Published online by Cambridge University Press: 12 June 2017
Napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide] applied with simazine [2-chloro-4,6-bis(ethylamino)-s-triazine] reduced by 47 to 82% the severity of simazine symptoms on California privet (Ligustrum ovalifolium Hassk.), staghorn sumac (Rhus typhina L.), and ‘Moonlight’ broom (Cytisus X praecox Bean). Oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) had a similar but smaller effect (40% reduction) when applied with simazine on broom in a field experiment and an effect equal to napropamide with simazine on privet in a greenhouse experiment. Both napropamide and oryzalin prevented some of the growth reduction from simazine on privet, broom, and ‘Baltic’ ivy (Hedera helix L. ‘Baltica’) in field experiments. In the greenhouse study with privet, napropamide prevented much of the growth-reducing effects of simazine on both shoots and roots of privet. Oryzalin appeared to have a similar effect.