UV-B radiation decreased yield per plant compared to natural light. The decrease for H339 yield per plant was 39.1%; that of HN35 41.4% and that of KN18 50.6%. UV-B radiation decreased pod number per plant of three soybean culti-vars by 29.6% for H339, 30.4% for HN35, 43.5% for KN18 (Table 4).UV-B radiation decreased seed number per plant of three soy-bean cultivars by 31.4% for H339, 33.3% for HN35, 44.2% for KN18(Table 4).