Links to technology articles and websites
Below, you'll find links to articles about water treatment technologies.
Please note that some links require subscription to access content.
Technology overviews
- Plant pathogens in irrigation water: Challenges and opportunities
- Review of literature on plant pathogens, provides information on detecting pathogens in water, and reviews treatment options (including prevention). Abstract available on the journal website, subscription or purchase required to view full article.
- Hong, C.X. and G.W. Moorman (Virginia Polytechnic Institute and State University)
- Critical Reviews in Plant Science Volume 24 Issue 3: 189-208
- Food Safety and Produce Operations: What Is the Future?
- This article discusses water quality and other factors to consider in developing hazard analysis critical control point programs for the food processing industry. Also reviews some technologies available for treating water. The first page of the article is posted here; to find the complete article, please conduct a web search of the Journal title.
- EPA review of disinfectants and oxidants other than chlorine
- A comprehensive description of technologies such as ozone and chlorine dioxide, with a drinking water/human pathogen focus.
- US Environmental Protection Agency
- Check list for choosing water treatment options
- Review of factors to consider when deciding on which treat system would be appropriate for your situation.
- Fisher, P.R. and R. Wick (Water Education Alliance for Horticulture)
- GMPro, Mar 2009: 16-20
- Overview of Water Treatment Technologies
- The first article in our series on water treatment for pathogens and algae. Helpful summary tables describing pros and cons of available treatment options.
- Fisher, P.R., William Argo, Ratus Fischer, Peter Konjoian, Rob Larose, Alan Miller, Gary Miller, Robert Wick and Rick Yates (Water Education Alliance for Horticulture)
- GMPro, March 2008:19,21-24.
- Back to the basics, Part 1
- This series of articles explains the basic chemistry of water, and the technologies used to treat water so the purchaser can make an educated attempt to find the right solution for a particular application. The first article explains that water from different sources will be of different qualities.
- Roseman, J. (Aqua Ion Plus+ Technologies)
- Water Quality Products Volume 7 Issue 5: 22-24
- Cleaning and disinfecting the greenhouse
- Overview of the importance of greenhouse sanitation, discussion of techniques and products available.
- Smith, T. (University of Massachusetts)
- University of Massachusetts Extension
- How critical is greenhouse water treatment?
- Increasingly, growers are collecting runoff for irrigation water. This article highlights the importance of filtering and disinfesting recycled water.
- Merril, L. and P. Konjoian (Selective Micro Technologies LLC)
- Merrill&KonjoianJune2006(GHwatertrtmt).pdf
- GMPro June 2006: 88-91
- Are your plants drinking dirty water?
- When it comes to keeping plants healthy, clean water may be your secret weapon. This article helps growers decide whether they need to treat their water, and describes several treatment options.
- Powell, C.C. (Plant Health Advisory Services, Columbus, Ohio)
- Grower Talks
- Disinfestation of recirculating nutrient solutions in greenhouse horticulture
- This review discusses and compares five broadly different methods of disease control: heat, filtration, chemical, radiation, and biological control. Reprinted with permission from Agronomie. Copyright 2001 by EDP Sciences.
- Ehret, D.L., B. Alsanius, W. Wohanka, J.G. Menzies, and R. Utkhede (Agriculture and Agri-Food Canada)
- Ehretetal2003Agronimie(disinfestation_recirc).pdf
- Agronomie Volume 21: 323-339
- Treatment of greenhouse recirculation water with bio-sand filtration
- Compares costs and efficiency of some treatment options, and provides in depth discussion of bio-sand filtration set-up, flow rates, and maintenance.
- British Columbia Ministry of Agriculture, Food, and Fisheries
- Order No. 512.000-2
- A review of possibilities for disinfection of recirculation water from soilless cultures
- Provides some recommendations for the use of heat, UV, ozone, filtration (membrane and sand), iodine, and hydrogen peroxide.
- Runia, W. Th. (Glasshouse Crops Research Station, The Netherlands)
- Runia1995ActaHort(review_possibilities_disinfection).pdf
- Acta Horticulturae Volume 382: 221-228
- Water quality: Is it an issue?
- Results of a grower survey on water treatment- level of concern, testing conducted, and types of treatments used.
- Burns, C. (GPN)
- Greenhouse Product News October 2004: 74-75
- Current research into water disinfestation for the nursery and cut flower industries
- Reviews a broad range of water treatment technologies, from chlorination to UV and ozone. Discusses some bromination techniques.
- Mebalds, M., D. Beardsell, A. van der Linden, and M. Bankier (Institute for Horticultural Development, Knoxfield, AU)
- Mebaldsetal.1996CombProc(current_research).pdf
- Combined Proceedings International Plant Propagators' Society Volume 46: 89-92
Calcium hypochlorite (solid)
- Grower 101: Get cultured- how to adjust irrigation water pH
- Chlorine treatment of nursery irrigation systems is probably one of the most popular methods of pathogen control. This article discusses the advantages, disadvantages, and different types of chlorine treatment.
- Merhaut, D.J. (University of California, Riverside)
- GPN Volume 15 Issue 4: 40
- Sodium and calcium hypochlorite technologies
- Specific examples of chlorination systems using liquid sodium hypochlorite or solid calcium hypochlorite, from our series on water treatment for pathogens and algae.
