Brief Summary of Minutes of Annual Meeting

Twenty-seven attendees from fifteen institutions met for the 2013 NC1186 multistate research project annual meeting in Palm Desert, CA. The meeting was held in conjunction with the annual meeting of the American Society of Horticultural Science. Attendees were comprised of USDA staff, industry, and faculty, students, and staff from thirteen academic institutions that represented five national regions including the pacific-west, mid-west, mid-atlantic, southeastern and southern United States. The meeting began with a tour led by Dr. Don Merhaut. Tour stops included a progressive cutflower grower (Mellano and Co.), the entomology and plant breeding research areas of Altmans Plants, and The Sand Diego Botanical Garden. The next day, the formal annual meeting began. We started with our administrators report on both our successful mid-term review and the need to begin planning for renewing the project. Then each university and government agency provided a 5 to 10 minute oral station report (Written station reports are in the attached meeting minutes) that included their current activities within the five interrelated areas relevant to this project: 1) source water management and quality, 2) irrigation management, 3) runoff water management and quality, 4) substrate and nutrition management, and 5) pathogens and crop health management. Each oral presentation echoed the 1 to 2-page station report submitted by each state. Each state provided a separate update on trends in water use, emerging issues, and regulatory issues in their region. New business included discussions of 1) using the website both to share information resource among researchers, but also to use it as a mechanism to share information resources with the public; 2) the potential for NC1186 members to collaborate to release videos on various water issues relevant to the US, which are hosted on the website; 3) the 2014 meeting in Washington D.C., and 4) publication of current research needs related to water as a three part series in Nursery Management as a form of outreach. The formal meeting was adjourned on time. Also, other business related to future group meetings and agreed upon goals were addressed. Accomplishments: Water resource and management survey of ornamental plant producers was initiated in 2011. In 2012 the survey was disseminated nationwide. Analysis of data from the survey and round-table discussions conducted to define stakeholder needs were completed, and findings were presented on a poster at the 2013 American Society for Horticultural Science meeting in Palm Desert. The results from the survey are be utilized by the NC1186 research project as a baseline defining trends in industry behavior and cultural practices. Furthermore, results of the survey and round-table discussions are being used to guide extension priorities and program development, as well as coordination of a SCRI-CAP grant, in which the majority of collaborators are members of NC1186. Participants in the NC1186 research group released a three-part series of publications called the State of Water to Nursery Management, a national trade magazine . The articles served to educate specialty crop producers about current water issues, use patterns, and practices to more efficiently manage water. Member Impact Statements: Researchers in Alabama identified several common landscape plant species as suitable components of runoff water capture and filtration systems for production or in the landscape During the past four years, researchers at Clemson University have monitored the efficacy of two constructed wetlands to facilitate removal of nutrient and pathogen contaminants from runoff. The wetlands reduced export of total nitrogen by 69%, phosphorus by 39%, and Phytophthora spp. (a pathogen) by 80%. Over 630,000 gallons of water flow through these wetlands each day, and an average of 143 lbs. of nitrogen and 0.12 lbs. of phosphorus are removed from runoff on a daily basis. Given that it takes only 0.02 ppm phosphorus to contribute to nutrient enrichment and potential impairment of surface waters, optimizing best management practices to reduce nutrient export into surface waters is critical. This technology to filter contaminants from runoff not only helps to protect our surface waters, but can also be applied to increase re-use of irrigation runoff to save potable water sources for other uses. Irrigation water is a finite resource. Research at Colorado State University has shown that irrigation can be precisely applied on a species or genotype need basis. This can be done with the use of mechanistic models that predict how much water the plants need based on their physiology and its interactions with the environment. Research indicates this can be scaled up to a whole production site. Studies conducted at Kansas State University related to sustainable production practices, which include identifying and using locally sourced materials for potting media (substrates) in order to reduce fossil fuel used to ship standard materials (pine bark and peat moss) from distant regions, have helped to widen the base of knowledge for using Eastern Red