The invention relates to a laminar body for making greenhouse roofs, comprising at least one laminar layer, which defines at least one main surface of the laminar body and comprises a polymer matrix and nano-particles of titanium dioxide TiO2 in the anatase and/or rutilium form, dispersed in the polymer matrix. The nano-particles have dimensions not greater than 100 nm. The titanium dioxide is present with a concentration in weight of between ′30 and 1500 ppm in relation to the polymer matrix. The invention also relates to a method of greenhouse cultivation and the use of the laminar body according to the invention for making greenhouse roofs. The invention also relates to a greenhouse having a roof comprising at least one laminar body according to the invention and to a masterbatch for making a laminar layer of a laminar body according to the invention.
