URBANA, Ill. Homeowners use a lot of pesticides. Statistics show that homeowners use three times more pesticides per acre than commercial agriculture producers. The United States Fish and Wildlife Service estimates the number to be even higher; their reports claim pesticide use in lawns is 10 times higher than in commercial agriculture.
Though not quite ready to ditch the bug and weed killers, homeowners are seeking alternatives to conventional pesticides. Many homeowners are turning to organic pesticides due to the growing perception that these pesticides are safer. But are organic pesticides safer than their conventional cousins?
That is a good question, says University of Illinois Extension horticulture educator Chris Enroth. First we should define what makes a pesticide organic. In most circumstances, an organic product, whether it is a pesticide or a fertilizer, is derived from the remains or byproducts of a living or once-living organism. Typically these products are marketed as natural, which reinforces the image these products are from nature and are therefore harmless.
Enroth cautions, Just because something is labeled organic or natural does not mean it is safer to the homeowner or unable to cause harm to the environment. Botanically derived pesticides are not always safer; in fact, some can be more dangerous.
Before being sold, all pesticides undergo studies to define their acute toxicity. In other words, these studies look to determine what immediate dangers specific pesticides pose. Scientists rank the acute toxicity of a product based on the lethal dose that kills 50 percent of the test sample, termed the LD50. Because a low LD50 means it takes a smaller amount of a product to cause harm, a lower LD50 translates to a higher toxicity in a product. Several botanically derived pesticides have a low LD50, meaning they are quite toxic to humans. Examples include nicotine, rotenone, and some pyrethrins.
Fortunately, several of these products have been taken off the market, says Enroth. However, many home recipes incorporating these dangerous active ingredients still exist online.
The important thing to keep in mind is that, like synthetic pesticides, organic products vary and have a broad range of toxicity levels, says Enroth. Some organic pesticides can be very harmful to humans, while many others are perfectly safe.
All pesticides, synthetic or organic, must be stored in a locked cabinet out of reach from children. When applying any pesticide, always read the product label and research the toxicity and environmental hazards. Take proper precautions to protect yourself, your neighbors, and the environment.
Although pesticides are an important tool in our tool belt, they should always be our last resort, says Enroth. In my yard, pest prevention starts with good plant culture. Correctly maintaining your plants will give them a competitive edge on weeds, insects, and disease.
When a pest becomes overwhelming, first research the offending organism and then take appropriate action. Start with the least offending measures, such as picking off troublesome insects or removing diseased foliage. Sharp streams of water can knock down many pest insects such as aphids.
Horticultural soaps and oils are useful for slower-moving insects and protecting from certain diseases when applied at the appropriate time.
When these efforts fail to control a pest, a pesticide may be the final option, says Enroth.
Whether you choose a synthetic pesticide or an organic pesticide, be conservative in what chemicals you add to the landscape.
Or maybe just accept the pest and cut out the pesticides altogether, Enroth says. After all, the blooming creeping Charlie and dandelions are a sight to behold in my lawn.
University of Illinois Extension