Glasshouse trials with controlled drop application of some foliage‐applied herbicides

Summary: MCPA, mecoprop, dichlorprop, dicamba, 2,3,6‐TBA, bentazone, ioxynil/bromoxynil (a mixture), barban, difenzoquat and chlorfenprop‐methyl were applied by spinning disc in controlled drop sizes from 150‐350μm and at very low volume rates (5–45 1/ha), to the foliage of some dicotyledonous weed species or wild oats (Avena fatua L.). The same herbicides were also applied by means of conventional hydraulic nozzles at volume rates of about 200 1/ha. Most of these herbicides performed as well at very low volume rates as with the conventional application, the major exceptions being bentazone, ioxynil/bromoxynil (both of which have distinct contact effects) and dichlorprop. Comparisons between oil and water as the diluent at a very low volume rates suggest that there may be situations when oil is preferable and others when water is.