Herbicides

‘workin on it

View also the subpage Glyphosate in Agriculture & Horticulture

Herbicides
A list of herbicides and what they kill on National Sunflower Association website

General Properties of Herbicides

Ch 6 In Weed Control Methods Handbook, The Nature Conservancy, Tu et al. (2001)

Timberland herbicide spraying sickens a community
Rebecca Clarren for High Country News Nov 10, 2014

GLYPHOSATE

Glyphosate inhibits melanization and increases susceptibility to infection in insects
Daniel F. Q. Smith et al., 2021 in PLOS BIOLOGY “Melanin, a black-brown pigment found throughout all kingdoms of life, has diverse biological functions including UV protection, thermoregulation, oxidant scavenging, arthropod immunity, and microbial virulence. Given melanin’s broad roles in the biosphere, particularly in insect immune defenses, it is important to understand how exposure to ubiquitous environmental contaminants affects melanization. Glyphosate—the most widely used herbicide globally—inhibits melanin production, which could have wide-ranging implications in the health of many organisms, including insects… Overall, these findings suggest that glyphosate’s environmental accumulation could render insects more susceptible to microbial pathogens due to melanin inhibition, immune impairment, and perturbations in microbiota composition, potentially contributing to declines in insect populations” Also view John Hopkins Media Release

Glyphosate Sprayed on GMO Crops Linked to Lake Erie’s Toxic Algae Bloom
By Lorrain Chow for www.ecowatch.com July 5,2019

Beyond Pesticides ChemicalWatch Factsheet: Glyphosate
Five pages; comprehensive referenced overview. Latest ref is 2012.

Study reveals Monsanto manipulated glyphosate approval process
Dallas McQuarrie for NB Media Co-op, Aug 13, 2018. It cites a research paper in the Journal of Public Health Policy: Roundup litigation discovery documents: implications for public health and journal ethics by Sheldon Krimsky and Carey Gillam. 2018. Journal of Public Health Policy August 2018, Volume 39, Issue 3, pp 318–326.

HOW MUCH GLYPHOSATE IS SPRAYED EVERY YEAR IN FORESTRY?
Page on forestinfo.ca


In Canada… the total area treated [each year] may be closer to 150,000 ha per year. The typical use rate for glyphosate-based herbicides in conifer release programs is 1.9 kg of active ingredient/ha…Most areas that are planted to conifer trees, and many naturally regenerating areas targeted for conifer dominance will require some degree of tending to maintain conifer dominance and promote adequate growth. As such, as many as 444,000 ha require tending each growing season in Canada. Provinces such as Ontario and New Brunswick apply herbicides to about as much area as they plant, relying on alternative methods to tend additional area. In contrast, a provincial restriction on herbicide use in Crown forests was invoked in the province of Quebec in 2001… forcing virtually all tending there to be done without herbicides.

Industry Perspectives: See forestinfo.ca/resources
e.g. Environmental risk of glyphosate use in Canadian forestry (audio/slides)
Dr. Chris Edge* on July 17, 2018. Includes Q&A View slides in PDF
– On Aug 31, 2018 I sent an e-mail to Dr. Edge to ask “could you send me PDFs or references to papers related to your presentation at Environmental risk of glyphosate use in Canadian forestry“. (I asked for those as I could not find papers reporting many of the results he cites in the presentation; some papers related to herbicides by Dr. Edge that I could find are listed below.)

Glyphosate Toxicity

I looked for recent reviews in recognized scientific journals:

Glyphosate Based Herbicides and Cancer Risk: A Post IARC Decision Review of Potential Mechanisms, Policy, and Avenues of Research
Michael J Davoren Robert H Schiestl Carcinogenesis, bgy105, Published: 28 July 2018 . PDF of Accepted MS “Glyphosate’s potential for carcinogenic effects is likely complex in nature. If glyphosate is a true carcinogen, mechanisms of action are most likely to include effects such as endocrine or microbiome disruption. Traditional carcinogenicity testing methods may no longer be relevant for evaluating a substance with such effects. Much of the framework used by international regulatory agencies is also tailored to set “safe” levels only for compounds that function via classical dose-response mechanisms, allowing potentially nonmonotonic carcinogen effects, such as in the case of glyphosate, to be overlooked. These agencies must modernize their standards of testing and regulation in order to properly respond to new science.”

Environmental and health effects of the herbicide glyphosate
AHC Van Bruggen et al., 2018 Science of The Total Environment Volumes 616–617, March 2018, Pages 255-268
Highlights:
• Glyphosate and its degradation product AMPA have accumulated in the environment.
• Chronic low dose effects on animals and humans have been documented recently.
• Shifts in microbial community composition in soil, plants and animal guts resulted.
• Glyphosate and antibiotic resistance have arisen in fungi and bacteria in parallel.
• Glyphosate may serve as one of the drivers for antibiotic resistance.

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*Related papers by Chris Edge (‘workin on it)

The response of amphibian larvae to exposure to a herbicide (Roundup WeatherMax) and nutrient enrichment in an ecosystem experiment
Christopher B Edge et al., 2014 Ecotoxicology and Environmental Safety

Effects of the glyphosate-based herbicide Roundup WeatherMax (R) on metamorphosis of wood frogs (Lithobates sylvaticus) in natural wetlands
Chantal M Lanctôt et al., 2013 Aquatic Toxicology

Laboratory and field exposure of two species of juvenile amphibians to a glyphosate-based herbicide and Batrachochytrium dendrobatidis
Christopher B Edge et al., 2012 Science of The Total Environment

Amphibian development in variable wetlands: Does altering wetland ecosystems with herbicide application and nutrient enrichment result in changes to development rates in natural wetlands
Christopher B Edge et al., 2014 Conference paper

Exposure of juvenile green frogs (Lithobates clamitans) in littoral enclosures to a glyphosate-based herbicide
Christopher B Edge et al., 2011Ecotoxicology and Environmental Safety

A silviculture application of the glyphosate-based herbicide VisionMAX to wetlands has limited direct effects on amphibian larvae
Christopher B Edge et al., 2012. Environ Toxicol Chem. 2012 Oct;31(10):2375-83.