Tree-Row-Volume & Spray by Canopy, Not Ground

TRV sprays an orchard according to the size of the canopy rather than the ground area. It treats each row as a wall of foliage and works out the canopy volume per hectare from the canopy height, width and row spacing, then applies a fixed spray rate in millilitres per cubic metre of canopy. This matches the dose to the leaf surface that actually needs covering.

A per-hectare ground rate over-doses small, young trees and under-doses tall, dense canopies, because the same hectare can hold very different amounts of foliage. Spraying by canopy volume scales the dose to the actual leaf wall, giving even coverage, less waste and less drift across trees of different sizes and growth stages.

Tree-Row-Volume per hectare = canopy height × canopy width × (10,000 ÷ row spacing). The row-spacing term converts to the metres of row in one hectare. For example a 3 m tall, 2 m wide canopy on 4 m rows gives 3 × 2 × (10,000 ÷ 4) = 15,000 m³ of canopy per hectare.

Multiply the TRV per hectare by your spray rate in millilitres per cubic metre of canopy, then convert to litres. At 15,000 m³/ha and, say, 80 mL/m³, that's 15,000 × 80 = 1,200,000 mL ÷ 1000 = 1,200 litres of spray per hectare. The total tank volume is that rate multiplied by the area you're treating.

It depends on the target, product label and canopy density — common values fall in a moderate range per cubic metre of canopy, higher for dense foliage or pests needing thorough coverage and lower for open canopies. Always follow the product label and local recommendations; the calculator lets you enter the rate that suits your crop and target.

Canopy height is the vertical depth of foliage from the lowest to the highest leaves on the tree wall, not the trunk-to-tip height. Canopy width is the average thickness of the foliage wall across the row. Measure a representative section of the orchard, since these set the volume of leaf the sprayer must cover.

Yes — closer rows pack more canopy into each hectare, so TRV per hectare and therefore spray litres per hectare rise as row spacing falls. Wider rows give fewer metres of canopy per hectare and a lower volume. That's exactly why the method uses row spacing rather than assuming a fixed planting density.

Yes — any crop grown as a row of foliage walls suits the canopy-volume approach, including vineyards, hedgerow orchards and trellised plantings. Measure the canopy height, width and row spacing the same way. Very irregular or freestanding trees are harder to characterise as a uniform wall, so measure a fair average.

Once you know the litres per hectare, set the airblast sprayer's nozzles, pressure and forward speed so it outputs that volume over a hectare at your row spacing. Use the Sprayer Calibration tool to dial in the output, then check with a measured run. The TRV figure is the target; calibration delivers it accurately.

They're solid planning figures. Real coverage depends on canopy density, sprayer air settings, wind, droplet size and how evenly the air carries spray into the tree. Use the TRV result to set the volume and rate, calibrate the machine to match, and verify coverage with water-sensitive papers — it's a guide for accurate dosing, not a guarantee.