Progress 07/01/05 to 09/30/09

Outputs
OUTPUTS: OUTPUTS. The major obstacles to small-scale hydroponic production identified by stakeholders in Missouri include limited knowledge about: 1) the design, operation and management of viable hydroponic systems; 2) hydroponic crop production, including nutrient selection and management; 3)small-scale hydroponic growers prefer a single compound fertilizer formulation for growing most of their vegetables rather than mixing a number of mineral nutrient reagents; and 4) small scale growers usually practice mixed cropping by growing many different varieties on a single nutrient-recirculating Nutrient Film Technique(NFT) hydroponic system. In response to the needs of the stakeholders identified above, several experiments were conducted. 1) to screen many varieties of vegetables and herbs in both NFT and aggregate hydroponic systems (same as those used in commercial production). Crops evaluated include: arugula, three basil varieties, beetroot, Chinese cabbage, chives, cos lettuce, collards, eggplant, kale, Kohl-rabi, Leaf mustard varieties, radish, Rhubarb chard, sage, tomato Roma-VF variety. 2) Since stakeholders prefer single compound fertilizers as mineral nutrient source several experiments were conducted with vegetable varieties and one herb crop to evaluate three commonly available soluble commercial fertilizers (Peters General Purpose soluble fertilizer [20-20-20], Peters Peat-Lite Special [15-16-17], and Peters Ecxel-Cal-Mag [15-5-15]), and one trade marked fertilizer "All-Purpose Hydroponic Nutrient." 3) Two experiments were conducted to assess the effect of mixed cropping on yield and quality of a) arugula, sweet basil, and beetroot, and b) three varieties of basil, using a nutrient recirculating NFT hydroponic system. The second phase of the project will focus on nutrient management strategies and soilless substrate evaluation. DISSEMINATION. Information generated from these experiments were shared with stakeholders during field days, multiple onsite tour presentations to extension specialists, Missouri Department of Agriculture staff, master gardeners, hydroponic growers and hobbyists in Missouri and the North Central Region (NCR) of the United States. Presentations at professional conferences include those at the American Society for Horticulture (ASHS) conferences in 2006 (New Orleans, Louisiana), 2007 (Las Vegas, Nevada), 2008 (Orlando, Florida), 2009 (St. Louis, Missouri). Other presentations were made at 1) the Great Plains Vegetable Growers' Conference in 2009 (St. Joseph, Missouri), and 2) the 16th Colloquium of the International Plant Nutrition Institute (IPNI), 2009 (Sacramento, California). Annual onsite presentations and tours were conducted for 60 students from Linn Technical Community College in Missouri effective 2007 to the present to educate them about controlled environment agriculture technology, energy and water conservation, nutrient management and environmental stewardship. Visitors to the hydroponic project also came from outside Missouri, and other countries including Malawi, South Korea and Afghanistan. Since 2006 the average annual number of visitors to the hydroponic project is about 250. PARTICIPANTS: During the reporting period, Jonathan N. Egilla (P.I.) completed the design, and supervised the construction of two new commercial prototype hydroponic systems. The P.I. was responsible for designing and setting up all the experiments, collected and analyze data from the experiments, prepared conference presentations, and manuscripts for peer review journal publications. Supervised and trained one technician and three students. Isabelle Nyirakabibi (Research Technician) assisted in setting up experiments, data collection and supervision of undergraduate