Article
Growth responses of three Brachiaria species to light intensity and nitrogen supply
Registro en:
Tropical Grasslands (2008) Volume 42, 75–87
0049-4763
Autor
Guenni, Orlando
Saiter, Stephan
Figueroa, Rosana
Institución
Resumen
Biomass production, dry matter partitioning and
nutrient accumulation of 3 Brachiaria species
(B. brizantha, B. decumbens and B. dictyoneura)
were investigated under 3 photon fl ux densities
(100, 57 and 29%) and 2 levels of soil N availability
(with and without N added). Plants were
grown in a controlled greenhouse under shade
cloths in pots containing a mixture (1:1) of fi eld
soil and perlite. Measurements were carried out
at the end of 2 growth periods: 34 days after
planting (GP) and 41 days after cutting (RGP).
Artifi cial shade reduced biomass production
during both growth periods but the effect was
greater during GP. Nitrogen availability played
an increasing role only as the study progressed.
A light intensity × N interaction was observed
in B. brizantha and B. decumbens, but not in
B. dictyoneura. Shading increased plant allometric
ratios and leaf N concentration. At 57%
sunlight, total plant biomass in B. brizantha and
B. decumbens was similar to that at full light
conditions, when no N was added to the soil.
B. dictyoneura had the lowest potential to adjust
to restricted light conditions. The implications of
these results in terms of forage yield and quality,
and persistence under defoliation are discussed. CDCH-UCV