Chapter 11

Insect Pest Management for Organic Crops

Insecticides for Organic Crops

The U.S. Department of Agriculture’s (USDA) National Organic Program (NOP) practice standards suggest the use of systems-based practices (cultural practices, sanitation, crop rotation, trap crops) and mechanical practices (insect netting, row covers, and hand-picking) to prevent insect pest colonization and impact on crops. The NOP requires organic farmers to try and use non-pesticide methods to manage pests before using a pesticide (§ 205.206 – Crop pest, weed, and disease management practice standard). The use of these methods must also be documented in the organic system plan. Further, the pesticides used are limited to those allowed by the NOP and must be used according to their labeled instructions. Just as with traditional chemical insecticides organic insecticides should be used as a last resort to control insect pests on crops. This section briefly describes the various Environmental Protection Agency (EPA) categories of toxicity for OMRI-approved insecticides, biopesticides, organic system plan documentation, and insecticides that have been approved by the Organic Materials Review Institute (OMRI) for organic crop production.

Toxicity Categories for OMRI-Approved Insecticides

Organic insecticidal formulations approved by OMRI must be applied in the recommended manner. Producers must read the insecticide label before use; the label is the law. On the basis of exposure route, the EPA has established four levels of toxicity that apply to all insecticidal formulations. Note that organic insecticides may not need EPA registration; however, most established products carry an EPA registration number and a full insecticide label for promoting correct usage.

Organic System Plan

The conditions for using the allowable material or substance (i.e., insecticides) must be documented in the organic system plan. The grower should have a plan for how and when they will react to an insect pest outbreak with an allowable substance. A grower must know which organic pesticides are allowable, what materials are labeled for their crops, and the efficacy of those materials against the intended target pests. In all cases, if a grower has any questions as to whether a material is allowable or not, they should check with their organic certification agency to determine if specific materials are allowed, restricted, or prohibited in the organic system. Use of a non-allowed substance can result in the loss of certification and the need to re-transition the affected land for 36 months.

Pest Management Program

Most important of all is the emphasis that is placed on sanitation (described in the rule as “removal of pest habitat, food sources and breeding areas”); exclusion, or pest proofing (“prevention of access to handling facilities”); and the use of physical controls. A careful look at the Standard debunks the myth that only materials named in the National List may be applied in organic farming operations, and that, if a material is named on the National List, it may be applied indiscriminately and without first taking other action.

Biopesticides

Biopesticides, as defined by the Environmental Protection Agency (EPA), are certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals.  Biopesticides as defined by the EPA include the following categories: 1) microbial pesticides, in which a microorganism (e.g., a bacterium, fungus, virus or protozoan) is the active ingredient; 2) biochemical pesticides, which are naturally occurring substances that control pests by non-toxic mechanisms, such as sex pheromones that interfere with mating and scented plant extracts that attract insect pests to traps; and 3) Plant-Incorporated-Protectants (PIPs), in which pesticidal substances are produced by crop plants as a result of genetic material being added to the plant (e.g., Bt insecticidal protein). There are some biopesticides that are NOT approved for organic crop production by USDA’s National Organic Program. Some biopesticides, like salts of phosphorous acid and all genetically-engineered PIPs, are not allowed for organic crop production.

Advantages/Disadvantages

Biopesticides target pests and closely related organisms, and they are usually inherently less toxic than conventional pesticides, thus they do not have the same potential to affect birds, beneficial insects, and mammals. They generally decompose fast and sometimes are effective in very small quantities, thus exposure is lower and potential pollution problems are avoided.

Insecticides Allowed for Organic Crop Production

Organic farmers can use insecticides derived from natural sources and insecticides that include synthetic substances within the regulations of the USDA NOP if other strategies and cultural management practices fail to control pests and diseases. The National List of Allowed and Prohibited Substances managed by the NOP identifies substances that may or may not be used in organic crop production.

Allowed Insecticides

Generally speaking, pesticides derived from natural materials or living organisms are allowed in organic production as long as they do not contain synthetic additives or are not specifically prohibited on the National List under § 205.602. By contrast, most synthetic pesticides are not allowed; those few that are can be found on the National List under § 205.601. Allowed insecticides typically include but are not limited to the following:

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