POTASSIUM NUTRITION OF RICE (ORYZA-SATIVA L) VARIETIES UNDER NACL SALINITY

A salt-tolerant (Pokkali) and a salt-sensitive (IR28) variety of rice (Oryza sativa L.) were grown in a phytotron to investigate the effect of K (0, 25, 50 and 75 mg K kg-1 soil) application on their salt toler ance. Potassium application significantly increased potential photosyn thetic activity (Rfd value), percentage of filled spikelets, yield and K concentration in straw. At the same time, it also significantly red uced Na and Mg concentrations and consequently improved the K/Na, K/Mg and K/Ca ratios. IR28 responded better to K application than Pokkali. Split application of K failed to exert any beneficial effect over bas al application.