Progress 11/27/02 to 11/26/08
Outputs
OUTPUTS: During the life time of the project, three major topics were investigated: 1) foliar applied plant nutrition, 2) cultural practices related to greenhouse production, and 3) studies on iron nutrition and the physiology of the iron absorption mechanism. These projects resulted in the training of 17 graduate students (11 Masters and 6 PhD), 35 refereed journal articles, 58 scientific abstract presentations, 2 patent applications, 1 book, 13 popular articles, and 111 related presentations to industry clientele. PARTICIPANTS: During the life time of the project, three major topics were investigated: 1) foliar applied plant nutrition, 2) cultural practices related to greenhouse production, and 3) studies on iron nutrition and the physiology of the iron absorption mechanism. These projects resulted in the training of 17 graduate students (11 Masters and 6 PhD), 35 refereed journal articles, 58 scientific abstract presentations, 2 patent applications, 1 book, 13 popular articles, and 111 related presentations to industry clientele. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
One book (Reed. D.W.,Editor and Author. 1996. Water, Nutrition and Media for Greenhouse Crops, Ball Publishing, Batavia, IL) relay and apply the research findings to the industry. Over 100 invited industry presentations to inform the industry of how to incorporate the research findings into practice. Training of 17 graduate students.
Publications
- Valdez-Aguilar, L. and D.W. Reed. 2008. Influence of Potassium Substitution by Rubidium and Sodium on Growth, Ion Accumulation, and Ion Partitioning in Bean (Phaseolus vulgaris L.) under High Alkalinity, J. Plant Nutrition (accepted)
- Valdez-Aguilar, L., J. Cornell and D.W. Reed. 2008. Quantitative Separation of the Bicarbonate from the Counter-cation Effect in Bean Plants. J. Amer. Soc. Hort. Sci. (accepted).
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Finalized refereed publication from Ph.D. student's dissertation and presented abstract on recycled water from M.S. student's research. Initiated new research project of testing caotyred/recycled water in wholesale nursery production facilities. Collected captured/recycled water sample from across the State of Texas. Used the waters in a hydroponic growing study utilizing a variety of ornamental crops. The Objective was to identify beneficial (due to increased nutrient content) or detrimental (due to salinity and toxic chemicals present) effects. Preliminary results indicate no beneficial effects from accumulated fertilizer run-off, such as N. Also, no glaring detrimental effects. Data analysis is still in progress.
PARTICIPANTS: Matt kent, Senior Research Associate
TARGET AUDIENCES: Scientific community. Texas producers.
Impacts
Capturing and recycling run-off irrigation water is becoming a necessity. There is little research on the positive and negative effects of using captured/recycled water, and how it should be managed. The results of the study will supply information for management of captured/recycled water.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
Finalized research and several publications on the effect of alkalinity of irrigation water on ornamental plants. Separated the cation from the bicarbonate effect. Continued studies on using mixture experiemtns to determine the toxicity limits of anionic and cationic soluble salts in irrigation water. Idetnified optimum P nutrition in peat moss based growing medium for ornamental crops; roughly .7-1 mM.
Impacts
Inable producers to know toxicity limits of water quality for the purpose of evaluating irrigation water, know when to take mitigating steps to counter act poor water quality, and when leaching is required. Develop recommendatio to producers for optimum phosphorous fertility.
Publications
- Valdez-Aguilar, L. and D.W. Reed. 2007. Response of selected greenhouse ornamental crops to alkalinity in irrigation water. J. Plant Nutrition 30:(in press)
- Valdez-Aguilar, L. and D.W. Reed. 2006. Comparison of growth and alkalinity-induced responses in two cultivars of hibiscus (Hibiscus rosa-sinensis L.). HortScience 41(7): 1704-1708
- Andrew Cartmill and David Wm. Reed. 2007. Effect of Phosphorus Concentration on Catharanthus roseus (L.) G. Don cv. Pacifica Red in a Recirculating and Top Watering System. 2007 Southern Region ASHS Annual Meetings.
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Progress 01/01/05 to 12/31/05
Outputs
Major focus was on greenhouse production systems for containerized plants that minimize water use and runoff. Three areas of activity were: 1) publish research from Dr. Valdez (PhD graduate) on alkalinity in irrigation water. Publish studies will identify toxic levels of Na bicarbonate in several species and separate the toxic effects of Na from bicarbonate in Na bicarbonate: 2) begin PhD work of another PhD student on phosphorus nutrition of greenhouse crops. First study identified the optimum level of P in subirrigation vs. top watering. Generally, a bit less that 1 mM was optimum. 3) finalize data and prepare publication of toxic levels of anions using mixture experiments in subirrigation vs topwatering. Toxicity of cations was ranked: bicarbonate > chloride > sulfate.