work-study students working with the hydroponic research team. Rufus Jones assisted in the supervision of the RT and undergraduate students on the project. Wesseh Wollo assisted in market survey and identification of economically viable vegetable crops in Missouri to be included in hydroponic trials. Isabelle and all other RTs that assist with the hydroponic project received training on hydroponic techniques and production systems. Every semester, three students on work-study continue to improve their knowledge of agriculture, biology and environmental science while working with the hydroponic research team. TARGET AUDIENCES: TARGET AUDIENCES. The agricultural audiences, which include small-scale limited resource farmers, professional and prospective hydroponic producers, the horticulture industry in Missouri, master gardeners and hobbyists, and cooperative extension specialists in Missouri and the North Central Region of the United States. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
OUTCOME/IMPACT. More time is required before the impact of this project can be effectively measured. However, seven prospective hydroponic growers have acquired the knowledge of hydroponic crop culture from this project through direct visitation training, and to my knowledge two have successfully established their own hydroponic system in Missouri. Follow up effort will continue with the other growers. The growing interest in hydroponic vegetable production throughout Missouri and the NCR has significant positive implications, since hydroponic production utilizes only a small fraction of the water and land required to generate the same output by traditional field cultivation of the same crops. This hydroponic project continues to increase the knowledge of the cooperative extension specialists, and master gardeners, who disseminate information about hydroponic production to the agricultural audiences, hobbyists and part-time farmers throughout Missouri. Two Lincoln University technicians have been trained in hydroponic techniques, and every semester about three students on work-study continue to improve their knowledge of agriculture, biology and environmental science while assisting in the hydroponic project. Preliminary results from this project indicates that with good nutrient management practices, most leaf vegetables and herb varieties can yield good market quality crops in liquid (NFT) and soilless substrate (Aggregate) hydroponic cultures when grown with selected general purpose soluble commercial fertilizers. This finding is significant because these fertilizers are commonly available in local chain stores, and are cheaper than specialty hydroponic fertilizer formulations. However, these commercial fertilizers are usually low in calcium and magnesium, and need to be supplemented with these elements. Appropriate sources of the two elements for best crop yield and quality will be investigated during the second phase of this project. Data from preliminary experiments shows that despite differences in pH tolerance and EC requirement, good market quality crop can be obtained from mixed cropping of different vegetable varieties in a single nutrient recirculating system. Arugula, basil and beetroot were grown successful using a closed recirculating NFT hydroponic system, at a pH range of 6.5-6.9, and EC of 1.6-2.0. Three basil varieties were also grown successfully in the same NFT system. This finding is significant because mixed cropping enables growers to satisfy niche market demand for different crops from their NFT hydroponic system. The additional experiments needed to screen vegetable varieties for compatibility in a single source recirculating nutrient solution will be conducted in subsequent phases of this project.

