Persistence of imidacloprid on grape leaves, grape berries and soil

Residues of imidacloprid were estimated in grape leaves, grape berries and soil following four applications of Confidor 200SL at 400 and 800 mL ha(-1) using 1,000 L water. The average initial deposits of imidacloprid on grape leaves were found to be 10.01 and 16.97 mg kg(-1) at single and double dosages, respectively. These residues of imidacloprid dissipated to be the extract of 98.8% and 97.0%, respectively, at single and double dosages in 15 days, with half-life period of 2.35 and 2.97 days. Residues of imidacloprid in grape berries at harvest time were observed to below determination limit of 0.05 mg kg(-1) at single dose and 0.06 mg kg(-1) at double dose. However, acceptable daily intake (ADI) of imidacloprid is 0.06 mg kg(-1) body weight day(-1), which means an adult of 60 kg and a child of 10 kg can safely tolerate intake of 3,600 and 600 microg imidacloprid, respectively, without any appreciable risk to their life. Assuming consumption of 200 g grape berries contaminated at 0.06 mg kg(-1), it will lead to an intake of only 12 microg of imidacloprid, which is quite safe for a child as well as for an adult. Hence, the use of imidacloprid on grape crop seems to be toxicologically acceptable.