Greenhouses in the order of 10 hectares and more are being created and continue to be erected in the socialist countries.
They express the great possibilities and growth of the forces of production in the conditions of the socialist system.
The development of modern transport should be considered in respect to these new conditions.
It is necessary to make a difference between transport work carried out prior to planting the beds in the greenhouses and such during the vegetation period.
Therefore, a difference should be made between the preparatory work for the planting (soil transportation, for example) and the transportation vegetable produce.
Towards a further rationalization of the working processes in greenhouses, the problems concerning the mechanization of transport, to a fuller extent, should be intensified.
This requirement should not be extended only to the design of tractors and trailers, in accordance with the necessary greenhouse dimensions, but also the basic elements in the construction of greenhouses should be in conformity with the existing processing technique.
Such basic elements are the height of the greenhouses, the height of the doors and location of the heating installations and the spray irrigation aggregates.
The 35 to 40 hp tractors are generally considered most appropriate.
These tractors are distinguished by their considerably low width and height, while their traction power corresponds to the necessary requirements.
The absolute height of the doors (from 2.40 to 2.60 m) and their width, 2.40 m, has been determined as standard dimensions.
The plan of the inner space has also been standardized to meet the necessary requirements towards a free passage and manipulation of the above mentioned types of tractors, Particular attention should be paid to the construction of the necessary elements for the erection of block type greenhouses.
In the German Democratic Republic, the design of MZG C/69 greenhouses fully meets these requirements.
The problems concerning the mechanized transportation processes of the plants present greater difficulties.
To arrive at a higher efficiency in the greenhouse yields, it is absolutely necessary that the relative share of the paths occupy the smallest possible area out of the total production area.
Principally there exist two possibilities of the realization of this aim, depending on the type of design of the greenhouses.
In greenhouses with a width over 12 metres, designed specially for the growing of cucumbers and tomatoes, transversal planting is recommended, so that the transportation of the ripe vegetables, especially in block greenhouses, be carried out across a wider path, serving two distinct sheds.
In greenhouses of narrower width it is recommended to carry out the planting in the conventional manner, along the length of the greenhouse.