Stability of Deltamethrin on Pulses During Storage and the Effect of Processing

Stability and persistence of deltamethrin was evaluated on cowpea (Vigna synensis L. Savi ex. Hassk.), greengram (Vigna radiata Wilczek) and lentil (Lens culanaris Medik. syn. L. esculenta Moench.) during storage under laboratory conditions. The cowpea and lentil grains were treated at 2 and 3 mg kg4 levels of deltamethrin while at 2 and 4 mg kg”1 levels in case of greengram and stored for 6 months. The presence of 54–74% of deltamethrin on all the pulses after 6 months revealed its high persistence and stability. The processing effects like washing and washing followed by steaming dislodged the residues by 34 to 48% and 43 to 70%, respectively, in case of 0 day treated pulses. Maximum concentration of the deltamethrin was found on seed coat (84 to 90%). The insecticide did not affect the germinability of treated pulse grains.