Spring check list for when the spray window opens

Use less water, check temperatures and fit as wide tyres as possible is the latest advice for spray operators itching to get out and on to wet spring soils.

Sprayer experts add picking the right nozzle and understanding how sensitive sprays are to cool weather will be key in what could be a cold and wet spring-spraying season.

Many late-drilled autumn crops went into wet winter soils and are looking bedraggled and patchy and in need of a spring tonic from the sprayer or fertiliser spreader.

“The biggest problem will be waterlogging, so we advise growers to go for low water volumes, realise a lot of chemicals don’t work effectively under 8C and use wide tyres,” Syngenta’s spraying guru Tom Robinson told Farmers Weekly.

Many growers already use spray rates of 100 litres/ha, but Mr Robinson urges those still using 200 litres/ha to switch to the lower rate as less water will mean less weight on fields.

Herbicide and plant growth regulators tend to be more sensitive to low temperatures than fungicides, so he advises growers not to waste money spraying when temperature are too low.

Syngenta’s application specialist says the group’s own Moddus (trinexapac-ethyl) plant growth regulator is less sensitive than other rival regulator products when used at low temperatures.

He advises using Defy nozzles for early in the season as they work well in tricky weather conditions producing a relatively narrow fan angle of 83 degrees, which cuts down on drift.

The fan angle produces a slightly more coarse droplet than other nozzles, particularly useful when spraying at higher speeds and when sprayers are limited on how low the spray boom can go.

Wind tunnel testing has shown the nozzle gives good spray deposition and a 50% reduction in drift compared with more conventional flat fan nozzles.

Later in the season, he suggests a switch to an Amistar nozzle when crops start meeting in the rows as this produces a relatively fine spray and was developed specifically for cereal ear treatments.

His advice is to stick to traditional sprayer speeds of 12km/hr for herbicide and growth regulator sprays, and only consider faster speeds of 16km/hr for fungicides.

Arable grower and sprayer operator James Stafford advises growers to make sure their machines are ready for action for when there is an improvement in the weather and a window for spraying appears.

Mr Stafford, who farms in west Wiltshire, knows a thing or two about spraying as he was the Farmers Weekly Farm Sprayer Operator of the Year in 2012.

“Make sure your sprayer has had a good winter service and is in tip-top condition, as in a season like this good spraying days may be limited,” Mr Stafford says.

He farms 200ha at Pickwick Lodge Farm, Corsham, near Chippenham, and in poor autumn conditions he only managed to drill 30-40% of the farm on his brashy and silty clay soils.

He uses 650mm-wide tyres on tractor and sprayer in the early stages of the season to minimise soil damage, before switching to row crop-sized wheels later in the season.

“Don’t apply sprays when the ground is waterlogged, as the chemical will simply go down the drain,” he warns.

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