Cedar as a replacement or component of pine bark-based substrates in the Great Plains region of the U.S. New substrate materials come with their own challenges and learning to manage water (irrigation) is a significant opportunity to potentially reduce inputs and efficiently manage existing water and substrate supplies. Growers from Kansas, Oklahoma, Missouri, and Nebraska met at the biennial NurseryWorks conference and were taught watering methods that were life changing for some participants. Many Best Management Practices for irrigating container-grown crops are largely unknown in Kansas, as many growers have not had a local opportunities to learn from industry leaders across the U.S. Providing a local, affordable, hands-on event for Great Plains growers has already changed many producers growing practices. Irrigation and water management has been a focus for LSU AgCenter education programs in 2013. Training programs and research studies have been conducted targeting water related issues in both landscape/home gardening and nursery production. At the University of Kentucky Research and Education Centers we are looking at fertilization of native plants in container production, efficient water use and use of rain gardens to remediate runoff from small container production and garden centers. As previously reported in 2012, Maryland is leading a Specialty Crops Research Initiative (SCRI) Grant to investigate Precision Irrigation and Nutrient Management for Nursery, Greenhouse and Green Roof Systems, using Wireless Sensor Networks. The significant engineering effort put into the development of the advanced monitoring and control (nR5) node and supporting software (Sensorweb) during 2010 and 2011 was implemented in a number of research situations and commercial operations during 2012. Mississippi State University graduate student Diana Cochran determined that foliar application of the plant protectant products Pageant and Regalia SC to greenhouse-grown impatiens under water stress did not result in increased drought tolerance. And, University of Southern Mississippi graduate student Anthony Witcher determined that alternative substrates prepared with processed whole pine trees could be used most successfully for commercial cutting propagation, particularly when this renewable material is blended with peat moss. Researchers at Penn State University frequently isolate numerous non-pathogenic Pythium species by from recycled irrigation water in two commercial greenhouses indicates that commercially available diagnosis kits that detect the presence of all members of the genus Pythium do not provide the information growers need in order to decide whether their irrigation water is a significant source of plant pathogenic Pythium that could cause crop losses. Any Pythium detected must be identified to species in order to assess whether the species present is a serious plant pathogen or an innocuous resident of the environment. Researchers at Purdue University are beginning a new project with the goal of quantifying the processes whereby nitrogen is lost from container production systems and to identify the management practices that increase or decrease these losses. Optimization of nutrition in intensively managed greenhouse crops is important to maximize productivity, minimize fertilizer inputs and production costs and reduce potential environmental impacts. Preliminary research at Texas A&M AgriLife-Uvalde indicates that nutrient solution formulations containing high levels of calcium in relation to other cations, like potassium and magnesium (namely 85:10:5 Ca-K-Mg ratios), have higher flower productivities and better foliage quality. Irrigation of landscape plants with alternative irrigation waters like reclaimed, stormwater and graywater, can reduce potable water dependence in urban areas. Research at Texas A&M AgriLife-Uvalde indicates that most laundry graywaters, except those containing high levels of bleaching agent (chlorox), can be used to satisfactorily grow annual and herbaceous perennials plants used for urban landscaping applications. Researchers at the University of Tennessee evaluated physiologically-based on demand and daily water use systems in an outdoor nursery that reduced water use by 63 and 56%, respectively, for 3 gallon crops compared with the industry standard of 1 inch of water per day. Researchers at Texas A&M AgriLife-Uvalde calculate that by irrigating landscape plants with reclaimed water, millions of gallon of portable water can be saved for other purposes. By irrigating plants at 20-30% soil moisture content instead of 40%, irrigation water can be conserved by 30 to 70%. Researchers at Virginia Tech are conducting a technology demonstration utilizing remote sensing, conducting educational workshops and providing on-farm training of water management techniques to increase water use efficiency of containerized crops, and have achieved the following impacts: 1) One new species Phytophthora aquimorbida and one new taxon P. aquatilis were formally named. 2) One new species P. hedraiandra was found in Virginia nursery water. 3) Some new findings about pathogen aquatic biology were published.

