Published online by Cambridge University Press: 12 June 2017
Woollyleaf bursage [Ambrosia grayi (A. Nels.) Shinners # AMBGR] and Texas blueweed (Helianthus ciliaris DC. # HELCI) increasingly are weed problems on the Texas High Plains. Field experiments were established to evaluate dimethylamine, potassium, sodium, calcium, and aluminum salts of dicamba (3,6-dichloro-2-methoxybenzoic acid) applied at 1.1, 2.2, and 4.4 kg ai/ha to infestations of each species. Initial woollyleaf bursage control was better than initial Texas blueweed control. Dimethylamine and potassium salts provided highest control levels, and increasing rates improved control. One-year control was higher for Texas blueweed than woollyleaf bursage, and 1-yr control of both species improved with increased rates.