Integrated control of herbicide resistant Lolium rigidum in extensive rainfed cropsWorkshop on Weed management in arid and semi-arid climate European Weed Research Society

Jos M Montull and Andreu TabernerUniversitat de LleidaDept. de Hortofruticultura, botnica i jardineriaThe main objective is to study different alternatives for herbicide-resistant L. Rigidum control in rainfed cereal cropping systems, integrating three different crops in rotation different herbicides approved for each crop.MATERIAL & METODS:OBJECTIVERESULTS:CONCLUSIONS:Untreated winter wheatUntreated spring field peaUntreated spring barleyThe effect of sowing in late January has been enough to avoid applying herbicides against L. rigidum in barley crop.

In this field, low efficacy has been achieved with ALS and ACCase inhibitors due resistance to these groups of herbicides, including new herbicides still unsold.

Auros and Kerb efficacy was conditioned by the drought at winter in the application time.

Only Mutual and Auros in spring pea, have been achieved efficaccy up to 90%.

90 plants/m2 of L. rigidum in winter wheat justify its control.

15 plants/m2 of L. rigidum in spring barley not justify its control.

10 plants/m2 of L. rigidum in spring pea justify its control.oliumIf this field, infested by a L herbicide resistant biotype, the best solution was the crop change.* Still unsold in the spanish market

CropHerbicideActive ingredientHRAC GroupDoseTreatment timingWinter WheatAtlantisIodosulfuron 0,6% +mesosulfurn 3%B500g/ha21BBCHBroadwayFlorasulam 2,28% +Pyroxulam 6,83%B275g/ha21BBCHAurosProsulfocarb 80%N4 l/ha09BBCHUntreatedClortoluron 50%Chlortorluon 50%C24l/ha11BBCHCaliban duoIodosulfurn 1% + propoxicarbazone 16,8%B330 g/ha21BBCHSpring BarleyAxialPinoxaden 10%A600cc/ha13BBCHHerbaflexBeflubutamide8,5% +Isoproturon 50%C2+F2,5l/ha11BBCHHussar plusIodosulfuron + mesosulfuronB265g/ha13BBCHUntreatedClortoluron 50%Chlortoluron 50%C24l/ha11BBCHSplendor 40Tralkoxidim 40%A1l/ha21BBCHSpring Field PeaAurosProsulfocarb 80%N4l/ha09BBCHMutualImazamox 1,67% +Pendimetaline 25%K1+B3l/ha09BBCHKerb floPropizamide 40%K11,875l/ha14BBCHUntreatedFusilade MaxFluazifop-P 12,5% Strong A2l/ha14BBCHAramo 50Tepraloxidim 5%Strong A2l/ha14BBCH

HerbicideResistance gradeIloxan****Splendor***Axial**Fusilade-Max**Atlantis***Clortolurn*AurosS

HerbicideEfficaccy (%)Winter wheatAtlantis41,6Broadway*55,6Auros36,1Clortoluron 50%83,3Caliban Duo*63,9Spring barleyAxial33,3Herbaflex83,3Hussar plus*33,3Clortoluron 50%50Splendor 4050Spring field peaAuros 92,8Mutual85,7Kerb flo64,3Fusilade Max64,3Aramo 5035,7