Environment friendly agar and alginate-based thiram delivery system

Abstract

Agar and alginate have been used for preparation of beads for slow delivery of the fungicide thiram. The beads were characterized by scanning electron microscopy and swelling studies. The beads were prepared with varying amounts of agar, alginate, and crosslinker, and the effect of composition on swelling and release dynamics of the fungicide was studied. Entrapment efficiency, bead size, percentage equilibrium swelling of the beads, and diffusion mechanism for thiram release were evaluated. In all cases, entrapment efficacy was more than 90%. Maximum swelling (250 ± 5%) and thiram release (16.3 ± 0.6 mg g⁻¹) occurred with beads prepared with a solution containing 2.5% agar, 1.5% alginate, and 0.1 mol L⁻¹ Ca²⁺ as crosslinker.

Keywords:

• alginate
• agar
• slow fungicide release

Acknowledgements

The authors wish to thank the Ministry of Environment and Forests, Govt. of India, New Delhi for providing the financial assistance for this work (Project No. 19/101/2008-RE dated 10.02.2009).