Residue Levels in Apples and Pears Field-Treated with Two Experimental Chlorothalonil Formulations

Chlorothalonil is a well-known product largely used in several countries against a broad spectrum of pathogenic fungi which affect economically important crops (I, 2, 3). Chlorothalonil has been recently considered by I.A.R.C. (4). In Italy, Chlorothalonil is included in a list of pesticides presently under revision. A deeper and updated knowledge about its toxicological and environmental properties will improve the evaluation of risks related to the use of that pesticide. In this framework t he determination of the residues in crops treated with Chlorothalonil formulations was performed. As new types of Chlorothalonil formulations become available, itis essential to check both their efficacy and their residue levels after treatment. Two different types of experimental Chlorothalonil formulations bave been tested in a field treatment carried out by the Regional Plant Protection Service (Bologna, Italy) on apple and pears cultivations. This paper presents the levels of Chlorothaloni! residues in treated apple and pear samples, harvested afte�9 several time intervals, under the experimenta! conditions described below.