On Thursday the U.S. EPA ordered E.I. DuPont de Nemours (DuPont) to immediately halt the sale, use or distribution of Imprelis. The order, issued under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). https://www.epa.gov/enforcement/reference-news-release-epa-issues-stop-sale-order-dupont-sale-and-distribution-imprelis
DuPont’s Imprelis Herbicide (aminocyclopyrochlor) was approved by the EPA in August 2010 for use to control dandelions, ground ivy, violets, clover and other weeds in lawns after they emerged from the ground. Imprelis was developed and marketed to kill emerged weeds and control future weed growth in lawns, and works by both direct uptake through the leaves as well as root uptake by interfering with a plant’s normal hormonal balance. It was designed to be long lasting and does not break down easily, in other words, it is environmentally persistent. Imprelis was never approved for use in New York and California because both states have separate review procedures for new herbicides. New York State officials were concerned that the herbicide does not bind with soil, and may leach into groundwater. California never completed its review.
http://www.nytimes.com/2011/07/15/science/earth/15herbicide.html?pagewanted=all
Beginning in June 2011, EPA started receiving complaints from state pesticide agencies about evergreen damage related to the use of Imprelis. University Extension Offices across the country reported injury to evergreens on lawns and golf courses treated with Imprelis. Homeowners, lawn service operators and others reported browning of shoots and needles and twisting and stunting of shoots, especially near tops of trees on current year growth on tree tops and outer branches. The damage occurred quickly, within two to three weeks of application of Imprelis. The most commonly affected trees were Norway spruce, Colorado blue spruce and eastern white pine. There were also reports of damage to firs and yews.
By the end of July, DuPont officially acknowledged to the EPA that there has been damage to trees associated with Imprelis use. By the first week in August 2011, DuPont had submitted to the Agency over 7,000 adverse incident reports involving damage (including death) of trees impacted by Imprelis. Test data from DuPont has confirmed certain coniferous trees, predominately Norway spruce and white pine, as susceptible to being damaged or killed by the application of Imprelis. On August 4, 2011, DuPont voluntarily suspended sales of Imprelis and announced a forthcoming product return and refund program. The DuPont website has recommendations for trying to save impacted trees. It is the same advice given to me by the local extension office and if you have impacted trees you might try to save them.
The EPA order to stop the sale and distribution of Imprelis is based on a technical violation of FIFRA labeling, not the fact that an environmentally persistent herbicide had unexpected consequences. This was a consequence that occurred within three weeks of application, and would have been hard to miss in appropriately designed field testing. The testing performed for Imprelis appears to have been inadequate to evaluate impact to and protect non-target species, such as conifer trees. New York state officials concern for potential impact to groundwater does not even appear to have been addressed by the EPA approval process. The fate and transport of chemicals sprayed into the environment should be evaluated before the chemical and its commercial formulation are approved for sale, not after.
The studies originally submitted were found to be adequate to allow for the conditional registration of the herbicide. The conditional registration required that an additional toxicity study be performed to evaluate environmental degradation and (re)submission of avian and invertebrate reproduction studies to evaluate animal endocrine disruption. The EPA web site states that Aminocyclopyrachlor is a low-risk pesticide. The human health and ecological risk assessments found that the herbicide posed low risk to both humans and other terrrestrial and aquatic organisms, except for plants. Aminocyclopyrachlor is related to other herbicides, including clopyralid and aminopyralid, which have caused plant damage when present in compost or manure as a result the label recommended against use of grass clipping for compost, but the tree deaths were unexpected.
http://www.epa.gov/pesticides/regulating/imprelis.html
Disclosure: In the 1970's and 1980's I worked for both the US EPA and DuPont as a Chemical Engineer.