Impact Nugget: Collaborative relationships fostered by the NC-1186 research group generated and distributed knowledge to ornamental crop producers and extension agents, emphasizing water use efficiency, water conservation, and use of alternative water resources to maximize economic profitability and enhance environmental sustainability. Issue: The ornamental plant industry ranks 5th (>$14.6 billion) in US agriculture commodities and is in the top 5 commodities for 26 states (USDA, 2004). Water issues, specifically irrigation scheduling, surface water management, salinity and runoff water quality are topics of major concern to ornamental producers. Drought, urban competition for water resources, and increasing legislation at state and county levels increase the need for ornamental producers to manage water more effectively and/or use alternative water sources that are often of inferior quality. Regardless of the area of the United States in which an operation is located, challenges exist regarding sufficient quantities of quality water sources. Since few states have the expertise to integrate all these issues, we need a national multi-disciplinary approach to water management. There are five interrelated areas relevant to this project: 1) source water management and quality, 2) irrigation management, 3) runoff water management and quality, 4) substrate and nutrition management, and 5) pathogens and crop health management. What has the project done so far?: The following participants and stakeholders have used information and resources developed by NC-1186 members to maintain/enhance productivity while changing water use practices for the purpose of enhancing environmental, economic, and/or crop-health indicators: 1. Producers (greenhouse and nursery) utilize personnel and resources generated by NC-1186 collaborators to inform decision making with regard to water handling from managing initial water quality to remediating production runoff. 2. Extension agents utilize information resources generated by NC-1186 to aid in advising producers with management decisions related to water. 3. Researchers utilize NC-1186 meetings to develop and maintain professional relationships that enhance the potential for collaborative research and extension projects supporting the objectives of NC-1186. Specifically, NC-1186 members developed and distributed a national survey Understanding Ornamental Irrigation and Runoff Management Practices Nationwide and the Utility of Irrigation Sensor Networks. The survey was completed and released to growers in December 2011. Results of the survey are being used to establish baseline water management and use practices, as well as provide economic indicators for ornamental crop producers. Research priorities derived from the survey and round table discussion sessions with grower stakeholders at five regional trade meetings (2011-2012) were presented in a poster at the 2013 American Society for Horticultural Science meeting. Both the survey and the round-table discussions were a collaborative effort of NC-1186 participants. The survey was facilitated by collaborations among NC-1186 members as co-investigators for the Specialty Crops Research Initiative Planning Grant  Containment, Remediation, and Recycling of Irrigation Water for Sustainable Ornamental Crop Production, and researchers collaborating on the Specialty Crops Research Initiative Grant (2009-2014): Precision Irrigation and Nutrient Management for Nursery, Greenhouse and Green Roof Systems: Wireless Sensor Networks for Feedback and Feed-Forward Control (Dr. John Lea-Cox, PI, University of Maryland). NC-1186 members collaborated to host multiple workshops, symposia, and colloquia to enhance knowledge related to water issues supporting our core objectives. We also facilitated information transfer regarding ongoing research projects that directly relate to the core objectives of NC-1186. This information sharing mechanism has synergistically increased collaborative research developed among members. We have also increased member recruitment to extend to plant pathologists, entomologists, environmental engineers, economists, life cycle assessment modelers, and sociologists, whose input and expertise will guide water conservation and remediation technology development and help us understand and convey