A news item caught my eye today. In the story from Science Daily, University of Guelph researchers Rebecca Hallett and Christine Bahlai compared the effectiveness and environmental impact of organic pesticides to those of conventional and novel reduced-risk synthetic products on soybean crops. The result? The two organic pesticides had a greater overall impact on the environment, including unintended mortality of beneficial insects.
The point of the research is not to try to say organic pesticides are always inferior, or to strike a blow for conventional pesticides, but simply to point out that real life is never as simple as a slogan or ideology would make it.
A current point of view among green advocates is that to be green in landscape maintenance and pest control, you should go “organic”. In many cases this means providing a list of approved organic pesticides and solutions and assuming that this will make pest control safe and effective. The truth is more complicated.
In the Canadian study, the research team looked at a mineral oil compound and a fungal pathogen for control of soybean aphid, an important emerging pest of soybeans. Compared to two conventional pesticides and two reduced-risk, synthetic pesticides, the two organic products were less effective and actually had a higher environmental impact quotient than the other pesticides.
The authors concluded that
“In terms of making pest management decisions and trying to do what is best for the environment, it’s important to look at every compound and make a selection based on the environmental impact quotient rather than if it’s simply natural or synthetic. It’s a simplification that just doesn’t work when it comes to minimizing environmental impact.”
I couldn’t have said it better.
In addition to product selection, Greenies (an affectionate term, under which I like to include myself) should not forget the idea of integrated pest management (IPM). Under IPM pesticides (organic or synthetic) are just one part of the pest control picture. Identification of the pest (thereby learning about it’s biology and life cycle vulnerabilities); monitoring; use of thresholds; physical, mechanical and cultural controls; and careful pesticide selection are key components of IPM. Good pest control is not simply switching an organic pesticide for a synthetic one.
Rather than buying into a strict organic approach, I believe we need to take a broader, low impact approach to managing pests–whether it’s in a school, home garden, landscape or our homes. There are many good pesticides today that are not necessarily organic. Check out the list of some of these on this website. This is not to throw out the use of organic products. It just means that organic products should be compared with the best of the rest of the pest control tools we have today. And may the greenest methods win!