EFFECT OF WATER STRESS ON YIELD, CLOROPHYLL AND BIOMASS IN WHEAT

Abstract

Variables associated with the response of wheat under restricted irrigation conditions are important, so the aim of this study was to identify varieties with higher yields, which is necessarily related to physiotechnical variables that allow them to adapt to stress conditions. Four genotypes were evaluated under full and restricted irrigation in two environments, field and shade house in the localities of Celaya and Salamanca, Guanajuato, Mexico. In the field, a complete randomized block design was used under a split-plot arrangement, the whole plot corresponded to the irrigation schedules and the split plot to the genotypes; The variables grain yield, normalized differential vegetation index (NDVI), chlorophyll index, leaf area and canopy temperature were quantified. In the house shade a completely randomized design with factorial arrangement was used, where the first factor was the moisture condition (with and without stress) and the second factor was the genotypes; the accumulation of dry matter of the root, stem, leaf and spike was measured. The greatest variability of yield occurred between localities, the application of four irrigations allowed a higher yield (14.1 %) and chlorophyll index (1.3 %), relative to the application of three irrigations. A higher grain yield was obtained at the locality of Celaya. The variety Bárcenas S2002 presented superior averages in yield with 5.5 and 3.9 t ha^-1 with four and three irrigations, respectively. In the house shade without water stress, a greater accumulation of dry matter was obtained in the root, aerial part, stems and leaves. The variables that gave rise to a differential response were yield, leaf area, NDVI and root dry weight. The variety Bárcenas S2002 presented the highest yields under restricted irrigation conditions based on reduced dry matter of the aerial part and root, with lower reductions in chlorophyll.