.R., B.M. Cregg, D. Mota-Sanchez, D.G. McCullough, T.M. Poland, and R.M. Hollingworth. 2008. Distribution and persistence of Imidacloprid in ash trees: Spring versus fall injection. HortScience 43(4):1160. Presented at ASHS-2008 Annual Conference, July 21-24, 2008, Orlando, FL.
- Klooster, W.S., B.M. Cregg, R.T. Fernandez, and P. Nzokou. 2008. Fertilization and media effects on growth and physiology of conifers in Pot-in-Pot production. HortScience 43(4):1263. Presented at ASHS-2008 Annual Conference, July 21-24, 2008, Orlando, FL.
- Nzokou, P., N. Gooch, and B.M. Cregg. 2008. Plant stress as an indicator for irrigation scheduling in Fraser fir production. HortScience 43(4):1104. Presented at ASHS-2008 Annual Conference, July 21-24, 2008, Orlando, FL.
- Nikiema, P, P. Nzokou, D. Rothstein, and B.M. Cregg. 2008. Effect of different groundcover management in Fraser fir production on soil pH, moisture, and microbial biomass C and N. HortScience 43(4):1184. Presented at ASHS-2008 Annual Conference, July 21-24, 2008, Orlando, FL.
- Warsaw, A., R.T. Fernandez, B.M. Cregg, and J. Andresen. 2008. Water conservation and growth of container-grown woody ornamentals when irrigation is based on daily water use. HortScience 43(4):1193. Presented at ASHS-2008 Annual Conference, July 21-24, 2008, Orlando, FL.
- Warsaw, A., R.T. Fernandez, B.M. Cregg, and J. Andresen. 2008. Nitrate and phosphate concentrations in container nursery run-off from four overhead irrigation regimes. HortScience 43(4):1193. Presented at ASHS-2008 Annual Conference, July 21-24, 2008, Orlando, FL.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: During the reporting period we compared fertilizer requirements for seven cultivars of landscape shade trees and compared fertilizer requirements and container substrates for four species of container-grown landscape conifers. Growth response of shade trees grown in 25-gallon containers in a pot-in-pot system varied by species. Caliper growth of Accolade elm, Triumph elm, Freeman maple increased with increasing fertilizer addition up to 500 grams of 15-9-12 controlled releaser fertilizer. Growth of tulip-poplar, red maple, and planetree peaked at approximately 375 grams per container. Caliper growth of red oak did not respond to fertilization. SPAD meter readings were highly correlated with fertilizer addition and foliar nutrition but variable chlorophyll fluoresce (Fv/Fm) was not. Growth of four conifer species (eastern white pine, Fraser fir, Colorado blue spruce and Black hill spruce) grown in 3 gallon containers in a pot-in-pot system peaked at 60 grams of 15-9-12 per
container. Response of the conifers to container substrate was relatively small although caliper growth of eastern white pine was greatest with the smallest percentage (10%) of peat moss in the media. We measured growth and soil moisture of landscape shrubs grown with 6 combinations of landscape mulch (no mulch, no mulch + weed control, cypress mulch, red pine bark, hardwood bark, and recycled pallets. Weed competition was also assessed. All mulches were effective in controlling weeds through the end of the 2005 growing season. Weed suppressing effect of mulch began to break down during the 2006 growing season. All mulches improved soil moisture relative to the un-mulched treatments. Peaks in soil moisture on un-mulched plots correspond to major rain events. Growth of the shrubs was generally greatest on plots with the pine bark mulch. Maintaining plots weed free resulted in growth similar to mulching for most shrubs. This may indicate that potential nutrient tie-up by mulch may
off-set conservation of soil moisture. Mulches did not affect soil pH. Research results were presented at the American Society of Horticulture Science meeting in Scottsdale Arizona. This research was also presented to nursery growers and landscapers at the Michigan Nursery and landscape Association Great Lakes Trade Expo as well as at MSU Extension grower field days.
