WATER USE BY DRIP IRRIGATED ONE-YEAR OLD PEAR TREES

Crop coefficients (Kc) of pear trees ‘Abate Fetel’ were determined at EEA INTA Alto Valle during the second growing season after planting. Individual trees were placed in each of three lysimeters at the time of orchard establishment. The culture was watered every day by drip irrigation with emitters delivering 4 L/h every 0.50 m. During the growing season the following determinations were performed: water volume applied and drained, soil water tension, trunk sectional area, intercepted photosynthetic radiation and percentage of shaded surface. Maximum monthly crop water evapotranspiration (ETc) was also determined in January, with a value of 2.1 mm day^-1. This was equivalent to 16.8 L per tree day^-1 taking into account the planting. The crop coefficients increased from 0.22 at full bloom to 0.36 at the middle of December and from there on they remained almost constant until the middle of February when they decreased up to 0.28 at the end of April. Annual evapotranspiration for pear tree ‘Abate Fetel’, during the second growing season, was 315 mm; taking into account rainfall, irrigation and drainage water (15% of applied water) from the lysimeters.