Impacts
1) We have identified the toxic levels of Na bicarbonate in several ornamental greenhouse crops, and have separated the toxic effects of Na from that of bicarbonate. 2) We have identified the toxic levels of several anions and determined their rank of toxicity of bicarbonate > chloride > sulfate. 3) We are furthering research of the optimum level of P in ornamental crops.
Publications
- Witcher, C. and D.W. Reed. 2005. Phosphorus concentration affects New Guinea impatiens and vinca in recirculating subirrigation. HortScience 40(7):2047-2051
- Arnold, M.A., T. Davis and D.W. Reed. 2006. A survey of horticulture graduate programs and faculty salaries at North American Universities, HortTechnology
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Progress 01/01/04 to 12/31/04
Outputs
Three areas of study were undertaken over the past year: 1) A Master of Science research project, Trisha Blessington, was concluded and published. The study concluded that K fertilizer concentration supplied can be reduced by nearly half and yield adequate growth compared to that traditionally recommended for top-watered plants. In addition, the K is more efficiently used in subirrigation and no K is lost to the environment that could end up in groundwater.. 2) A Ph.D. research project was concluded that identified the toxicity level of bicarbonate in irrigation water. The toxicity limit for a variety of ornamental crops ranged from 2.1 to 5.9 mM sodium bicarbonate. Using mixture experiments, it was determined that the toxicity to sodium bicarbonate at moderate concentrations was equally due to sodium and bicarbonate, which at high concentrations sodium was more toxic than bicarbonate 3) Intensive studies are beginning on using mixture experiments to determine
toxicity limits to irrigation salts in recycled subirrigation versus top watering.
Impacts
1) Determine the optimum soluble K fertility level in subirrigation versus top watering to allow minimum use of fertilizer inputs, 2) To better evaluate the usefullness of irrigation waters, a) identify the toxicity levels of sodium bicarbonate, and b) expand the studies to identify the toxicity level of other salt in irrigation water
Publications
- Blessington Haley, T. and D.W. Reed. 2004. Optimum potassium concentrations in recirculating subirrigation for selected greenhouse crops. HortScience 39(6):1441-1444.
- Richards, D.L. and D.W. Reed. 2004. New Guinea impatiens growth response and nutrient release from controlled release fertilizer in a recirculating subirrigation and top-watering system. HortScience 39(2):280-286
- Valdez-Aguilar, L. 2004. Effect of alkalinity in irrigation water on selected greenhouse crops. Ph.D dissertation, Texas A&M University.
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Progress 01/01/03 to 12/31/03
Outputs
The research focused on two areas: 1) The use of mixture experiments to identify the toxic level of salt in irrigation water. In general, the ranking of the toxicity of anionic salts were chloride > bicarbonate > sulfate; the results with cationic salts are still being analyzed. 2) Identification of the optimum level of nutrients in minimial leach systems. Experiments were finalized with K that identified the optimum level to be approximately 100-150 mg/l constant feed. Preliminary results with P identified the optimum level to be approximately 70 mg/l.
Impacts
1) more effectively evaluate irrigation waters for use in ornamental crop production, and 2) recommend the optimum level of nutrition in ornamental crop production where water recycling is employed.
Publications
- Blessington, T. and D.W. Reed. accepted 2003. Optimum potassium concentrations in recirculating subirrigation for selected greenhouse crops. HortScience (accepted Nov. 2003)
- Richards, D. and D.W. Reed. accepted 2003, in press. New Guinea impatiens growth response and nutrient release from controlled-release fertilizer in a recirculating subirrigation and top watering system. HortScience (accepted Aug 2003, in press)
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Progress 01/01/02 to 12/31/02
Outputs
The research over the past year has emphasized the effect of water quality on growth of ornamental greenhouse crops. We have identified the alkalinity toxicity limits of several crops, which ranged from 2-5 mM. We have identified the relative toxicity of several anions, and in general the ranking was chloride>bicarbonate>sulfate. Another project is detemining the optimum nutrition level of phosphorus in subirrigation , and tentatively it appears to be about 1 mM. We finished a similar project on K nutrition, and identified the optimum level at approximately 1/2 the level of of a typical constant liquid fertilizer program.
