CONTROL OF HONEY MESQUITE (PROSOPIS-JULIFLORA VAR GLANDULOSA) AND MACARTNEY ROSE (ROSA-BRACTEATA) WITH SOIL-APPLIED HERBICIDES

Seven herbicides were applied to the soil surface or subsurface for control of honey mesquite [P. juliflora (Swartz.) DC. var. glandulosa (Torr.) Cockerell] and Macartney rose (R. bracteata Wendl.). Liquid formulations were applied in bands about 1 cm wide, 1.2 m or more apart, and granule or sphere formulations were applied on the soil surface either broadcast or in rows 1.2 m or more apart. On honey mesquite, karbutilate [tert-butylcarbamic acid ester with 3 (m-hydroxy-phenyl)-1,1-dimethylurea] and tebuthiuron [N-[5-(1,1-dimethyl)-1,3,4-thiadiazol-2-yl]-N,N''-dimethylurea] were the most effective herbicides with subsurface spray injections being generally more effective than surface applications. On honey mesquite, differences among row spacing treatments with liquid, granule or sphere formulations of karbutilate were generally either small or insignificant. Roller chopping reduced the honey mesquite canopy but did not influence the percentage of plants killed by karbutilate at rates of 4.5 kg/ha and below. Bromacil (5-bromo-3-sec-butyl-6-methyluracil), diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], picloram (4-amino-3,5,6-trichloropicolinic acid), prometon [2,4-bis(isopropylamino)-6-methoxy-s-triazine], and 2,3,6-TBA (2,3,6-trichlorobenzoic acid) generally were ineffective as soil treatments for controlling honey mesquite. Of all the herbicides evaluated on Macartney rose, only picloram at 4.5 kg/ha and tebuthiuron at 2.2 and 4.5 kg/ha, as soil treatments, killed a significant number of plants.