RESPUESTA FISIOLÓGICA DEL TRIGO (Triticum aestivum L.) CULTIVAR INCA TH 4 AL DÉFICIT HÍDRICO.

In areas of the National Institute of Agricultural Sciences (INCA) an experiment was conducted with crop wheat in order to assess their physiological response to water stress by default, for which the effect of two irrigation treatments on soil moisturecontent, development variables, water relations, yield and water use efficiency (WUE) in culturewere evaluated. The INCA TH 4 cultivar was grown at double row in concrete containers of 1,56 m 2. The two irrigation treatments T 100 and T 50, they consisted of applying 50 to 100 % of standard crop evapotranspiration (ETc.), respectively. Background fertilization was performed before planting with complete formula NPK (9-13-17) and urea (46-0-0) applied to each container 0,1 and 0,04 kg., respectively. Irrigation was applied using an automated system micro sprinkler and water delivery was controlled by valves placed in each treatment. The results showed a significant effect of treatments on soil water content and T 50 at 52 and 67 days after sowing (DDS) that dropped below 15 %, something that was confirmed with the values of potential deficit soil moisture (Dp) which was 178 in T 50 and 77 mm in T 100, respectively. Also the results of leaf water potential (Yfoliar) showed that T 50 plants were exposed to severe water deficit at 41 and 62 DDS, with lower values of -1.5 MPa and T 100 at 62 DDS. Stomatal conductance (gs) showed greater sensitivity to water stress than the remaining variables of water relations. Studied treatments hardly exerted any effect on growth variables, mainly in the accumulation of dry matter and leaf area. In T 50 plants had a lower yield and water use efficiency (WUE) was slightly higher than the T 100. [ABSTRACT FROM AUTHOR]