1. Testing: The kit used to read level of copper ions given in MG/L of water. 2. Layout: The experiment layout, Plants with the upturned brown pots are the ones which were wetted with the copper/silver ionised water. The trays without the brown pots were lifted away to ensure no drift of the copper/silver ions landed on these control trays. 3. Powdery: Powdery mildew infection beginning on the contril plant. 4. Myso: Mysotis plant showing ability to hold water/ion particles on their leaf surface due to tiny hais covering the leaf surface. Copper/Silver ions would gain immediate contact with any dispersed fungal spores and therefore preventing germination. 5. Electrode: Electrode housing fitted to garden hose. 6. Testing: The testing kits used to read level of copper ions given in MG/L of water glass jar without dissolved tablet. The jar with the purple hue is inserted into the testing kit where then a photometric signal passes through to give a digital reading of the level of copper ions in MG/L. Silver is considered to be 10% of this reading as the electrodes are an alloy of copper and silver.Kevin Cahill, student of horticulture at the National Botanic Gardens Glasnevin reports on research he undertook to investigate the impact of wetting foliage with copper/silver ionised water on preventing the establishment of powdery mildew.
Water containing copper and silver ions is used worldwide in swimming pools and hospital water systems to eradicate harmful diseases. In a trial lasting over seven years and involving 16 hospitals, copper/silver ionisation was proven to eradicate and suppress cases of legionella in over 95% of tested sites where other forms of treatment, such as hyperchlorination or thermal eradication both proved insu°cient in controlling these diseases. Evidence suggests that this treatment may be an untapped source for the control of fungal diseases in the horticulture industry. Charlie Hosty, a grower in Galway, began using the copper/silver ionised water in his nursery in 2013 and good control of powdery mildew was achieved, especially on plants such as Spiraea and Potentilla, which are very susceptible. Good results were also achieved on Prunus lusitanica in the protection from a bacterial disease causing shot-hole. Additionally, Charlie also noticed very little moss and liverwort growth on pots and floor liners throughout the nursery and that could be another benefit of this treatment.
In a student experiment leading to a BSc in Horticulture in the Teagasc College of Amenity Horticulture in the National Botanic Gardens, I tested if wetting foliage of Myosotis (Forget-me-not) with copper/silver ionised water would prevent the establishment of powdery mildew. I chose this subject as I found the idea of a new way to control harmful fungi without the use of chemicals very exciting and worthwhile. This project required a lot of research, both scientific and practical, and also involved meeting the company director Mike McGrath of Necon Technologies Ltd to gain a better understanding of the system. Applied knowledge was obtained by joining Mike on a trip to Galway to meet the nurseryman Charlie Hosty who had recently began using the copper/silver ionised system from Necon Ltd. It was great to see the system in an operating nursery and by the end of the visit I knew exactly which way I was going to conduct my own experiment.
The experiment itself consisted of 80 disease-free plants, 40 of which the foliage was wetted three times per week for four weeks with copper/silver ionised water (1.5mg/l Cu2+ and 0.15mg/l Ag2+) while the remaining plants received mains water only. The ionised water came from a housing containing electrodes made of copper and silver which was easily attached to a regular garden hose (see image). The experiment was conducted in one of the non-public glasshouses in the National Botanic Garden and I would like to thank all the sta¤ and technicians that helped me during the experimental period for the plants and advice as well as providing the space to conduct the trial. Everyone was very helpful and enthusiastic about the experiment. The results of the experiment showed that all plants treated with the copper/silver ionised water remained free from powdery mildew, whereas all plants receiving only mains water had varying levels of infection (on average 15 % of the leaf area). A second experiment was carried out to determine if this treatment could also eradicate powdery mildew from already infected plants. The concentration of ions for this experiment was doubled to 3mg/l Cu2+ and 0.3mg/l Ag2+. The results show that at this concentration the treatment does not eradicate the existing infection within a 4 four week period, but that infection levels remained static. In the untreated (control) plants the infection levels doubled.
This research showed that wetting plants with a low concentration of copper/silver ions in solution can prevent powdery mildew establishing, but that control of an established infection is not so easily achieved. The experiment also highlighted that this application could easily be adapted for use in the nursery stock industry as it is remarkably easy to install and can easily be combined with an existing irrigation system, as was done by Charlie in his nursery. This treatment potentially reduces labour cost, as there will be a reduced need for chemical spraying by knapsack, in addition to giving peace of mind as the automatic irrigation system takes care of everything. Although the system is in its early stages regarding horticultural use, it should be explored further and I expect articles like this will spark interest throughout the nursery stock industry.
This project was very beneficial to me as it made me research what has gone before, which then made me think of what could be done now. If I were to start this project again I would consider using a larger number and a wider variety of plants. I would also like to test varying concentrations of ionised water for their effectiveness. Some of these questions are hopefully taken on in next years’ student projects. With thanks to Necon Technologies Ltd for their assistance and supply of equipment.
One of the subjects taught at the National Botanic Gardens is nursery stock production. Within the nursery industry, growers are always looking for improvements and trying out novel ways of doing things. Students are equally keen to do this as part of their year-three projects. In this case, Necon Technologies Ltd. contacted the gardens with their product and we saw opportunities for student projects using their technology. Currently there are three students completing work on this equipment, assessing its use for controlling damping o¤, extending vase life and Kevin for the control of powdery mildew on Myosotis. Dr. Paul Fitters, Lecturer, The National Botanic Gardens, Glasnevin.
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KEVIN CAHILL has just completed a BSc in Horticulture at the National Botanic Gardens Glasnevin. He has a keen interest in all areas of horticulture and intends to further explore areas such as pitch construction and maintenance, to indoor plants and their health benefits. His immediate aim is to go on to complete an honours degree before taking a year to travel to warmer climates where he hopes his qualifications may open up work opportunities along the way. Ultimately he sees himself maintaining a large garden estate.