Abstract:
The objective of this report is to study the feasibility of harvesting wine grapes mechanically in South Africa. In order to do this it was necessary in the first instance to look at the operation of mechanical harvesters from a viticultural and wine-making point of view. It was seen that wine quality was no lower with machine-harvested grapes, provided a few elementary precautions were taken. From a viticultural point of view, however, close attention must be paid to vineyard layout, trellising systems and the choice of grape cultivar. If machine harvesting is to be efficient then these three factors must be given careful consideration - planning for mechanical harvesting is a long-term project. The wine industry, particularly during the harvest season, is highly labour-intensive and the availability and cost of labour will have a direct effect on the farmers' decision on whether or not to harvest mechanically. In general, farmers have not been faced with labour shortages yet, but they are having to pay more for their labour. This trend is likely to continue, but both the availability and cost of labour will depend closely on the overall condition of the South African economy. Under condition of full employment, farmers will have to pay high salaries to their staff in order to hold them against the pull of commerce and industry where employment opportunities are greater. A break-even analysis has been performed on the costs of harvesting by machine and by hand. It was shown that it would be necessary to pick between 6000 and 8000 tonnes of grapes per machine each season before mechanical harvesting was cost justified. This presupposes two important assumptions. Firstly, wine cellars would have to remain open for extended hours for the acceptance of grapes, and secondly that grape yields were high enough to allow a mechanical harvester to pick this quantity of grapes in a season. Both these requirements would require changes to be made within the industry. The extended cellar opening hours would require extra expenditure , but this could be offset by the production of better quality wines due to the grapes being picked at optimum ripeness. With regard to grape yield, the Olifants and Orange River regions in particular have grape yields which would justify machine harvesting, but certain structural changes would have to be made in regard to the trellising systems, which at present are not suited to machine harvesting. On the basis of accumulated evidence, estimates of the potential market for mechanical harvesters have been made. These estimates show that between 40 and 70 machines could potentially be required over a period of 5-10 years. However, when present economic conditions are considered, machine harvesting is not really justifiable because of high unemployment levels. The time will come though when mechanical harvesting will be more convenient and more flexible. It would be wise for the South African wine farmer to plan ahead for this, so that efficient use can be made of mechanical harvesters when the need arises.
