EFFECTS OF HERBICIDE AND NITROGEN-FERTILIZER APPLICATION ON GRAIN-YIELD AND QUALITY OF WHEAT AND BARLEY

Field trials in commercial cereal crops were carried out over three gr owing seasons between 1988 and 1991 on farmland near Basingstoke, Hamp shire to monitor the effects of reduced agrochemical use on crop quali ty. The lack of highly competitive weeds on the study sites gave littl e benefit in yield from the use of herbicide. In some cases no weed co ntrol or half rate applications gave significantly better yields than the full recommended rate. Herbicide applied at the full recommended r ate significantly increased grain N in two of the experiments, despite no notable yield benefit from weed control. Grain N was the only aspe ct of grain quality to show a consistent decline with even moderate re ductions in N application rate.