Volatilization and Metabolism of Pesticides Under Simulated Outdoor Conditions

The fate of 14C-labelled formulated parathion-methyl was investigated for 24 h after application to French beans in a laboratory chamber, where the air temperature and air humidity fluctuations as measured outdoors during a day in August 1993 could be simulated. The wind velocity directly above the plant stand and the radiation intensity could also be simulated with slight restrictions. Under these conditions, 65.9 % and 65.3 % of the A.I. applied volatilized and were directly determined in air samples in two experiments carried out under identical conditions. 28.9 % and 27.8% were determined after 24 h on the plants, only a part of this radioactivity still representing unchanged parathion methyl. The recovery of the radioactivity applied was 94.8 % and 93.1 %, respectively in the two experiments.