On the growth of the crops and leaf tissue as affected by increase in UV-B radiant quantities

On the assumption of the increase in UV-B radiant quantities in natural light by the ozone layer depletion, the effect of UV radiation on the growth, dry matter production and leaf tissue of crops were investigated. Results obtained are as follows. 1) The growth of dwarf bean, rice plant and cucumber became very inhibited, when UV-B radiant quantities in natural light increased. 2) Especially the effect of the increase of UV-B radiant quantities caused large failure in the growth of the leaf, and the amount of dry matter production lowered. 3) As an effect of UV-B on the tissue of dwarf bean leaf, death of epidermal cell and morphological abnormality of palisade tissue cell were observed. 4) From the result of this study, it was considered that crop production received a very important effect, when UV-B radiant quantities in the natural light increased 20% further than the present