UV (ultraviolet radiation)

UV radiation is a component of natural sunlight. In small amounts, it can stimulate plants to produce protective compounds, including anthocyanins. However, excessive exposure increases the risk of tissue damage and fruit burns. Some modern tunnel films partially filter UV radiation, affecting the conditions inside the tunnel. Seedlings must be gradually hardened off, and the fruit must be protected by healthy leaves; after sudden exposure to strong sunlight, temporary shading may be applied.