PAR assessment within an Almeria-type greenhouse in integrating a photovoltaic roof

The aim of this study was to evaluate for the area of Almeria (southeast Spain), the effect of reduced PAR in the greenhouse in the production and quality of cv. Daniela tomatoes crop, due to the installation on the roof of flexible solar panels to produce electricity. This study was undertaken in a commercial raspa y amagado greenhouse (area 1024 m(2)), typical of the Almeria region (Spain), with a thermoinsulating polyethylene cover that allowed for 12.50% passive ventilation. Tomato plantlets were transplanted into the greenhouse's sand-covered soil at a density of 0.75 plants m(-2). The flexible solar panels were mounted on two parts of the roof in different arrangements (T1 and T2), so that between them blacking out 9.79% on the soil surface of T1 and T2; a control area (TO) was fitted with no panels. Significant differences were observed for PAR between the three treatments, showing a better distribution of PAR treatment with as many panels but tighter. No significant differences were seen in terms of total or marketable production, mean fruit mass, maximum fruit diameter and pulp firmness of cv. Daniela tomatoes under these three arrangements. Tomatoes of TO has greater fruit color intensity that T1 and T2. Differences were seen between the control and both shade arrangement treatments with respect to degrees Brix and pH fruit. The 9.79% roof blacking produced by these solar panels is therefore compatible with commercial tomato production (Solanum lycopersycum L.).