02372naa a2200265 a 450000100080000000500110000800800410001910000190006024501150007926000090019452016660020365000100186965000220187965000130190165000150191465000120192965000130194165000160195465000230197065000250199365300060201865300060202470000190203077300570204916249962003-11-24       2003    bl ---       0--  u    #d1 aARAÚJO, A. P.  aNitrogen and phosphorus harvest indices of common bean cultivarsbImplications for yield quantity and quality.  c2003  aBreeding for yield in common bean (Phaseolus vulgaris L.) should consider the efficiency of biomass and nutrient partitioning to grains. In field experiments, 9 and 18 bean cultivars were cultivated in 1998 and 1999, respectively, to identify the genotypic variability of harvest index (Hl) and N and P harvest indices (NH1 and PH1), and to evaluate the relationships between these indices and grain yield. Cultivars differed for grain yield, Hl, NH1 and PH1 in both years, but these indices varied less than grain yield. Growth habit markedly influenced HI, with prostrate cultivars possessing higher Hl, NH1 and PH1 than erect cultivars; hence selection for HI should be performed within each phenological group. Grain yield was strongly associated with grain N and P contents, and positively but weakly correlated to H1, NH1 and PH1; the indices were highly correlated among themselves. Multiple-regression analysis showed that most genotypic variation of grain yield was associated with the amount of N and P accumulated by the crop at maturity, and some yield variation was associated with seed nutrient concentration, particularly P concentration, whereas NH1 and PH1 had a minor role. Combined analysis of both experiments showed that grain yield diminished by 57% from 1998 to 1999, whereas Hl remained almost stable and NH1 and PH1 decreased slightly, but the significant year x cultivar interaction revealed different degrees of phenotypic plasticity of biomass partitioning among cultivars. Selection solely for increased H1 would scarcely result in improved grain yield, raising concomitantly NH1 and PH1 and probably reducing grain P concentration.  abeans  agenetic variation  anitrogen  aphosphorus  aFeijão  aFósforo  aNitrogênio  aPhaseolus Vulgaris  aVariação Genética  aN  aP1 aTEXEIRA, M. G.  tPlant and Soil, Dordrechtgv. 257, p. 425-433, 2003.