Dissipation of Propineb in Onion

In order to study the dissipation of propineb in/on onion, a field trial was conducted at Vegetable Research Station, Anand Agricultural University, Anand. After 44 days of transplanting, foliar application of the fungicide was made thrice at 10 days interval @ 1225 and 2450 g ai ha−1. The fresh samples comprising green leaves and immature eulb were collected at 0 (2 h), 1, 3, 5, 7, 10 and 15 days after the third spray. The initial deposiis were 1161 and 4.03 μg g−1 of propineb (on CS2 basis), which persisted upto the 7th and 10th day at lower and higher dose of application, respectively. The half-llfe values of propineb ranged from 2.3 to 2.4 days. No MRR for propineb is fixed by PFA in India. Considering the MRL of 4.0 μg CS2 g−1 prescribed db Australia, the recommended dose can be considered safe even on the day of application.