Silício na produção, enraizamento e severidade de oídio em miniestacas de eucalipto

Abstract

In the last few years, there has been checked a constant increase by the clonal production of the eucalyptus genre, aiming mainly the alignment of the plantation. High productivity, competitive cost. Among the various methods of asexual propagation, stands out minicutting.. In the minigarden covered clonal, the environmental conditions found are in favor of the incidence of several diseases, being these the oidium, causing significative losses to the seeding producers. The oidium control is made generally by the use of resistant clones or fungicides, being necessary, however, to find alternative ways of control of this fungus with the objective to reduce the using of these chemical products such as the costs. In view of the Silicon (Si) is a nutrient who excels in the control of fungal diseases and in the raise of the productivity of several cultures, the aim of this study is to evaluate his influence in productivity, rooting and severity in oidium in eucalyptus minicutting. Therefore, an experiment was conducted in nursery seedings, belonging to the Forestry Department of the Federal University of Viçosa-MG. The experimental design was a randomized complete block design with four replications in a split plot design, being the first relative factor to the Si doses (0;0,5;1,0;1,5 and 2 mol L1) and the second relative factor to the five clones of Eucalyptus grandis x Eucalyptus urophylla (I144, I224, 3334, GG100, GG680.) Were evaluated the following characteristics: Proportion of Si accumulated, oidium severity, productivity (number of minicutting) and rooting. There wasn\'t any interaction between the factors: silicon and clones in relation to the concentration of Si in the minicutting. However, observed that the raise of the Si concentrations in the nutrient solution caused an increase in Si content in these seedlings. To the other characteristics evaluated ( rooting, minicutting productivity and oidium severity), the clones answer in relation to the Si increase was similar, I mean, there wasn\'t any interaction between treatments and there wasn\'t any change of these characteristics with the increase of the Si concentrations. Differences were found only among the studied clones. The clone GG100 and the clone 3334 were the ones who has presented, respectively, the best and the worst results to all the studied traits.