Progress 09/01/08 to 08/31/10
OUTPUTS: The tomato and similar crop production program has assisted existing and prospective hydroponic growers in Ohio, U.S. and abroad with technical, cultural, and marketing support through one-on one consultations and site visits, telephone and e-mail communications, conference presentations, publications and a hydroponic website http://www.oardc.ohio-state.edu/hydroponics. From 9/1/2008 to 8/31/2010, there were 25,496 visits to the website from 165 countries. Of these, about 70% were first-time visitors. Website was redesigned based upon outside review by ASABE. Three experiments were conducted during year 10/1/09 to 9/30/10 to evaluate and optimize hydroponic lettuce growing processes in a greenhouse. Two projects were funded by external sources and conducted under proprietary agreements. The first experiment (Autumn 2009) compared five exclusive formulations of polyurethane cubes to traditionally-used rock wool cubes while growing two cultivars (Green Bib Flandria RZ and Red Bib Skyphos RZ) at two growing solution flow rates (1 Lpm and 2 Lpm). The second experiment (Winter 2010) compared two light emitting diode (LED) lighting systems to traditionally-used high pressure sodium (HPS) lighting while growing three lettuce cultivars and one herb cultivar in a hydroponic growing system at two growing solution temperatures [21.1 Deg C (70 Deg F) and 26.7 Deg C (80 Deg F)]. The third experiment (Summer 2010) was designed to evaluate the growth of two hydroponically grown lettuce cultivars (Green Bib Flandria RZ and Red Bib Skyphos RZ) while using three proprietary polyurethane formulations as growing cubes compared to lettuce grown in rock wool and coconut coir cubes while using three growing solution flow rates (1 Lpm, 2 Lpm and 3 Lpm). All treatments were evaluated based on average fresh weight produced per head. Selected (non-proprietary) results from these experiments were delivered via Power Point presentations to the leadership team at CropKing, Inc., Lodi, Ohio, January 20 and to the Greenhouse and Nursery Technology Applications Session of the Annual International Meeting of the American Society of Agricultural and Biological Engineers, Pittsburg, PA, June 21. A poster describing the research was displayed at the annual Ohio Agricultural Research and Development Center's Scarlet and Gray Green Fair, Wooster, Ohio, April 20, 2010 and at the annual Ohio State Farm Science Review, London, Ohio September 21, 22 and 23, 2010. A hydroponic demonstration unit featured lettuce, tomatoes and cucumbers at the Green Fair. Written reports and associated Power Point presentations were delivered to key personnel from the two funding sources, April 30 and May 25. A study was conducted to evaluated the potential recoverable heat from ventilation exhaust and the MS thesis, "Cooling Capacity Assessment of Semi-closed Greenhouses", completed. Also, studies conducted on collection of adult whiteflies B. tabaci from poinsettia (Euphorbia pulcherrima) canopies using an air assisted mobile insect vacuum prototype and MS thesis, "Development of an Autonomous Insect Collection Prototype for Greenhouse Applications.", completed. PARTICIPANTS: Harold M. Keener, Professor in Food, Agricultural, and Biological Engineering, Specialist in Systems Engineering; Beth Fausey, Floriculture and Hydroponics Vegetable Extension Educator and Director Agricultural Business Enhancement Center; Peter Ling, Associate Professor and Extension Specialist in Controlled Environmental Plant Production; Chad Draper, Program Specialist in Web Based Systems; Robert Hansen, Research Associate in Nursery and Hydroponic Systems; Bill Bauerle, OSU Faculty Emeritus in Horticulture and Crop Science, and Willoway Nurseries, Inc. TARGET AUDIENCES: Growers, Extension Agents, Public, and Educators PROJECT MODIFICATIONS: Not relevant to this project.