- Fisher, P.R., J. Huang, A. Looper, D. Minsk, W.R. Argo, R. Vetanovetz, and Y. Zheng (Water Education Alliance for Horticulture)
- GMPro, July 2008: 15-22
- Sodium and calcium hypochlorite principles
- Chemistry, pH effects, ORP, and mode of action of sodium and calcium hypochlorite from our series on water treatment for pathogens and algae.
- Fisher, P.R., W.R. Argo, C. Hong, J. Huang, A. Looper, D. Wiegers, R. Vetanovetz, and Y. Zheng (Water Education Alliance for Horticulture)
- GMPro, June 2008:21-25
- Characterization and control of Pythium pathogens in recycled irrigation water
- This article discusses the efficacy of current Phytophthora chlorination controls for Pythium control.
- Kong, P., P.A. Richardson, and C. Hong (Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University)
- KongetalApril2004(Pythiumreport).pdf
- Research Report F-2004-2, Floriculture Industry Research and Scholarship Trust
- Chlorination and post harvest disease control
- Written from a post-harvest perspective, this article explains the chemical action of different forms of chlorine, and factors that influence the activity of chlorine (e.g. pH). The first page of the article is posted here; to find the complete article, please conduct a web search of the Journal title.
- Boyette, M.D., D.F. Ritchie, S.J. Carballo, S.M. Blankenship, and D.C. Sanders (North Carolina State University)
- BoyetteetalHortTech(chlorination).pdf
- HortTechnology Volume 3 Issue 4: 395-400
- Treating irrigation systems with chlorine
- Chlorine is increasingly being used for cleaning and maintaining irrigation systems. This article provides information on sources of chlorine and the amounts required for treating irrigation water and systems to control pathogen growth.
- Clark, G.A. and A.G. Smajstrla (University of Florida)
- Edis
Sodium hypochlorite (liquid bleach)
- Dose curves of disinfestants applied to plant production surfaces to control Botrytis cinerea
- Sanitation is a proven component of limiting the spread of pathogens. In this study, lethal dose curves are calculated for six disinfectants (including hydrogen dioxide, quaternary ammonium compounds, and sodium hypochlorite) applied to seven different surfaces contaminated with Botrytis.
- Copes, W.E (USDA Small Fruit Experiment Station)
- Plant Disease Volume 88 Issue 5: 509-515
- Surface sanitation: efficacy of disinfestants applied to plant production surfaces
- Comparison of efficacy of several chemicals including bleach, activated peroxygen (ZeroTol), quaternary ammonium chloride (Greenshield), and other products for control of Botrytis cinerea spores on different surfaces, and emphasizes that a high rate is required on porous production surfaces such as wood.
- W. E. Copes (USDA-ARS)
- 2003 SNA Research Meeting Proceedings Vole 48:212-214
- Efficacy of chlorine on multiple species of Phytophthora in recycled nursery irrigation water
- Reviews advantages and disadvantages of various water treatment technologies for Phytophthora control, develops guidelines for chlorination using sodium hypochlorite.
- Hong, C.X., P.A. Richardson, P. Kong and E.A. Bush (Virginia Polytechnic Institute and State University)
- Plant Disease Volume 87 Issue 10: 1183-1189
- Disinfect with sodium hypochlorite
- Like all other water treatments, sodium hypochlorite poses some safety risks. This article offers guidelines and protocols for the safe handling, storage, and use of sodium hypochlorite.
- Callery, A.G. (Portacel, Inc.)
- CEP Magazine Volume 99 Issue 3: 42-46
- Effect of pH on the efficacy of sodium hypochlorite solution as cleaning and bactericidal agents
- Reports how pH affects sodium hypochlorite's use as a bactericide and a cleaning agent. Sodium hypochlorite is better at removing biofilm at higher pH, but once the bacteria is free from the biofilm, it is more effectively killed at lower pH.
- Fukuzaki, S., H. Urano, and S. Yamada (Industrial Technology Center of Okayama Prefecture)
- Journal of The Surface Finishing Society of Japan Volume 58 Issue 8: 465-469
- Heat treatments control extension growth and enhance microbial disinfection of minimally processed green onions
- Study shows that heat treatment in combination with chlorination is more effective at post harvest microbial disinfection than either treatment alone. Abstract available, subscription or purchase required to view full article.
- Cantwell, M.I., G. Hong, and T.V. Suslow (University of California, Davis)
- HortScience Volume 36 Issue 4: 732-737
- Treating irrigation systems with chlorine
- Chlorine is increasingly being used for cleaning and maintaining irrigation systems. This article provides information on sources of chlorine and the amounts required for treating irrigation water and systems to control pathogen growth.
- Clark, G.A. and A.G. Smajstrla (University of Florida)
- Edis
- Hygiene in the nursery: Disinfecting production surfaces; cement, gravel, capillary mats and sand beds
- Advice and guidelines for sanitizing porous surfaces in the greenhouse. Tested efficacy of copper ionization, chlorination, and quaternary ammonium compounds against fungi, bacteria, and nematodes on several different surfaces.
- Stovold, G. (Tropical Fruit Research Station, Alstonville, AU)
- The Nursery Papers Volume 2000 Issue 5: 1-4
- Grower 101: Get cultured- how to adjust irrigation water pH
- Chlorine treatment of nursery irrigation systems is probably one of the most popular methods of pathogen control. This article discusses the advantages, disadvantages, and different types of chlorine treatment.
