UPLAND RICE GENOTYPES EVALUATION FOR PHOSPHORUS USE EFFICIENCY

Phosphorus (P) deficiency is one of the most important yield-limiting factors in acid soils in various parts of the world. The objective of this study was to evaluate the growth and P-use efficiency of 20 uplan d rice (Oryza sativa L.) genotypes at low (0 mg P kg(-1)), medium (75 mg P kg(-1)), and high (150 mg P kg(-1)) levels of applied P on an Oxi sol. Plant height, tillers, shoot and root dry weight, shoot-root rati o, P concentration in root and shoot, P uptake in root and shoot, and P-use efficiency were significantly (P<0.01) affected by :level of soi l P as well as genotype. Shoot weight and P uptake in shoot were found to be the plant parameters most sensitive to P deficiency, suggesting that these two parameters may be most suitable for screening rice gen otypes for P-use efficiency under greenhouse conditions.