Publications

• Egilla, J. N. 2009. Yield and mineral element concentration of beetroot in response to nutrient source in hydroponic solution. Proceedings of the 16th International Plant Nutrition Colloquium; Sacramento, CA, August 26 to 30, 2009. http://repositories.cdlib.org/ipnc/xvi/1385.
• Jonathan Egilla. 2009. Interaction between nutrient source and growing substrate on the yield of beetroot in NFT hydroponic culture. Abstr. No. 167 106h Annual International Conference of the American Society for Horticultural Science. St. Louis, MO. July 25-28, 2009. HortScience 44 (4): 1119.
• Jonathan Egilla, Rose Ogutu and Isabelle Nyirakabibi. 2009. Commercial fertilizer source affects marketable leaf yield of collards in NFT hydroponic culture. Abstr. No. 168 106h Annual International Conference of the American Society for Horticultural Science. St. Louis, MO. July 25-28, 2009. HortScience 44 (4): 1119-1120.

Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: PROGRESS: 2007/10 TO 2008/09. Beets are good sources of essential vitamins and minerals, especially vitamins A, C, E, and K; calcium, iron, magnesium, potassium, as well as folate, riboflavin, and thiamin. Most of these are stored in the leaves, thus the significance of including beet leaves in salad mixtures. Beetroot (Beta vulgaris `Bull's Blood') is grown traditionally as garden or field crop. However, year-round, high quality beetroot; unblemished by pests or adverse weather, from greenhouse-especially hydroponic production is marketed to modern consumers as a niche crop. The effect of mineral nutritional status, temperature and substrate on the growth and yield of beetroot was evaluated in an NFT experiment. The crop was raised from seed in oasis or rockwool cube slabs inside standard F1020 plastic trays. Seedlings were transferred into rows (28 cm apart) of PVC Hydro-Troughs (5.1 x 10.2 cm x 3.7 m) with 4.45 cm diameter holes spaced 20 cm apart (along the trough) at the two true-leaf stage at a plant density of 18.5 plants/sq. m (5.6 plants/ sq. ft). Seedlings were grown until harvesting, either with Peters Excel-CAL-MAG (CAL-MAG; J. R. Peters, Inc., Allentown, PA), or All-Purpose Hydroponic Nutrient (APHN; Hollister's Hydroponics, Grand Junction, CO), with % N-P2O5-K2O of 15-5-15, and 9-4-15, respectively, in a closed recirculating NFT system. CAL-MAG solution was prepared to supply 200 mg nitrogen (N)/liter, and APHN at manufacturer's recommended concentration, supplying 108 mg N/liter (1-lb of the compound per 100 gallon of water [1.2 g/liter]). The recirculating nutrient solution for each treatment was replaced with a fresh stock every three weeks. Beetroot yield responded more positively to higher nutrient solution EC (3.1-4.8 mS/cm) compared with lower (2.0 mS/cm) between pH 5.8 and 7.4. Beetroot has a high K and Na uptake capacity; however, petiole sap K and Na concentration had negative relationship with yield. Neither ambient temperature in the range 24 C (75.2 F) to 39 C (102.2 F), nor nutrient solution temperature ranging from 24 C (75.2 F) to 34.2 C (93.6 F) significantly affected growth rate, leaf and root yield. However, leaf and root yield decreased under higher light intensity at those temperatures. CAL-MAG increased fresh and dry mass yield by 2-3 fold compared with APHN, where the nutrient solution EC was beyond 2.0 mS/cm. With CAL-MAG, yield parameters (except root dry mass and root/leaf ratio) increased significantly in rockwool substrate compared with oasis cube, but to a limited extent in APHN. Over 250 visitors including hydroponic growers, hobbyists master gardeners, extension educators and students visited the hydroponic research facility during this period. About ten prospective growers planning to start a hydroponic production greenhouse also visited the facility at Lincoln University of Missouri. PARTICIPANTS: Principal Investigator: Jonathan N. Egilla, Ph.D. Collaborators: Rufus Jones, Ph.D. Wesseh Wollo, Ph.D. A Research Technician and two undergraduate students at Lincoln University of Missouri continue to receive training on hydroponic crop production methods and water resources conservation. On-site presentations were made to over 250 visitors including extension educators, professional hydroponic growers and prospective growers from within and outside the state of Missouri. These stakeholders were given a tour of the controlled environment hydroponic research greenhouses at Carver Research Farm, Lincoln University of Missouri. TARGET AUDIENCES: The targeted audiences include 1) The general public 2) Greenhouse producers of vegetables, herbs and spices for local Farmers Markets, grocery stores and restaurants. 3) Professional hydroponic and aquaponic producers, 4) Hobbyists, part-time farmers and persons interested in food or flower crop production enterprises. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
This study identifies differences in the yield response of beetroot to growth substrate, mineral nutrient source, electrical conductivity of the recirculating nutrient solution as well as temperature, in NFT production system. These findings are useful to hydroponic or greenhouse growers in making crop management decisions under different production environments regarding optimization of crop yield and improvements in profitability.

Publications

• Jonathan Egilla, Isabelle Nyirakabibi, and Jimmie Garth. 2008. Mineral nutrient source and duration in NFT, culture: Effect on yield and elemental concentration of radish. (Abstr. #124). 105th Annual Conference of the American Society for Horticultural Science. Orlando, FL. July 21-24, 2008. HortScience 43 (4): 1245-1246.

