Abstract

Chlorine shows some of the characteristics which qualify it as a micronutrient element for the early growth of Adzuki bean plants in solution cultures: 1. Chlorine was required only in a minute amount in the medium; increased growth was observed when some micronutrient elements were supplied as chlorides instead of sulfates. 2. As is true in all the currently known micronutrient elements, chlorine is toxic to Adzuki bean plants when present in a large amount in the medium. 3. The absence of chlorine in the medium results in growth depression. The chlorine content of both shoots and roots, especially of the shoots, increases with the increase of the chlorine concentration of the medium. The growth depression in high chlorine media was due to the chlorine accumulated in the plant body. The chlorine content of Adzuki bean seeds (bought on the market) is in the order of 0.65 mg per gm dry weight (=650 ppm). This value was nearly in agreement with that of shoots and roots of the Adzuki bean plants which showed the best growth in this experiment. From this, it is thought that "seed analysis" will provide more reliable information concerning mineral nutrition of certain plants, especially in their early growth, than "leaf analysis".