Self-propelled sprayers are not the hottest sellers here in Ireland, and so those growers who wish to acquire one are limited in choice if they wish to buy new and have the machine supported by a dealer network.

One machine that is readily available throughout the whole of Ireland is the Fendt Rogator 600, which was launched 15 years ago and still remains well ahead of the competition, according to the company.

It was on a chilly November day that a Rogator 645 was brought to Farmworks Machinery in Co. Dublin, where its features were demonstrated by Anthony Risdon, product specialist for the company.

He puts this down to one particular key engineering feature of the sprayer - the chassis.

No more ladders

From the dawn of commercial motoring, the ladder chassis has provided the platform to which all the mechanical components were attached and upon which the load was supported.

This was extended to self-propelled sprayers in general.

However, Fendt chose to adopt a whole new concept for the Rogator - a purpose-designed frame and axle arrangement that would provide a soft and comfortable ride.

The purpose in doing so was not just to keep the operator happy - though that is always a bonus - but to provide a platform for the boom that was already stable and responsive, saving on the cost, weight and complexity of a sophisticated boom mast to do the same job.

This then is the underlying feature that Fendt claim places the Rogator well in front of its competitors, and it it confers a large array of benefits.

Double wishbone suspension

A key advantage of doing away with the ladder chassis is that there is the freedom to incorporate the optimum suspension system, which Fendt considers to be a double wishbone arrangement at each corner.

This enables much larger wheels to be fitted while maintaining a tight turning circle, down to 3.2m with the narrower tyre width.

The larger diameter wheels of up to 2.05m also help reduce ground pressure.

Normally this effect is associated with wider tyres, but the longer footprint provided via a larger diameter acts in the same way and keeps any soil compaction to a narrower strip.

The wheels are powered by Rexroth hydraulic motors, a company owned by Bosch.

According to Anthony, they have proven to be hugely reliable over the years.

The double wishbone suspension with a hydraulic system providing the dampening also enables the ground clearance to be set at at either 75cm or 120cm.

Track width and power levels

Track width can also be adjusted from 1.8m to 2.25m and the oil flow to each motor can be regulated to ensure traction at all times.

This is a form of active diff lock which helps maintain a constant ground speed when conditions do not provide a consistent level of grip at each wheel.

Power is provided by a low-slung six cylinder AGCO Power unit tuned to suit whichever of the three Rogator models it is fitted to.

This varies from 210hp in the Rogator 645 to 300hp in the Rogator 665.

To enable extra water to be taken along to a field, all models have a 16t towing capacity for bowsers, with the required braking systems as standard.

Rogator boom

As noted, the chassis is a leading design that has stood the test of time and there are no immediate plans to change it, although the Rogator models have been tweaked over the years.

The stable and well-suspended platform provided by the frame ensures that the boom does not need a suspension system of its own.

Instead, it can be mounted directly to the lift arm at the rear, saving the weight of a mast.

The boom itself is available in widths of between 24-39m, the latter being a size specific to Germany while for the UK and Ireland 30-36m would be the norm.

Being aluminium, the twin fold booms are light, robust, and easily repairable should an unfortunate encounter with a tree or pylon occur.

Independent nozzle control

With regard to nozzles, Fendt have decided not to go down the route of Pulse Width Modulation (PWM), but have instead opted for its own air actuated Opti Nozzle system.

This enables each nozzle to be controlled independently allowing section control to be brought down to half metre sections across the whole boom width.

Coupled with prescription maps these offer a fine degree of control over the application area, and Fendt indicate that there is more to come with spot spraying being one idea mooted.

At the heart of the spraying system lies a 785L per minute pump which is of the centrifugal rather than diaphragm type, removing the risk of diaphragm failure and reducing maintenance time.

Dealer support

Yet none of these technical innovations are of any use if the machine lies stranded in the shed or side of the field, waiting the attention of a technician or part.

It is here that the Rogator scores, for, due to being a part of the Fendt tractor family, it shares many components and systems with other machines, including the Ideal combine.

Fendt dealers are therefore immediately familiar with many of the control systems; for instance, it is the usual Fendt diagnostic software that is used, while parts and warranty are also the same.