- Merhaut, D.J. (University of California, Riverside)
- GPN Volume 15 Issue 4: 40
- Chlorination and post harvest disease control
- Written from a post-harvest perspective, this article explains the chemical action of different forms of chlorine, and factors that influence the activity of chlorine (e.g. pH). The first page of the article is posted here; to find the complete article, please conduct a web search of the Journal title.
- Boyette, M.D., D.F. Ritchie, S.J. Carballo, S.M. Blankenship, and D.C. Sanders (North Carolina State University)
- BoyetteetalHortTech(chlorination).pdf
- HortTechnology Volume 3 Issue 4: 395-400
- Response of container-grown nursery plants to chlorine used to disinfest irrigation water
- An assessment of the effect of 2.4mg/L of free chlorine in the irrigation water on evergreen and deciduous shrubs applied with overhead irrigation.
- Cayanan, D.F., Dixon, M., Zheng, Y., and Llewellyn, J. (Controlled Environment Systems Research Facility, Department of Environmental Biology, University of Guelph)
- HortScience
- Monitoring Mortality of Pythium zoospores in chlorinated water Using oxidation reduction potential
- This research shows data that indicate that adjusting water pH prior to chlorination may result in an more efficient control of Pythium.
- Lang, J.; Rebits, B.; Newman, S.E. and Tisserat, N. (Department of Bioagricultural Sciences and Pest Management, Colorado State University)
- Plant Health Progress
- Monitoring mortality of Pythium zoospores in chlorinated water using oxidation reduction potential
- This research shows data that indicate that adjusting water pH prior to chlorination may result in an more efficient disease control treatment. Adjusting the water to pH to 6.0 prior to chlorination resulted in higher ORP values; therefore, less chlorine is required for complete disinfestation.
- Lang, J., Rebits, B., Newman, S.E. and Tisserat, N. (Department of Bioagricultural Sciences and Pest Management, Colorado State University)
- Plant Health Progress
- Characterization and control of Pythium pathogens in recycled irrigation water
- This article discusses the efficacy of current Phytophthora chlorination controls for Pythium control.
- Kong, P., P.A. Richardson, and C. Hong (Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University)
- KongetalApril2004(Pythiumreport).pdf
- Research Report F-2004-2, Floriculture Industry Research and Scholarship Trust
- Sensitivity of five container-grown nursery species to chlorine in overhead irrigation water
- The effect of different concentrations of free chlorine were evaluated in diverse woody container grown plants. The results indicate that a concentration chlorine of 2.5mg/L or less should not result in adverse effect in the plants.
- Cayanan, D.F., Zheng, Y., Zhang, P., Graham, T., Dixon, M., Chong, C., Llewellyn, J. (Controlled Environment Systems Research Facility, Department of Environmental Biology, University of Guelph)
- HortScience
- Methods to control Pythium and Phytophthora in cold plastic houses
- In this study, sodium hypochlorite and UV ares used to treat water infested with Pythium and Phytopthora. Sodium hypochlorite reduced plant mortality, but the best plant health was observed when the water was not infested with pathogens in the first place.
- Berenguer, J.J., I. Escobar, and M. Garcia (Estacion Experimental, La Nacla, Granada)
- Berengueretal2001ActaHort(Pyth&Phyt_cold_plastic_houses).pdf
- Acta Horticulturae Volume 559: 759-763
- Efficacy of chlorine for decontaminating water infested with resting spores of Plasmodiophora brassicae
- An early study in which chlorine was proved to control club root of cabbage at 2mg Cl /L when exposed for 5 minutes. Under field conditions reduction of the disease was observed at 200mg Cl/L nonetheless reduction of plant quality and stand was also observed under these conditions.
- Datnoff, L.E., Kroll, T.K. and Lacy, G.H. (Virginia Polytechnic Institute and State University)
- Plant Disease
- Pythium and recycled irrigation water
- This article reports a new technique for identifying Pythium species, and provides guidelines for chlorination to control Pythium in recycled water using sodium hypochlorite.
- Kong, P, P.A. Richardson and C. Hong (Virginia Polytechnic Institute and State University)
- GPN Volume 14 Issue 5: 32-35
- Fluctuations of Phytophthora and Pythium spp. in components of a recycling irrigation system
- A study about the presence of Phytophthora and Pythium in perennial container nursery in which water is recycled. Both pathogens were recovered through out the year; however, chlorination significantly reduced the diversity and total number.
- Effects of temperature, concentration, age, and algaecides on Phytophthora capsici zoospore infectivity
- This study evaluated the efficacy of different commercial products when interacted with different temperatures and Phytophthora capsici concentrations on cucumber infection.
- Effects of temperature, concentration, age, and algaecides on Phytophthora capsici zoospore infectivity
- This study evaluated the efficacy of different commercial products when interacted with different temperatures and Phytophthora capsici concentrations on cucumber infection.
- Sodium and calcium hypochlorite technologies
- Specific examples of chlorination systems using liquid sodium hypochlorite or solid calcium hypochlorite, from our series on water treatment for pathogens and algae.
- Fisher, P.R., J. Huang, A. Looper, D. Minsk, W.R. Argo, R. Vetanovetz, and Y. Zheng (Water Education Alliance for Horticulture)
- GMPro, July 2008: 15-22
- Sodium and calcium hypochlorite principles
- Chemistry, pH effects, ORP, and mode of action of sodium and calcium hypochlorite from our series on water treatment for pathogens and algae.