economic data to facilitate changes in practice. Research Needs for Future Impacts: The research group needs to develop an integrated online mechanism to share research knowledge collated by NC-1186 participants. We should continue recruitment efforts to increase participation of additional engineers, economists, and sociologists with research or extension efforts related to water. We are evaluating information gained from survey and round-table discussions to plan future research projects and fostering collaborations among NC-1186 members to continue accomplishing our objectives and finally to serve ornamental crop producers. Cooperators: CA, CO, FL, GA, HI, IN, KS, KY, LA, MD, MI, MS, NC, NJ, OH, OR, PA, SC, TN, TX, VA

Collaborative among NC1186 Members: Ingram, D.L. and T. Fernandez. 2012. Life Cycle Assessment: Implications for the Green Industry. University of Kentucky Cooperative Extension Service. HO-90. http://www2.ca.uky.edu/agc/pubs/ho/ho90/ho90.PDF Fulcher, A. and T. Fernandez. 2013. Sustainable nursery irrigation management, Part I. Water use in nursery production. University of Tennessee W278. https://utextension.tennessee.edu/publications/Documents/W278.pdf Fulcher, A. and T. Fernandez. 2013. Sustainable nursery irrigation management, Part II. Strategies to increase nursery crop irrigation efficiency. University of Tennessee W279. https://utextension.tennessee.edu/publications/Documents/W279.pdf Fulcher, A. and T. Fernandez. 2013. Sustainable nursery irrigation management, Part III. Strategies to manage nursery runoff. University of Tennessee W280. https://utextension.tennessee.edu/publications/Documents/W280.pdf Fulcher, A., G. Niu, G. Bi, M. Evans, R.T. Fernandez, R. Geneve, A. Koeser, S. Nambuthiri, N. Pershey, J. Ryan Stewart, S. Verlinden, X. (Vickie) Wang, and R. Brumfield. 2013. Pulp fiction or fact. Can pulp-based biocontainers hold up during nursery production? The South Carolina Nurseryman. May/June 32-33. (Reprint permission by South Carolina Nursery and Landscape Association.) Fulcher, A., G. Niu, G. Bi, M. Evans, R.T. Fernandez, R. Geneve, A. Koeser, S. Nambuthiri, N. Pershey, J. Ryan Stewart, S. Verlinden, and X. (Vickie) Wang. 2013. Pulp fiction or fact? Can pulp-based biocontainers hold up during nursery production? Nursery Views. 43(1):18-19. Fulcher, A., G. Niu, G. Bi, M. Evans, R.T. Fernandez, R. Geneve, A. Koeser, S. Nambuthiri, N. Pershey, J. Ryan Stewart, S. Verlinden, and X. (Vickie) Wang. 2013. Pulp or Plastic? American Nurseryman. February 20-24. White, S.A., J.S. Owen, J.C. Majsztrik, R.T. Fernandez, P. Fisher, C.R. Hall, T. Irani, J.D. Lea-Cox, J.P. Newman, and L.R. Oki. 2013. Containment, Remediation, and Recycling of Irrigation Water for Sustainable Ornamental Crop Production: Results of a SCRI Planning Grant. HortScience. 48(9):S427-S428 (poster presentation). Hong, C.X., P. A. Richardson, W. Hao, S. R. Ghimire, P. Kong, G. W. Moorman, J. D. Lea-Cox and D. S. Ross. 2012. Phytophthora aquimorbida sp. nov. and Phytophthora taxon aquatilis recovered from irrigation reservoirs and a stream in Virginia, USA. Mycologia. 104:1097-1108 HagenM, D., S. Nambuthiri, A. Fulcher, and R. Geneve. 2012. Comparing substrate moisture-based daily water use and on-demand irrigation regimes for oakleaf hydrangea plants grown in two container sizes. HortScience. 47(7):S157. Wang, X., R.T. Fernandez, G. Bi, A. Fulcher, R. Geneve, G. Niu, S. Verlinden, B. Cregg, M. Ngouajio, T. Kijchavengkul, and R. Auras. 2012. Performance of alternative containers and plant growth and water use of Euonymus fortunei. HortScience 47(7):S87. Kong, P., Lea-Cox, J. D., Moorman, G. W., and Hong, C. X. 2012. Survival of Phytophthora alni, P. kernoviae and P. ramorum in a simulated aquatic environment at different levels of pH. FEMS Microbiology Letters DOI: 10.1111/j.1574-6968.2012.02574. Kong, P., Lea-Cox, J. D., and Hong, C. X. 2012. Effect of electrical conductivity on survival of Phytophthora alni, P. kernoviae and P. ramorum in a simulated aquatic environment. Plant Pathology DOI: 10.1111/j.1365-3059.2012.02614. Chappell, M., M. van Iersel, J. Ruter, E. Lichtenberg, J. Majsztrik and P. Thomas. 2012. Drop by Drop: Precision Irrigation Saves Significant Costs. Nursery Management. 37(6):47-48. White, S.A., C. Boyer, and A. Niemiera. 