Slow-release formulations of sulfometuron incorporated in micelles adsorbed on montmorillonite

Yael Golda Mishael, Tomas Undabeytia, Onn Rabinovitz, Baruch Rubin, Shlomo Nir*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Scopus citations


The design and tests of slow-release formulations of sulfometuron (SFM), an anionic sulfonylurea herbicide, are described. The formulations are based on incorporation of the herbicide in octadecyltrimethylammonium (ODTMA) micelles, which adsorb on a clay mineral, montmorillonite. An optimization of herbicide/micelle clay ratios yielded high adsorption of SFM (95%), and at a 1% (w/w) water suspension only 0.5% of the adsorbed SFM was released at times varying from hours to 9 days. An analytical test in Seville soil showed that under excessive irrigation (400 mm) 100% of the commercial formulation leached, whereas the micelle-clay formulations showed only 50-65% elution. A plant bioassay in Rehovot soil showed that the commercial dispersible granule formulation (Oust, 75% ai sulfometuron methyl) yielded only 23% root elongation inhibition at the top 5 cm of the soil, whereas complete inhibition was achieved with the micelle-clay formulation. The detected concentration of SFM for the micelle-clay formulation at a depth of 15-20 cm was half of that detected for the commercial one, indicating a reduction in leaching when applying the micelle-clay formulation. A 10-fold reduction in the applied dose of SFM in the micelle-clay formulations resulted in good herbicidal activity of 60-87% inhibition. These characteristics make the new formulation promising from the environmental and economic points of view.

Original languageAmerican English
Pages (from-to)2864-2869
Number of pages6
JournalJournal of Agricultural and Food Chemistry
Issue number10
StatePublished - 8 May 2002


  • Bioassay
  • Micelles
  • Montmorillonite
  • Octadecyltrimethylammonium
  • Slow release
  • Soil column
  • Sulfometuron


Dive into the research topics of 'Slow-release formulations of sulfometuron incorporated in micelles adsorbed on montmorillonite'. Together they form a unique fingerprint.

Cite this