- Fisher, P.R., W.R. Argo, C. Hong, J. Huang, A. Looper, D. Wiegers, R. Vetanovetz, and Y. Zheng (Water Education Alliance for Horticulture)
- GMPro, June 2008:21-25
- Greenhouse sanitation: Efficacy of disinfectants on cutting blades using Tobacco Mosaic Virus on petunia as a model.
- Different commercial and non-commercial disinfectants were evaluated for the efficacy to prevent TMV spread with contaminated razor blades. 1:10 bleach, 20% non-fat milk, 20%non-fat dry milk plus surfactant and 1% Virkon® for 1 minute were the most effective to control TMV spread.
- Hayes, A.J. (The Ohio State University)
- Knowledge bank of The Ohio State University
- Efficacy of chlorine in controlling five common plant pathogens
- This research article illustrates how the effectiveness of water treatments, more specific chlorine, depends on the pathogen to control and the dose concentration and time.
- Cayanan,D.F., Zhang, P., Liu, W., Dixon, M., and Zheng, Y. (Controlled Environment Systems Research Facility, Department of Environmental Biology, University of Guelph)
- HortScience
Chlorine dioxide
- Activity of Chlorine Dioxide in a Solution of Ions and pH against Thielaviopsis basicola and Fusarium oxysporum
- Chlorine dioxide is chemically different from hypochlorites and chlorine gas. This article reports the results of experiments to determine how pH and dissolved inorganic ions affect the disinfecting activity of chlorine dioxide.
- Copes, W.E., G.A. Chastaganer, and R.L. Hummel (USDA Small Fruit Experiment Station)
- Plant Disease Volume 88 Issue 2: 188-194
- Biofilm Technical Bulletin
- Technical review about biofilm in the irrigation system and the use of chlorine dioxide to remove it.
- Khurana, K. (AquaPulse Systems)
- Sensitivity of Pathogens Inocula to Chlorine Dioxide Gas.
- Chlorine gas at relatively 25mg/L can be used to disinfect inert surfaces from Penicillium, Botrytis and Alternaria pathogens.
- Chastagner, G.A. and Riley, K.L. (Washington State University)
- Acta Horticulturae
- Chlorine dioxide technical bulletin
- Technical review of the properties of chlorine dioxide.
- Khurana, K. (AquaPulse Systems)
- KhuranaClO2.pdf
- Chlorine dioxide
- Chlorine dioxide discussion from our series on water treatment for pathogens and algae.
- Fisher, P.R., W.R. Argo, J. Huang, P. Konjoian, J.M. Majka, L. Marohn, A. Miller, R. Wick, and R. Yates (Water Education Alliance for Horticulture)
- GMPro, September 2008:14-17
- Toxicity responses of herbaceous and woody ornamental plants to chlorine and hydrogen dioxides
- Chlorine dioxide and hydrogen dioxide are used in greenhouses for foliar disease management but can damage treated plants. This study tested the effects of different rates of chlorine and hydrogen dioxide on several ornamental plants.
- Copes, W.E., G.A. Chastaganer, and R.L. Hummel (USDA Small Fruit Experiment Station)
- Copesetal2003(toxicity).pdf
- Plant Health Progress
- Greenhouse sanitation: Too important to ignore
- Discusses the need for and benefits of greenhouse sanitation, and reviews some options for treating recycled water. Article begins on page 2 of linked publication.
- Rettke, S.K. (Ornamental IPM Program Associate, Rutgers Cooperative Research & Extension)
- Northeast Greenhouse IPM Notes Volume 14 Issue 7: 2-5
- Using ultra violet radiation and chlorine dioxide to control fungal plant pathogens in water
- Reports UV levels and chlorine dioxide concentrations needed to control some pathogens. Comments on sensitivity of UV to dissolved solids, and of chlorine dioxide to pH.
- Mebalds, M., A. van der Linden, M. Bankier, and D. Beardsell (Institute for Horticultural Development, AU)
- The Nursery Papers Volume 1996 Issue 5: 1-2
- Have algae met their match?
- Algae control can be a major challenge for greenhouse growers. This article outlines the use of chlorine dioxide to control algae.
- Konjoian, P. (Konjoian's Floriculture Education Services)
- KonjoianApril2005(algae).pdf
- GMPro April 2005: 49-51
Chlorine gas
- Grower 101: Get cultured- how to adjust irrigation water pH
- Chlorine treatment of nursery irrigation systems is probably one of the most popular methods of pathogen control. This article discusses the advantages, disadvantages, and different types of chlorine treatment.
- Merhaut, D.J. (University of California, Riverside)
- GPN Volume 15 Issue 4: 40
- Treating irrigation systems with chlorine
- Chlorine is increasingly being used for cleaning and maintaining irrigation systems. This article provides information on sources of chlorine and the amounts required for treating irrigation water and systems to control pathogen growth.
- Clark, G.A. and A.G. Smajstrla (University of Florida)
- Edis
- Chlorination and post harvest disease control
- Written from a post-harvest perspective, this article explains the chemical action of different forms of chlorine, and factors that influence the activity of chlorine (e.g. pH). The first page of the article is posted here; to find the complete article, please conduct a web search of the Journal title.
