The political and economic situation surrounding casual labour, combined with constant drives to improve efficiency, have led to renewed development in harvesting rigs for high-value horticultural crops.
While carrots, parsnips, red beet, turnips, cabbage, chives and leeks can now be harvested mechanically, salad crops, asparagus, celery, spring onions, blueberries and strawberries still rely on manual labour. Such crops can benefit from innovation to reduce the number of pickers required, increase the productivity per person, reduce and speed the chain from field to transport or store, reduce waste or improve quality.
Some ideas have been developed from other crop sectors. For example, the Haygrove Pic-King, designed for strawberries, has been modified and is in use on asparagus. Some arose from the entrepreneurial ingenuity of innovative automotive engineering business and Grower of the Year winner Tektu - Tech2Reality.
Others, such as BrimaPack of the Netherlands, have been specialising for a decade and can produce highly sophisticated field factories that tower over the pickers in the crop. Individual farmers continue to specify bespoke rigs from local agricultural engineers.
Haygrove and Tektu rigs acknowledge the fact that pickers work best when comfortable. Both companies can demonstrate increases in productivity by 25 to 30 per cent and in each case the workers are lying, prone, over the crop.
Tektu operations director Rob Stone reckons that experienced, committed pickers are hard to improve on, whatever the machine. But they account for only five per cent of the workforce. For the remainder, the chance to work lying down improves interest in the job and increases productivity. It also improves retention and recruitment among a hard-to-find group of people.
The Haygrove Pic-King rigs for strawberries are by now well known, but with the company forecasting a growth in elevated strawberry growing in a medium, it is perhaps not surprising that recent sales have been for another crop. Grower John Chinn has teamed up with Haygrove to develop a harvesting rig for asparagus and recently purchased a third machine.
The business had earlier experimented with its homemade rig that lifted up the polythene 14 rows at a time but wasted plastic because of wind damage. The new machine harvests just eight rows at a time. But Chinn says "this makes the machine much more stable and compact - allowing the rig to carry the harvest workers who lie on a bed above the asparagus row".
He adds: "One supervisor can drive the rig, collect up full trays and oversee the harvesting performance of each worker. The polythene is lifted to one side of the row but kept low and therefore not affected by wind, before being splayed out neatly back over the row once it has been harvested.
"The Haygrove rig is an expensive machine at £70,000 but it has the potential to reduce harvest costs by 28p per kilogram and so, if harvesting 100 tonnes of asparagus each year, can repay the investment within three years. It also reduces the number of harvest workers needed but major breakdowns are very stressful as there are no longer enough people available to harvest the fields by hand."
Haygrove products are born out of its own experience as a grower. The Tektu T100 strawberry picker, however, was designed by the innovative automotive engineering business Tech2Reality, which grew from the ashes of MG Rover.
A three-dimensional CAD model was designed and mock ups built to simulate the actual picking operation before a full prototype was built. By 2008, finished models started to impress to the extent that the rig was awarded Technical Product of the Year 2010.
Now, following feasibility studies, the company hopes to expand into spring onions, asparagus and blueberries. The next step is to take the concept to growers.
"The T100 can be viewed as simply a platform with wheels at all four corners. What goes on in the middle is open to experiment," says Stone, who rather modestly fails to add that the T100 can work in one of 16 gradients, knee-deep mud, short headlands at tunnel ends and in all weathers. As an all-electric machine, typical Tektu T100 costs are around 10 per cent of what it costs to run an internal combustion engine equivalent.
Tektu ensures growers' needs are met by consulting with them at the early stages of the development process. For example, in developing its spring onions model Tektu consulted with growers and experts, in depth, to fully understand the harvesting process.
It then identified different methods of loosening soil and making the crop easy to lift without damaging it before designing a 3-4m module with a blade placed to avoid damaging the crop. The model exists as a CAD design but is yet to be built and proved.
