Written by Donald Lester.
Biological products are beneficial living organisms sold to ou-compete detrimental organisms. There are several good bacteria on the market that kill or out-compete bad bacteria that thrive in water. This is particularly important in hydroponics because bacteria thrive in water. If you can maintain a balance of good and bad bacteria, or establish a population of good bacteria up-front, then you can prevent some pretty nasty bacterial diseases or even fungal diseases like the water mould root rots Pythium and Phytophthora.
The concept of using one biological organism to fight another is called biological control, and it is becoming more important in commercial agriculture. Biological control is also happening in the food industry. Many types of yoghurt have beneficial bacteria in them, known as probiotics. Many of the organisms sold for biological control exist naturally, so why do you need to buy them? The organisms sold in the marketplace are generally selected for their killing power, meaning you are buying and adding a “big brother” to beef up your natural flora of organisms. And the good part is that you can use these powerful tools in your indoor gardening program.
Arguably the most powerful beneficial bacteria is Bacillus subtilis. This bacterium is so tough it can withstand severe pressure differentials; enough that NASA uses this bacterium as a model organism for space research. Bacillus subtilis is well known in the research world because not only can it out-compete other bacteria for space and nutrients, Bacillus subtilis produces powerful enzymes and antibiotics that it uses on competitors. Unlike fungal biological products that grow on plant roots, Bacillus products have a small tail(s) or flagella, making them motile and able to go on seek-and-destroy missions in your nutrient solution.
Biological products, overall, are better at preventing disease rather than curing it. Therefore, it is important to establish a population of beneficial microorganisms at planting time and maintain them through the growing cycle. There are several things you can do to stack the deck in your favour: select the proper organism, buy quality material, avoid temperature extremes, maintain hygienic conditions and avoid the use of strong chemicals.
In shopping for biological products, first look for biological organisms, not extracts of living organisms. This is an important distinction. Extracts can provide protection for a short time, but a living organism is self-maintaining and can even grow in strength under the right conditions. Another consideration is determining what pathogen or detrimental organism you are trying to prevent. Hydroponics keeps the roots of plants immersed in a liquid-growing solution. Poor hygiene and other factors can lead to disastrous disease infections. Knowing your production history and problems can help you out here. If you don’t know what disease is plaguing your operation, seek help from your county extension agent or university. These professionals can help you choose the right product to control the infection and guide you in selecting the proper biological to use as a follow-up for maintaining a healthy growing system.
Biologicals are living organisms, so they do best in certain environmental conditions. Use fresh products and avoid sterilizers, bactericides, fungicides and other strong chemicals when using biologicals. The shelf life of biologicals can vary greatly, so look for those that last 18 months to two years. Avoid using products that require refrigeration; you don’t know if they got warm and degraded before you bought them. Also, be sure the label has a guaranteed analysis, meaning a count of the organisms is actually listed so you know what you are getting. Avoid products with more than three living organisms; more organisms mean fewer of each and possibly a weak product. And continue adding the product as the label indicates to maintain high levels of beneficial organisms.
Biological products typically come as liquid or powders and are quite easy to use. One of the big advantages to using biologicals is that they are completely safe for people, pets, children, houseplants and the environment. You can literally apply these things with your bare hands and have no fear of hurting yourself. Moreover, biologicals have no re-entry limits, no harvest intervals to worry about and no toxic residues.
With the marketplace moving toward organically grown foods, public demand for chemical-free foods, safety and liability issues associated with conventional products and the high cost of conventional product registrations, the future of plant pest control is biological. Consider putting biological products to work in your indoor garden today.
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