02052naa a2200301 a 450000100080000000500110000800800410001910000220006024501040008226000090018652011850019565000120138065000140139265000130140665000250141965000170144465000130146165000250147465000130149965000240151265300290153665300170156565300160158265300180159865300180161665300230163477300930165713731632021-01-25       2000    bl uuuu     u00u1 u    #d1 aDIAS FILHO, M. B.  aGrowth and biomass allocation of the C4 grasses Brachiaria brizantha and B. humidicola under shade.  c2000  aThe growth and biomass allocation responses of the tropical forage grasses Brachiaria brizantha cv. Marandu and B. humidicola were compared for plants grown outdoors, in pots, in full sunlight and those shaded to 30% of full sunlight over a 30day period. The objective was to evaluate the acclimation capacity of these species to low light. Both species were able to quickly develop phenotypic adjustments in response to low light. Specific leaf area and leaf area ratio were higher for low-light plants during the entire experimental period. Low-light plants allocated significantly less biomass to root and more to leaf tissue than high-light plants. However, the biomass allocation pattern to culms was different for the two species under low light: it increased in B. brizantha, but decreased in B. humidicola, probably as a reflection of the growth habits of these species. Relative growth rate and tillering were higher in high-light plants. Leaf elongation rate was significantly increased on both species under low light; however, the difference between treatments was higher in B. brizantha. These results are discussed in relation to the pasture management implications.  aBiomass  aleaf area  aPastures  aSpecific growth rate  aÁrea Foliar  aBiomassa  aGramínea Forrageira  aPastagem  aTaxa de Crescimento  aÁrea foliar específica  aFeed grasses  aGrowth rate  aLight regimes  aRegime de luz  aSpecific leaf area  tPesquisa Agropecuária Brasileira, Brasília, DFgv. 35, n. 12, p. 2335-2341, dez. 2000.