- Boyette, M.D., D.F. Ritchie, S.J. Carballo, S.M. Blankenship, and D.C. Sanders (North Carolina State University)
- BoyetteetalHortTech(chlorination).pdf
- HortTechnology Volume 3 Issue 4: 395-400
- Gas chlorination
- Chlorine gas discussion from our series on water treatment for pathogens and algae.
- Majka, J.M., W.R. Argo, P.R. Fisher, and C. Hong (Water Education Alliance for Horticulture)
- GMPro, Aug 2008:17-19
- Sensitivity of Pathogens Inocula to Chlorine Dioxide Gas.
- Chlorine gas at relatively 25mg/L can be used to disinfect inert surfaces from Penicillium, Botrytis and Alternaria pathogens.
- Chastagner, G.A. and Riley, K.L. (Washington State University)
- Acta Horticulturae
Quaternary ammonium compounds
- Surface sanitation: efficacy of disinfestants applied to plant production surfaces
- Comparison of efficacy of several chemicals including bleach, activated peroxygen (ZeroTol), quaternary ammonium chloride (Greenshield), and other products for control of Botrytis cinerea spores on different surfaces, and emphasizes that a high rate is required on porous production surfaces such as wood.
- W. E. Copes (USDA-ARS)
- 2003 SNA Research Meeting Proceedings Vole 48:212-214
- Dose curves of disinfestants applied to plant production surfaces to control Botrytis cinerea
- Sanitation is a proven component of limiting the spread of pathogens. In this study, lethal dose curves are calculated for six disinfectants (including hydrogen dioxide, quaternary ammonium compounds, and sodium hypochlorite) applied to seven different surfaces contaminated with Botrytis.
- Copes, W.E (USDA Small Fruit Experiment Station)
- Plant Disease Volume 88 Issue 5: 509-515
- Hygiene in the nursery: Disinfecting production surfaces; cement, gravel, capillary mats and sand beds
- Advice and guidelines for sanitizing porous surfaces in the greenhouse. Tested efficacy of copper ionization, chlorination, and quaternary ammonium compounds against fungi, bacteria, and nematodes on several different surfaces.
- Stovold, G. (Tropical Fruit Research Station, Alstonville, AU)
- The Nursery Papers Volume 2000 Issue 5: 1-4
Hydrogen dioxide / Activated peroxygen
- Activated peroxygen (peracids/PAA) and hydrogen dioxide (hydrogen peroxide)
- PAA and hydrogen dioxide discussion from our series on water treatment for pathogens and algae.
- Larose, R., P.R. Fisher, E. Austen, V. Choppakatla, A. Frances, W.E. Horner, J. Huang, R. Wick, and R. Yates (Water Education Alliance for Horticulture)
- GMPro, November 2008:14-19
- Hydrogen peroxide detection with improved selectivity and sensitivity using constant current potentiometry
- Article describing technologies to measure hydrogen peroxide activity.
- Anh, D.T.V., W. Olthuis, and P. Bergveld (University of Twente, The Netherlands)
- Sensors and Actuators B Volume 91: 1-4
- Surface sanitation: efficacy of disinfestants applied to plant production surfaces
- Comparison of efficacy of several chemicals including bleach, activated peroxygen (ZeroTol), quaternary ammonium chloride (Greenshield), and other products for control of Botrytis cinerea spores on different surfaces, and emphasizes that a high rate is required on porous production surfaces such as wood.
- W. E. Copes (USDA-ARS)
- 2003 SNA Research Meeting Proceedings Vole 48:212-214
- Toxicity responses of herbaceous and woody ornamental plants to chlorine and hydrogen dioxides
- Chlorine dioxide and hydrogen dioxide are used in greenhouses for foliar disease management but can damage treated plants. This study tested the effects of different rates of chlorine and hydrogen dioxide on several ornamental plants.
- Copes, W.E., G.A. Chastaganer, and R.L. Hummel (USDA Small Fruit Experiment Station)
- Copesetal2003(toxicity).pdf
- Plant Health Progress
- The reason why chlorine-treated water and peroxyacetic acid treated water register different oxidation-reduction potential (ORP) responses
- This article explains how ORP is determined, and why operators must draw on previous experience or historical measurements when using ORP to evaluate the effectiveness of an oxidizing agent.
- Howarth, J. (Enviro Tech Chemical Services)
- HowarthEnvTech2007(ReasonWhy).pdf
- Enviro Tech fact sheet 10/30/2007
- Dose curves of disinfestants applied to plant production surfaces to control Botrytis cinerea
- Sanitation is a proven component of limiting the spread of pathogens. In this study, lethal dose curves are calculated for six disinfectants (including hydrogen dioxide, quaternary ammonium compounds, and sodium hypochlorite) applied to seven different surfaces contaminated with Botrytis.
- Copes, W.E (USDA Small Fruit Experiment Station)
- Plant Disease Volume 88 Issue 5: 509-515
- Controlling algae in irrigation ponds
- A description of the biology of algae and management strategies.
- Camberato, D.M. and Lopez, R.G. (Purdue University)
- Purdue Extension
Ozone
- Ozone
- Ozone discussion from our series on water treatment for pathogens and algae.
- Hayes, C., L. Evans, P. Fisher, A. Frances, R. Vetanovetz, and Y. Zheng (Water Education Alliance for Horticulture)
- GMPro, Jan. 2009:16-20
- Pesticide removal by combined ozonation and granular activated carbon filtration
- Thesis work in which micropollutants (atrazine) is removed from water by using a combination of biological carbon filtration, ozone and granular activaded carbon.
