Impact of - IDL-BNC @ IDRC - International Development Research ...

A development plan has been identified for synthetic products (Braunholtz
1977), but none is available for natural plant products. Our experience with
endod provided insight into problem areas, the linkages between steps in the
process, and likely costs for the different stages of development. Through trial
and error, we learned that the process must be followed carefully if such a
product is to be internationally approved and recommended as a molluscicide.
The initial phase of the development strategy begins with the discovery of the
new plant biocide and identification of the active chemical compound(s)
(Fig. 1). A simple laboratory screening test to determine efficacy will indicate
its possible value. This can be followed by a controlled preliminary field trial.
Once the potential role of the botanical compound has been identified, the
process that leads to its successful approval is a complex one involving three
interactive phases.
Chemistry and toxicology
The physicochemical characterization of the active principle;
Identification of a standard extraction protocol; and
Production of a bulk sample for acute toxicology. ecotoxicology. and
mutagenicity tests.
Agrobotanical studies
Field trials
Identification of plant type with highest yield (HYV. high-yielding
variety), potency, and pesticidal activity;
Propagation;
Insect/plant pathogen resistance;
Cropping, harvesting, and processing; and
Costbenefit analysis
Vector ecology;
Identification of transmission sites and peak infection periods; and
Formulations and biodegradation.
Identification of the plant type with the highest biocidal potential, insect
resistance, and potential for cultivation must be determined very early in the
process. The standard product must be reproducible, not only for the toxicity
tests but for long-term production, distribution, and use. The identification of
a standard extraction protocol under "good laboratory practices" is a
mandatory requirement for registration. Without such a protocol, the toxicity
tests will not be accepted by any registration agency. The potential toxicologic
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