PARTICIPANTS: Wendy Kooster, M.S. graduate student Sara Tanis, M.S. gradusate student Partner organizations Michigan Nursery and Lanscape Association Michigan Christmas Tree Assoication J. Frank Schmidt and Sons Nursery Nursery Supplies, Inc. Renewed Earth, Inc.
TARGET AUDIENCES: Nursery growers Lanscapers
Impacts
The results of our pot-in-pot research have demonstrated the need for species-specific fertilizer prescription in order to optimize fertilizer application for deciduous shade trees. The results of the pot-in-pot conifer trial demonstrated that an intermediate container substrate (80% pine bark:20% peat moss) is suitable for most crops. Intermediate rates of fertilizer (e.g., 60 grams per 3 gallon container) can result in increased growth compared to higher rates. The landscape mulch trial demonstrated that the growth benefits of mulch were due more to weed control than soil moisture conservation, which is counter to conventional wisdom. The reduction of growth and photosynthetic rate of several shrub species with cypress mulch suggests a possible allopathic effect, which warrants further investigation.
Publications
- Klooster, W.S., B.M. Cregg, R.T. Fernandez, and P. Nzokou. 2007. Growth and physiology of landscape conifers in response to nutrition and container media for pot-in-pot production. Proc. Southern Nursery Assoc. Res. Conf. 52:62-65.
- Klooster, W.S., B.M. Cregg, R.T. Fernandez, and P. Nzokou. 2007. Growth and physiology of landscape trees in response to varying nutrient levels for pot-in-pot production. HortScience 42(4): 861.
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Progress 01/01/06 to 12/31/06
Outputs
We installed two Pot-in-Pot nursery systems in the spring of 2006 at the Michigan State University Horticulture Teaching and Research Center: one for large shade trees and one for smaller conifers and table-top Christmas trees. Shade Tree System We installed 160 25-gallon (95 liter) socket pots on a 1.8m x 1.8m spacing in the spring of 2006. We planted 20 trees of eight species or cultivar (Autumn Blaze maple, Red sunset maple, Bloodgood planetree. Tulip poplar, red oak, Triumph elm, Accolade elm, and hackberry) in 25 gallon (95 l)containers in a pine bark:peat moss (85:15) mix. The trees were 2.5-3.2 cm bare-root liners. Trees were initially watered with an overhead irrigation system which was subsequently replaced with a spray-stake micro-sprinkler system. The trees were irrigated every other day to provide approximately 3.2 cm of water per week. We examined growth and physiological response of trees to varying rates of fertilizer. We applied controlled release
fertilizer (Osmocote Plus 15-9-12) at four rates 100, 200, 300, or 400 g per container. The response to fertilization differed among species. For example, caliper growth of Triumph elm appeared to plateau at 300 g of fertilizer, whereas caliper growth of the tulip poplar may increase beyond the highest rate of fertilizer applied (400 g). Maximum photosynthetic rates peaked for all species in August. However, the mid-summer peak was less pronounced for maples compared to the other species, suggesting they may have depleted available nutrients more quickly than the other species. Landscape conifer/Table-top Christmas trees We installed 3 gallon (11 liter) socket pots on a 0.6m x 0.9m spacing after covering the ground with weed barrier fabric. We established 400 conifers of 4 species (Black hills spruce, Fraser fir, Colorado blue spruce, and eastern white pine) in 3 gallon (11 l) containers. We planted 2 + 2 or plug + 2 transplants of each species in one of three substrate mixes (90
percent Pine bark: 10 percent Peat moss, 80 percent:20 percent, and 70 percent:30 percent). For each substrate type we applied one of three fertilizer treatments (20g, 40g, or 80g per container) using a controlled release fertilizer (Osmocote Plus 15-9-12). Field observations suggest that the Eastern white pine and Fraser fir were more sensitive to fertilizer additions than the spruces. Pines and firs in the lowest (20 g) fertilizer treatment began to show visible nutrient deficiency symptoms by mid-summer. Maximum photosynthetic rate varied with fertilizer addition. Analysis of chlorophyll fluorescence measured in mid-July indicated that photosynthetic efficiency peaked at the intermediate fertilizer level (40 g per container). Nitrate concentration increased significantly with increased fertilization in the pour through leachate samples collected in mid-June. Nitrate levels were lower from samples collected from the Fraser fir than those collected from the pine, suggesting the firs
may be more efficient in absorbing nutrients than the pines.