Impacts
Help evaluate water quality and develop preventative measures.
Publications
- No publications reported this period
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Progress 01/01/01 to 12/31/01
Outputs
Research over the past year centered on nutrition, water quality and salinity related to the production of greenhouse crops. 1) A project was completed that addressed optimum K nutrition in recirculating subirrigation. The optimum k range varied from about 50 to 150 mg/l K, depending on the species. Crops such as New Guinea Impatiens were at the low end and petunia at the upper end. All of the concentrations are less than half the level normally used in conventional irrigation systems. K balance studies indicated that subirrigation was much more efficient in K use than top watering. 2)Effect of water alkalinity on greenhouse crops is still in progress. Hibiscus, miniature roses, sunflower, vinca and petunia tolerated alkalinity limits higher that expected, some up to approx. 500 mg/l sodium bicarbonate. Studies are in progess using mixtured experiments to separate the bicarbonate effect from the cation effect. 3)Growth response to salinity of irrigation water. A
series of mixture experiments were conducted to separate the cation and anion effects. Tentative studies rank the salinity toxicity of cations sodium >magnesium>calcium, and bicarbonate>chloride>sulfate.
Impacts
The primary objective is to better evaluate water quality for use in horticultural crop production.
Publications
- Blessington, T. 2002. Potassium nutrition of New Guinea Impatiens in subirrigation. M.S. Thesis, Texas A&M University, College Station, TX.
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Progress 01/01/00 to 12/31/00
Outputs
Research over the past year centered on nutrition, water quality and salinity related to the production of greenhouse crops. 1) Optimum K nutrition in recirculating subirrigation. Four species of greenhouse flower crops were grown in subirrigation at various levels of potassium. The optimum range varied from about 50 to 150 mg/l K. Crops such as New Guinea Impatiens were at the low end and petunia at the upper end. All of the concentrations are less than half the level normally used in conventional irrigation systems. 2)Effect of water alkalinity on greenhouse crops. Several species of greenhouse crops were screened for alkalinity tolerance limits. Hibiscus and miniature roses were more sensitive than sunflower, vinca and petunia. All species tolerated alkalinity limits higher that expected, some up to approx. 500 mg/l sodium bicarbonate. These studies are being repeated. 3)Growth response to salinity of irrigation water. A series of mixture experiments are being used
to determine the upper salinity limits of irrigation water salts. A response surface of cation and anion salts are being tested. One preliminary study has been conducted, but the data has not yet been fully analyzed.
Impacts
Overall, we are attempting to determine limits of water quality that our growers can use to determine the suitability of irrigation water and whether or not water treatment, container leaching, etc. will be needed.
Publications
- Richards, D.L. and D.W. Reed. 2001. New Guinea impatiens growth response and nutrient release from controlled release fertilizer in a recirculating subirrigation system. J. Amer. Soc. Hort. Sci. in review.
- Blessington-Haley, T. and D.W. Reed. 2001. Identification of optimum potassium nutrition in greenhouse plants grown in subirrigation. 61th Annual Meeting of the Southern Region Meeting of the American Society for Horticultural Sciences, Fort Worth, TX
- Valdez-Aguilar, L.A. and D.W. Reed. 2001. Effect of bicarbonate irrigation water on selected greenhouse crops. 61th Annual Meeting of the Southern Region Meeting of the American Society for Horticultural Sciences, Fort Worth, TX
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Progress 01/01/99 to 12/31/99
Outputs
Research focused on greenhouse production of ornamental crops using controlled-release fertilizers in recycled subirrigation. Studies were finalized that identified the optimum controlled-release complete fertilizer rate and placement for subirrigation. Optimum rates were identified to be 1.25x to 1.75x the label recommended rate. The best placement was incorporation into the growing medium, but dibble and bottom dress were also acceptable. The release rate in subirrigation was similar to the release rate in top watering. Soluble salt build-up was only a problem above 2x the label rate.
Impacts
Allow recommendations to be made for use of controlled-release fertilizers in recirculated subirrigation.
Publications
- Richards, D. 1999. The growth of New Guinea impatiens with controlled-release fertilizer in a recirculating subirrigation system. Masters Thesis, Texas A&M Universtiy.
