O ataque de insetos pragas tem sido um dos grandes entraves para a expans?o da
eucaliptocultura no Brasil. Dentre essas pragas destaca-se o psil?deo de concha Glycaspis
brimblecombei que vem causando s?rios danos ?s planta??es no pa?s. A nutri??o mineral tem
se apresentado como uma boa estrat?gia para o controle de pragas e doen?as, e o Sil?cio (Si)
tem ganhado destaque em diversas pesquisas nesse sentido nos ?ltimos anos. O objetivo deste
estudo foi verificar se a fertiliza??o silicatada com micross?lica tem potencial para ser usada no
controle do psil?deo de concha na cultura do eucalipto. O delineamento experimental utilizado
foi em faixas com cinco tratamentos, distribu?dos em oito blocos casualizados, tendo como
fonte de sil?cio a micross?lica (teor de SiO2 4,18%). Para o experimento via solo, os tratamentos
foram: T1 - Controle, sem aplica??o de sil?cio; T2 - 62,7 g Si/planta; T3 - 83,6 g Si/planta; T4
- 104,5 g Si/planta e T5 - 125,4 g Si/planta. Para o experimento via foliar, foi feita uma solu??o
de micross?lica, ?gua e espalhante adesivo, onde os tratamentos foram: T1 - Controle, sem
aplica??o de sil?cio; T2 - 20,9 mg Si/litro; T3 - 41,8 mg Si/litro; T4 - 62,7 mg Si/litro e T5 -
83,6 mg Si/litro. Os fatores avaliados foram n?mero de ovos e ninfas do psil?deo de concha e o
teor de clorofila das folhas de eucalipto. No experimento via solo as doses de sil?cio n?o
apresentaram efeito significativo no n?mero de ovos e de ninfas do psil?deo de concha. No
experimento via foliar as doses de sil?cio interferiram estatisticamente no n?mero de ovos e
ninfas do psil?deo de concha. Tanto no experimento via solo quanto foliar, n?o houve altera??es
significativas no teor de clorofila, indicando pelos valores encontrados que as plantas j? se
encontravam faixas ideais de clorofila nas folhas. As quantidades de ovos e ninfas variaram ao
longo dos meses apresentando baixos coeficientes de correla??o com a precipita??o mensal. A
micross?lica como fonte de sil?cio se mostrou capaz de reduzir o n?mero de ovos e ninfas do
psil?deo de concha quando aplicada via foliar. Aplicada via solo, nas doses avaliadas, n?o se
mostrou capaz de reduzir o n?mero de ovos e ninfas do inseto.Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2020.The attack of insect pests has been one of the major obstacles to the expansion of Eucalyptus
culture in Brazil. Among these pests, the shell psyllid (Glycaspis brimblecombei) stands out,
which has been causing serious damage to plantations in the country. Mineral nutrition has been
presented as a good strategy for the control of pests and diseases and Silicon (Si) has gained
prominence in several studies in this regard in recent years. The objective of this study was to
verify whether silicate fertilization with microsilica has the potential to be used in the control
of the shell psyllid in the eucalyptus culture. The experimental design used was in bands with
five treatments, distributed in eight randomized blocks, using microsilica as the silicon source
(SiO2 content 4.18%). For the soil application, the treatments were: T1 - Control, without
silicon; T2 - 62.7 g Si / plant; T3 - 83.6 g Si / plant; T4 - 104.5 g Si / plant and T5 - 125.4 g Si
/ plant. For the leaf application, a solution of microsilica, water and adhesive spreader was
made, where the treatments were: T1 - Control, without silicon; T2 - 20.9 mg Si / liter; T3 -
41.8 mg Si / liter; T4 - 62.7 mg Si / liter and T5 - 83.6 mg Si / liter. The factors evaluated were
the number of eggs and nymphs of the shell psyllid and the chlorophyll content of the eucalyptus
leaves. In the soil experiment, silicon doses did not have a significant effect on the number of
eggs and nymphs of the shell psyllid. In the foliar experiment, silicon doses statistically
interfered with the number of eggs and nymphs of the shell psyllid. Both in the soil application
and in the leaves application, there were no significant changes in the chlorophyll content,
indicating by the values found that the plants already found ideal ranges of chlorophyll in the
leaves. The quantities of eggs and nymphs varied throughout the months, presenting low
correlation coefficients with monthly precipitation. Microsilica as a source of silicon has been
shown to reduce the number of eggs and nymphs of the shell psyllid when applied in leaf.
Applied in soil, at the doses evaluated, it was not able to reduce the number of eggs and nymphs
of the insect
