Percent Solution in the Tank

Not every application is a broadcast one. Spot treatment with a handgun or knapsack, greenhouse work, weed wiping and many horticultural sprays are dosed as a percentage of the tank rather than a rate per hectare, because the operator sprays to wet the target rather than covering a measured area. A 1% mix is one litre of product in 100 litres of finished spray.

The reason for the different convention is that area is genuinely unknown in this kind of work. An operator moving through a plantation treating individual weeds cannot say what fraction of a hectare has been covered, so a per-hectare rate has nothing to attach to. Fixing the concentration and spraying to a defined endpoint — usually "to the point of runoff" — gives a reproducible dose per plant instead.

The honest caution is that percentage and per-hectare rates are not interchangeable, and converting between them requires knowing the spray volume actually applied. A 1% mix applied at 1,000 L/ha delivers ten litres of product per hectare, which is far above almost any broadcast label rate. That is not an error — high-volume dilute spraying genuinely uses those volumes — but it explains why a label carrying both a broadcast rate and a handgun percentage will look inconsistent until you multiply through. Where a label gives only one of the two, use that one; do not derive the other and assume it is permitted.