1. Lettuce grown in one polyurethane (PE) formulation of growing cubes yielded over 13% more lettuce per head than rock wool during a 34 day growing period from seedling transplant to harvest (p<0.05). Three formulations of PE yielded more than rock wool, one yielded about the same and one was less. 2. Fresh weight yields for Red Bib lettuce averaged over 20% greater than Green Bib (p<0.05) while the yield differences between solution flow rates at 1 and 2 Lpm were not significant. 3. Yields were 33% greater for Red Bib lettuce than Green Bib when grown in channels using a solution flow rate of 1 Lpm whereas they were only 9% greater at a flow rate of 2 Lpm. 4. Average yields (Summer 2010) for Red Bib lettuce increased 19% and Green Bib increased by 37% when using a solution flow rate of 3 Lpm compared to 1 Lpm. 5. For a rock wool medium and for all five PE formulations tested (Summer 2010), lettuce yields were significantly higher when using a solution flow rate of 3 Lpm compared to 1 Lpm for both Red Bib and Green Bib cultivars (p<0.12). 6. An evaluation of lettuce quality (Summer 2010) indicated Red Bib lettuce was more susceptible to tip burn than Green Bib (p<0.08) while tip burn severity for lettuce grown with a solution flow rate of 1 Lpm was significantly higher than either 2 or 3 Lpm (p<0.11). 7. Two Master's Thesis were produced in the area of improving sustainability of greenhouse operations. Topics focused on greenhouse energy efficiency to reduce fossil fuel consumption and on reducing pesticide usage by improving effectiveness of integrated pest management.
- Biffi, Alfredo. 2010. Development of an Autonomous Insect Collection Prototype for Greenhouse Applications. M.S. Thesis. The Ohio State University.
- Wee Fong Lee. 2010. Cooling Capacity Assessment of Semi-closed Greenhouses. M.S. Thesis. The Ohio State University
Progress 09/01/08 to 08/31/09
OUTPUTS: The tomato and similar crop production program has assisted existing and prospective hydroponic growers in Ohio, U.S. and abroad with technical, cultural, and marketing support through one-on one consultations and site visits, telephone and e-mail communications, conference presentations, publications and a hydroponic website http://www.oardc.ohio-state.edu/hydroponics. There were 12,558 visitors to website in 2009, compared to 4,447 during same period of 2008 resulting in 67,772 page views. Of these, 9,252 were first-time. The top content on the site was: the hydroponic photo gallery, the interactive tomato model, the video podcasts, the economic budgets, and the graphs of the tomato growth stages. Research results for 2008/9 from hydroponic research laboratory at Ohio Agricultural Research and Development Center (OARDC) indicate choice of growing cube composition has a marked impact on yields (or conversely growing time) when using nutrient film technique (NFT) for hydroponically-grown lettuce crops. Rock wool growing cubes are currently hydroponic lettuce growers standard. Lettuce that was grown in a new plastic fiber growing cube yielded 29% less mass (wb) than rock wool in Autumn 2008 (Experiment No. 1) and 34% less in Spring 2009 (Experiment No. 2). However, for Experiments No. 3 and 4 (Summer, 2009), lettuce grown in coconut core cubes and a commercially available mix of peat moss, perlite and vermiculite (Oasis fertis) cubes yielded 19% and 14% more lettuce (wb), respectively, than rock wool. A study of the interaction between growing cube composition and flow rate showed that a flow rate of 2 Lpm resulted in a 10% increase in yield compared to 1 Lpm when growing lettuce in Oasis fertis cubes while flow rate had little or no impact on yields for plants grown in rock wool. A strong interaction between growing cube composition and cultivar selection was also discovered showing that a red butterhead cultivar yielded 13% more than a green butterhead variety when grown in Oasis fertis cubes compared to only 5% more yield when grown in rock wool cubes. A greenhouse insect collection system was designed and tested since scouting for insect pest is the backbone of all Integrated Pest Management (IPM). Results from OARDC research showed an air assisted mobile insect vacuum collector had reliable insect collection efficiency unaffected by greenhouse temperature at 13.5 and 28.5C. Assessment of greenhouse energy systems continued. Dutch researchers have reported significant benefits of closed greenhouse systems. Analysis for Ohio conditions suggests that semi-closed greenhouses are more operationally efficient. For example, a 50% peak cooling load design can meet the cooling needs 90% of the time. Cooperative project with an Ohio pot-in-pot nursery was continued with research focused on water quality, fertilizer practices and cultural practices using newly developed commercially adaptable technologies. Results gave 35% savings on fertilizer and 30-40% accelerated plant growth. Completed a draft of an OSU Extension Bulletin titled, "Storm Water Recovery and Re-use: Controlling pH for Optimum Nutrient Utilization". Currently under peer review. PARTICIPANTS: Harold M. Keener, Professor in Food, Agricultural, and Biological Engineering, Specialist in Systems Engineering; Beth Fausey, Floriculture and Hydroponics Vegetable Extension Educator and Director Agricultural Business Enhancement Center; Peter Ling, Associate Professor and Extension Specialist in Controlled Environmental Plant Production; Chad Draper, Program Specialist in Web Based Systems; Robert Hansen, Research Associate in Nursery and Hydroponic Systems; Jonathan Frantz, USDA-ARS; Bill Bauerle, OSU Faculty Emeritus in Horticulture and Crop Science, and Willoway Nurseries, Inc. TARGET AUDIENCES: Growers, Extension Agents, Public, and Educators PROJECT MODIFICATIONS: Not relevant to this project.
