02068nam a2200277 a 450000100080000000500110000800800410001910000170006024501170007726001550019430000140034950000140036352011620037765000210153965000150156065000210157565000160159665000130161265000250162565000160165065000300166665300290169665300220172565300220174770000210176919035282023-03-03       2011    bl uuuu     u00u1 u    #d1 aMARIN, F. R.  aIrrigation requirements and transpiration coupling to the atmosphere of a citrus orchard.h[electronic resource]  aIn: CONGRESSO BRASILEIRO DE AGROMETEOROLOGIA, 17., 2011, Guarapari. Riscos climáticos e cenários agrícolas futuros: anais. Guarapari: Incaperc2011  c1 CD-ROM.  aCBA 2011.  aCrop evapotranspiration (ETc) was measured as evaporative heat flux from an irrigated acid lime orchard (Citrus latifolia Tanaka) using the aerodynamic method. Crop transpiration (T) was determined by a stem heat balance method. The irrigation requirements were determined by comparing the orchard evapotranspiration (ETc) and T with the reference evapotranspiration (ETo) derived from the Penman-Monteith equation, and the irrigation requirements were expressed as ETc/ETo (Kc) and T/ETo (Kcb) ratios. The influence of inter-row vegetation on the ETc was analyzed because the measurements were taken during the summer and winter, which are periods with different regional soil water content. In this study, the average Kc values obtained were 0.65 and 0.24 for the summer and winter, respectively. The strong coupling of citrus trees to the atmosphere and the strong coupling of the sensitivity of citrus plants to large vapor pressure deficits and air/leaf temperatures caused variations in the Kcb in relation to the ETo ranges. During the summer, the Kcb value ranged from 0.34 when the ETo exceeded 5 mm d-1 to 0.46 when the ETo was less than 3 mm d-1.  aCitrus latifolia  aIrrigation  aLeaf conductance  aMeteorology  aOrchards  aSprinkler irrigation  aIrrigação  aIrrigação por Aspersão  aCondutância estomática  aMicrometeorologia  aPomares cítricos1 aANGELOCCI, L. R.