Influence of volume rate and nozzle angling on control of potato late blight with flat fan, pre-orifice and air induction nozzles

摘要

The influence of volume rate and nozzle angling on potato late blight control with flat fan, pre-orifice and air induction nozzles were investigated in a number of field experiments. Generally application was carried out with weekly intervals using two dose rates of a contact fungicide. The volume rates tested using flat fan and pre orifice nozzles were 160 and 320 L ha~(-1). At 160 L ha~(-1) control of late blight was compared using traditional flat fan nozzles, pre-orifice nozzles and air inductionnozzles. There was no difference between 160 and 320 L ha~(-1) spray volume in late blight control. Surprisingly the control of late blight was comparable with the three different nozzle types despite the large difference in droplet size and coverage. With the flat fan nozzle a 30° backward angling of the spray was also included. However, compared to the standard vertical spray, no advantage in control of late blight was found.