Published online by Cambridge University Press: 12 June 2017
In field plantings, granular 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) were the most effective herbicides, but injured Spiraea media, S. trichocarpa, Syringa prestoniae and Physocarpus opulifolius. Diuron also injured newly planted evergreens. Granular 3-amino-2,5-dichlorobenzoic acid (amiben), isopropyl N-(3-chlorophenyl)carbamate (CIPC), 2-chloroallyl diethyldithiocarbamate (CDEC) and 4,6-dinitro-o-sec-butylphenol (DNBP) did not cause injury. Preplanting application of ethyl N,N-di-n-propylthiolcarbamate (EPTC) reduced the vigor of the deciduous shrubs. Chamaecyparis and Thuja species were tolerant to simazine under greenhouse conditions, while tolerance in Juniperus varied according to species.