Garden & Greenhouse


Understanding Synthetic and Biological Pesticides

Posted June 23rd, 2016 by Garden & Greenhouse in ,

Even though microbes naturally act to control pathogens (bacteria and fungi) through a process known as “competitive-exclusion” it still pays to be cautious with decisions to use pesticides. Pesticides are labeled according to plant, pest type and have precautions and compatibility statements on what is known to be compatible or not. It is illegal to sell or purchase a product that is not properly labeled or is sold for a claim other than what is on the label. There are often fines associated with violations. Misuse can lead to people becoming sick or even death.

Know the law and be conscious of what is said and how it is said. The law in question is the Fungicide Insecticide Rodenticide Act (FIRA). The EPA and Food and Agriculture Organization of the United Nations (FAO) define pesticides as follows:

“any substance or mixture of substances intended for preventing, destroying or controlling any pest, including vectors of human or animal disease, unwanted species of plants or animals causing harm during or otherwise interfering with the production, processing, storage, transport or marketing of food, agricultural commodities, wood and wood products or animal feedstuffs, or substances which may be administered to animals for the control of insects, arachnids or other pests in or on their bodies. The term includes substances intended for use as a plant growth regulator, defoliant, desiccant or agent for thinning fruit or preventing the premature fall of fruit, and substances applied to crops either before or after harvest to protect the commodity from deterioration during storage and transport.”

Pesticides are applied to control pests. Pests can be defined as an insect, a disease, a fungus, a weed, or

something that one just does not want in the general area. Plant Growth Regulators (PGRs) are considered pesticides as well. “Plant hormones and growth regulators are chemicals that affect flowering; aging; root growth; distortion and killing of leaves, stems, and other parts; prevention or promotion of stem elongation; color enhancement of fruit; prevention of leafing and/or leaf fall; and many other conditions. Very small concentrations of these substances produce major growth changes”. (Oregon Agricultural Extension website)  Pesticides can be synthetically made or biological controls. Pesticides are strictly regulated by the EPA. Violators are fined for each offense, and there is even a possibility of incarceration for severe violations.

Until recently, all products making pesticides claims required an EPA registration. In order for a product to receive a registration number a tremendous amount of testing needs to be conducted to prove effectiveness and establish safety parameters. Products go through an array of tests regarding manufacturing processes, analysis, etc. This is all done through a third party. It is extremely costly and can be very time consuming. (If interested in the process and requirements, visit the EPA’s website. All of the requirements for the US market are listed on their website.)

Once testing is complete, products are then registered for a specific use based on the EPA application process. This means there are often several labels for the same product for different sectors (home market vs commercial market). And, if a pesticide label says it is registered for one type of plant, that product cannot be sold (and is not supposed to be used by a grower) for another type of plant or for another problem. This is called “off-label” usage. There are stiff penalties for misuse and for selling a product for a use for which it is not registered. An example of this is selling a fumigant that is registered for fusarium, but is also known to kill nematodes and using it to kill nematodes.

Another issue with pesticides is record keeping and application licensing. Every time a pesticide is used, a log is supposed to be made to document how much of each chemical was used and when it was applied. Notices are supposed to be posted notifying people of the application and are to be in place for a specified time after applying the pesticide. This is for safety reasons as people entering the area can expose themselves to chemicals than can make them sick or even cause death. Additionally, each person that is mixing or applying the pesticides is supposed to maintain a pesticide application certification. Frequently one person from a farm will maintain this certification and follow the requirements of the certification including the documentation of use, current certification, and attend various seminars for Continuing Education Units (CEU).

Cornell University has a great website that goes into vast detail on each type of pesticide, their mode of action, and use. For more information visit the Cornell site.

Exceptions to the designation of “pesticides” are drugs, fertilizers, biological control agents, or “low-risk” ingredients such as oils. The EPA maintains a list of exempted pesticides. The “Biological Control Agents”, for the most part, do not require registration on a Federal level, but may require registration at the state level.  These agents include certain microorganisms, birds and insects that have been reviewed and approved to achieve exempted status. The information provided here is for a very basic understanding of what is classified as a pesticide, their use, and to know the interactions with pesticides and our microbial products. Always read the labels and follow directions exactly to avoid unwanted exposure. Following instructions is also important with biological and low-risk or exempt pesticides as sometimes these products can damage plants.

Eric Lancaster is the Executive Vice President of TeraGanix, Inc., the exclusive North American distributor of Effective Microorganisms® and EM® Bokashi products. To learn more about Effective Microorganisms, please visit

Want more information? Read these articles:

Attracting Beneficial Insects to Your Yard

Azadirachtin and Neem: What is the Difference?

The Proper Use of Organic Sprays and Pesticides

The Advantage of Minimum Risk Pesticides

Tips for Keeping a Greenhouse Pest Free

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