Articles
DISINFECTION OF RECYCLING WATER IN ROSE CULTURES
Article number
547_15
Pages
121 – 127
Language
Abstract
New laws concerning water savings and polluting throwing limitation compel rose producers to find solutions to reduce effluents especially in soilless cultures.
Recycling drainage water not only answers to these environment imperatives but also permit to reduce fertiliser’s costs and to maintain production quality.
However this technique imposes an efficient mineral management and an assessment of microbiological contamination.
Actually, recycling water is an excellent way for pathogens dissemination.
Concentrations of 106 bacteria per ml are commonly observed in drainage water of plant cultures.
To avoid potential risks for plant health, the disinfection of irrigation water is an alternative.
Indeed, techniques like the thermodisinfection were shown to be effective but request substantial investments.
The characteristics of the floricultural farms of the south of France (size, capacity of investment…) directed our laboratory towards the search for a methodology effective but less expensive.
Analogous to drinking water disinfection, experimentation using chlorine was performed.
Feasibility studies were carried out in the laboratory to evaluate the sensitivity of Agrobacterium tumefaciens that is likely to be disseminated in recycled water.
These studies demonstrated that an amount of 4 mg/l of active chlorine applied over 30 minutes was necessary and sufficient to obtain disinfection of bacteria.
After these tests, active chlorine disinfection was applied to rose cultures in order to test chlorine phytotoxicity and to observe chlorides concentration.
No significant differences in the production yields were found and systems using chlorine gas were set up in rose farms.
No plant health problem was detected after 3 years of operation.
Thus, disinfecting with chlorine gas is an excellent preventive method.
Recycling drainage water not only answers to these environment imperatives but also permit to reduce fertiliser’s costs and to maintain production quality.
However this technique imposes an efficient mineral management and an assessment of microbiological contamination.
Actually, recycling water is an excellent way for pathogens dissemination.
Concentrations of 106 bacteria per ml are commonly observed in drainage water of plant cultures.
To avoid potential risks for plant health, the disinfection of irrigation water is an alternative.
Indeed, techniques like the thermodisinfection were shown to be effective but request substantial investments.
The characteristics of the floricultural farms of the south of France (size, capacity of investment…) directed our laboratory towards the search for a methodology effective but less expensive.
Analogous to drinking water disinfection, experimentation using chlorine was performed.
Feasibility studies were carried out in the laboratory to evaluate the sensitivity of Agrobacterium tumefaciens that is likely to be disseminated in recycled water.
These studies demonstrated that an amount of 4 mg/l of active chlorine applied over 30 minutes was necessary and sufficient to obtain disinfection of bacteria.
After these tests, active chlorine disinfection was applied to rose cultures in order to test chlorine phytotoxicity and to observe chlorides concentration.
No significant differences in the production yields were found and systems using chlorine gas were set up in rose farms.
No plant health problem was detected after 3 years of operation.
Thus, disinfecting with chlorine gas is an excellent preventive method.
Authors
C. Poncet, M. Offroy, G. Bonnet, R. Brun
Keywords
recycling, irrigation water, disinfection systems, chlorine
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