Benbrook, 2016a
Charles M. Benbrook, “Trends in glyphosate herbicide use in the United States and globally,” Environmental Sciences Europe, 2016, 28:3, DOI 10.1186/s12302-016-0070-0.
ABSTRACT:
BACKGROUND: Accurate pesticide use data are essential when studying the environmental and public health impacts of pesticide use. Since the mid-1990s, significant changes have occurred in when and how glyphosate herbicides are applied, and there has been a dramatic increase in the total volume applied.
METHODS: Data on glyphosate applications were collected from multiple sources and integrated into a dataset spanning agricultural, non-agricultural, and total glyphosate use from 1974–2014 in the United States, and from 1994–2014 globally.
RESULTS: Since 1974 in the U.S., over 1.6 billion kilograms of glyphosate active ingredient have been applied, or 19 % of estimated global use of glyphosate (8.6 billion kilograms). Globally, glyphosate use has risen almost 15-fold since so-called “Roundup Ready,” genetically engineered glyphosate-tolerant crops were introduced in 1996. Two-thirds of the total volume of glyphosate applied in the U.S. from 1974 to 2014 has been sprayed in just the last 10 years. The corresponding share globally is 72 %. In 2014, farmers sprayed enough glyphosate to apply ~1.0 kg/ha (0.8 pound/ acre) on every hectare of U.S.-cultivated cropland and nearly 0.53 kg/ha (0.47 pounds/acre) on all cropland worldwide.
CONCLUSIONS: Genetically engineered herbicide-tolerant crops now account for about 56 % of global glyphosate use. In the U.S., no pesticide has come remotely close to such intensive and widespread use. This is likely the case globally, but published global pesticide use data are sparse. Glyphosate will likely remain the most widely applied pesticide worldwide for years to come, and interest will grow in quantifying ecological and human health impacts. Accurate, accessible time-series data on glyphosate use will accelerate research progress. FULL TEXT
Evans et al., 2015
Jeffrey A Evans, Patrick J Tranel, Aaron G Hager, Brian Schutte, Chenxi Wu, Laura A Chatham, and Adam S Davis, “Managing the evolution of herbicide resistance,” 2015, Pest Management Science, 72, DOI 10.1002/ps.4009.
ABSTRACT:
BACKGROUND: Understanding and managing the evolutionary responses of pests and pathogens to control efforts is essential to human health and survival. Herbicide-resistant (HR) weeds undermine agricultural sustainability, productivity and profitability, yet the epidemiology of resistance evolution – particularly at landscape scales – is poorly understood. We studied glyphosate resistance in a major agricultural weed, Amaranthus tuberculatus (common waterhemp), using landscape, weed and management data from 105 central Illinois grain farms, including over 500 site-years of herbicide application records.
RESULTS: Glyphosate-resistant (GR) A. tuberculatus occurrence was greatest in fields with frequent glyphosate applications, high annual rates of herbicide mechanism of action (MOA) turnover and few MOAs/field/year. Combining herbicide MOAs at the time of application by herbicide mixing reduced the likelihood of GR A. tuberculatus.
CONCLUSIONS: These findings illustrate the importance of examining large-scale evolutionary processes at relevant spatial scales. Although measures such as herbicide mixing may delay GR or other HR weed traits, they are unlikely to prevent them. Long-term weed management will require truly diversified management practices that minimize selection for herbicide resistance traits. FULL TEXT
Vandenberg et al., 2017
Laura N Vandenberg, Bruce Blumberg, Michael N Antoniou, Charles M Benbrook, Lynn Carroll, Theo Colborn, Lorne G Everett, Michael Hansen, Philip J Landrigan, Bruce P Lanphear, Robin Mesnage, Frederick S vom Saal, Wade V Welshons, John Peterson Myers, “Is it time to reassess current safety standards for glyphosate-based herbicides?”, Journal of Epidemiology and Community Health, 2017, 0, DOI: 10.113/jech-2016-208463.
ABSTRACT:
Use of glyphosate-based herbicides (GBHs) increased ∼100-fold from 1974 to 2014. Additional increases are expected due to widespread emergence of glyphosate-resistant weeds, increased application of GBHs, and preharvest uses of GBHs as desiccants. Current safety assessments rely heavily on studies conducted over 30 years ago. We have considered information on GBH use, exposures, mechanisms of action, toxicity and epidemiology. Human exposures to glyphosate are rising, and a number of in vitro and in vivo studies challenge the basis for the current safety assessment of glyphosate and GBHs. We conclude that current safety standards for GBHs are outdated and may fail to protect public health or the environment. To improve safety standards, the following are urgently needed: (1) human biomonitoring for glyphosate and its metabolites; (2) prioritisation of glyphosate and GBHs for hazard assessments, including toxicological studies that use state-of-the-art approaches; (3) epidemiological studies, especially of occupationally exposed agricultural workers, pregnant women and their children and (4) evaluations of GBHs in commercially used formulations, recognising that herbicide mixtures likely have effects that are not predicted by studying glyphosate alone. FULL TEXT
Zimdahl, 2011
Robert L. Zimdahl, “My View: Editorial,” Weed Science, 2011, 59:3, DOI: 10.1614/WS-D-11-00010.1.
ABSTRACT:
Not Available
Harker et al., 2012
K. Neil Harker, John T. O’Donovan, Robert E. Blackshaw, Hugh J. Beckie, C. Mallory-Smith, and Bruce D. Maxwell, “Our View,” Weed Science, 2012, 60, DOI: 10.1614/WS-D-11-00177.1.
