The pre-emergent herbicidal activity of certain acetaldehyde and chloro-substituted aldehyde addition products and related compounds

Three series of chloro-substituted aliphatic aldehyde addition products, mostly derived from chloral, together with related compounds, have been examined for pre-emergent herbicidal activity. The herbicidal investigations were carried out in the laboratory and greenhouse with both mono- and dicotyledonous plants as test species. Some of the compounds showed selective activity at low dosage rates per acre and appeared to warrant further examination under field conditions. The chloral–nitro-paraffin and chloral–amide addition products showed selective herbicidal toxicity which might depend on their breakdown in soil to trichloroacetic acid. The unsaturated dehydration products of the nitro-alkanols, their acetyl derivatives and the corresponding methoxy compounds exhibited little toxicity towards any plant species tested. All active compounds tested were toxic towards wheat and other monocotyledonous species and almost inactive towards dicotyledonous plants.