OECD/FAO Zoning Project

Quantics provided statistical analysis of various aspects of pesticide residue data for the OECD pesticide zoning study. The aim of the study was to examine the possibility of identifying geographic zones (rather than zones defined by national boundaries) for the testing of pesticide residues in agricultural crops.

Quantics provided 3 statistical discussion papers:

The Contribution of Zero-day Residue Values to the Variability of Residues Measured at Harvest: A Gould, 7 March 2002 (Revised 16 August 2002)
Statistical Analysis of the Relationship between Climate Factors and Pesticide Residues: Analysis of Data from the USA: A Gould, 5 February 2002 (Revised 16 August 2002)
The Relationship between Application Parameters and Residues Measured at Harvest - Analysis of Selected Crop/Pesticide Combinations: A Gould, 21 June 2002.

See [N.B. Title of document would work better here, rather than the file name]: www.oecd.org/dataoecd/27/0/2955870.pdf

Work by Quantics resulted in the following findings:

The differences in residue behaviour between the proposed residue zones were inconsistent and that the use of a residue zoning scheme based on refinements of existing climate maps could not be validated using the available data.
A general lack of significant correlation between the pre-harvest climatic conditions and residues at harvest reported in comparable residue trials. In the few cases where significant effects were observed, these effects were inconsistent.
Application factors such as spray concentration, treatment rate, the number of sprays and pre-harvest intervals explain a large proportion of the variation in residues at harvest; the additional effect of pre-harvest climate is relatively small, and 'other factors' are likely to be of more importance.