Showing posts with label Norway spruce. Show all posts
Showing posts with label Norway spruce. Show all posts
Monday, August 15, 2011
Thursday, July 21, 2011
Tree Deaths from Herbicide Use
This spring as usual I prepared my garden for summer, deadheaded some of perennials (which I promise to do more aggressively this year in early winter), cleanup the dead leaves and remove any dead plants. The incredibly harsh winter of 2009-2010 followed by the heat wave last summer killed off four shrubs and 6 evergreens. It was a sad and expensive loss. In preparation for planting the six replacements and one additional tree I purchased seven Treegator Pro Jr. watering bags to ensure that my hollies and Crytomeria would be watered for their first season. For extra insurance I planted them with seaweed and fish heads. Even after the 100 degree days in May and June and the return of heat in July my new trees are looking good.
However, I can not say that about my Japanese dogwood. It is withering. After four years of surviving the hot summers of Virginia it is withering and so I began my investigation when I noticed one more odd thing in my garden. In the stone garden around my septic controls the weeds had withered. In no other place in my garden had the weeds withered. I do not use herbicides or pesticides in my garden. The beds are weeded by hand. Weeding is the work of gardeners. So what had caused the weeds to die off in this little spot and was that related to my Dogwood? Despite my asking my septic service company and the company that cuts my lawn there seems to be no source of herbicides on my garden. However, while I was investigating my problem I came across the suspected Imprelis caused tree deaths.
University Extension websites from Kansas to Pennsylvania have reported injury to evergreens on lawns and golf courses treated with Imprelis. Homeowners, lawn service operators and others have observed browning of shoots and needles and twisting and stunting of shoots, especially near tops of trees. Symptoms are usually most severe on current year growth on tree tops and outer branches. Unlike insect and disease problems, Imprelis damage occurs quickly, within two to three weeks of application. The most commonly affected trees are Norway spruce, Colorado blue spruce and eastern white pine. Firs and yews may also be affected. My dogwood is a Cornus species and not reported to be impacted.
http://news.msue.msu.edu/uploads/files/122/Imprelis%20homeowner%20factsheet_Bert%20Cregg.pdf
Imprelis is a new herbicide from DuPont, approved for use in 48 states last fall. The U.S. Environmental Protection Agency approved Imprelis (aminocyclopyrochlor) last year for commercial use in controlling dandelions, ground ivy, violets, clover and other weeds in lawns. It’s not available for use by homeowners, so it is unlikely that my neighbors used it. In addition, the damage from Imprelis appears unlikely to be from pesticide drift. Imprelis was developed and marketed to control weeds in lawns and works by both direct uptake through the leaves as well as root uptake by interfering with a plant’s normal hormonal balance. It was designed to be long lasting and does not break down easily. Imprelis is not approved for use in New York and California because both states have separate review procedures for new herbicides. New York State officials identified a problem: the herbicide does not bind with soil, and may leach into groundwater. California has not completed its review.
http://www.nytimes.com/2011/07/15/science/earth/15herbicide.html?pagewanted=all
Reportedly, Imprelis went through about 400 trials, including tests on conifers, and reportedly performed without problems. The U.S. Environmental Protection Agency reviewed the herbicide for 23 months before granting its conditional approval, though all of the safety data was not yet in, the agency believed Imprelis to be a good product. Now, however, The EPA will begin an "expedited review" by the end of July into whether the weed-killer Imprelis is harming or killing some species of evergreens. Most Imprelis applications have not reported damage to spruce or pine, but cases of damage cause alarm when dealing with a newly released herbicide.
The reported cases from Indiana indicate that this may not be a simple herbicide drift issue, but rather from root uptake. Clippings from lawns treated with Imprelis should not be composted because the chemical survives the process and can kill flowers and vegetables that are treated with the compost. That warning is included on the Imprelis product label. The types of trees that are reported to be most commonly affected typically grow vigorously and are therefore good candidates for recovery from minor injury. Reduce drought stress by watering during dry periods. Avoid over-watering that causes water-logging. This is the same advice that the forest service and nursery gave me to try and save my dogwood.
http://news.msue.msu.edu/news/article/what_to_do_with_imprelis_affected_trees
I am reminded of my neighbor’s comment about how bad the dandelions were this spring. My own reaction was to embrace dandelions as pretty and anything green growing in what passes for a lawn around here is considered good- crab grass, clover and other weeds. We need to rethink the use of herbicides in ornamental gardens. Unintended consequences.
