Physico-chemical properties and biological activity of controlled-release granular formulations for the herbicide dicamba

방출조절형 dicamba 입제의 물리화학성 및 생물효과

  • Oh, Kyeong-Seok (National Institute of Agricultural Science & Technology, RDA) ;
  • Oh, Byung-Youl (National Institute of Agricultural Science & Technology, RDA) ;
  • Park, Seung-Soon (National Institute of Agricultural Science & Technology, RDA) ;
  • Lee, Jae-Koo (Department of Agricultural Chemistry, College of Agriculture, Chungbuk Notional University)
  • 오경석 (농업과학기술원 작물보호부) ;
  • 오병렬 (농업과학기술원 작물보호부) ;
  • 박승순 (농업과학기술원 작물보호부) ;
  • 이재구 (충북대학교 농과대학 농화학과)
  • Published : 1999.05.25

Abstract

Dicamba (3,6-dichloro-o-anisic acid) granular formulations for controlled release (DGFCRs) were prepared with biodegradable polymers, corn starch and pregelatinized starch, to minimize harmful side effects, extend weed control performance, and control the releasing rate of the active ingredient. Physico-chemical properties and biological activity of DGFCRs were studied. Six different granules were formulated by applying two processes, granulation and extrusion. Formulation efficiencies of active ingredient (A.I.) in the granules prepared by granulating and extruding were $90.0{\sim}96.3%$. Incorporation ratios of A.I. in the granules prepared by granulating and extruding showed $89.5{\sim}94.5%$ and $46.7{\sim}82.0%$, respectively. The highest swellability was DG-2 formulation prepared with corn starch. Whereas, the lowest floatability in water was DG-2 formulation, while the highest one was DG-1 formulation prepared with pregelatinized starch, Miragel 463. The degradation rates of dicamba in the granules under the elevated temperature of $50^{\circ}C$ were less than 5% for DG-1 and DG-2 formulations even after 90 days, meanwhile, those of DE-1 formulations prepared with pregelatinized starch, Mirasperse, were more than 5%. The release rates of A.I. from the granules into water under a static condition were about 100% after 2 weeks. Weeding effects of the granules on broad leaf weeds tested in greenhouse were more than 90% after 30 days.

Keywords

Dicamba