Impacts
Michigan's landscape tree nursery producers are faced with the challenge of growing scores of species and cultivars with varying nutritional requirements. Improving our understanding of nutrient requirements of landscape nursery crops can improve grower efficiency and sustainability by ensuring that crops are not nutrient deficient while avoiding over-fertilization that may lead to nutrient leaching or run-off. Results from our current research suggests that growers may be able to group or block plants based on nutrient demand (e.g., high, intermediate, or low) in order to maximize growth and optimize operational efficiency.
Publications
- Cregg, B.M. 2006. MSU Pot-in-Pot research program: A Growing partnership. The Michigan Landscape 49(12): 49-52.
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Progress 01/01/05 to 12/31/05
Outputs
We measured height and diameter growth of 12 landscape trees species under four levels of fertigation in a field nursery in southwestern Michigan between 2001 and 2005. The nursery trial was installed in 2001 as a split-plot design with fertigation treatments (control, irrigation only, fertilizer only, irrigation plus fertilizer) as the main plot and tree species as the sub-plot. Irrigated plots received 0.75 in. to 1.5 in. of water per week though a drip irrigation system depending upon PET and rainfall. Fertilizer was applied at the rate of 150 lbs/ac per year as ammonium nitrate through the drip system. Tree growth (height and stem diameter at 12 in.) was measured every year. The tree species were: Norway maple, red maple, sugar maple, swamp white oak, scarlet oak, bur oak, pin oak, redbud, honeylocust, goldenchain, dawn redwood and baldcypress. Height and diameter growth of landscape trees varied (P less than 0.0001) by species. After four years in the nursery,
mean height of the honeylocust was 17.5 ft. Norway maple was the slowest growing species (7.1 ft. after four years). After the establishment year, all of the oak species averaged more than 2 ft. of height growth per year. Irrigation increased height and diameter more than fertilization. Foliar N varied from 2.5 percent in dawn redwood to 3.2 percent in honeylocust. Foliar N increased with fertilization and decreased with irrigation. During the summer of 2004 we investigated the physiological bases for species and fertigation treatment effects on growth of the landscape trees. In the summer of 2004 we measured light saturated photosynthetic rate (Amax) with a portable photosynthesis system (Li-6400, Li-Cor, Inc.) on three dates. Amax varied among species and was correlated with species growth rate. Mean Amax of bur oak and swamp white oak was approximately 19 micromoles of CO2/m2/s, whereas the Amax of Norway maple and sugar maple was 10 micomoles/m2/s or less. The ratio of
photosynthesis to leaf conductance was relatively constant among species, suggesting that species differences in photosynthesis were largely related to stomatal limitations to gas exchange.
Impacts
Improving our understanding of stress physiology of trees in nursery and Christmas tree plantations can greatly enhance managmeent of trees in Michigan's $300 million nursery and Christmas tree industry. Increased efficeincy of irrigation and fertilization can improve grower productivity adn reduce potential environmental impacts.
Publications
- Rothstein, D.E. and Cregg, B.M. 2005. Effects of nitrogen form on nutrient uptake and physiology of Fraser fir (Abies fraseri) For. Ecol. and Mgmt.219:69-80.
- Zhang, J. and Cregg, B.M. 2005. Growth and physiological responses to varied environments among populations of Pinus ponderosa For. Ecol and Mgmt. 219:1-12.
- Behe, B.K., Walden, R.M., Duck, M.W., Cregg, B.M. and Kelley, K.M. 2005. Consumer preferences for tabletop Christmas trees. HortScience 40:409-412.
