Since the mid-1990s there has been a dramatic increase in the volume of glyphosate herbicides that have been applied and it is now the most heavily used weed-killer in history, new research has found.
The research, called 'Trends in glyphosate herbicide use in the United States and globally', was undertaken by Charles Benbrook.
Since the introduction of Roundup Ready, genetically engineered glyphosate-tolerant crops, in the mid-1990s global glyphosate use has risen almost 15-fold, it found.
Meanwhile, since 1974 in the US, over 1.6 billion kilograms of glyphosate active ingredient have been applied, or 19% of estimated global use of glyphosate (8.6 billion kilograms).
In the US, two-thirds of the total volume of glyphosate applied between 1974 to 2014 has been sprayed in just the last 10 years, Benbrook found.
Globally, the corresponding share is 72%, according to the research.
Genetically engineered herbicide-tolerant crops now account for about 56% of global glyphosate use and Benbrook found that in the US, no herbicide has come remotely close to such intensive and widespread use.
While published global herbicide use data is sparse, this is likely the case globally, the research found.
It also found that glyphosate will likely remain the most widely applied herbicide worldwide for years to come, and interest will grow in quantifying ecological and human health impacts.