... .BiologyandEcologyThree yellow- floweredCentaureas.Fromlefttoright:tocalote,Sicilian starthistle, and yellow starthistle. 8 | YELLOW STARTHISTLE MANAGEMENT GUIDE YSTMgmt(FINAL).indd 8 10/12/06 12:49:30 PM YELLOW STARTHISTLE MANAGEMENT GUIDE ... starthistle willdevelopamoreerect,slenderstemwithfewbasalleaves.Theseplantsarerelativelybrittleandeasytoremove.Inaddition,theyrarelyhaveleavesattachedCHA PT ER 4 : MechanicalControl YELLOW STARTHISTLE MANAGEMENT GUIDE | 17YSTMgmt(FINAL).indd 17 10/12/06 12:49:50 PM18 | YELLOW STARTHISTLE MANAGEMENT GUIDE TillageTillageismorecommoninagriculturalareasthaninnon-cropareas.Onoccasion,tillagecanbeusedinrangelands,alongroadsides,andinutilityrights-of-way.Tillageusingplowsordiscscancontrolannualweedsbyburyingplantparts.Thisismoreeffectiveonannualsthanperennials.Incontrast,tillageusingharrows, ... Asanaddedbenefitofshortdurationintensive YELLOW STARTHISTLE MANAGEMENT GUIDE | 21YSTMgmt(FINAL).indd 21 10/12/06 12:49:55 PM22 | YELLOW STARTHISTLE MANAGEMENT GUIDE grazeiswhenplantsaremost...