SPRAYER testing is mandatory in many European countries. In the UK the Agricultural Engineers Association protocol for sprayer testing is voluntary and serviced by 50 test centres.
However, pressure on margins, the high value of chemicals flowing through the machines and the need to build government and public confidence, mean sprayer testing could be a wise move.
"Every sprayer we test needs some attention," says Barry Shearman, divisional manager for machinery depots for HL Hutchinson of Wisbech, Cambs. Tests cost about £120 for a 12m sprayer and £180 for a 24m version with many machines tested on-farm by mobile fitters, says Mr Shearman.
Most test failures come from worn jets, boom defects, worn hoses, water or hydraulic leaks, inaccurate pressure gauges, unsafe power take-offs, unreadable sight gauges and missing control labels, says the AEA.
It is wise to check those items not only before the machine goes in for test but throughout the season, suggests Mr Shearman. That will help contain unnecessary costs, which can easily add up to £5.60/ha (£2.25/acre), as well as minimising breakdowns.
"It can be a bit of everything that we find wrong. Sprayer owners dont realise how much their nozzles are worn or if the pressure gauge has been strained, even on sprayers that are only one or two years old."
Before a machine is tested it must be thoroughly decontaminated by the farmer, using appropriate cleaning agents. In addition to tank rinsing and washing the outside of the unit, nozzles, filters and other removable parts must be thoroughly cleaned. If they are not, the test will not be carried out.
Boom stability is often overlooked. Testing is by deflection and noting whether and how fast booms return to their proper position. Many growers dont pay enough attention to that, given its importance for accurate even app-lication, especially with reduced doses, says Mr Shearman. *