Raspberry harvesting gets a lift

Press, 13 April 1984, Page 28

Raspberry harvesting gets a lift

Two commercial raspberry growers are now producing fruit of the highest quality using the Lincoln canopy system and harvesting machines designed by the Agricultural Engineering Institute. One of the growers is marketing his fruit in Ikg punnets which are filled on the harvester and sold fresh for dessert without any further sorting. The other grower blast freezes most of his crop for sale and export in a freeflow form. The sorters ride on the machines, and their sole job is to remove the small amount of trash and substandard berries as the fruit moves along the conveyors. The raspberries drop into shallow trays, all in perfect condition and attract premium prices. The harvesters work over the fruiting areas two or three times a week. The larger of the two growers’ machines covers its 4.4 hectare block quite easily in two six-hour days.

Some “knockers” have

criticised the Lincoln system, claiming the yields are poor and the establishment costs are high. Mr John Dunn and Mr Mike Watson of the N.Z.A.E.I. visited both growers recently while harvesting was in progress and found the operations were running very smoothly. In the Lincoln method of training, the dormant winter canes are tied down horizontally on either side of the row to form a continuous canopy. When the

new growth comes away in the spring it develops in the normal upright manner. This separation of the fruiting and the non-fruiting canes means that only the fruiting canes are shaken by the mechanical harvester. The harvesting action of the machine is much more effective and the fruit loss much lower. It does not have to cope with the mass of new growth which acts as padding and prevents effective shaking of the canes.

The normally grown upright raspberry plants get fairly rough treatment from conventional harvesting machines. The new growth is often bruised and broken and the bases of the canes are frequently scraped by the spring loaded fishplates. It is not only the plants that get the rough treatment either. With the machines built to harvest raspberries from normally trained canes, most of the fruit drops a metre or more.

It tumbles down a helterskelter course through a tangle of leaves and canes until it lands with a splat on the conveyors or steel fishplates. After that sort of treatment the raspberries are rather mashed and messy, and there is no way the sorters can pick out all the bits of leaves and rubbish.

With the Lincoln system the fruiting canes grow out sideways. The harvesting machine shake the canes from above, so the fruit has only a short distance to drop on to a resilient conveyor. The result is a firstclass product, untouched by hand.

The variety of raspberry has an important bearing on the final product. So far, “Fairview” from North America has come out tops for yield, berry quality, and ease of harvesting. Its colour and exquisite flavour make it a completely different product from the old tart-tasting varieties which were only fit for jam. Even better varieties may be on the way. East Mailing Research Station in England is developing new types of raspberries specifically for the canopy system of harvesting.