In the greenhouse, dicamba amine (dimethylamine of 3,6-dichloro-o-anisic acid) at 1.1 and 2.2 kg/ha (a.i.) controlled young seedlings of leafy spurge (Euphorbia escula L.) and prevented shoot formation 66 days after herbicide application. The 2,4-D amine (dimethylamine of 2,4-dichlorophenoxyacetic acid) did not effectively control the growth of leafy spurge at 0.6 and 1.1 kg/ha, but gave good control at 2.2 kg/ha. In a separate test, dicamba at 2.2 kg/ha controlled growth of shoots and roots of 100-day-old stands of leafy spurge more effectively than 2,4-D at the same rate. Dicamba killed mother stands and prevented the production of new shoots, whereas 2,4-D suppressed root growth of mother stands but induced more new shoot growth than found in untreated check plants. In a 5-year (1977-1981) field study (Brandon, Manitoba) of naturally established leafy spurge in a 'Carlton' smooth brome (Bromus inermis Leyss.) pasture, dicamba at 2.2 kg/ha, applied each year from 1977 to 1979, controlled leafy spurge satisfactorily and resulted in increased smooth brome yield. The 2,4-D at 2.2 kg/ha controlled the weed satisfactorily in 1977 and 1979, but not in 1978 and 1981. The mixture of 2,4-D (2.2 kg/ha) and dicamba (1.1 kg/ha) improved weed control and increased smooth brome yield. The smooth brome yield was inversely proportional to leafy spurge control. Under field conditions from 1978 to 1979, 14C-dicamba in the plant translocated to the lower part of stems and accumulated in roots of established leafy spurge more readily than did 14C-2,4-D, measured at 7, 47 and 350 days after herbicide application. It was concluded tht dicamba applied each year gave better spurge control than 2,4-D and resulted in a large yield increase of smooth brome due to killing young seedlings and mother stands. This prevented the spread of root system and seed multiplication of leafy spurge on pasture. This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020
Scholarly peer-reviewed articles published by the Society for Range Management. Access articles on a rolling-window basis from vol. 1, 1948 up to 5 years from the current year. Formerly Journal of Range Management (JRM). More recent content is available by subscription from SRM.