BEHAVIOR OF ENDOSULFAN RESIDUES IN PEPPERS, CUCUMBERS AND CHERRY TOMATOES GROWN IN GREENHOUSE - EVALUATION BY DECLINE CURVES

Decline of endosulfan residues in pepper, cucumber and cherry tomatoes grown in greenhouses, and the corresponding statistical parameters, w ere evaluated assessing the formal approaches proposed by Timme, Frehs e and Laska to study the behaviour of pesticide residues in crops. In all cases, the first-order reaction function was confirmed to describe the behaviour of endosulfan residues, but functions that best fit the experimental data were first-order for cucumber, RF-first-order for p epper and RF-1.5th-order for tomato. Half-life periods of endosulfan r esidues determined from the first-order function were 11.1(+/-1.3) day s (cucumber), 15.2(+/-3.3) days (pepper) and 20.1(+/-6.6) days (tomato ), whereas the values obtained from the optimal functions were close t o 10 days for the three plantations.