- Orlandini, E. (Wageningen University)
- Back to the basics, Part 3
- In this last section of a three-part series, the use of ozone, copper and silver ionization, distillation and aeration is discussed.
- Roseman, J. (Aqua Ion Plus+ Technologies)
- Water Quality Products Volume 7 Issue 7: 16-19
- Reclaim greenhouse water
- The need for reclaiming water, and the need for treating reclaimed water, are discussed. The article then describes a study of the use of copper ionization and ozone to control Pythium.
- Roseman, J. (Aqua Ion Plus+ Technologies)
- Water Quality Products Volume 6 Issue 10
- Effect of ozone and storage temperature on two post harvest diseases and physiology of carrots (Daucus carota L.)
- Written from a post-harvest perspective. This article reports the results of an experiment testing the effects of ozone and storage temperature on two fungal species, including the relationship between temperature and residual ozone. Abstract available, subscription or purchase required to view full article.
- Liew, C.L. and R.K. Prange (Agriculture and Agri-Food Canada)
- Journal of the American Society for Horticultural Science 119 (3): 563-567
- Water sanitation really matters: Techniques that work
- The presentation provides data for ozone efficacy and UV efficacy, and proposes a system where the two treatments can be used together.
- Fynn, R.P. and M.D. Gurol (Pure O Tech Inc.)
- Fynn&Gurol2007(OFApresentation).pdf
- OFA Shortcourse 2007
UV
- Methods to control Pythium and Phytophthora in cold plastic houses
- In this study, sodium hypochlorite and UV ares used to treat water infested with Pythium and Phytopthora. Sodium hypochlorite reduced plant mortality, but the best plant health was observed when the water was not infested with pathogens in the first place.
- Berenguer, J.J., I. Escobar, and M. Garcia (Estacion Experimental, La Nacla, Granada)
- Berengueretal2001ActaHort(Pyth&Phyt_cold_plastic_houses).pdf
- Acta Horticulturae Volume 559: 759-763
- Ultraviolet light
- Ultraviolet light discussion from our series on water treatment for pathogens and algae.
- Fynn, R.P., P. Fisher, A. Frances, and W.R. Argo (Water Education Alliance for Horticulture)
- GMPro, Feb. 2009:16-21
- Disinfection of Nutrient Solution in Closed Soilless Systems in Italy
- An efficacy comparison of sand filtration, UV radiation, Na dichloroisocianurate, and metalaxyl on Phytphthora cryptogea on Gerbera plants. By the end of the season, the best control was observed with metalaxyl, followed by sand filtration and U.V. radiation with a 97, 84, and 76% disease control compared to the untreated plants, respectively.
- Garibaldi, A., Minuto, A. and Salvi, D. (Di. Va.P.R.A. Plant Pathology Department)
- Acta Horticulturae
- Using ultra violet radiation and chlorine dioxide to control fungal plant pathogens in water
- Reports UV levels and chlorine dioxide concentrations needed to control some pathogens. Comments on sensitivity of UV to dissolved solids, and of chlorine dioxide to pH.
- Mebalds, M., A. van der Linden, M. Bankier, and D. Beardsell (Institute for Horticultural Development, AU)
- The Nursery Papers Volume 1996 Issue 5: 1-2
- Back to the basics, Part 2
- In the second article of a four-part series, filtration and UV treatment are discussed.
- Roseman, J. (Aqua Ion Plus+ Technologies)
- Water Quality Products 7(6): 10-12
- Water sanitation really matters: Techniques that work
- The presentation provides data for ozone efficacy and UV efficacy, and proposes a system where the two treatments can be used together.
- Fynn, R.P. and M.D. Gurol (Pure O Tech Inc.)
- Fynn&Gurol2007(OFApresentation).pdf
- OFA Shortcourse 2007
Heat pasteurization
- Disinfection of recirculation water from closed cultivation systems by heat treatment
- Study finding that heat treatment is effective at temperatures lower than the currently recommended 95 C. However, at lower temperature, longer exposure time is required.
- Runia, W.T. and J.J. Amsing (Research Station for Floriculture and Glasshouse Vegetables, The Netherlands)
- Acta Horticulturae Volume 548: 215-222
- Heat treatments control extension growth and enhance microbial disinfection of minimally processed green onions
- Study shows that heat treatment in combination with chlorination is more effective at post harvest microbial disinfection than either treatment alone. Abstract available, subscription or purchase required to view full article.
- Cantwell, M.I., G. Hong, and T.V. Suslow (University of California, Davis)
- HortScience Volume 36 Issue 4: 732-737
Copper ionization
- The effect of silver and other metal ions on the in vitro growth of root-rotting Phytophthora and other fungal species
- Tests the toxicity of a range of ions to Phytophthora, and finds that copper to be of relative high toxicity, second only to silver. Note that this article focuses primarily on silver.
- Slade, S.J. and G.F. Pegg (University of Reading, UK)
- Annals of Applied Biology Volume 122: 233-251
- Copper ionization
- Copper ionization discussion from our series on water treatment for pathogens and algae.
- Fischer, R., P. Fisher, and A. Frances (Water Education Alliance for Horticulture)
- GMPro, Dec. 2008:18-21
- Back to the basics, Part 3
- In this last section of a three-part series, the use of ozone, copper and silver ionization, distillation and aeration is discussed.
