Pesticide Use and IPM

I think many of you will find this statement interesting and very applicable for both conventional and organic producers of all crops.


Statement on “Least Toxic” & “Last Resort”

Recommendations and decisions to use “least toxic pesticides” and “pesticides as a last resort” have flourished in the last decade, but according to three scientific organizations – the Weed Science Society of America (WSSA), the American Phytopathological Society (APS) and the Plant-Insect Ecosystems Section of the Entomological Society of America (P-IE ESA) – these are not the correct approaches to the pesticide component of an Integrated Pest Management (IPM) program. The three organizations have joined to take an objective look at these two descriptions and prepared a position statement.

It is essential to practice integrated pest management (IPM), whether managing weeds, insect pests or plant disease - on the farm, on commercial sites, on public lands, or in or around the home. Key components of IPM include making the habitat unfavorable for pests, excluding pests where feasible, using proper sanitation practices, monitoring the infestation level, knowing the pest tolerance level for the specific situation and implementing the necessary management practices. Judicious use of pesticides is a critical component of many IPM programs.

Judicious (careful) use refers to various practices - following all label directions and making all appropriate stewardship decisions required in the particular situation. This includes applying a product registered for the target pest(s) after accurate pest identification, and consideration of the level of infestation and the potential for economic, health or other negative pest impacts. Careful use extends beyond pesticides to household chemicals, automobiles, medicines, alcoholic beverages, and countless other products that are part of our daily lives.

“Least toxic” implies there are pesticides available for every pest spectrum that are least toxic to everything else. This is not true. The toxicity of a pesticide depends on what is being evaluated and who or what may be affected. It is also important to remember that toxicity is not the same as risk, which is dependent on both toxicity and exposure. The risk associated with the use of pesticides and other chemicals is managed by establishing safe exposure levels based on the toxicity specific to each product. Assigning a “most” or “least” toxic rating does not equate to actual risk when the product is properly applied.

“Last resort” implies that pesticides will work as well when every non-chemical control technique is attempted first. However, delaying application of a pesticide can cause buildup of the pest(s) in crops, gardens, buildings and other sites, with negative impacts on yield, quality and/or health. In fact, delaying treatment can significantly increase the ecological and economic damage to crop and non-crop areas.

Using pesticides as the last line of defense can result in a more limited choice of pesticides, as well as reduced crop tolerance, the need for higher rates, and less effective control because of higher infestation levels and/or more tolerant pest stages. For example, seedling weeds and early-stage insect larvae and diseases are usually more easily controlled than later pest stages. Effective pesticide choices, when they are applied as a “last resort,” means fewer options to rotate pesticides, which is a critical step in preventing a pest from becoming resistant to a pesticide. “Last resort” pesticide strategies may also increase the need for multiple products and higher application rates to control the pest effectively. The term also suggests pesticides are always the worst choice, which is not true. First using non-chemical techniques that are ineffective or inefficient has the potential to add to the cost of pest management, intensify the pest problem or create new problems.

Finally, by branding pesticides as the “last resort” choice certainly does not stimulate a strong public interest in funding education on their proper use. Pesticides are widely used, but discretionary federal funding of the U.S. Pesticide Safety Education Program has been eliminated in 2011 and 2012.

This program is vital to educate pesticide users and dealers who must be certified to apply or sell pesticides, and to teach the public how to use pesticides safely. There is no benefit or scientific basis to simplistic messages like “use least toxic pesticides as a last resort” for the large number of pesticide users who apply pesticides according to the label and practice good stewardship. Nor are these messages beneficial for those who neither seek training nor adequately read the label believing instead that it is safe, practical, and effective to simply choose a product considered a “least toxic pesticide” and apply it only as a “last resort.” These messages hinder pesticide safety and stewardship education and practices that are in the best interest of the pesticide user, our food supply, public health and ecosystem preservation.

(WSSA/APS/P-IE ESA joint statement, 11/12/12).