Risk assessment of mixture formulation of spirotetramat and imidacloprid in chilli fruits.

Persistence and risk assessment of spirotetramat and imidacloprid in chilli fruits were studied following three applications of a mixture formulation of spirotetramat (12%) and imidacloprid (12%) at 1000 and 2000 mL ha(-1). Residues of spirotetramat and imidacloprid in chilli were estimated by high-performance liquid chromatograph (HPLC). Residues of spirotetramat and imidacloprid dissipated to more than 65% after 3 days at both the dosages. Residues of spirotetramat on chilli fruits were found to be below its limit of quantification (LOQ) of 0.03 mg kg(-1) after 5 and 7 days for recommended and double the recommended dosages, respectively. Similarly, imidacloprid residues were found to be below its LOQ of 0.01 mg kg(-1) at 7 and 10 days, respectively. Half-life periods for spirotetramat were found to be 1.91 and 1.30 days, whereas, for imidacloprid, these values were observed to be 1.41 and 1.65 days at recommended and double the recommended dosages, respectively. Red chilli samples collected after 20 days of the last application did not show the presence of spirotetramat and imidacloprid at their respective determination limit. As the theoretical maximum residue contributions on chilli fruits are found to be less than the maximum permissible intake values on initial deposits, a waiting period of 1 day may follow to reduce risk before consumption at the recommended dose.

Persistence and risk assessment of emamectin benzoate residues on okra fruits and soil.

Emamectin benzoate, a synthetic derivative of abamectin, is found effective against fruit borer and jassid in okra crops. The present studies were carried out to study the dissipation pattern of emamectin benzoate on okra and to suggest a suitable waiting period for the safety of consumers. Following three applications of emamectin benzoate (Proclaim 5 SG) at 68.1 and 136.2 g a.i. ha-1, the average initial deposits of emamectin benzoate were observed to be 0.22 and 0.42mg kg-1, respectively. These residues dissipated below the limit of quantification (LOQ) of 0.05 mg kg-1 after 5 days at both the dosages. Soil samples collected after 15 days did not reveal the presence of emamectin benzoate at LOQ of 0.05 mg kg-1. Acceptable daily intake (ADI) of emamectin benzoate is 0.0005 mg kg-1 body weight day-1, which means an adult of 55 kg weight can safely tolerate an intake of 27.50 microg emamectin benzoate. Assuming an average consumption of 80 g okra fruit and multiplying it by average and maximum residues observed on 0 day at recommended dosage, the intake of emamectin benzoate comes out to be about 20 Itg and these values are quite safe in comparison to its ADI. These studies, therefore, suggest that the use of emamectin benzoate at the minimum effective dosages do not seem to pose any hazards to the consumers if a waiting period of 1 day is observed.

Risk assessment of ß-cyfluthrin and imidacloprid in chickpea pods and leaves.

Dissipation of ß-cyfluthrin and imidacloprid in chickpea pods and leaves was measured following three applications of Solomon 300 OD (ß-cyfluthrin 9 percent +imidacloprid 21 percent) at 200 and 400mLha(-1). Residues of ß-cyfluthrin on chickpea pods and leaves were found to be below its limit of quantification (LOQ) of 0.01mgkg(-1) after 7 days at both the dosages. Similarly, imidacloprid residues were found to be below its LOQ of 0.01mgkg(-1) at 10 days. Half-life periods on chickpea pods and leaves for ß-cyfluthrin were found to be 1.06 and 0.58 days, whereas for imidacloprid these values were observed to be 2.07 and 1.75 days at recommended dose. As the theoretical maximum residue contributions on chickpea pods and leaves are found to be less than the maximum permissible intake values even on 0 day, therefore consumer health risks are minimal at both the dosages on chickpea.

Residual behaviour and risk assessment of flubendiamide on chickpea (Cicer arietinum L.).

The study was undertaken to determine the disappearance trends of flubendiamide residues on chickpea under field conditions and thereby, ensure consumer safety. Average initial deposits of flubendiamide on chickpea pods were found to be 0.68 and 1.17 mg kg(-1), respectively, following three applications of flubendiamide 480SC @ 48 and 96 g a.i. ha(-1) at 7d intervals. Half-life of flubendiamide on chickpea pods was observed to be 1.39 and 1.44 d, respectively, at single and double dosages whereas with respect to chickpea leaves, these values were found to be 0.77 and 0.86 d. Desiodo flubendiamide was not detected at 0.05 mg kg(-1) level on chickpea samples collected at different intervals. Theoretical maximum residue contribution (TMRC) for flubendiamide was calculated and found to be well below the maximum permissible intake (MPI) on chickpea pods and leaves at 0-day (1 h after spraying) for the both dosages. Thus, the application of flubendiamide at the recommended dose on chickpea presents no human health risks and is safe to the consumers.