The platform carrying the module is the now proven T100, a 7.5x6m platform with four wheels, each with a drive motor and a steer motor controlled by computer. In transport, the platform moves at 4-5mph; at work, from one to seven metres per minute.
Operators will pick to punnets, which are dispatched via a central conveyor to the "driver" and packed to boxes. The ultimate, says Stone, is to build a mobile packhouse.
Len Wright Salads in Lancashire is a producer marketing organisation that has historically built its own rigs. The organisation contracts with independent growers providing sales and marketing, technical advice, quality control, distribution and packhouse facilities for lettuce, celery and Chinese leaves.
Quality assurance manager Vivien Watson explains that the rigs at work throughout the organisation cover everything from the simple to the extremely complex.
However, in essence, two broad types are at work. Firstly, for the supermarket products such as iceberg, gem and cos with celery, celery hearts and Chinese leaf are picked, processed and wrapped by the rig. Secondly, for processing, lettuce and baby leaf are cut naked into large crates that are then sent to the processors.
The largest and by far the most sophisticated rig at work is a newly-commissioned design from Brima Pack in the Netherlands. The VePack P-rig serves some nine pickers and lifts the cut lettuce vertically into the integral processing plant.
The new VePack 200-P has been developed for the packaging of iceberg lettuce, cabbage, root celery and other vegetables in (perforated) C-PP-film - "NicePack". The VePack 200-P is a modular packaging system. More modules can be integrated into one overall system, which will result in extremely high packaging productivity.
Automated in-feed systems, including grading on size, weight and colour and film optimisation systems are available for indoor applications (horizontal systems) as well as for rig applications in the field (vertical systems). Lettuce emerges wrapped, labelled and crated ready for the market.
Another grower in the organisation has recruited Vegetable Harvesting Systems (VHS) of Spalding to build a tractor adaptation to carry crates. The company offers a wide range of seeding, planting and harvesting equipment with the ability to design and build machines from scratch, giving tailor-made options.
The VHS self-propelled harvester can travel up to 20mph on the road or 60 metres per hour in field mode. It has selectable two-wheeled drive and twoand four-wheeled steer and can be up to 9m long and up to 6m wide. Any type of harvesting unit can be fitted to the front.
The company's engineers and designers, supported by the latest CAD facilities, have the ability to take original concepts and ideas and develop them into sophisticated pieces of equipment. It is perhaps true to say that no two machines in this sector are identical - such is the degree of specialisation and bespoke expertise.
Established in 1986, VHS has become established as one of the leaders in this field for rigs of moderate to high complexity. For more modest and simple rigs and transport trailers, many of the Len Wright growers will shop locally.
Since the early 1980s, John Bond - a local agricultural engineer from Moss Lane - has been fabricating picking rigs from scratch. Now over 70 years of age, Bond has completed some 10-12 rigs, all different and built to farmers' specifications.
The latest completed model is for chopped lettuce and is 35ft long with a 30ft row of cups along the front. Six workers cut the crop and load the cups. The machine is self-propelled and tows a trailer. The machine currently under construction has boxes on the front that are filled directly by the cutting gang.
The farm customer purchases the materials - axles, gearboxes and engine, typically from JCB - and the resulting machine is four-wheel drive and four-wheel steer. The most sophisticated build so far is 37ft wide and carries a generator to power an electric wrapper.
These machines are operated without a driver but at least two companies (VHS and Keith Collingwood) are known to make conversion systems that allow tractors to move forward at creep speeds in remote positions.
- Haygrove 01531 633659
- Tech2reality 01789 450244
- VHS (Vegetable Harvesting Systems) 01775 821222
- BrimaPack +31 (0) 315 640 731
- Keith Collingwood 01205 460486
- John Bond 01772 812124
- Len Wright Salads 01772 812647
- Harvetec SL (Spain) (espana) 968 579098
- Everett Bros (also Asa-Lift) 01842 828028