ROOT HYDRAULIC CONDUCTIVITY AND PHOTOSYNTHETIC CAPACITY OF EUCALYPT CLONAL CUTTINGS WITH ROOT MALFORMATION INDUCTIONS

A redu\ue7\ue3o do ganho em biomassa de lenho em \ue1rvores tem sido atribu\uedda \ue0 ocorr\ueancia de deforma\ue7\uf5es radiculares ainda na fase de viveiro. O objetivo deste trabalho foi avaliar a condutividade hidr\ue1ulica do sistema radicular, trocas gasosas e a efici\ueancia fotoqu\uedmica de mudas clonais de eucalipto com e sem indu\ue7\ue3o de deforma\ue7\uf5es radiculares. Os tratamentos foram: 1 \u2013 mudas sem a indu\ue7\ue3o de deforma\ue7\uf5es radiculares (produzidas de acordo com metodologia operacional do viveiro da Fibria Celulose S.A.) e 2 \u2013 mudas com indu\ue7\ue3o de deforma\ue7\uf5es radiculares. A indu\ue7\ue3o da deforma\ue7\ue3o radicular n\ue3o resultou em queda no volume radicular. Contudo, deforma\ue7\uf5es radiculares provocaram redu\ue7\ue3o na condutividade hidr\ue1ulica do sistema radicular, assim como foram verificadas quedas na taxa fotossint\ue9tica das mudas ao longo do dia. A queda da taxa fotossint\ue9tica em mudas com indu\ue7\ue3o de deforma\ue7\uf5es radiculares est\ue1 associada a fatores estom\ue1ticos e n\ue3o estom\ue1ticos.The gain reduction of wood biomass in trees has been assigned to root deformations even in the nursery phase. The objective of this work was the evaluation of the root system hydraulic conductivity, gas exchanges and photochemical efficiency of eucalypt clonal cuttings with and without root deformation inductions. The treatments were: 1) operational cuttings without root malformation inductions (grown according to the used methodology of Fibria Cellulose S.A.); 2) root deformation inductions. These inductions did not promote decrease in the root volume. However, the deformations brought reduction of the root system hydraulic conductivity. Lower photosynthetic rates were also observed along the day in the cuttings in the root deformed cuttings. This decreasing rate is connected to stomatal and non stomatal factors