Progress 10/01/06 to 09/30/07

Outputs
OUTPUTS: PROGRESS: 2006/10 TO 2007/09. Mixed cropping simplifies the production system, and help to satisfy the product mix demanded by fresh produce customers. However, individual crop species differences in pH, EC and mineral nutrient requirements are often difficult to satisfy under this condition. The effect of mixed cropping on yield and quality was evaluated in an NFT experiment involving crops with different pH and EC requirements. Arugula (Eruca vesicaria sativa `Astro'-pH 6.0-6.2; EC 1.3-1.6 mS/cm), basil (Ocimum basilicum `Caesar'-pH 5.5-6.0; EC 1.09-1.75 mS/cm), and beetroot (Beta vulgaris `Bull's Blood'- pH 6.0-6.5; EC 1.97-5.5 mS/cm) were raised from seed in oasis cube slabs in standard F1020 plastic trays. Seedlings were transferred into rows (28 cm apart) of PVC Hydro-Troughs (5.1 x 10.2 cm x 3.7 m) with 4.45 cm diameter holes spaced 20 cm apart (along the trough) at the two to three true-leaf stage. The plant density was 18.5 plants/sq. m (5.6 plants/ sq. ft). Seedlings were grown as a mixed crop until harvest, either with Peters Excel-CAL-MAG (15% N-5% P2O5-15% K2O; [EXCL]), Peat-Lite Special (15% N-16% P2O5-17% K2O; [PLTE; J. R. Peters, Inc., Allentown, PA]), or All-Purpose Hydroponic Nutrient (9% N-4% P2O5-15% K2O; [APHN, Hollister's Hydroponics, Grand Junction, CO]) in a closed recirculating NFT system. Both EXCL and PLTE were added to supply 200 mg nitrogen (N)/liter, and APHN was added at manufacturer's recommended concentration, supplying 108 mg N/liter (1-lb of the compound per 100-gallon of water [1.2 g/liter]). Mean solution pH and EC (mS/cm) were 6.9, 1.68; 6.8, 1.81; 6.9, 1.61 for APHN, EXCL, and PLTE, respectively, and the recirculating nutrient solutions were replaced with a fresh stock every three weeks. Plant fresh mass was recorded at harvest, while dry matter content was recorded after drying at 70 oC for 72 h in an air-forced oven. Mean ambient temperature during the growing period ranged from 22.5 to 27.4 oC. Harvested fresh produce satisfied the United States Standards for grades of arugula, basil and beet green for good fresh market quality. However, fresh mass yield and dry matter content of arugula, and beetroot were variable. With arugula, mineral nutrient source had no effect on the fresh mass of leaves. APHN promoted greater axillary shoot formation in basil compared with both EXCL, and PLTE, and increased the shoot fresh mass (sfm) of basil over PLTE. However, PLTE (with the highest % of nitrate-N) produced plants with higher dry matter content compared with both APHN and EXCL. The greatest sfm and sdm of beetroot was obtained from PLTE, and the lowest EXCL, but differences among the nutrient sources were not significant. Also, PLTE increased root fresh mass (rfm) over both APHN and EXCL, and produced significantly greater root dry mass (rdm) and root-to-shoot ratio than EXCL, but not APHN. On-site presentations and tours were given to over 20 visitors to the hydroponic facility during this period, including two entrepreneurs planning to start a hydroponic production business. TARGET AUDIENCES: Economically disadvantaged (limited resource, minority) hyroponic growers. Information on findings was delivered to audiences through PowerPoint presentations and on-site tours of research and hydroponic production facilities.

Impacts
Despite differences in pH tolerance and EC requirement, good market quality crop was obtained from mixed cropping of arugula, basil and beetroot using a closed recirculating NFT system. A pH range of 6.5-6.9, and EC of 1.6-2.0 gave satisfactory growth and yield for arugula, basil and beetroot green, although root yield of beetroot was below average compared with monoculture. These findings indicate that limited resource growers can satisfy niche market demand for these crops using the simplified method of mixed cropping with these soluble fertilizers. For optimum yields and better market quality in NFT mixed cropping system however, it is recommended that growers select crops with similar vigor, growth habit, pH and EC requirements.

