Science Letters

Cypermethrin Chemodynamics in Okra Crop Agro-ecosystem in Bangladesh

Aaseif Uddin 1, Md. Shamim Hossain 1, Md. Mahbubar Rahman 1, Shahinoor Rahman 2*, Md. Abdur Razzak Choudhury 3

1 Department of Entomology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh

2 Department of Entomology, EXIM Bank Agricultural University, Bangladesh

3 Department of Entomology, Sylhet Agricultural University, Bangladesh

Abstract

Cypermethrin is a non-systemic insecticide widely used for the controlling okra shoot and fruit borer infestation in Bangladesh. At the time of cypermethrin application in the okra field by knapsack sprayer, it not only goes to the target site (plant), but also goes into the soil, air and other environmental component through drifting. Field research was carried out to study the dissipation pattern of cypermethrin in different growth ages of okra crop and laboratory research was directed to determine the residue of cypermethrin from fruit and soil. The highest deposition of cypermethrin (58.2%) was found in the target area (plant) at 105 days after sowing (DAS) and the lowest (47.3%) was at 45 DAS of okra crop. The drift loss of cypermethrin in air ranged from 4.65% to 7.85%. The drift loss was highest in soil recorded at 45 DAS (48.05%) and the lowest (36.25%) was at 120 DAS. Cypermethrin residues determined from fruit and soil samples sprayed at 1 ml/L in the field were above maximum residue limits (MRLs) up to three days after spraying (0.862 ppm) in fruit samples and up to five days after spraying in soil samples (0.554 ppm). In case of spraying 2 ml/L of cypermethrin, fruit samples have residues above MRLs up to seven days after spraying (0.668 ppm) and soil samples have up to five days after spraying (0.653 ppm). So, okra may consume after three to seven days of spray application for the human health safety.

Keywords Agro-ecosystem, cypermethrin, dissipate, environment, residue.

Received June 26, 2016 Accepted September 10, 2016 Abstract Published October 06, 2016 Manuscript Published December 15, 2016

*Corresponding author Shahinoor Rahman E-mail shahinoor_ent@yahoo.com Tel +8807815352529 Fax +88078153531