Pesticides and Minor Crops

D. Wauchope
April 7th 2010




Pesticides and Minor Crops


In pesticide terminology there are three ways in which the term “minor crop” is used. 


First, a crop may be called “minor” if such small amounts are grown it will be a minor market for pesticides. The consequence of this is that pesticide producers will have little incentive to do the expensive research and development work needed for registration of pesticides for use on the crop, and the crop will have limited pest protection options. 


Second, a crop may be such a minor crop economically in a given region that it will not receive the attention from exporting or importing governments needed to permit it in trade. Specifically, a lack of action for food safety certification, especially for pesticide residues, is often the hindrance.


Third, a crop may be eaten in such small amounts that any residues present from pesticide use may be expected to contribute minor or negligible amounts to human exposure. An example is spices. These “very minor crops” typically suffer from both of the above issues and efforts are being made to recognize their unique situation.


These three minor crop issues are consequences of the way pesticides are developed by the industry and subsequently regulated by national or regional agencies.  In general, for a pesticide to be legally used on a crop, an experiment must be made to determine how much pesticide “residue” will occur in the resulting food. These studies are a combination of field experiments, in which the chemical is applied in the manner it is proposed to be used in the crop, followed by laboratory analysis of the food for the pesticide.  These data are then combined with data on how much of the food is consumed by individuals to determine how much pesticide will be ingested, and then these amounts are compared with the toxicity of the pesticide to humans.  The studies to determine residue amounts alone are very expensive: typically a single study in a single crop location can cost $US 100,000 and multiple locations are often required.  Thus the industry will prioritize such studies to crops which are large markets and likely to justify such an investment.  Similarly, governments and their regulators will give the same crops their highest priority since pesticide usage on these crops has the greatest potential environmental and food safety impact. 


But crops are never “minor” to those who produce them and often are far from minor economically to a given region or specific country.  Thus, a wide variety of “third party” (meaning non-manufacturer) initiatives have been undertaken to obtain legal uses of pesticides for minor crops, and approvals for allowed residue levels in foods for commerce. Examples include:

Innovative measures for using research data from one crop for a similar crop, e.g., grouping pome fruits together and assuming that residues of a pesticide in apples are likely to be similar to those observed in cherries.

Making simple but conservative assumptions for residues in very minor crops; even large overestimated residues in spices, for example will contribute very small amounts to pesticide intake.

Using funds from sources such as grower groups or taxes to fund the field and laboratory investigations needed to clear specific used of pesticides on minor crops.


Currently, minor crops are receiving a lot of international attention. The lack of crop protection options and regulatory neglect causes hardships for (often small and marginalized) producers.  These problems are a source of continuous trade conflicts. These obstacles can be overcome: there are many success stories.  But a global effort must be encouraged to recognize the importance of these crops for a healthy, diverse human diet.


Useful sources of information are:


IR-4, the US publicly-funded minor use registration project


The Minor Use Global Summit Conference, Rome, December 2007


Global Minor Use information Portal


European Initiative on Minor Uses


US Environmental Protection Agency, Pesticides, New Approaches to Minor Uses, April 2010


UK Minor Uses Network


European and Mediterranean Plant Protection Organization (EPPO), Minor Uses of Plant Protection Products


OECD, OECD Series on Pesticides, Number 38, Survey of the Pesticide Risk Reduction Steering Group on

Minor Uses of Pesticides$FILE/JT03228678.PDF


OECD, OECD Guidance Document On Defining Minor Uses Of Pesticides, ENV/JM/MONO(2009)39, 2009



Original Author: R. Don Wauchope


Last modified April 7th 2010


Date added: 2010-05-10 01:37:48   
Last Updated -0001-11-30 00:00:00   
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