Selective Micro Technologies recently had the pleasure of discussing chlorine dioxide with Dr. Peter Konjoian, an expert and leader of plant sciences and floriculture. Dr. K has lifelong experience with horticulture and agriculture, as he grew up on his family farm growing vegetables. He began his formal education at the University of New Hampshire—where he attained his B.S.—and then continued his education, achieving both his Master’s Degree and Ph.D. from The Ohio State University.
Dr. K also spent two years as a faculty member at the University of Maryland before returning to his roots and helping run his family’s greenhouse business (Konjoian’s Greenhouses) in Andover, Massachusetts. Dr.Konjoianalso spends time running his private research and consulting firm, Konjoian’s Horticulture Education Services, Inc., dedicating his time and effort into researching the use of hydroponics and LED lighting to aid the locally grown food movement.
First Encounter with ClO₂
Dr. Konjoian first encountered SMT’s pure chlorine dioxide in the 2000s when the two joined together in researching possible applications for the greenhouse and horticultural industries. When asked what they initially set out to accomplish, Dr. K provided that “80 percent of our efforts were to clear irrigation lines of organic growth and pathogens, while 20 percent was to discover the benefits of residual ClO₂ on the plants themselves.”
It was discovered that chlorine dioxide was very capable of clearing the bioslime and algae from irrigation lines while also providing plants a very healthy environment by removing pathogens that would otherwise negatively affect the plants. After this discovery, Dr. K began implementing these protocols in his own retail greenhouse.
Recently, Dr. K began to move away from growing ornamental flowers and towards growing food. This movement comes from an effort to provide a younger population with healthy, locally grown food. Naturally, Dr. K looked to chlorine dioxide once again to discover if he could duplicate his earlier successes. In order to achieve this, SMT and Dr. Konjoian have begun research in order to discover the effects on produce in hydroponic systems.
Some of the questions he is currently attempting to answer are: is a plant more sensitive to ClO₂ in a hydroponic system versus normal growing media, what is the necessary amount of ClO₂ in a hydroponic system, and in what part(s) of the irrigation system is the ClO₂ most effective?
Dr. Konjoian’s hope is that the use of chlorine dioxide in these hydroponic systems will yield the same positive outcomes he witnessed with ornamental plants, resulting in healthier, more robust produce.
The Positives and Negatives
When asked about some of the positives and negatives of working with chlorine dioxide, Dr. K explained that the compound is the best he has seen in eliminating biofilm. He told us in terms of ridding the growth, “ClO₂ is the gold standard in terms of biofilmremoval.”
He also took this opportunity to discuss some other possible methods of ridding a system of biofilm. For instance, of peracetic acid he said it is “widely used, but I would put it last on the list of efficacy. No effect on biofilms in my experience” and of UV treatment, “I’ve not met one grower that is satisfied with it as a sole source treatment option. It is expensive to install, the turbidity of water in our industry reduces its effectiveness, and it cannot remove existing biofilm.”
Although very effective against bioslime, chlorine dioxide is not without its drawbacks. Its name, for example, is one of them. Dr. K alerted us that “over the ten years I’ve been involved with chlorine dioxide, I’ve had to spend so much time explaining to fellowgrowers that this product is not chlorine.” This is a problem for him because as he explained, “direct chlorine injection is on its way out” and the nomenclature of the chemical can be very confusing as chlorine dioxide is not chlorine.