When it comes to buying a sprayer, it’s not just GPS-controlled auto-boom shut-off systems that are on everyone’s shortlist – auto boom height control is becoming just as popular.

The principle is simple. Two (or sometimes four) ultrasonic sensors on the boom measure the distance between the boom and the crop and raise or tilt the boom automatically to keep crop-to-nozzle clearances uniform. The basic idea has been around for 15 years, but it’s the higher processing power of modern electronic black boxes that has made them work quickly and efficiently.

At least three specialist makers, Norac (sold by Precise Solutions), Raven (sold by Patchwork) and Muller (sold by David King Electronics) have systems that can be fitted to sprayers with electro-hydraulic boom control and Deere and Chafer have their own in-house-developed systems. All five report sharp rises in requests for these systems on both 24m and 36m booms.

Hardi, for instance, which uses a Norac-based system, says 50-60% of its big sprayers are being fitted with auto height control. Deere, meanwhile, says almost all its self-propelled sprayers and most of its big 800i trailed sprayers go out with auto height control.

What’s the attraction? Instead of the sprayer operator having to keep making manual adjustment to keep the booms parallel with the ground, these systems do it automatically. They’re not just useful on undulating ground, either. Some of the bumpy seed-beds produced by min-till systems also induce the sort of boom bounce that can be largely cancelled out by auto boom height control.

Other benefits are less damage to booms, better spray application and the ability to work more accurately in low-light conditions. Allied with GPS-activated auto-boom shut-off on headlands, it makes for a high-tech, almost foolproof set-up.

Costs vary according to whether the system just lifts and lowers the boom or whether it can tilt the two sides of the boom, too. Precise Solutions quotes £2995-£4995, Deere £2000-£2200, Chafer £3500 and Muller about £2800. Patchwork comes in at between £4500 and £5000.