01998naa a2200241 a 450000100080000000500110000800800410001910000190006024500890007926000090016852013340017765000160151165000160152765000210154365000100156465000140157465000170158865000150160565300240162070000180164470000210166277300730168318975792020-01-17       2011    bl uuuu     u00u1 u    #d1 aFAGERIA, N. K.  aLowland rice genotypes evaluation for phosphorus use efficiency in tropical lowland.  c2011  aLowland rice is a staple food for more than 50% of the world's population and phosphorus (P) deficiency is one of the main constraints in rice production in tropical lowlands. A field experiment was conducted for two years consecutive with the objective to evaluate 12 lowland rice genotypes for P use efficiency. The P rates used were 0, 22, 44, 66, and 88 kg P-1 (0, 50, 100, 150 and 200 kg P2O5 ha-1) applied to an Inceptisol. The genotypes used were BRS Jacana, CNAi 8860, BRS Fronteira, CNAi 8879, CNAi 8880, CNAi 8886, CNAi 8885, CNAi 8569, BRSGO Guara, BRS Alvorada, BRS Jaburu and BRS Bigua. There were significant and quadratic responses of genotypes to phosphorus fertilization. Adequate P rates for maximum grain yield varied from genotype to genotype. However, across 12 genotypes, maximum grain yield was obtained with the application of 54 kg P ha-1. Genotype BRS Jacana was most efficient and genotype CNAi 8569 was most inefficient in P use efficiency. Shoot dry weight and panicle number was also increased significantly and quadratically with increasing P rates in the range of 0 to 88 kg P-1. These two plant parameters were positively associated with grain yield. Agronomic efficiency (kg grain produced per kg P applied) was significantly decreased with increasing P rates in the range of 22 to 88 kg P ha-1.  aGrain yield  aInceptisols  aYield components  aArroz  aGenótipo  aOryza sativa  aRendimento  aProdução de grão1 aSANTOS, A. B.1 aHEINEMANN, A. B.  tJournal of Plant Nutrition, Londongv. 34, n. 8, p. 1087-1095, 2011.