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Progress 01/01/98 to 12/31/98
Outputs
Researh concentrated in 2 areas. 1) Subirrigation of greenhouse crops. Studies were conducted using controlled-release fertilizers in ebb&flow. For most crops the 1x label rate was optimum, which is different from soluble fertilizer programs were previous studies showed that the rate must be cut in half. Studies are underway to determine the release rates in subirrigation. Studies were conducted using 24 waters of different qualities. Correlations are being made between growth and chemical parameters. As of yet, no one chemical parameter of water quality is correlated with the growth observed. The research is still in progress. 2)Develop hydroponic techniques to grow Camptotheca, which produces the anti-cancer compound camptothecin. Procedures were refined that allowed excellent growth in both aerated culture and a subirriation nutrient-flow technique.
Impacts
(N/A)
Publications
- Richards, D. and D.W. Reed. 1998. The growth of New Guinea impatiens with controlled-release fertilizer in a recurculating subirrigation system. HortScience 33:556 Abstract.
- Todd, N. and D.W. Reed. 1998. Characterizing salinity limits of New Guinea impatiens in recirculating subirrigation. J. Amer. Soc. Hort. Sci. 123(1):156-160.
- Nolte, B., L. Griffing, D.W. Reed, D. Lineberger, and M. Rumpho. 1998. Production and subcellular localization of the anticancer alkaloid camptothecin. Amer. Soc. Plant Physiol. Annual Meeting, Abstract.
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Progress 01/01/97 to 12/31/97
Outputs
The focus of our research was on water quality and fertility of ornamental crops in recirculating ebb-and-flow subirrigation. The research focused on two areas. 1) Identifying the optimum nitrogen nutrition of a typical flowering pot plant, New Guinea impatiens, and foliage plant, spathiphyllum. Optimum nutrition was identified to be in the range of 100 mg/l N, which is about one-half the recommended rate for traditional productions systems. Higher levels were damaging due to salinity build-up in the growing medium. The salts were found to accumulate in the top one-third of the growing medium in the container. Roots were found to proliferate in the lower two-thirds where the salinity level was acceptable. 2) Effect of irrigation water salinity. New Guinea impatiens were grown under conditions of increasing salinity stress from a mixture of calcium chloride and sodium chloride. Little effect was noticed for the first half of the prouduction cycle, after which salts
began to build-up in the growing medium and adversely effect grown. Again, salts built-up in the upper one-third of the growing medium. The effect on growth was proportional to the increase in salinity stress. About 100 to 150 mg/l salinity was tolerable without a significant impact on plant growth or quality.
Impacts
(N/A)
Publications
- Kent, M.W. and D.W. Reed. 1997. Nitrogen nutrition of four foliage plant species with recirculating subirrigation. In preparation.
- Todd, N. and D.W. Reed. 1998. Characterizing salinity limits of new Guinea impatiens in recirculating subirrigation. J. Amer. Soc. Hort. Sci. 123(1):156-160.
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Progress 01/01/96 to 12/30/96
Outputs
Major focus was on greenhouse production systems for containerized plants that minimize water use and runoff. Three major studies were completed using New Guinea impatiens in a recirculated subirrigation system.. First, the optimum N nutrition was identified to be 112 to 140 mg/l N. This allowed maximum growth with no salinity damage. Second, the maximum salinity tolerance was determined to artificial salt (calcium and sodium chloride). The maximum tolerable salinity without significant salinity damaged was 600 mg/l total calcium and sodium concentration (1:2 ratio). Third, actual irrigation waters of varying salinity were tested. There was poor correlation between total salinity and plant response. Response was more salt specific. Waters with high harmful salts (sodium, chloride) were more damaging than waters with high less harmful salts (calcium, magnesium, sulfate), regardless of total electrical conductivity. In all studies, salts accumulated to high levels in
the upper layer of the growing medium, and this was not always harmful. It was only when growing medium electrical conductivity in the middle and bottom layers of the container exceeded recommended levels (approximately 1.2 to 1.5 dS/M) that salinity damage was observed.
Impacts
(N/A)
Publications
- Kent, M.W. and D.W. Reed. 1996. Nitrogen nutrition of New Guinea impatiens 'Barbados' and Spathiphyllum 'Petite' in a subirrigation system. J. Amer. Soc. Hort. Sci. 121(5):816-819.
- Todd, N.M. and D.W. Reed. 1996. The response of New Guinea impatiens to varying salinity levels in a subirrigation system. J. Amer. Soc. Hort. Sci. (in preparation).
- Armstrong, T., M.W. Kent and D.W. Reed. 1996. Response of New Guinea impatiens to various water qualities in a subirrigation system. HortScience 31(4):701 (abst.).
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