However, I can not say that about my Japanese dogwood. It is withering. After four years of surviving the hot summers of Virginia it is withering and so I began my investigation when I noticed one more odd thing in my garden. In the stone garden around my septic controls the weeds had withered. In no other place in my garden had the weeds withered. I do not use herbicides or pesticides in my garden. The beds are weeded by hand. Weeding is the work of gardeners. So what had caused the weeds to die off in this little spot and was that related to my Dogwood? Despite my asking my septic service company and the company that cuts my lawn there seems to be no source of herbicides on my garden. However, while I was investigating my problem I came across the suspected Imprelis caused tree deaths.
University Extension websites from Kansas to Pennsylvania have reported injury to evergreens on lawns and golf courses treated with Imprelis. Homeowners, lawn service operators and others have observed browning of shoots and needles and twisting and stunting of shoots, especially near tops of trees. Symptoms are usually most severe on current year growth on tree tops and outer branches. Unlike insect and disease problems, Imprelis damage occurs quickly, within two to three weeks of application. The most commonly affected trees are Norway spruce, Colorado blue spruce and eastern white pine. Firs and yews may also be affected. My dogwood is a Cornus species and not reported to be impacted.
http://news.msue.msu.edu/uploads/files/122/Imprelis%20homeowner%20factsheet_Bert%20Cregg.pdf
Imprelis is a new herbicide from DuPont, approved for use in 48 states last fall. The U.S. Environmental Protection Agency approved Imprelis (aminocyclopyrochlor) last year for commercial use in controlling dandelions, ground ivy, violets, clover and other weeds in lawns. It’s not available for use by homeowners, so it is unlikely that my neighbors used it. In addition, the damage from Imprelis appears unlikely to be from pesticide drift. Imprelis was developed and marketed to control weeds in lawns and works by both direct uptake through the leaves as well as root uptake by interfering with a plant’s normal hormonal balance. It was designed to be long lasting and does not break down easily. Imprelis is not approved for use in New York and California because both states have separate review procedures for new herbicides. New York State officials identified a problem: the herbicide does not bind with soil, and may leach into groundwater. California has not completed its review.
http://www.nytimes.com/2011/07/15/science/earth/15herbicide.html?pagewanted=all
Reportedly, Imprelis went through about 400 trials, including tests on conifers, and reportedly performed without problems. The U.S. Environmental Protection Agency reviewed the herbicide for 23 months before granting its conditional approval, though all of the safety data was not yet in, the agency believed Imprelis to be a good product. Now, however, The EPA will begin an "expedited review" by the end of July into whether the weed-killer Imprelis is harming or killing some species of evergreens. Most Imprelis applications have not reported damage to spruce or pine, but cases of damage cause alarm when dealing with a newly released herbicide.
The reported cases from Indiana indicate that this may not be a simple herbicide drift issue, but rather from root uptake. Clippings from lawns treated with Imprelis should not be composted because the chemical survives the process and can kill flowers and vegetables that are treated with the compost. That warning is included on the Imprelis product label. The types of trees that are reported to be most commonly affected typically grow vigorously and are therefore good candidates for recovery from minor injury. Reduce drought stress by watering during dry periods. Avoid over-watering that causes water-logging. This is the same advice that the forest service and nursery gave me to try and save my dogwood.
http://news.msue.msu.edu/news/article/what_to_do_with_imprelis_affected_trees
I am reminded of my neighbor’s comment about how bad the dandelions were this spring. My own reaction was to embrace dandelions as pretty and anything green growing in what passes for a lawn around here is considered good- crab grass, clover and other weeds. We need to rethink the use of herbicides in ornamental gardens. Unintended consequences.
Subscribe to:
Posts (Atom)