01476naa a2200253 a 450000100080000000500110000800800410001910000200006024501090008026000090018930000140019850001210021252006720033365000110100565000090101665000120102565000090103770000160104670000220106270000170108470000180110170000200111977300830113916442611993-10-01       1991    bl uuuu     u00u1 u    #d1 aOLIVEIRA, R. A.  aUrease activity in ortho red-yellow podzolic soil planted with pera orange trees affected with declinio.  c1991  ap.306-309  aConference of the International Organization of Citrus Virologists, 11., 1991, Riverside, California, Proceedings...  aUrease activity of soil under declinio-affected citrus trees was studied to determine a possible relationship of declinio with soil and rhizosphere. Forty trees of each of four stages of declinio: healthy trees, initial, intermediate and severe stages  of the disease were examined. The soil samples at 0-20 cm were collected from four different locations at the dripline  of each tree, in September and November 1988 and in January and April 1989. Higher urease activity was found in all soil samples under September 1988 and January 1989. These data suggest that there may be a higher biological activity in nitrogen metabolism under declinio-affected citrus trees.  aCitrus  aurea  aDoença  aSolo1 aMELO, W. J.1 aBERETTA, M. J. G.1 aROSSETTI, V.1 aCHELLI, R. A.1 aLEITE, S. A. S.  tRiverside, California: International Organization of Citrus Virologists, 1991.