Expert Report

Each report is produced by a committee of experts selected by the Academy to address a particular statement of task and is subject to a rigorous, independent peer review; while the reports represent views of the committee, they also are endorsed by the Academy. Learn more on our expert consensus reports.

Mycoherbicides, which are developed from plant pathogenic fungi that infect specific host plants, have been proposed as a targeted means of preventing or reducing the cultivation of illicit drug crops. This study focused on mycoherbicides intended to target illicit plantings of cannabis, coca, and opium poppy. The committee was asked to examine questions about the efficacy of the mycoherbicides, their persistence in the environment, the feasibility of their large-scale manufacture and delivery, their potential for mutation, their potential to have detrimental effects on nontarget plants, animals, or humans, and the need for additional research and development. The committee concluded that the research done on these pathogens was not adequate to draw conclusions about the feasibility of developing them to control illicit drug crops.

Key Messages

  • The degree of control that might be provided by the proposed mycoherbicides and the mechanisms by which they cause disease have not been established.
  • Large-scale production of the proposed mycoherbicides appears to be possible, but rough estimates suggest that producing the amount of mycoherbicides required for global control efforts may not be feasible due to cost or technical limitations.
  • It is likely that the mycoherbicide strains would persist at some level once introduced into the environment, but no data are available on whether they could persist indefinitely at densities that provide continuous control.
  • There are insufficient data to draw conclusions about whether the proposed mycoherbicides would pose a risk to nontarget plants, other microorganisms, animals, or humans.
  • Additional research is needed to assess the efficacy and safety of the proposed strains of mycoherbicides.
  • Some impediments to the development and use of mycoherbicides include the need for international approval and cooperation, and the development of countermeasures.