- Roseman, J. (Aqua Ion Plus+ Technologies)
- Water Quality Products Volume 7 Issue 7: 16-19
- Response to copper toxicity for three ornamental crops in solution culture
- Tests to determine level where phytotoxic responses to copper become apparent in three ornamental crops.
- Zheng, Y., L. Wang, and M. Dixon (University of Guelph, Canada)
- HortScience Volume 39 Issue 5: 1116-1120
- Greenhouse pepper growth and yield response to copper application
- Tests for phytotoxic responses to copper in young and old hydroponically grown pepper plants.
- Zheng, Y., L. Wang, and M. Dixon (University of Guelph, Canada)
- HortScience Volume 40 Issue 7: 2132-2134
- Reclaim greenhouse water
- The need for reclaiming water, and the need for treating reclaimed water, are discussed. The article then describes a study of the use of copper ionization and ozone to control Pythium.
- Roseman, J. (Aqua Ion Plus+ Technologies)
- Water Quality Products Volume 6 Issue 10
- Hygiene in the nursery: Disinfecting production surfaces; cement, gravel, capillary mats and sand beds
- Advice and guidelines for sanitizing porous surfaces in the greenhouse. Tested efficacy of copper ionization, chlorination, and quaternary ammonium compounds against fungi, bacteria, and nematodes on several different surfaces.
- Stovold, G. (Tropical Fruit Research Station, Alstonville, AU)
- The Nursery Papers Volume 2000 Issue 5: 1-4
- Sensitivity to copper and phosphite of Phytophtora species associated with ink diseases of chestnut
- Reports an experiment to determine the toxicity of copper ions to Phytopthora in chestnut. Inhibition of Phytophthora growth increased with increasing copper concentrations.
- Chelho, V., S. Coutinho, and M.E. Gouveia (Instituto Politecnico de Braganca, Portugal)
- Acta Horticulturae Volume 693: 641-643
Filtration
- Recycling water, nutrients, and waste in the nursery industry
- Irrigation water recycling provides an answer to concerns about our environment and resources. This excerpt from a speech explains how simple and sophisticated filtration systems clean water for re-use.
- Skimina, C.A. (Monrovia Nursery Company)
- Skimina1992(waternutrients&waste).pdf
- HortScience Volume 27 Issue 9: 968
- Vibratory screener solves water-recycling problem
- This article relays the experience of one grower who solved a water quality problem through the installation of a vibratory screener filter. System specs and advantages are discussed.
- Alamzad, H. (Kason Corp.)
- GPN Volume 17 Issue 4: 46-48
- Water Filtration Overview
- Overview of filtration options, including a useful summary table of filter types and uses.
- Konjoian, P., R. Fischer, P.R. Fisher, and W.R. Argo (Water Education Alliance for Horticulture)
- GMPro, May 2008: 17-21
- Grower 101: Reverse osmosis- the pros and cons
- This article discusses the advantages and disadvantages of treating water through reverse osmosis, and explains the difference between electrical conductivity and total dissolved solids.
- Jeff Roseman (Aqua Ion Plus+ Technologies)
- Greenhouse Product News June 2003 Volume: 13 Number: 6
- How critical is greenhouse water treatment?
- Increasingly, growers are collecting runoff for irrigation water. This article highlights the importance of filtering and disinfesting recycled water.
- Merril, L. and P. Konjoian (Selective Micro Technologies LLC)
- Merrill&KonjoianJune2006(GHwatertrtmt).pdf
- GMPro June 2006: 88-91
- Treatment of greenhouse recirculation water with bio-sand filtration
- Compares costs and efficiency of some treatment options, and provides in depth discussion of bio-sand filtration set-up, flow rates, and maintenance.
- British Columbia Ministry of Agriculture, Food, and Fisheries
- Order No. 512.000-2
- Back to the basics, Part 2
- In the second article of a four-part series, filtration and UV treatment are discussed.
- Roseman, J. (Aqua Ion Plus+ Technologies)
- Water Quality Products 7(6): 10-12
- Avoid irrigation system design flaws
- This article lists common irrigation system design flaws that can lead to problems with algae and pathogen contamination.
- Merril, L. and P. Konjoian (Selective Micro Technologies LLC)
- Merrill&KonjoianSept2006(irridesign).pdf
- GMPro September 2006: 66-69
- Is your water filtration system doing an adequate job?
- One of the most common flaws encountered in growing operations is inadequate water filtration. This article explains how filtration works, and offers guidance on choosing a filter mesh size.
- Konjoian, P. and L. Merrill (Konjoian's Floriculture Education Services)
- Konjoian&MerrillApril2007(filtration).pdf
- GMPro April 2007: 50-52
- Removing contaminants from recycled water
- Growers who recycle water must employ the appropriate technologies to avoid also recycling steadily higher concentrations of salts, metals, organic solids, and other contaminants that can harm both crops and equipment.
- Kovach, J. (Nexus Greenhouse Systems)
- GPN
Other treatment technologies
- Some problems in water recycling
- Recounts the experience of an Australian nursery owner who installed a recycling system and had to solve algae problems encountered along the way. He finds success by treating his pond with aerators and concentrated microbes.
- Leach, S.
- Combined Proceedings International Plant Propagators' Society Volume 55: 128-131
- Controlling algae in irrigation ponds
- A description of algae growth and development and the factor that prompt its formation. The authors described physical, chemical and biological management strategies to control algae.
