02244nam a2200253 a 450000100080000000500110000800800410001910000250006024501050008526000410019030000090023149000230024050000680026352015380033165000120186965000100188165000170189165000120190865000110192065300120193165300130194365300100195665300240196616220301996-07-24       1979    bl uuuu  m   00u1 u    #d1 aANDRADE, J. M. de S.  aSmutgrass (Sporobolus poiretii [Roem. and Schult.] Hitchc.) control with grazing management systems.  aFlorida: University of Floridac1979  a89p.  aTese de Doutorado.  aTese de Doutorado: Orientada por: G. O. Mott e W. R. Ocumpaugh.  aThe purpose of the experiment was to determine the effect of grazing management upon the persistence of smutgrass (Sporobolus poiretii [Roem. and Schult.] Hitchc.) and whether manipulation of length of rotation cycle and grazing pressure could be used to control this grass weed. Five lengths of rotation cycle (grazing period plus rest period) and five levels of grazing pressure were superimposed upon the smutgrass-infested bahiagrass (Paspalum notatum Flugge) pastures.The grazing treatments were an incomplete factorial set, arranged in a response surface design of 13 tratment combinations of rotation cycles and grazing pressures. On one set of pastures, molasses was sprayed in an attempt to increase the acceptability of the smutgrass to the grazing animal, the second set was not sprayed and was consideredthe control. Equal quantities of molasses and water were mixed and sprayed on standing firage of the molasses set of pastures at the rate of 3,644 liters/ha prior to introducing the animals. Lengths of rotation cycles were 0, 14, 28, 42, and 56 days. Grazing pressures were measured in terms of residual dry matter/ha (RDM) remaining in the pasture after grazing periods. The target RDM levels were 0.5, 1.3, 2.1, 2.9, and 3.7 metric tons/ha in 1976 and 0.5, 1.0, 1.5, 2.0, and 2.5 metric tons/ha in 1977. The quantity of smutgrass as percent ground cover measured with the line transect and permanent quadrad methods was not affected by the length of rotation cycle (P= 0.82) nor by spraying molasses (P= 0.74). ....  agrazing  aweeds  aErva Daninha  aPastejo  aPlanta  aControl  aControle  aPlant  aSporolobus poiretii