by Amanda Williams
How to minimize water borne disease in hydroponics
Heat and moisture in an irrigation system left untreated can create an optimal atmosphere for the development of water molds, like Pythium and Phytophthora. These molds can be brought into contact with plants through growing media, which in the case of hydroponics means through recirculating water. These molds can also be transferred from dirty plant trays and plugs or dirty greenhouse surfaces. The microflora in a hydroponics system can develop very quickly. Within 20 hours of planting infected plants, bacteria can be traced throughout a system.
Symptoms of Pythium present themselves as it eats away at the plant root and attacks the root, which results in stunted growth and plant death. Growers often refer to this mold as root rot.
Phytophthora comes in two major varieties that are known to attack floriculture crops, causing root, crown and foliar blight. Essentially, both varieties of this bacterial disease can decimate a crop very easily if using hydroponics systems without an additional filtering system.
Some systems come with screen or paper filters to filter out large-sized particles and debris, but often more is needed to combat water borne diseases effectively. For this reason, it is recommended to add or combine a number of additional filtering systems.
Grower’s Supply carries a few different filters and accessories. Granular Activated Carbon Filter Cartridges effectively reduce organic material, color, unwanted tastes and odors, including chlorine.
Dual Lite Manual Netafim Disc Filters require practically no maintenance. The multiple disc ring is manufactured from durable polypropylene components for increase chemical resistance and is designed to capture more debris than traditional screen filters.
HydroLogic Purification Systems ensure top quality water for any hydroponic, aquaponic or aeroponic operation. HydroLogic Evolution RO1000 is capable of producing 42 gallons of pure water each hour and removes at least 94 percent of all parts per million.
In combination with implementing filtering systems, disinfecting greenhouse surfaces should become habit. Using disinfectant products to clean between successive plantings will be a huge help in the battle against water borne disease. If root rot is really bad, try a fungicide flush to drench the roots of plants. Keep in mind, Pythium is just one kind of root rot. Not all fungicides will counter all varieties of root rot, so look for a fungicide that controls Pythium, Rhizoctonia and Thielaviopsis. These different varieties can be tested by a soil testing lab, in case you need to change the course of action in combating the fungus. Fungi sometimes build up a resistance to fungicides, so whenever root rot presents itself, it is wise to get it tested, see what is working to combat the strain of the fungus and correct or record experiences for next season.
When applying chemical fungicide treatments to a recirculating system, which is recommended more commonly for ornamental crops, many chemicals do not challenge pathogens without harming competing beneficial microflora. Just be conscious of what you’re using and remember, a cleaner greenhouse will cut down on instances of rapidly spreading disease and lower the need to use a chemical fungicide flush.
Starting with a clean greenhouse between each growing succession is the best tool for a healthier crop, and maintaining the proper filtration is an ideal way to maintain the cleanest and healthiest environment for your hydroponic crops.
For more information:
GrowSpan Greenhouse Structures
1395 John Fitch Blvd
South Windsor, Connecticut 06074
Toll-free USA: (800) 476 9715
International: +1 860 528 9550
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www.growspan.com