AVALIAÇÃO DE BACTÉRIAS COMO PROMOTORAS DE CRESCIMENTO E ENRAIZAMENTO DE MUDAS DE Eucalyptus spp. SOB DIFERENTES FORMAS DE DISPENSA

Abstract

The use of beneficial micro-organisms as growth and rooting promoters of plants has proven to be an excellent alternative to stimulate increased productivity and development of the plant. Thus, the aim of this study was to evaluate the potential of rhizobacteria isolates and phylloplane residentes in the vegetative propagation of Eucalyptus dunnii, Eucalyptus grandis and Eucalyptus viminalis with the purpose of obtaining an isolate that promotes growth and either the rooting of cuttings in some of the species used in the study. The experiment was conducted in the laboratory of Forest Protection and at the Nursery of the Department of Forest Engineering - UNICENTRO. For the formation of clonal minigarden, the species were grown in mini gutters in sand, under selective pruning for shaping of the ministumps. Selected cuttings were collected in the morning and submitted to three different methods of bacteria deliver: immersion in bacterial suspension of cuttings before planting, spraying bacterial suspension on the phylloplane of the cuttings and the use together of the two mentioned methods. These were sown in greenhouse and, after 30 days, were transferred to shade house where they remained between 20 to 30 days. Then the seedlings were placed in full sun area for hardening. In the experiment, we evaluated the survival and rooting, height, dry and fresh weight of shoot and root the cuttings. The results obtained showed that the bacterial isolates tested demonstrated high variability in response to growth promoting and rooting of the minicuttings of E. dunnii, E. grandis and E. viminalis, not being noticed pronounced effect on the mode of application due to the absence of the promoting effect of the bacterial isolates used.