2013. BMP - Water and Nutrient Management Practices. Best Management Practices: Guide for Producing Nursery Crops. IN T. Yeager, T. Bilderback, D. Fare, C. Gilliam, J. Lea-Cox, A. Niemiera, J. Ruter, K. Tilt, S. Warren, T. Whitwell, R. Wright (eds.). Best Management Practices: Guide for Producing Nursery Crops. 3rd ed. Southern Nursery Association. Majsztrik, J.C., S.A. White, J.S. Owen and J.D. Lea-Cox. 2013. The State of Water in the Green Industry Part I: Water Resource Availability. Nursery Management. June. 29(6): 28, 30-32. Majsztrik, J.C., J.S. Owen, S.A. White and J.D. Lea-Cox. 2013. The state of water in the green industry Part II: Water Use Efficiency. Nursery Management. July. 29(7): 24, 26, 28. White, S.A., J.S. Owen, J.C. Majsztrik and J.D. Lea-Cox. 2013. The state of water in the green industry Part III: Water Quality. Nursery Management. August. 29(8): 20-21,23-25. Chappell, M.R., J.S. Owen, S.A., White and J. Lea-cox. 2013. Irrigation management practices. In: T. Yeager, T. Bilderback, D. Fare, C. Gilliam, J. Lea-Cox, A. Niemiera, J. Ruter, K. Tilt, S. Warren, T. Whitwell and R. Wright (eds.) Best management practices: Guide for producing nursery crops. 3rd edition. Southern Nursery Association, Atlanta, GA. In press in English and Spanish. Owen, J.S., Jr., H.M. Stoven# and J.E. Altland. 2012. Something new in the mix: Researchers evaluate alternative substrates for ornamental crop production in the Pacific Northwest. Digger 56(12):34-37. White, S.A. and L.R. Oki. 2013. Ecologically Based Water Treatment Systems Part II: Small-scale Systems. SC Nurseryman. May/Jun: 17-19. White, S.A. and L.R. Oki. 2013. Ecologically Based Water Treatment Systems Part I: Large-scale Systems. SC Nurseryman. Mar/Apr: 31-33. Oki, L.R. and S.A. White. 2012. Constructed Wetlands  Learn how to remediate pesticides from recycled water and runoff. Nursery Management. 28(6): 24, 26-28. Individual Papers supporting NC1186 Objectives: Wilson, E. and A. Fulcher. 2012. Development of an oxygenation system for nursery crop irrigation water. HortScience. 47(7):S162-163. Zhu, H. E. Ozkan, R.D. Derksen, M.E. Reding, C.M. Ranger, L. Canas, C.R. Krause, J.C. Locke, S.C. Ernst, R.H. Zondag, A. Fulcher, R. Rosetta, H.Y. Jeon, Y. Chen, J. Gu, H. Liu, Y. Shen, and A.A. Rios. 2012. Development of intelligent spray systems for nursery crop production. HortScience. 47(7):S145-146. Ridge, G.A., S.A. White, I.M. Meadows, and S.N. Jeffers. 2012. Developing a method to evaluate plants used in constructed wetlands for susceptibility to five species of Phytophthora. SNA Research Conference Proceedings. 57, 251-256. Nyberg, E.T., I.M. Meadows, S.N. Jeffers, and S.A. White. 2012. Influence of microbial community development in substrates used to filter zoospores from recycled irrigation water. SNA Research Conference Proceedings. 57, 347-354. Campoe, O., J.L. Stape, Y. Nouvello, J-P., W.L. Bauerle, D. Binkley, and G. Le Maire. 2013. Stem production, light absorption and light use efficiency between dominant and non-dominant trees of Eucalyptus grandis across a productivity gradient in Brazil. Forest Ecology and Management, 288:14-20. Gspaltl, M., W.L. Bauerle, D. Binkley, and H. Sterba. 2013. Leaf area and light use efficiency patterns of Norway spruce under different thinning regimes and age classes. Forest Ecology and Management, 288:49-59. Cochran, D.R., R.L. Harkess, P.R. Knight, E.K. Blythe, and C.H. Gilliam. 2011 (published 2012). Evaluating potential plant health strengtheners. Comb. Proc. Intl. Plant Prop. Soc. 61:493-498. Cochran, D.R., R.L. Harkess, P.R. Knight, E.K. Blythe, M. Tomaso-Peterson, and C.H. Gilliam. 2012. Antitranspirant effects on water use efficiency in impatiens. Southern Region of North America, International Plant Propagators' Society Annual Meeting, Auburn, Alabama, October 14-17 (poster presentation). Cochran, D.R., R.L. Harkess, P.R. Knight, M. Gu, M. Tomaso-Peterson, E.K. Blythe, and C.H. Gilliam. 2012. Evaluating the effects of Pageant and Regalia on drought tolerance of impatiens. Proc. Southern Nursery Assn. Res. Conf., 57th Annu. Rpt. p. 324-330. Cochran, D.R., R.L. Harkess, P.R. Knight, M. Tomaso-Peterson, E.K. Blythe, C.H. Gilliam, and M. Gu. 2012. Evaluating the effect of selected fungicides on drought tolerance in tomatoes. HortScience 47:S20 Cochran, D., R.L. Harkess, P. Knight, M. Tomaso-Peterson, E.K. Blythe, and C.H. Gilliam. 