I live next to Highway 20, and it's where I see the biggest blackberries in town. However, I think the Department of Transportation may spray herbicides along roads to prevent overgrowth. How is this application done? If I eat these berries, will the herbicides damage my health?
You are right about roadsides - They are often sprayed by the Oregon Department of Transportation to keep the shoulders clear. The weed killers are not intended to be sprayed on (or near) food crops. That means it is hard to guess the level of risk. We don't have the studies to show how long it takes for the product(s) to break down on foliage, or in soil.
You will make the decision based on your own risk tolerance. Some questions to ask yourself:
- Do you see any signs of plant damage on the blackberry bushes? Or close-by? It would look as though parts of the plant have died, or dried up. Early in the process, you may see yellowing leaves, or curling leaves.
- Was the area sprayed before fruit developed? If so, there may still be small residues inside the plant, but the surfaces would be free of residue.
- Are you able to wash the fruit well?
You can call our local ODOT office, located in Corvallis, and ask about any recent applications on Highway 20. If you're able to learn about a specific weed killer that was sprayed, call the National Pesticide Information Center (NPIC) at 1-800-858-7378, which is located here at OSU. They can offer more information.