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Progress 01/01/04 to 12/31/04
Outputs
In 2001 and 2002, we compared fertilization based on the 'relative addition rate' (RAR) method to standard (operational) fertilizer practices of two nurseries in southwestern Michigan in Taxus (yew) and Euonymus (burning bush) fields. These practices were also compared to control plots that did not receive N fertilizer. Nitrate-N in soil water beneath the RAR plots was intermediate between the control and operational treatments, suggesting reduced fertilization can decrease nitrate-N leaching. Euonymus fields showed higher levels of soil water nitrate-N than Taxus. Foliar nitrogen and total plant growth in the RAR plants did not differ from the operational plots. Vector analysis showed Taxus plants were more responsive than Euonymus to fertilization treatments. Both species indicated that luxury consumption was occurring, and deficiencies were generally not seen within either fertilizer method. With plant quality unaffected by the reduced fertilization, there is an
environmental as well as economic benefit in reducing fertilization practices in field grown woody ornamentals.
Impacts
Overall the results of this study indicate that growth of nursery crops can be maintained, and nitrate losses reduced, by matching nitrogen additions to crop demand. Moreover, a better understanding of the overall N balance in field nursery crops is needed to further optimize crop growth and quality while minimizing N losses and adverse environmental impacts. Nursery managers need to consider crop species, age and growth habit in developing nutrient prescriptions. Our research indicates attention needs to be paid to: -Understanding mineralization rates and other factors controlling availability of N besides fertilizer additions. In our study the un-fertilized controls grew as well as either of the fertilized treatments in both species. This raises the questions of how long N supply from mineralization of organic matter can meet crop demand. -Crop growth and development. In the present study Euonymus has a determinant growth habit, completing crown growth by mid-July.
In contrast, the Taxus plants continued to grow late into summer depending on availability of soil moisture. This suggests that Taxus would be better able to take advantage of late season N additions than the Euonymus. Also, more detailed information of total crop demand for N can help guide fertilization decisions. - Importance of other N forms, particularly organic N. Dissolved organic N can be an important component of agricultural N losses.
Publications
- Briggs, D. 2004 Land use and field nursery fertilization effects on nitrate-N in groundwater and soil water in southwest Michigan. M.S. Thesis. Michigan State Univerversity. 88 pp.
- Cregg, B.M., Rios, C., Hart, J.B.and Briggs, D. 2004. Fate of nitrates in field nursery production systems. USDA Forest Service National Nursery Proceedings RMRS-P-33. pp 50-54.
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Progress 01/01/03 to 12/31/03
Outputs
We established fertilization plots in Japanese yew (Taxus xmedia) and burning bush (Euonymus alatus 'Compactus') fields in two commercial nurseries in Ottawa county, Michigan in the spring of 2001. Three replicate plots in each field were assigned to one of three fertilization treatments: 1)Control - no additional fertilization 2)Operational - fertilization based on industry standard [150 kg N ha-1 split into 2 applications (April & July)] 3)Relative addition rate (RAR) - fertilization based on crop growth rate. Crop biomass growth was estimated from periodic measurements of crown volume (Fig. 2). Nitrogen uptake was estimated as the change in standing crop nitrogen between measurement periods. Nitrogen was added to replace the amount taken up assuming 50% uptake efficiency. Nitrate concentrations of soil water collected in the lysimeters were affected by species and fertilization treatment. In the Taxus fields, fertilization significantly increased soil water nitrate
concentration below the root zone relative to the control. Soil water nitrate in the RAR plots were intermediate between the Control and the Operational treatment. Soil water nitrate levels were higher in the Euonymus than the Taxus, particularly on the Control plots. Since the Euonymus fields were younger than the Taxus plots, this effect may reflect mineralization of residual organic matter from manuring and cover crops during the fallow period prior to plantation establishment. Nitrate levels in soil water ranged from 10 to 150 mg L-1 in the Euonymus plots and from near zero to 100 mg L-1 in the Taxus plots. Crown volume growth of Euonymus and Taxus did not differ (P>0.42) among the fertilization treatments (data not shown). Fertilization increased foliar nitrogen levels relative to the controls in Taxus but not Euonymus. Vector analyses indicated luxury uptake of N in the Taxus plants.
