A NEW electrostatic spray rig is making its mark for Pakenham apple grower Priest Bros. TOM McKENNY reports

Long-term fans of electrostatic spray technology, Priest Bros has had Silvan electromisers since the mid-1990s.

Now, a new-generation, Italian-built Martignani provides the right combination of size and performance for the fourth-generation orchardists.

Priest's orchard represents 80 years of apple growing in Pakenham - an industry that once dominated the region - with Norm Priest's grandfather having bought an orchard from the Salvation Army in 1926.

Priest Bros, now in the hands of Norm and his two sons Paul and Shane, grows 26ha of apples under net and provides packing services for other growers in a modern facility.

Regardless of apple trends, Priest Bros's professional focus has been firmly fixed on optimising production.

"We are probably moving more fruit in a week than what they did in a year back then," Norm said.

"It has even improved sinceI started."

A demonstration day of various sprayers arranged by Pakenham dealer Glenmac saw the miserly machinations of the Burder Industries-distributed Martignani raise eyebrows.

Passing all the tests and coating leaves top and bottom, the rig used a fraction of the water of other sprayers.

"If you do a dye test under ultraviolet light, these things get spray on both sides of the leaf," Norm said.

"Paul tested it at 150 litres/ha on the demo and it gave us even coverage over the top, bottom and middle of the tree - 10 times better than anything else.

"A few others were all right, but they weren't good enough design for our systems.

"If you are conventional-spraying 1000 litres/ha, dye tests show it is running off the leaves and all over the grass.

"This is a fine mist, and getting underneath the leaf is very important for mites.

"There's not a small electromiser available any more - the few available are for the big boys at 2000 to 4000 litres - they're designed for big acreages and big headlands."

Conventional sprayers also had towers, which weren't practical for the netted orchard.

Physically, the Martignani is a whippet. Carrying just 1000 litres and hand wash and rinse tanks, the machine covers 6ha at just 165 litres/ha.

"If you are standing in the middle of the next row, your pants won't even get wet," Paul said.

"If I'm passing the Martignani in another tractor when we are spraying, I'd barely get mist on the windscreen."

The electrostatic technology efficiency has saved Priest's chemical.

"We have dropped our chemical use but it can depend on what we are chasing," Norm said.

"We don't muck around with mites or woolly aphides, but for fungicides and normal insecticides we are probably using only 75 per cent of the normal chemical rates most times.

"The other saving is in time and fuel. We're spraying at about 9km/h."

The machine has performed flawlessly since arrival and plugged straight into the same tractor, "speaking universal Italian", according to Norm.

"We won't operate spray pumps without computers - it is very important to know exactly what you are putting on," he said.

"If your tractor slows or you get wheel spin, it can drop speed - a computer can compensate for that."

The cabin display has four boom section controls and provides volume, speed and tank volume data in an easy-to-read format.

Service-wise, Burder is ticking all the boxes.

"We've had a couple of questions and Burder have responded," Norm said. "At this stage, we can't complain, they've been checking how it is going.

"In the fruit industry, word travels fast so it is important, and to their credit, they are very good."

Above all, the Martignani is a time saver.

"You can cut your spray times and fuel use down by more than 50 per cent," Norm said.

"Even if you don't save anything on chemicals, your labour, fuel and wear and tear is cut by 50 per cent.

"The reason we like this is its low volume, less drift and better coverage.

"We are certainly using less chemical per ha - you can get the rates down and how much chemical you can save would depend on how game you want to get.

"When we first bought electrostatic sprayers, it was very hard to get used to putting about the same amount of chemical in 200 litres as you used to put in 2000.

"That's especially the case with chemical fruit thinning where you could take off the lot or nothing.

"The amount of times when I first used them, I came around with a calculator - it is very hard to get your head around it.

"I can understand why some people don't use them, but if you do the training, the benefits far outweigh the negatives."