Persistence and dissipation pattern of deltamethrin 2.8 EC in Okra

Deltamethrin 2.8 EC is often sprayed on Okra (Abelmoschus esculentus L.) to control shoot and fruit borer. Its recommended dose is 0.028%. The two sprays of deltamethrin 2.8 EC (0.028 and 0.056%) were applied to okra plants at fruit setting stage at 10 days interval to study the persistence and dissipation pattern. The initial deposits of deltamethrin 2.8 EC were 0.134 and 0.173 μg/g, respectively at recommended and double to recommended dose. The deltamethrin residues were progressively declined at later stages and were below detection limit on fifth day on ward. The half-life of deltamethrin was 1.28 and 0.79 days for recommended and double dose, respectively. Therefore, observation of one day waiting period is suggested for managing the problem of deltamethrin residues in okra under south Gujarat conditions.