Responses of winter wheat growth and production under sub-ambient UV-B irradiance

The greater UV-B radiation has heightened concern that it has adverse impact on agricultural production and natural plant ecosystems. The effect of UV-B enhancements on plants includes reduction in grain yield, alteration in species competition, decrease in photosynthetic activity, susceptibility to disease, and changes in plant structure and pigmentation. Plant responses to UV-B enhancements also include increased accumulation of flavoids, increased leaf thickness, increased reflectance of leaves, reductions in growth, and direct damage to photosynthetic mechanisms. One-third to one-half of all plant species tested are deleteriously affected by UV-B irradiance levels "above ambient". This experiment was conducted to study responses of winter wheat growth and production under both ambient and sub-ambient UV-B irradiance (15.3% UV-B irradiance decrease from ambient level). Sub-ambient UV-B irradiance increased winter wheat growth and production, which indicates that current levels of ambient UV-B irradiance might have an adverse effect in tested areas.