Practical considerations can have a big influence on a grower’s choice of sprayer – not least when restrictive railway bridges are frequently on the yard-to-field route. Peter Hill reports

Is there enough power for hilly ground? Will it take big enough tyres to avoid making a mess? Just two of the many considerations to take into account when planning to shift up to a bigger sprayer.

In Jim Bryce’s case, the size of local railway bridges was also a factor that had to be taken into account and which led to him opting for the Chafer 5000-litre spray pack to go on his new Multidrive 6185 applications vehicle.

“We had discussions with several manufacturers of demount sprayer systems for the Multidrive unit, but Chafer was the only one that would work with us on some specific requirements,” says Mr Bryce. “For example, the railway bridges in this area impose strict height restrictions, so we needed the boom folding height reduced. The people at Chafer were flexible in their approach and helped with redesigns and adjustments while sticking to their original price.”

The rationale for changing from a smaller Multidrive unit operated by J L Bryce Farms, at Mortimer near Reading, Berkshire, was simply to get more daily and seasonal capacity.

“We needed to increase our spraying capacity to cope with the workload on our own farm and for contract work,” says Jim Bryce. “The Multidrive 4140 we had before carried a 3500-litre Sands spray system. It had always done a good job, but to take on more work we needed to improve operating efficiencies and increase output.”

The 4140 had proven the Multidrive as a robust applications vehicle with its heavy-duty mechanical drive axles, diff-locks at both ends and effective suspension. It’s a combination that Mr Bryce reckons gives better performance in the field and superior stability on the road than a typical hydrostatic drive vehicle – important considerations when operating up to 20 miles from base on contract work.

Some customers, he admits, were concerned about the size of the machine when it turned up in the yard. But the longer wheelbase of the 6185 over the 4140 he operated before carries the bigger load effectively.

“The total weight has increased by 2t when fully loaded, but distributed better, so it’s actually quite light on its feet,” says Mr Bryce. “It helps that we’re running on 650mm wide tyres, but in we can always travel part-loaded in wet conditions to ease the weight off a bit.”

But it’s when the 5000-litre tank is used to full capacity that the gains in output begin to clock up.

Typically, it takes four or five fill-ups a day – the same for the previous unit – but, of course, it carries enough for an extra 12ha per fill. Spray volumes of 100-150 litres/ha are now normal, but the extra capacity of a big tank means there is still good output to be had at rates up to 300 litres/ha when necessary.

“Our seasonal average is now 9ha/hour compared with about 7ha for the previous unit; that’s including all fill-ups and stoppages and it means we can handle more than 1600ha extra spraying in a season,” notes Mr Bryce. “Put that in terms of an operating cost of about £30/hour, including depreciation, labour and diesel, and we’re getting more than 1.5ha an hour extra output for our money.”

Multidrive 6185 spec

• Engine: John Deere 6cyl 185hp
  
• Transmission: Six forward, three reverse automatic shift
  
• Driveline: Beam axles on coil spring suspension
  
• Steering: Multi-mode two- and four-wheel
  
• Top speed: 50kph
  
• Load capacity: 10t
  
• Chafer demount
  
• Capacity: 5000 litres (plus 500 litres clean water)
  
• Boom: 12/24m single-line twin fold
  
• Pump: Hydraulic drive 2in, 650-litre/min output
  
• Circulation: Pressure prime and purge
  
• Valves: Two manual main valves for all functions
  
• Controller: TeeJet 844 pressure-based rate controller