2012. Evaluating heat tolerance in Impatiens walleriana 'Super Elfin XP White' following the application of Pageant. HortScience 47(9):S340 (poster). Stoy, P.C. A.M. Trowbridge, A.M., W.L. Bauerle. 2013. Controls on seasonal patterns of maximum ecosystem carbon uptake and canopy-scale photosynthetic light response: contributions from both temperature and photoperiod. Photosynth. Res. DOI 10.1007/s11120-013-9799-0. Cabrera, R.I. 2012. Localized fertigation with stressing solutions and growth-quality responses in potted greenhouse roses. Acta Horticulturae 947: 63-67. Cai, X., T. Starman, G. Niu, C. Hall, and L. Lombardini. 2012. Response of selected garden roses to drought stress. HortScience 47(8):10501055 Niu, G., P. Osuna, Y. Sun, and D. Rodriguez. 2012. Seedling emergence, growth, and mineral nutrition of ornamental chile peppers irrigated with saline water. HortScience 47(11):16531657. Niu, G., D. Rodriguez, and S. McKenney. 2012. Response of selected wildflower species to saline water irrigation. HortScience 47(9): 1351-1355. Niu, G., M. Wang, D. Rodriguez, and D. Zhang. 2012. Responses of zinnia to saline water irrigation. HortScience 47(6):793797. Solís-Pérez, A.R. and R.I. Cabrera. 2012. Characterizing hourly, daily and seasonal ion and water uptake in hydroponically-grown roses. Acta Horticulturae 947: 347-354. Burgos-Garay, M., J. Edson, and G. W. Moorman. 2012. Influence of Pythium aphanidermatum, P. irregulare, and P. cryptoirregulare on the bacterial community in recycled irrigated water. Phytopathology 102:S1.2. Stoven H., J.S. Owen, Jr. and L. Santamaria. 2012. A safe substrate? Investigating the virulence of Verticillium in hammer-milled shade trees when used as an alternative substrate. Digger 56(8):122-127. Hoskins T., J.S. Owen, Jr. and H. Stoven. 2012. Monitoring from a distance: Using a remote moisture monitoring system to manage irrigation. Digger 56(7):41-44. Yang, X., Richardson, P. A., Ghimire, S. R., Kong, P., and Hong, C. X. 2012. Phytophthora hedraiandra detected from irrigation water at a perennial plant nursery in Virginia. Plant Disease 96:915 Brantley, E., K. Dylewski, K. Christian, A. Wright, and C. LeBleu. 2013. Stormwater and Streams  Understanding Opportunities to Improve, Involve, and Evolve. In: Auburn Speaks: Water. Auburn University Office of the Vice President for Research. Hunolt, A.. E. Brantley, J. Howe, A. Wright, and W. Wood. 2013. Comparison of native woody species for use as live stakes in streambank stabilization in the southeastern USA. Journal of Soil and Water Conservation. 68(5):384-391. Mickelbart, M.V., M.J. Gosney, and K.M. Stanton. 2013. Evaluation of accessions of Spiraea alba and S. tomentosa in Indiana. Native Plants Journal 14:17-23. Mickelbart, M.V., M.J. Gosney, J. Camberato, and K.M. Stanton. 2012. Soil pH effects on growth and foliar nutrient concentrations of Spiraea alba Du Roi and Spiraea tomentosa L. HortScience 47:902906. Solano, L., A. G. Ristvey, J. D. Lea-Cox and S. M. Cohan. 2012. Sequestering zinc from recycled crumb rubber in extensive green roof media. Ecol. Engineering 47: 284 290. Pool, J.R., J.J. Griffin, C.R. Boyer and S.L Warren. 2013. Short-term recurring drought affects growth and photosynthetic capacity of four conifer species. J. Environ. Hort. 31:39-42. Starr, Z.W., C.R. Boyer, and J.J. Griffin. 2013. Post harvest processing of eastern redcedar and hedge-apple substrates affect nursery crop growth. J. Environ. Hort. 31:7-13. Starr, Z.W., C.R. Boyer, and J.J. Griffin. 2012. Eastern redcedar (Juniperus virginiana) as a substrate component effects growth of three tree species. J. Environ. Hort. 30:189-194. Pool, J., J.J. Griffin, C.R. Boyer and S.L. Warren. 2012. Establishment and growth of transplanted conifers in the Southern Great Plains. J. Environ. Hort. 30:214-218. Boyer, C.R., T.V. Gallagher, C.H. Gilliam, G.B. Fain, H.A. Torbert, and J.L. Sibley. 2012. Description of clean chip residual forest harvest and its availability for horticultural uses in the southeastern United States. HortTechnology 22:381-387. Boyer, C.R., H.A. Torbert, C.H. Gilliam, G.B. Fain, T.V. Gallagher, and J.L. Sibley. 2012. Nitrogen immobilization in plant growth substrates: Clean chip residual, pine bark, and peatmoss. Intl. J. Agron. http://www.hindawi.com/journals/ija/2012/978528/