|GRACIA GARZA, JAVIER|
Submitted to: Office of National Drug Control Policy Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/18/1997
Publication Date: N/A
Interpretive Summary: Chemical herbicides form the mainstay of the strategies for control of narcotic plants presently being used. Strategies for biological control of narcotic plants are being developed by the Agricultural Research Service. Biocontrol offers potential long term control of narcotic plants with limited environmental impact. Plants being targeted include coca, poppy, and marijuana. A biocontrol strategy for coca using the host specific soi borne fungus Fusarium oxysporum has been developed and successfully field tested in small scale trials. Scale up for large field testing has not been carried out. The fungi Pleospora papaveracea and Dendryphion penicillatum are being evaluated as biocontrol agents for opium poppy. We continue to develop new formulations of the poppy pathogen for field testing. At present, biocontrol of marijuana is not considered a high priority. Narcotic crops exact a huge toll on today's society in both producing and consuming nations. The successful implementation of contro strategies for narcotic crops would be of immense benefit to society. Biocontrol, if used, could serve as a valuable tool in the overall control strategy for narcotic crops.
Technical Abstract: The USDA/ARS is developing bioherbicide products and technologies using plant pathogens (organisms which attack plants) for the control of narcotic plant production in the field. As a strategy for control of narcotic plant production, bioherbicides offer an alternative to chemical herbicides. Bioherbicides are environmentally safe and damage only the targeted plant species. The primary narcotic plant species being targeted are coca, poppy, and marijuana. These plants are distinctly different in growth requirements and habitats and therefore require distinctly different control strategies. Marijuana is often grown in small plots or even indoors making use of bioherbicides impractical. Opium poppy is grown as an annual crop, growing best under relatively cool conditions. For bioherbicides to be effective on poppy, they must be active under the proper growing conditions and aggressive enough to affect yield before the opium latex is harvested. Greatest success has been in the development of a bioherbicide for control of coca. Isolates of the fungus Fusarium oxysporum, which cause wilt of coca, have been formulated into stable bioherbicides which kill coca. The bioherbicide is slow acting but, since coca is a perennial persisting for 25 years or more, there is ample time for the bioherbicide to work. The potential effectiveness of the bioherbicide is further supported by studies of a natural epidemic of fusarium wilt which is currently damaging coca fields in Peru. We are continuing to evaluate new organisms and strategies for controlling narcotic plants with the goal of developing alternative control measures.