NEW GREENHOUSE STRUCTURES FOR THE SOUTH OF SPAIN

Low cost unheated greenhouses of wood or metallic structure, most of them with a flat roof, are the prevailing type used in the south of Spain.
Polyethylene (PE) film is used as cladding material.
Microclimate inside these greenhouses is far from optimal for vegetable production, because of insufficient ventilation and lack of heating.

Two new unheated greenhouse prototypes (an east-west orientated singlespan of asymmetrical roof -18° and 8°-angles and a north-south orientated multispan of symmetrical 17° roof angles) are been evaluated as alternatives to a conventional flat roof greenhouse, higher than usual, in Almeria.

Air temperatures in the conventional greenhouse are higher than in the others (up to 1.9°C difference in the monthly mean maxima), in the spring season.
Lower radiation levels inside the multispan, due to the light reducing materials of this structure, induce significantly (5% level) lower growth and yield for a climbing bean crop in a spring cycle.

II Workshop on Greenhouse Construction and Design

N. Castilla, P. Lorenzo, J. Pérez-Parra, J.I. Montero, E. Fereres, F. Bretones, J. López-Gálvez

https://doi.org/10.17660/ActaHortic.1990.281.17