[The yield of barley plants during growth in conditions of constant exposure to high-level UV-radiation].

The effect of high intensity UV-irradiation on barley productivity was investigated. Plant vegetation occurred in field conditions. The intensity of biologically effective UV-irradiation applied at the stages of the third leaf, onset of tillering and maturity was 0.053, 0.103, and 0.260 W/m2, respectively, which was 2, 4, and 10 times higher than the natural background in the city of Leningrad. Analysis of the yield value and structure showed that barley plants were UV-sensitive. Yield losses amounted to 22, 48, or 64%, when UV-irradiation increased 2, 4, or 10 times, respectively. Changes were found in all yield parameters such as productive bushiness, quantity and mass of developing seeds, the size of the latter being diminished (mass of 1000 seeds).