In Jaén, the regional government"s data for 1997 indicates a water deficit of 480 million m3 for the Guadalquivir river basin (Consejería de Medio Ambiente, 1997). This problem has been aggravated in recent years by the expansion in irrigated olive plantations (Pastor, Castro and Vega, 1998). It has been estimated that irrigated plantations in Jaén consume approximately 300 million m3 per year (EFNCP, 2000).

Many authors identified the mid-summer (pit hardening stage) as the less sensitive period for olive trees to water deficit. In such period it is possible to reduce or interrupt irrigation without a significant yield reduction as foreseen by the deficit irrigation strategies.