Bilancio energetico e consumi idrici in risposta a diversi regimi luminosi in pesco.

Net photosynthesis, at the base of plant productivity, increases with irradiance till a saturating point. All the extra absorbed energy may be considered excessive and can emphasize the photoprotective and photoinactivation mechanisms with a consequent decrease of plant dry matter accumulation. Several areas in which peach is commonly grown the excessive light is often associate with water limitation that can in turn exacerbate the loss due to photoinhibition increase and net photosynthesis reduction. In this study the ameliorative consequences of light reduction of about 40% trough a neutral shading net were pointed out. Light reduction, associate with temperature mitigation did not affect leaf net photosynthesis but it reduced water consumption and the amount of inactive photosynthetic complexes to be repaired at expense of dry matter accumulation. Under the shading net the entity of the photoprotective mechanisms decreased since leaves were less exposed to light excess. The consequence of this favourable state was probably the increase of dry matter accumulation, including fruit production.