Department of Entomology, Punjab Agricultural University, Ludhiana, 141 004, India
Online published on 31 October, 2011.
Chlorpyriphos when applied @ 375 g a.i. ha−1 on 30, 21 and 14 d before harvest of rice resulted in residues of 0.01, 0.02 and 0.02 g a.i. ha−1 respectively, on polished rice grain which was below the prescribed maximum residue limit (MRL) value of 0.10 mg kg−1. Rice husk contained high concentrations of chlorpyriphos and its average levels were observed to be 0.29, 0.34 and 0.46 mg kg−1 respectively. Residues of chlorpyriphos remained below its detectable level of 0.01 mg kg−1 in rice bran in all the treatments. Analysis of straw revealed maximum concentration of chlorpyriphos and its mean levels were 0 87 0 92 and 1 73 mg kg−1, respectively, in the samples collected from plots treated 30 21 and 14 d before harvest Therefore a strict regulation is required to avoid feeding of straw to milch catties for protection of their body burden by chlorpyriphos and yield of quality milk.
Chlorpyriphos, polished rice grain, rice husk, rice bran, straw, MRL