Perhaps the incidence and impact of glyphosate-resistant weed species are now great enough that real solutions to glyphosate resistance can be discussed without much backlash. It is clear to most weed scientists who are involved in herbicide research, and even those who are not, that the best way to reduce selection pressure for herbicide resistance is to minimize herbicide use. However, the ‘‘solutions’’ that have emerged in most recent meetings on herbicide resistance have usually involved more herbicide use—herbicide rotation, tank-mixtures, PRE- followed by POST-herbicides, ‘‘right-rates,’’ etc. To an unbiased observer, it would appear that many weed emperors are wearing no clothes. Are we as a weed science discipline choosing to ignore true integrated solutions to the herbicide resistance problem? FULL TEXT
Crews et al., 2007
David Crews, Andrea C. Gore, Timothy S. Hsu, Nygerma L. Dangleben, Michael Spinetta, Timothy Schallert, Matthew D. Anway, and Michael K. Skinner, “Transgenerational epigenetic imprints on mate preference,” PNAS, 2007, 104:14, DOI: 10.1073/PNAS.0610410104.
ABSTRACT:
Environmental contamination by endocrine-disrupting chemicals (EDC) can have epigenetic effects (by DNA methylation) on the germ line and promote disease across subsequent generations. In natural populations, both sexes may encounter affected as well as unaffected individuals during the breeding season, and any diminution in attractiveness could compromise reproductive success. Here we examine mate preference in male and female rats whose progenitors had been treated with the antiandrogenic fungicide vinclozolin. This effect is sex-specific, and we demonstrate that females three generations removed from the exposure discriminate and prefer males who do not have a history of exposure, whereas similarly epigenetically imprinted males do not exhibit such a preference. The observations suggest that the consequences of EDCs are not just transgenerational but can be ‘‘transpopulational’’, because in many mammalian species, males are the dispersing sex. This result indicates that epigenetic transgenerational inheritance of EDC action represents an unappreciated force in sexual selection. Our observations provide direct experimental evidence for a role of epigenetics as a determinant factor in evolution. FULL TEXT
Skinner, 2016
Michael Skinner, “Unified theory of evolution,” 2016, Aeon, available online at: https://aeon.co/essays/on-epigenetics-we-need-both-darwin-s-and-lamarck-s-theories.
ABSTRACT:
Not Available
Manikkam et al., 2014
Mohan Manikkam, M. Muksitul Haque, Carlos Guerrero-Bosagna, Eric E. Nilsson, Michael K. Skinner , “Pesticide Methoxychlor Promotes the Epigenetic Transgenerational Inheritance of Adult-Onset Disease through the Female Germline,” PLoS ONE, 2014, 9:7, DOI: 10.371/JOURNAL.PONE.0102091.
ABSTRACT:
Environmental compounds including fungicides, plastics, pesticides, dioxin and hydrocarbons can promote the epigenetic transgenerational inheritance of adult-onset disease in future generation progeny following ancestral exposure during the critical period of fetal gonadal sex determination. This study examined the actions of the pesticide methoxychlor to promote the epigenetic transgenerational inheritance of adult-onset disease and associated differential DNA methylation regions (i.e. epimutations) in sperm. Gestating F0 generation female rats were transiently exposed to methoxychlor during fetal gonadal development (gestation days 8 to 14) and then adult-onset disease was evaluated in adult F1 and F3 (great-grand offspring) generation progeny for control (vehicle exposed) and methoxychlor lineage offspring. There were increases in the incidence of kidney disease, ovary disease, and obesity in the methoxychlor lineage animals. In females and males the incidence of disease increased in both the F1 and the F3 generations and the incidence of multiple disease increased in the F3 generation. There was increased disease incidence in F4 generation reverse outcross (female) offspring indicating disease transmission was primarily transmitted through the female germline. Analysis of the F3 generation sperm epigenome of the methoxychlor lineage males identified differentially DNA methylated regions (DMR) termed epimutations in a genome-wide gene promoters analysis. These epimutations were found to be methoxychlor exposure specific in comparison with other exposure specific sperm epimutation signatures. Observations indicate that the pesticide methoxychlor has the potential to promote the epigenetic transgenerational inheritance of disease and the sperm epimutations appear to provide exposure specific epigenetic biomarkers for transgenerational disease and ancestral environmental exposures. FULL TEXT
Skinner, 2015
Michael K. Skinner, “Environmental Epigenetics and a Unified Theory of the Molecular Aspects of Evolution: A Neo-Lamarckian Concept that Facilitates Neo-Darwinian Evolution,” Genome Biology and Evolution, 2015, 7:5, DOI: 10.1093/GBE/EW073.
ABSTRACT:
Environment has a critical role in the natural selection process for Darwinian evolution. The primary molecular component currently considered for neo-Darwinian evolution involves genetic alterations and random mutations that generate the phenotypic variation required for natural selection to act. The vast majority of environmental factors cannot directly alter DNA sequence. Epigenetic mechanisms directly regulate genetic processes and can be dramatically altered by environmental factors. Therefore, environmental epigenetics provides a molecular mechanism to directly alter phenotypic variation generationally. Lamarck proposed in 1802 the concept that environment can directly alter phenotype in a heritable manner. Environmental epigenetics and epigenetic transgenerational inheritance provide molecular mechanisms for this process. Therefore, environment can on a molecular level influence the phenotypic variation directly. The ability of environmental epigenetics to alter phenotypic and genotypic variation directly can significantly impact natural selection. Neo-Lamarckian concept can facilitate neo-Darwinian evolution. A unified theory of evolution is presented to describe the integration of environmental epigenetic and genetic aspects of evolution. FULL TEXT
Casteel, 2017
Shaun Casteel, “Soybean Physiology: How Well Do You Know Soybeans?,” 2017, Slide Presentation Prepared for Purdue University Soybean Station.
ABSTRACT: Not Available