Effects of UV radiation on growth and postharvest characteristics of three pot rose cultivars grown at different altitudes

• UV radiation reduced growth of three rose cultivars grown at different altitudes.
• A higher level of solar UV radiation also delayed flowering by 7–10 days.
• Postharvest life and water usage were not significantly affected by UV radiation.
• Altitude difference affected postharvest life and water usage of the rose cultivars.

The ultra violet (UV) radiation reaching the ground is classified as UV-B (315–280) and UV-A (315–400 nm) and the levels vary with altitude and latitude. Numerous studies have shown that UV-B has various effects on morphology, biochemical composition and molecular responses of different species. It is well known that the climate conditions during growth also affect how plants behave after harvest. However, less is known about the effect of UV radiation during growth on postharvest characteristics of ornamentals, and especially the role of UV-B. In this study we investigated the effect of natural levels of UV radiation at different altitudes (2794 m a.s.l. (high altitude) and 1700 m a.s.l. (low altitude)) on growth responses like morphology and flowering, postharvest water usage and shelf life of three pot rose cultivars (‘Cygein’, ‘Snow White’, ‘Tom Tom’). Plants were grown under UV-transmitting or UV-blocking films at different altitudes. The results showed that UV radiation significantly reduced growth at both altitudes; however the effect was more prominent at lower altitude. Besides, higher level of solar UV radiation also delayed flowering by 7–10 days. Postharvest life and water usage were not significantly affected by UV radiation but rather by the altitude and plants produced at high altitude had a better control of water loss and a longer postharvest life compared to lower altitude-grown plants. In conclusion, UV radiation mainly affected morphology and development of the plants. However, stomata conductance, postharvest water usage and characteristics were rather affected by altitude differences than UV radiation.