New spray nozzle designs have not only had a big effect on the ability of farmers to apply pesticides more effectively, they have also made the job easier, believes a top sprayer operator.

“Nozzle technology has come on so much in recent years,” says James Stafford, Syngenta Farm Sprayer Operator of the Year. “It’s given us a choice of application techniques to suit different crops and weather conditions,” he points out.

“Combined with the better results we’ve seen from moving from 150-litre/ha to 100-litre/ha water volume, improved nozzle technology has given us the tools to apply chemicals more accurately and efficiently.”

The Knight ES3000 trailed sprayer he runs at Pickwick Lodge Farm near Corsham, Wiltshire, is kitted out with triplet nozzle holders occasionally carrying 025 conventional flat fan tips, but more often with some fine angled tips for pre- and early post-emergence spraying, and two air inclusion nozzles.

That selection deals with all herbicide and fungicide treatments used on the winter wheat, winter barley, spring barley and oilseed rape grown across 200ha on the home farm and about 120ha of similar crops, plus winter oats, contract sprayed on three neighbouring farms.

“In total, the annual workload adds up to about 1,620ha on fairly gently undulating ground in fields that vary from as little as 2ha to 18ha – in fact, one field I spray on a neighbour’s farm is only 0.6ha,” Mr Stafford says. “The sprayer’s boom is set up to run at 12m, 20m or 24m, but things are easier now that we’ve all switched to 24m tramlines, which had made the job a bit faster.”

With blackgrass a significant problem on the heavy clay loam soils that make up most of the farmed area, effective pre- and post-emergence treatments are crucial to minimise seed return and effect on yield.

“I bought a set of TeeJet 025 conventional flat fan tips with the sprayer specifically for blackgrass control, because I think they take a lot of beating,” says Mr Stafford. “But I can only use them when the weather’s perfect – and how often does that happen?”

In practice, then, they have been superseded by Syngenta’s 03 Defy tip for pre-emergence blackgrass control.

This purpose-made design produces an 80º flat fan at a 40º angle from vertical; Syngenta trials have shown up to 30% better weed control and half the drift of a straight-down spray from a flat fan tip.

“We follow Syngenta’s advice to arrange the tips alternately facing forward and backwards so you get complete coverage of clods,” says Mr Stafford. “I can also see the logic of the argument that this arrangement allows air to pass through the spray pattern instead of being displaced by the curtain of droplets, which must help with drift as well.”

Despite being content with the Defy nozzles, a different approach is being tried again this year as part of an Agrovista trial.

“They say they’re getting better control and yield from using conventional flat fan tips alternately vertical and angled forwards,” he explains. “It’s worth a look, but was a more drifty technique than using the Defy tips last year; we’re taking the trial to yield, so it’ll be interesting to see if there’s any improvement.”

The Defy tips remain in use for post-emergence blackgrass and broad-leaved weed treatments through to growth stage T1 as long as conditions allow, being replaced by air inclusion tips for added anti-drift performance when they do not, as well as for all fungicide sprays.

“The Hypro GuardianAir is the finest of all the air inclusion nozzles available and does a good job for us,” he says. “In good conditions, the 025 lets us spray at 12kph with 3-bar pressure and if I want to go faster in bigger fields, then the 03 gives us 14kph at the same pressure.

“When the wind gets up and we need to control drift more effectively, the 03 at 2-bar still gives me a good 12kph operating speed, but with a coarser spray pattern keeping the droplets where I want them,” he adds.

Ideally, he would like a little more life out of both nozzle types: “If I could get them with ceramic tips that would be great, because the ceramic-tipped TeeJet flat fans last ages and are well worth the extra cost,” he maintains.