title: Herbicidal activity of formulated sorgoleone, a natural product of sorghum root exudate.
abstract: BACKGROUND
  The allelochemical sorgoleone, a major component of the hydrophobic root exudates of Sorghum bicolor, was formulated as a wettable powder [4.6 WP] and evaluated as a natural herbicide on several weed and crop species under different growth conditions.
  
  
  RESULTS
  Formulated sorgoleone [4.6 WP] suppressed germination and shoot growth of weeds, with broadleaf species showing greater susceptibility than grass weed species. Germination and growth of broadleaf weed species were completely suppressed (100%) at 0.2 g a.i. L(-1) sorgoleone in a growth chamber study. Post-emergence applications of the wettable formulation of sorgoleone [4.6 WP] inhibited 20-25% higher growth of weeds than pre-emergence applications under greenhouse conditions. Broadleaf weeds were more susceptible than grass species to both methods of application. In all studies, growth was suppressed in more than 90% of the broadleaf weeds and two species, in particular, Rumex japonicus and Plantago asiatica, were completely suppressed at 0.4 kg a.i. ha(-1) sorgoleone. The crop species, on the other hand, were much more tolerant to sorgoleone, with 30% inhibition, at most, at the highest rate of 0.4 kg a.i. ha(-1) sorgoleone.
  
  
  CONCLUSIONS
  The results of this study reveal that sorgoleone, after formulation as a WP, is more effective in inhibiting weed growth, and crop species are tolerant to it. The strong weed suppressive ability of formulated sorgoleone therefore offers interesting possibilities as an effective natural environment-friendly approach for weed management.
authors.affiliation: Department of Crop Science, College of Agriculture & Life Sciences, Chungnam National University, 99 Daehangno, Yuseong-gu, Daejeon, 305-764, Korea.
authors.forename: Md Romij
authors.initials: MR
authors.lastname: Uddin
authors.forename: Sang Un
authors.initials: SU
authors.lastname: Park
authors.forename: Franck E
authors.initials: FE
authors.lastname: Dayan
authors.forename: Jong Yeong
authors.initials: JY
authors.lastname: Pyon
mesh_terms: D016227:Benzoquinones / Q000737:chemistry* / Q000633:toxicity*; D001688:Biological Products / Q000737:chemistry* / Q000633:toxicity*; D002626:Chemistry, Pharmaceutical; D018556:Crops, Agricultural; D004780:Environment, Controlled; D006540:Herbicides / Q000737:chemistry / Q000633:toxicity; D008055:Lipids / Q000737:chemistry* / Q000633:toxicity*; D018517:Plant Roots / Q000737:chemistry*; D011208:Powders; D045868:Sorghum / Q000737:chemistry*; D058728:Weed Control; D017155:Wettability
chemical_list: D016227:Benzoquinones; D001688:Biological Products; D006540:Herbicides; D008055:Lipids; D011208:Powders; C113738:sorgoleone
keywords: allelochemical; formulation; herbicidal activity; selectivity; sorgoleone