Publications

• Jonathan N. Egilla and I. Nyirakabibi. 2007. Influence of mineral nutrient source on the yield of arugula, basil and beetroot in NFT mixed cropping system. Abstr. No. 146, 104th Annual Conference of the American Society for Horticultural Science. Scottsdale, AZ. July 16-19, 2007. HortScience 42 (4): 936.

Progress 10/01/05 to 09/30/06

Outputs
PROGRESS: 2005/10 TO 2006/09 Hydroponic experiments were conducted using the Nutrient Film Technique (NFT system) with the objective of developing protocols for evaluating selected leaf vegetables, and herb varieties, and to determine factors affecting their adaptation to sustainable hydroponic culture under a controlled environment, including mineral nutrient source. Crops screened in preliminary experiments for adaptation into the available NFT system includes cos lettuce var. Cimmaron, rhubarb chard, radish var. Champion, arugula var. Astro, red beet var. Bulls Blood, basil varieties: Caesar, Sweet Dani, Purple Ruffles, and Dwarf Basil. On-site presentations and tours have been given to over 60 visitors to the hydroponic facility during this period. These include individual growers, homeowners, hobbyists, greenhouse contractors, agricultural extension employees and supervisors, and undergraduate students interested in hydroponic crop science and technology. Two experiments were conducted in July and September to evaluate the influence of mineral nutrient source and temperature on the yield and market quality of lettuce in NFT system either in a polycarbonate or polyethylene greenhouse. Lactuca sativa L. var. longifolia Lam; cos lettuce (also known as romaine lettuce) is more tolerant of unfavorably higher temperature conditions than either crisphead (including the popular variety iceberg) or butterhead lettuce. Two non-hydroponic soluble fertilizers (Peters Excel-Cal-Mag [Excel] and Peat Lite [J. R. Peters, Inc., Allentown, PA]) were compared with one hydroponic formulation (All Purpose Hydroponic Nutrient [AHN; Hollister's Hydroponics, Grand Junction, CO]). Mineral nutrient source had statistically significant influence on crop yield regardless of greenhouse environment. Lettuce grown with Excel (15% N-5% P2O5-15% K2O) had higher fresh mass and dry mass values at higher temperatures (July), compared with either Peat Lite; (15% N-16% P2O5-17% K2O or AHN (9% N-4% P2O5-15% K2O), at 35 and 30 days after transplanting into culture for the July and September crop cycles, respectively. At harvest, all lettuce crops had good market quality, regardless of mineral nutrient source. These results indicates that both good quality and sustained yield of lettuce can be obtained using Excel and Peat Lite soluble fertilizers, which are not formulated for hydroponic crop production, as well as AHN. The development of chlorosis was fastest for lettuce grown with AHN (containing the lowest N, P and Mg) compared to Excel; and no chlorosis with Peat Lite under the conditions of these experiments. These observations indicate that cos lettuce var. Cimmaron grown in NFT system can produce satisfactory yield under relatively high mean temperature conditions 27-30 oC.

Impacts
IMPACT: 2005/10 TO 2006/09 Determination of the impact of this project will continue until, and after its conclusion. However, preliminary results from this study indicates that most leaf vegetables and herb varieties can yield good market quality crops in NFT hydroponic system when grown with selected general purpose soluble fertilizer formulations. These fertilizers are commonly available in chain stores and are cheaper than special hydroponic fertilizer formulations. Reduced cost of small scale hydroponic production will enhance the adoption of the technology by limited resource growers.

Publications

• PUBLICATION: 2005/10 TO 2006/09
• Egilla, J.N.and I.Nyirakabibi. 2006. Influence of mineral nutrient source in NFT system and temperature on the yield of Cos Lettuce var. Cinnamon (Abstr. # 212). 103rd Annual Conference of the American Society for Horticultural Science. New Orleans, LA. July 27-31, 2006. HortScience 41 (4): 1083.