I recently bought a nice Satsuma tree from a local Home Depot. I was watering it the other day and notice a plastic tag buried in the potting soil (it’s still in a container). On the tag:
“This plant is protected from problematic Aphids, White Flies, Beetles, Mealy Bugs and other unwanted pasts by Neonicotinoids”. And “These pesticides are approved by the EPA”.
I know neonics, under certain conditions, can last a long time in soil, but I’ve never found information about how long they will persist in the roots, branches, leaves, blossoms, and fruits of trees.
I can wash the potting soil off the roots and add some fresh uncontaminated soil, but I wonder if the chemicals will stay in the sap for a long time. Or will they degrade to a harmless form in a year.
Neonicotinoids vary greatly in properties and concentration. Your question is difficult to answer without knowing the actual product and dosage used.
As an example, the consumer-grade Imidacloprid produced by Bayer is dosed in teaspoons per gallon and also has long residuals, but professional-grade neonicotinoids are typically dosed in milliliters per gallon and a few of them have lower residuals.
The way I see it, once it stops killing insects whose entire diet consists of parts of the tree, the amount of the material that may still exist in it is unlikely to represent any threat at all to your health. I’m pretty sure that being stuck in a traffic jam and breathing the exhaust of nearby cars creates exposure to carcinogens and threats to your cardiovascular system that would dwarf any danger of eating fruit from that tree, even if it produces its first year.
I would still encourage you not to buy your fruit trees from Home Depot.
From what I have read, neonicotonoids are taken up by plants and can persist for several years. They can have adverse effects on pollinating insects during this time. I don’t think anyone should buy plants from nurseries whose practices they don’t find in line with their own values.
Chetnut, my only problem with that statement is when folks values are based on feelings more than established facts. The politics and marketing of products in this country are highly manipulated by the emotional manipulation of “values”.
Excessive fear of residue in conventionally grown food falls into this category, IMO, and I believe I have the data to prove it. If you care to see that data, send me a private message. I welcome anyone else to do the same.
I just looked this up and its seems they are synthetic forms of nicotine. As I remember from biology class, nicotine and caffeine are natural pesticides produced by plants that stimulate the nervous system. In high enough concentration bugs will suffocate from spam of the muscles that control breathing. Humans can die a similar way if a high enough concentration is ingested. In low concentration they are considered a beneficial stimulant.
As far as the intended nicotine like properties, I would not be concerned at all, You would know if you have any of this in your system. You would feel it by hyperactivity or muscles spams in higher concentration. It’s any ignored functional groups on the synthetic compounds that might concern me. However that is true of all man-made synthetic chemicals and drugs.
I think they put the notice on the tags because the issues surrounding the effects on beneficial insects, such as bees.
I only do organic. I expect all nursery trees to have been chemically treated. But in the few years it takes for the tree to begin to fruit there is plenty of time and opportunity for the chemical to break down and/or leach out of the tree and that little bit of dirt that was in the pot. Your worry energy should be directed to something else.
JB did not state whether he bought a Satsuma plum or Satsuma mandarin. In the case of the latter, the USDA requires all Citrus plants sold retail in CA to be periodically treated by specific classes of foliar spray and soil drench pesticides to protect against ACP and hence Citrus Greening Disease ( http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74155.html ). The soil drench choices are all neonicotinoids. The dosage frequency is every 90 days. The time to wait until harvest after application (PHI) is 7 days. The application is rigidly monitored by the USDA ACP Task Force. So JB should have zero worries about eating fruit from his tree, nor should he have worries about killing beneficial insects after 90 days or so.