EFFECT OF THORIUM ON GROWTH AND UPTAKE OF SOME ELEMENTS BY MAIZE PLANT

A pot experiment (sand culture) was carried out to investigate the effect of thorium on maize dry matter
yield, contents and uptake of N,P ,K, Na and Fe and thorium accumulation in maize plant.The pots were
contaminated by thorium as Thorium Nitrate(Th (NO3)4,H2O)at concentrations 0,5,10,11,12,13,14,15
and 50 ppm. Pots irrigated by 1/10 Hogland solution for15 days, increased to1/4 Hogland solution after
that.The results show that the dry matter (shoot , root and whole plant)decreased with increasing thorium
concentration in soil up to 12 ppm and slightly increased with increasing Th to 13 ppm . The Nitrogen
content and its uptake decreased with increasing thorium concentration in media growth up to 11 ppm .They
were slightly increased at Th concentration between 11-14 ppm in maize shoot and root. The shoots always
contained N-content and uptake more than that found in roots . P- uptake decreased in both shoots and
roots with increasing in thorium concentration in media growth.