- Camberato, D.M. and Lopez, R.G. (Purdue University Cooperative Extension Service)
- Controlling algae in irrigation ponds
- A description of the factors affecting the growth and development of algae; in addition, physical, chemical and biological management strategies.
- Camberato, D.M. and Lopez, R.G. (Purdue University Cooperative Extension Service)
- Disinfection of Nutrient Solution in Closed Soilless Systems in Italy
- An efficacy comparison of sand filtration, UV radiation, Na dichloroisocianurate, and metalaxyl on Phytphthora cryptogea on Gerbera plants. By the end of the season, the best control was observed with metalaxyl, followed by sand filtration and U.V. radiation with a 97, 84, and 76% disease control compared to the untreated plants, respectively.
- Garibaldi, A., Minuto, A. and Salvi, D. (Di. Va.P.R.A. Plant Pathology Department)
- Acta Horticulturae
- Pesticide removal by combined ozonation and granular activated carbon filtration
- Thesis work in which micropollutants (atrazine) is removed from water by using a combination of biological carbon filtration, ozone and granular activaded carbon.
- Orlandini, E. (Wageningen University)
- Back to the basics, Part 3
- In this last section of a three-part series, the use of ozone, copper and silver ionization, distillation and aeration is discussed.
- Roseman, J. (Aqua Ion Plus+ Technologies)
- Water Quality Products Volume 7 Issue 7: 16-19
- Effects of storage conditions on chemical and physical properties of electrolyzed oxidizing water
- This article report the longevity of electrolyzed oxidizing water under different storage conditions. Parameters measured include pH, ORP, electrical conductivity, and others. Abstract available, subscription or purchase required to view full article.
- Hsu, S.-Y., and H.-Y. Kao (National Taiwan University)
- Journal of Food Engineering Volume 65 Issue 3: 465-471
- Effects of flow rate, temperature and salt concentration on chemical and physical properties of electrolyzed oxidizing water
- Electrolyzed Oxidizing Water has been used as a disinfectant in medical applications, for agricultural purposes, and in the food processing industry. This article describes its production and its sensitivity to salt concentration, temperature, and flow rate. Abstract available, subscription or purchase required to view full article.
- Hsu, S.-Y. (National Taiwan University)
- Journal of Food Engineering Volume 66 Issue 2: 171-176
- Fungicidal effectiveness of oxidizing water on postharvest brown rot of peach
- This article discusses the use of electrolyzed oxidizing water to control fruit pathogens post-harvest.
- Al-Haq, M.I., Y. Seo, S. Oshita, and Y. Kawagoe (University of Tokyo)
- HortScience Volume 36 Issue 7: 1310–1314
- Current research into water disinfestation for the nursery and cut flower industries
- Reviews a broad range of water treatment technologies, from chlorination to UV and ozone. Discusses some bromination techniques.
- Mebalds, M., D. Beardsell, A. van der Linden, and M. Bankier (Institute for Horticultural Development, Knoxfield, AU)
- Mebaldsetal.1996CombProc(current_research).pdf
- Combined Proceedings International Plant Propagators' Society Volume 46: 89-92
Combining treatment technologies
- Pesticide removal by combined ozonation and granular activated carbon filtration
- Thesis work in which micropollutants (atrazine) is removed from water by using a combination of biological carbon filtration, ozone and granular activaded carbon.
- Orlandini, E. (Wageningen University)
Phytotoxicity of treatments
- Sensitivity of five container-grown nursery species to chlorine in overhead irrigation water
- The effect of different concentrations of free chlorine were evaluated in diverse woody container grown plants. The results indicate that a concentration chlorine of 2.5mg/L or less should not result in adverse effect in the plants.
- Cayanan, D.F., Zheng, Y., Zhang, P., Graham, T., Dixon, M., Chong, C., Llewellyn, J. (Controlled Environment Systems Research Facility, Department of Environmental Biology, University of Guelph)
- HortScience
- Efficacy of chlorine for decontaminating water infested with resting spores of Plasmodiophora brassicae
- An early study in which chlorine was proved to control club root of cabbage at 2mg Cl /L when exposed for 5 minutes. Under field conditions reduction of the disease was observed at 200mg Cl/L nonetheless reduction of plant quality and stand was also observed under these conditions.
- Datnoff, L.E., Kroll, T.K. and Lacy, G.H. (Virginia Polytechnic Institute and State University)
- Plant Disease
Injectors
- Disinfect with sodium hypochlorite
- Like all other water treatments, sodium hypochlorite poses some safety risks. This article offers guidelines and protocols for the safe handling, storage, and use of sodium hypochlorite.
- Callery, A.G. (Portacel, Inc.)
- CEP Magazine Volume 99 Issue 3: 42-46
- Chemical injection methods for irrigation
- Methods of chemical injection can be classified into four major groups: centrifugal pumps, positive displacement pumps, pressure differential methods, and methods based on the venturi principle. This article discusses each group and their applications.
- Haman, D.Z., A.G. Smajstrla, and F.S. Zazueta (University of Florida)
- Edis CIR864
- Injection of chemicals into irrigation systems: Rates, volumes, and injection periods
- This article discusses the management aspects of chemigation and how chemigation influences other aspects of irrigation management. It provides calculations and examples for determining concentrations and rates.
- Clark, G.A., D.Z. Haman, and F.S. Zazueta (University of Florida)
- Edis BUL250
