Sensitivity of Crops to Increased Ultraviolet Radiation in Northern Growing Conditions

Crops growing at high latitudes are adapted to low intensities of solar ultraviolet B radiation (UV‐B). As a result of destruction of stratospheric ozone layer especially at the Polar Regions of the globe, the intensity of UV‐B is projected to increase at high latitudes. In order to find out the consequences of increased UV‐B on crops, the sensitivity of different varieties of barley, wheat, oats, clover, timothy, meadow fescue, tall fescue and potato was tested in Jokioinen, Finland. The experiment was conducted in the field, under natural light, with a continuous 30 % increase in UV‐B. Both increased UV‐B and the control with slightly increased UV‐A radiation affected the number of lateral shoots in cereals, and the specific leaf area and the content of phenolic substances in grasses. The effects varied according to plant variety and time of growing season. However, no visible damage, nor changes in biomass and yield production were found in any of the crops. Long‐term effects on, e.g. genetic stability and germination of crop seed remain to be studied.