Resumen

LOPEZ, Jorge  y  DENNETT, Mike. Water use estimation for onion (Allium cepa L.) crop under Quíbor conditions, Lara State, Venezuela. Bioagro [online]. 2007, vol.19, n.3, pp.127-132. ISSN 1316-3361.

Under conditions of the onion production system, in Quíbor Lara State, Venezuela, estimates were made of total water consumption. The study was carried out during two cycles of growth for the cultivars Texas Grano 438 and Utopia, taking into consideration the evapotranspiration by the onion crop and the free evaporation of the water in the furrows. The evapotranspiration was estimated using the original Penman-Monteith method, which allows for the direct calculation of this value  without  using  the  crop  coefficient.  In  the  first  season  (April-July),  the  total  value  of  water  for  the  onions  ranged about 450 mm per cycle for both cultivars, while the daily values ranged between 3.2 and 5.7 mm. In the second season (July-November) the use of water was lower. The daily consumption of water was always lower in the initial and final stages of the crop. The free evaporation of water directly from the furrow always exceeded the crop ET.

Palabras clave : Evaporation; evapotranspiration; irrigation.