Impacts
Overall the results of this study indicate that growth of nursery crops can be maintained, and nitrate losses reduced, by matching nitrogen additions to crop demand. Moreover, a better understanding of the overall N balance in field nursery crops is needed to further optimize crop growth and quality while minimizing N losses and adverse environmental impacts. Nursery managers need to consider crop species, age and growth habit in developing nutrient prescriptions. Our research indicates attention needs to be paid to: -Understanding mineralization rates and other factors controlling availability of N besides fertilizer additions. In our study the un-fertilized controls grew as well as either of the fertilized treatments in both species. This raises the questions of how long N supply from mineralization of organic matter can meet crop demand. -Crop growth and development. In the present study Euonymus has a determinant growth habit, completing crown growth by mid-July.
In contrast, the Taxus plants continued to grow late into summer depending on availability of soil moisture. This suggests that Taxus would be better able to take advantage of late season N additions than the Euonymus. Also, more detailed information of total crop demand for N can help guide fertilization decisions. - Importance of other N forms, particularly organic N. Dissolved organic N can be an important component of agricultural N losses
Publications
- Rios, C.M. 2002. Managing nitrogen additions and assessing water quality under the root zone in field nursery production. M.S. Thesis, Michigan State University, 87 pp.
- Cregg, B.M., Rios, C.M., Hart, J.B. and Briggs, D. 2004. Fate of nitrates in field nursery production systems. IN National Proceedings USDA Forest Service Forest and Conservation Nursery Association Meeting (In press).
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Progress 01/01/02 to 12/31/02
Outputs
The objectives of this study are to evaluate the impact of nitrogen fertilization approaches on crop growth and nitrate concentration of water under the root zone, and to determine the validity and logistics of applying relative addition rate principles to nursery crops. We established the study in collaboration withtwo major nurseries in western Michigan. In Nursery A there were two fields, one field growing Taxus x media 'Runyan' and the other growing Euonymus alatus 'Compactus'. In Nursery B there were two fields as well, one growing Taxus cuspidate 'Dark Green Spreader' and the other growing Euonymus alatus 'Compactus'. The fertilizer treatments were: 1) control (no fertilizer); 2) operational fertilization (based on the nurseries' current practices); and 3) relative addition rate (additions based on crop growth). Soil water below the root zone was collected after every significant rainfall event using porous cup lysimeters and the samples were analyzed for
nitrates. Soil water nitrate concentrations varied seasonally and among treatments. Mean nitrate concentrations were found to be high when compared to other agricultural systems, ranging from less than 7 ppm prior to fertilization to over 160 ppm in September. The RAR approach to fertilization reduced nitrate-N concentrations leaching under the root zone in two out of the four fields. There was no difference found in crop growth among the three treatments in any of the four fields. Foliar nitrogen levels significantly differed in only one of the four fields. Implications of the results indicate nursery management practices should be altered to improve fertilizer use efficiency.
Impacts
The results of this study clearly indicate that significant amounts of nitrate are leaching below the root zone of field nursery crops in western Michigan under current fertilization practices. These results, presented to growers through workshops and field tours, have begun to build awareness of the connection between fertilizer management and ground water quality. We are developing best management practices for fertilizer additions to aid growers in improving nitrogen use efficiency and reduce environmental impacts.
Publications
- Rios. C.M. 2002. Managing nitrogen additions and assessing water quality under the root zone in field nursery production. M.S. Thesis Michigan State University. 87 pp.
- Rowe, D.B. and Cregg, B.M. 2002. Effect of incorporating controlled-release fertilizer on adventitious rooting and growth of Artemisia, Gaura, and Nepeta. J. Env. Hort. 20:1-6.
