Dissipation behavior of pyridalyl was determined on cabbage crop following two applications of pyridalyl @ 50 (X), 62.5 (1.25X), and 100 g a.i. ha-1 (2X). QuEChERS method along with gas chromatography-mass spectrometry/mass spectrometry technique was used for the quantification of pyridalyl residues. Mean initial deposits were found to be 0.49, 0.60, and 1.12 mg kg-1 at X, 1.25X, and 2X doses on cabbage heads, and the residues reached below the limit of quantification (LOQ) of 0.01 mg kg-1 after 15th, 15th, and 20th days at the three doses, respectively. Mean initial deposit in soil was 0.11, 0.13, and 0.24 mg kg-1, which reached below LOQ on 7th to 15th days at all the doses. Half-life value of pyridalyl in cabbage was calculated to be 1.88, 2.48, and 2.58 days at single, 1.25X, and double dosages, respectively. Among various household processing methods, 2% NaCl solution along with boiling was highly effective in reducing the residue of pyridalyl up to 83.38%-86.12% in cabbage. Risk assessment done by calculating hazard quotient shows that the application of pyridalyl @ 50 and 100 g a.i. ha-1 is acceptable for consumption.
Singh et al. (Wed,) studied this question.