The interactive budget spreadsheets on website allow producers to realize their costs of production and make informed decisions that affect the long term financial health of their business. The budgets have also been useful for growers in obtaining loans to start up a business by predicting the annual expected income of the operation. The hydroponic extension program has provided production and marketing expertise and assistance that allow growers to conduct business in an increasingly competitive marketplace. Micro-feeding plant nutrients with continuous pH control of recycled water gave 36% nutrient saving compared to industry standard and increased growth rates 30-40% on pot-in-pot grown trees. Implementation of this commercially ready system will result in an economic advantage to the Ohio and US Nursery industry. Growing cube selection can potentially increase lettuce yields for growers by 20% or correspondingly reduce growing time and increase the number of crops produced during one growing season. Flow rate setting and choice of cultivar may also increase production, or conversely, reduce growing time significantly. The insect collection system developed in this project has shown reliable results unaffected by greenhouse temperature. The system can be used to improve reliability of insect population estimation over commonly used methods in production greenhouses. In addition, design tools developed to analyze air flow characteristics of the collection system can be used to improve collection efficiency thus allow earlier detection of insect threats to greenhouse crops. Studies showed an energy harvesting greenhouse can be used to capture heat/cold during cooling/heating operations then used to meet later heating/cooling needs, respectively. The proposed greenhouse cooling/heating assessment tool can be used to estimate energy harvesting potential of greenhouses to reduce fossil fuel dependency for climate control.
- Hansen, R.C., J. Balduff and H.M. Keener. 2009. A study of factors that have an effect on lettuce production in a hydroponic lettuce growing system. Paper No. 09-7244. Presented at the ASABE Annual International Meeting, Reno, Nevada. Jun 21 to 24. (Published on CD (search at http://asae.frymulti.com/)
- Bauerle, W.L. 2009. Storm water recovery and re-use: controlling pH in eutrophic water impoundments for optimum nutrient utilization. Presented at the International Symposium for Horticultural Growing Media, Charlotte, NC. June 1-5.
- Wee Fong Lee, Peter P. Ling, Harold M. Keener. 2009. Cooling Capacity Assessment of Semi-closed Greenhouses. Reno, NV. ASABE International Meeting. Paper No. 09-7059. Presented at the ASABE Annual International Meeting, Reno, Nevada. Jun 21 to 24. (Published on CD (search at http://asae.frymulti.com/)
- Ling, P.P. 2009. Knowing Exactly When to Apply Irrigation Water. Elison Chair in International Floriculture Webinar Series. 9/15/2009.(available https://tamu.webex.com/ec0605l/eventcenter/recording/recordAction.do; jsessionid=TbvjLMkTR6y1v6K6kpZygbm3khyvY8htZnvDCKM5L5XnfMhSJ9Tr!16668 31811theAction=poprecord&actname=%2Feventcenter%2Fframe%2Fg.do&apina me=lsr.php&renewticket=0&renewticket=0&actappname=ec0605l&entappname= url0107l&needFilter=false&&isurlact=true&entactname=%2FnbrRecordingUR L.do&rID=2382947&rKey=371d094903534987&recordID=2382947&rnd=148301401 3&siteurl=tamu&SP=EC&AT=pb&format=short
- Ling, P.P. 2009. Energy Saving Details. ForiBytes (IV):4. Pp 2-4.