Transfer of the fungicide vinclozolin from treated to untreated plants via volatilization

Abstract

Head lettuce plantlets ( Lactuca sativa L. var. capitata) were potted, treated with vinclozolin at the six-leaf stage according to application standards and allowed to dry for 24 h. The potted plantlets were then placed in either growth chambers with controlled temperature (20 and 25 °C, respectively) or in a greenhouse (approximately 12 °C), together with untreated spinach ( Spinacia oleracea L.) and standardized grass cultures ( Lolium multiflorum Lam. ssp.) While the treated lettuce pots remained in the respective growing compartments until the end of the experiments, spinach and grass were exposed to the compartment air for 24 h and their shoot material was analyzed for vinclozolin by GC-ECD and GC-high resolution mass spectrometry. Exposure and analysis of untreated spinach and grass were carried out at two- or three-day intervals during the course of the experiments. Also, air samples were taken from the compartments at intervals and analyzed for vinclozolin. Maximum vinclozolin concentration in the growth chamber air was about 330 ng m −3 while vinclozolin contamination of the untreated plants ranged from 50 to 200 μg kg −1 FW (fresh weight). In the greenhouse atmospheric vinclozolin concentration reached approximately 15 ng m −3 and maximum contamination of spinach and grass were 30–40 μg kg −1 FW. Our data clearly show that unintended contamination of plants growing in the vicinity of vinclozolin-treated plants can occur even if the fungicide layer is completely dry. Implications for safety testing and food plants are discussed.