Influence of shading screens on microclimate, growth and productivity of tomato

In the present study, the influence of four different shading nets with different colour and shading intensity, on the microclimate and on the crop growth and development of tomato crop, was experimentally investigated. Experiments were carried out during summer of 2003 in Nea Agchialos, Central Greece. The seedlings of tomato were transplanted into the soil and the following parameters were recorded regularly: solar radiation, air temperature and humidity and crop temperature. In parallel, parameters relative to crop growth and development were also measured. The reduction of solar radiation above the crop was proportional to the shading intensity of the net. Similar values of air temperature and air vapour pressure deficit were observed under the shading nets and outside. However, the canopy temperature and accordingly, the canopy-to-air vapour pressure deficit were significantly lower under the shading nets than in the open field. Finally, concerning the effects of shading on crop growth and development, it was found that shading increased leaf area index and total marketable yield production, reduced the appearance of tomato cracking about 50% and accordingly, the marketable tomato production was about 50% higher under shading conditions than under non-shading conditions