Abstract

TAFUR*, María Sara Mejía - de et al. Effect of water stress on accumulation and distribution of biomass in Eucalyptus grandis W. Hill ex Maiden. Acta Agron. [online]. 2017, vol.66, n.1, pp.56-62. ISSN 0120-2812.  https://doi.org/10.15446/acag.v66n1.52628.

In order to evaluate the effect of water stress on growth and biomass distribution of E. grandis, two experiments were established in pots outdoors in contrasting sites of Valle del Cauca, Colombia (Palmira, 23.5°C and Restrepo, 18°C),there were evaluated four genotypes (28-3, 18-3, 24A-5 and 1-19) to soil water availability (at field capacity (fc) 1/2 fc, 1/4 fc and saturation) using a divided plot design, with 16 treatments and 4 replications. The pots surface was covered with plastic fabric divided to prevent the entry of rain water. In both locations significant differences between treatments were presented. In Palmira the plants accumulated more biomass when the soil was at fc and in Restrepo with 1/2 fc and 1/4 fc. The most limiting treatment at both sites was soil saturation. Genotypes also differ in the ability to accumulate biomass being the 24A-5 and 28-3 those with greater stems weight but not in leaves. Positive and highly significant relationship between leaf area and biomass in stems and more water use efficiency (WUE) were with water deficit. However, the tolerance to stress caused the decrease in biomass accumulation, due to the wasted energy to activate the defense mechanisms, this could vary depending on the stress intensity and other environmental conditions such as temperature.

Keywords : Drought; Flooding; Water use Efficiency (WUE); leaf area; genotype-environment relationship.

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