Efecto de la aplicación de reguladores de crecimiento en el desarrollo radicular de plantines de Eucalyptus smithii

Eucalyptus smithii is one of the main species used in the Uruguayan forestry sector; it has arisen as an alternative to the introduction of Teratosphaeria nubilosa which caused several damages to Eucalyptus globulus plantations in 2007. The reason why E. smithii is chosen by forest producers is its wood, pulpable and silvicultural characteristics, as it can be its frost resistance. Nevertheless, plant mortality in early stages of the cycle without a clear diagnosis has been observed in the last few years. The objective of this research was to enhance seedlings quality indicators using growth regulators with effect on root development. The study took place in Saucedo nursery, located in Solis de Mataojo in Lavalleja province in Uruguay. The experiment was conducted in a completely randomized factorial design, with four levels of napthtalene-acetic acid (NAA) and three levels of aminoethoxy-vinil-glycine (AVG), resulting in twelve treatments. The foliar application was made 78 days after sowing. Afterwards, there were three evaluation instances; at 50, 70 and 90 days after the application. Then the morphological parameters were evaluated and the quality of indicators of seedlings estimated. Some treatments had an improvement in quality indicators, as it was the case of intermediate dose ANA 600 / AVG 125 being a possible treatment to be implemented since it obtained the highest DQI value (in the last measurement instance) and achieved seedlings with an improved balance between shoot and root systems without limiting height growth.