Variabilidade temporal e espacial de medidas de iluminância no interior de estufas.

Abstract

The Brazil area cultivated under plastic is about 2 thousand ha, at São Paulo state, and 59% was used for vegetables cultivation and 39% for ornamental. But the differences between the protected cultivation and the open environment should be related with the radiation differences, temperature and humidity. The experiment was reached out in three greenhouses. Inside the protected environment, was taken as base for the monitoring points, a matrix with nine points, covering the whole sampling surface. For the monitoring points, three different heights were stipulated: soil surface (0.0 m), 0.85 m and 1.70 m, in relation to soil surface, in three daily schedules (7:00, 13:00 and 18:00h), for 21 days. The obtained results evidenced that the schedules of 13:00, presented, in the 3 heights and during the time of measurement, the largest temporal and spatial variability and at the same date, exemplified by the values maximum and minimum.