CCH2O Crop Protection Bulletin:
by: Erik Biksa
An irrigation system biofilm is a cost to indoor hydroponics and soilless farmers, often unseen or hidden. Ever wonder what that scum is that accumulates on irrigation surfaces, emitters, filters, reservoirs, growing media or even roots? Chances are what you are observing is, yes, you guessed it, a biofilm.
An irrigation system biofilm can form and occur as complex collectives of microorganisms, competing with roots for resources like minerals and oxygen and may promote vectors for crop infection. They are nearly impossible to avoid. Studies demonstrate that as soon as water comes into contact with surfaces, especially irrigation pipes in warm well-illuminated places, these films begin to form–naturally, they can develop at faster rates and with a higher level of persistence when there is a constant source of moisture. Organic debris, nutrients, oxygen and microbes, among others, are key contributors to the existence and formation of an irrigation system biofilm.
“Build it, and they will come”–Field of Dreams
New irrigation systems are a significant investment in planning, sourcing, equipment and labor. Aside from some of the more obvious costs associated with a new irrigation system, having crop performance decline due to lack of maintenance and prevention to combat biofilms in irrigation systems can put a serious dent in your bottom line as a grower. Besides being unsightly and a potential source of crop infections, biofilms can accumulate and block emitters or create disproportionate flow rates in irrigation systems. Potentially starving or dehydrating what could otherwise be a healthy crop of plants. The bottom line, start fighting biofilms from your very first irrigation. Like most things in life, prevention is the best remedy.
If you have an existing irrigation system, it is most likely you have biofilms present. In severe cases, an irrigation system biofilm can develop so aggressively that they may be observed restricting water and nutrient flow, even in larger diameter pipes. If your growing operation experiences persistent issues or setbacks with root pathogens, it’s a pretty good bet that the sources of your woes have much to do with the presence of biofilms in your hydroponic systems or irrigation equipment–which are downstream from major sources like water holding tanks and water delivery mains that also require careful attention.
An irrigation system biofilm is persistent and maybe a fact of life for growers that must be addressed. Scrubbing and washing irrigation equipment, pots, trays, systems etc between crops helps but will not control levels during cropping when plants are present. Here are the two recommended approaches to controlling and eliminating the presence of biofilms in your growing operation.
Prevention & Control
Hypochlorous Acid is an effective and economical go-to solution for the modern grower looking to protect their cropping investment while maintaining a safe environment for both people and plants. Hypochlorous Acid (herein referred to as HCA) is safe to handle and does not harm plants (it helps them, more about that later). HCA can be diluted into your water reservoirs, nutrient tanks or be dosed into fertigation systems via injectors used DURING active cropping. HCA is Effective & SAFE and is available in economical and easy to handle liquid concentrates (Clear Line, Current Culture H2O).
HCA will be effective in protecting your plants, irrigation equipment and investment during cropping–start using it with every irrigation to help prevent and reduce the accumulation of biofilms during your crop growing cycle.
Elimination & Eradication of biofilms should be performed between crops, ie no crops are present, which affords the opportunity for using stronger measures. These include Strong Acids, Ozone and Oxidizers. Be cautioned that these chemicals and methods require a much stronger degree of caution with applications as they can be harmful to people and equipment if not used as recommended. Further, these types of chemicals and equipment tend to be more expensive to purchase and apply–again leading us back to the adage that an ounce of prevention is worth a pound of cure.
Other Benefits of Hypochlorous Acid:
- Better yields-studies demonstrate that plant development rates in hydroponics and soilless growing are highest when the root zone is sterile as roots have no competition for nutrients or oxygen while not expending precious energy fighting off pathogens.
- Helps maintain a hygienic environment for plants and people working in grow rooms-recent studies suggest that E.Coli can occur in hydroponic systems and is potentially transferred from roots to the aerial (upper green portions) of plants through handling and cultural practices.