Broad-leaved crops present a completely different target to cereals, with horizontal leaves interlocking into a closed canopy. Persuading the spray into that canopy is tricky – often only 10-15% of spray ends up where it's needed. Big drops hardly get below the surface, but fine drops can ride in horizontally on air turbulence.
Weed control
Water volume
100–200 l/ha depending on nozzle choice
Nozzle choice
Gold 04 Potato nozzle for slower applications or Orange 05 Potato nozzle, where conditions allow more forward speed - use alternately backward and forward. If conditions are marginal, use an equivalent sized AMISTAR nozzle.
Application speed
Gold 04 nozzle: 8-12 km/h
Orange 05 nozzle: 12-16 km/h
Other comments
Keep the boom low - 50 cm above the ridge and pressure moderate - 2 to 2.5 bar.
Coverage of both sides of the ridge is imperative - avoid spraying in cross winds.
Blight control
Angled nozzles such as the Syngenta Potato Nozzle, produce less drift and positively push a medium spray where it's needed. As the crop develops and the canopy closes, these nozzles can double the amount of chemical reaching the lower parts of the plants.
Water volume
200 l/ha
Nozzle choice
Gold 04 Potato nozzle for slower applications or Orange 05 Potato nozzle where conditions allow more forward speed - use alternately backward and forward. If conditions are marginal, use an equivalent sized AMISTAR nozzle.
Application speed
Gold 04 nozzle: 8-12 km/h
Orange 05 nozzle: 12-16 km/h
Other comments
Keep the boom low - 50 cm above the ridge and pressure moderate - 2 to 2.5 bar.
Lower volumes may be used in the very early part of the season but 200 l/ha is best for the majority of sprays
Desiccation
Using foliar desiccation sprays usually means a 2-spray programme (depending on the size of the haulm). The first spray takes the leaves off and the second then targets the stems.
Water volume
For very big haulms use 400 l/ha for the first spray to open up the crop, then use 200 l/ha for the second spray. 200 l/ha has been shown to be equal to or better than higher volumes after two sprays.
Nozzle choice
Gold 04 nozzle: 8-12 km/h
Orange 05 nozzle: 12-16 km/h
Use alternately forwards and backwards.
Application speed
As above
Other comments
If the crop is dense or growing vigorously, use 400 l/ha for the first spray; follow up 5 days later at 200 l/ha.