No abstract

No abstract

A number of series of related aliphatic and aromatic amides have been examined as pre-emergent herbicides in both laboratory and greenhouse tests using wheat, cabbage and rye-grass as test plants.Some of these compounds were found to show specific activities a t low dosage rates. Rates of hydrolysis of certain of the compounds were determined and the activity of the parent acids in standard tests for plant growth regulating activity was assessed. No general relationship could be drawn between pre-emergent herbicidal activity and chemical structure although the importance of ortho substitution in the benzamide and phenylacetamide series was established.In some cases selectivity was found to be greatly affected by slight structural modifications. o-Chlorophenylacetamide, for example, was markedly effective against cabbage at 10 lb./acre but not against wheat, whereas the opposite type of selectivity was shown by its NN-dimethyl-analogue. These two compounds and o-chlorobenzamide and o-toluamide were further examined elsewhere using a wider range of crop plants and weeds and useful selective herbicidal properties were found. It is suggested that some of the compounds might well be examined further under field conditions.

No abstract