- Cregg, B.M.2002. Selecting trees for improved drought tolerance: Theoretical and practical considerations. XXVIth International Horticultural Congress, Toronto, Canada. p. 462-463 (abstract)
- Cregg, B.M., M.R. Koelling, D.B. Rowe, M.W. Duck, and C.M. Rios. 2002. Screening exotic firs for pH tolerance. XXVIth International Horticultural Congress, Toronto, Canada. p. 461 (abstract)
- Rios, C.M., B.M. Cregg, J.B. Hart, R.T. Ferandez, and D.B. Rowe. 2002. Managing nitrogen additions and assessing water quality under the root zone in field production of Taxus and Euonymus. XXVIth International Horticultural Congress, Toronto, Canada. p. 464 (abstract)
- Duck, M.W., B.M. Cregg, R.T. Fernandez, B.K. Behe and R.D. Heins. 2002. The use of anti-transpirants to extend the shelf-life of table-top Christmas trees. XXVIth International Horticultural Congress, Toronto, Canada. p. 141 (abstract)
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Progress 01/01/01 to 12/31/01
Outputs
We established test plots in fields of common yew (Taxus x media) and burning bush (Euonymus alatus Compactus) at three commercial ornamental nurseries in western Michigan. In each field we installed three treatments with three replications. The treatments are: Control - no fertilizer Operational - fertilizer applied at the same time and rates as the rest of the field Relative Addition Rate - fertilization rate determined by periodic measurements of crop growth. Nitrogen is added to the plots in proportion to the amount taken up by the crop. Growth was measured periodically on each crop by measuring crown width and plant height. We used regression equations developed from prior sampling to estimate plant biomass from crown height and width. Foliar nutrient levels were also determined periodically through the growing season. The total amount of N in the standing crop was estimated from plant biomass and foliar nutrient levels. To determine the concentration of nitrate
leaching below the root zone we collected soil water samples using suction lysimeters. The lysimeters were installed to a depth of 45 cm, which is the below most of the roots for both species. Soil water samples were collected after each significant rainfall event in 2001. Two Thirds of the plots have shallow groundwater wells installed to measure nitrate concentrations in the shallow groundwater (1-1.5m) for the RAR, OPERATIONAL and CONTROL treatments with the two species and two growers. Samples were collected in early February, mid June and early July. In addition, sample wells are installed in two nearby forests, a nearby fallow field and a field recently harvested. Results are a measure of the combined effects of weather, crop, and management on groundwater. Initial data from the project indicate that both operational fertilization and relative addition fertilization of Taxus and Euonymus increased foliar N relative to the unfertilized controls. Initial measurements of crown
growth did not differ among treatments. Operational fertilization increased levels of nitrate in the soil water samples collected below the root zone in the late spring and early summer. However, the rank order of the treatments may change during the remainder of the season. Nitrate concentrations of water collected from the shallow wells indicated that nitrate levels were higher under the nursery fields than in adjacent fallow areas or forest stands. The lack of a fertilizer effect on growth and elevated nitrate levels in the unfertilized control suggest the field nursery crops may receive significant nutrition from manure applied during fallow.
Impacts
The results of the project to date indicate that current field nursery practices in western Michigan may impact ground water systems. Modifying fertilization rates and scheduling may reduce nitrate leaching to groundwater without reducing crop growth. Additional information on the release of nitrogen applied during fallow is needed to continue to refine nutrition management in these systems.
Publications
- Cregg, B.M. and Zhang, J. 2001. Physiology and morphology Pinus sylvestris seedlings from diverse sources under cyclic drought stress. Forest Ecology and Management 154:131-139.
- Cregg, B.M. and Dix, M.E. 2001. Tree moisture stress and insect damage in urban trees in relation to heat island effects. Journal Arboriculture 27:8-17.
- Cregg, B.M., Rowe, D.B., Fernandez, R.T., Duck, M.W., and Rios, C.M. 2001. Evaluating conifer nutrient status via chlorophyll fluorescence. HortScience 36:542.
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