Gleison Augusto dos Santos

Propagação vegetativa de cedro-rosa por miniestaquia

This work had the objective to evaluate the minicutting technique as a method for vegetative propagation of cedro-rosa (Cedrela fissilis), in terms of the production and survival of the ministumps after successive harvesting, as well as rooting and growth (height and root collar diameter) of the minicuttings. The minicuttings were obtained from seedlings of Cedrela fissilis, successively collected and submitted to different dosages of the growth regulator IBA. The results showed the efficiency of this technique in the vegetative propagation of this species. Up to 79% survival was obtained at 120 days of age, but when IBA was not applied, survival was higher. Overall, minicutting of Cedrela fissilis from material of seminal origin is technically viable. Its is an alternative method for producing seedlings of this species throughout the year, mainly when seeds are unavailable.

Enraizamento de miniestaca caulinar e foliar na propagação vegetativa de cedro-rosa (Cedrela fissilis Vell.)

This work aimed to evaluate the rooting of five different types of minicuttings (stem, apical stem, intermediate stem, apical stem with removed leaves and leaf), in the vegetative propagation of cedro-rosa (Cedrela fissilis), by applying the minicutting technique, using seedlings material. The results showed that stem cutting was the most efficient technique for the vegetative propagation of this species, with up to 84% survival at 90 days of age. Thus, this technique can be used as an alternative in the production of minicuttings of this species, throughout the year.

Desempenho silvicultural e seleção precoce de clones de híbridos de eucalipto

The objective of this work was to evaluate the genetic variability and silvicultural performance of clones from interspecific hybrids of Eucalyptus urophylla, E. globulus, E. maidenii, E. saligna, E. grandis, E. pellita, E. resinifera, E. kirtoniana and E. dunnii, and to determine the feasibility of early selection in selecting superior clones. The stem diameter at breast height at three (DAP3) and seven years (DAP7) and the total tree height at seven years were evaluated. A randomized complete block design, with138 clones, ten replicates and six plants per plot was used. Data were subjected to analysis of variance and clustered by the k-means method; the means were compared, and the Pearson correlation (r) was determined between variables. Clustering validation was performed using analysis of variance and Tukeys test. Clones of interspecific Eucalyptus hybrids showed genetic variability. Five groups of clones were established based on their silvicultural performance (DAP3, DAP7 and height). The DAP3 is highly correlated to DAP7 and height at seven years. The selection based on DAP3 can be used to identify superior clones of Eucalyptus with good growth vigor.

INTERAÇÃO GENÓTIPOS X AMBIENTES PARA PRODUTIVIDADE DE CLONES DE Eucalyptus L'Hér. NO ESTADO DO RIO GRANDE DO SUL

Este trabalho objetivou estudar a interacao genotipos em ambientes de clones de Eucalyptus em quatro ambientes do Estado do Rio Grande do Sul. Os ensaios foram conduzidos nas areas da empresa CMPC Celulose Riograndense, nos Municipios de Minas do Leao (Horto Florestal Cambara), Encruzilhada do Sul (Horto Florestal Capivara), Dom Feliciano (Horto Florestal Fortaleza) e Vila Nova do Sul (Horto Florestal Sao Joao). No ano 2007, foi implantada uma rede de testes clonais com 864 clones de Eucalyptus, pertencentes a 37 especies e hibridos. Aos 3 anos de idade, foram mensurados o diâmetro a altura do peito (dap) e a altura total (Ht) das arvores dos experimentos. O incremento medio anual (IMA) foi calculado de acordo com o volume individual por clone e o estande de plantas por hectare na idade de avaliacao do teste clonal. Os resultados da correlacao genotipica entre os ambientes variaram de 0,39 a 0,56, demonstrando que ocorreu interacao genotipos x ambientes significativa dos caracteres avaliados. Esses resultados indicam que e necessario selecionar clones especificos, nas combinacoes de ambientes com baixa correlacao genetica entre si. Ocorreu baixa correcao genetica entre os ambientes Cambara x Capivara; Cambara x Sao Joao; Capivara x Fortaleza; Capivara x Sao Joao; e Fortaleza x Sao Joao. Dessa maneira, para este estudo foram necessarias tres unidades de manejo para minimizar os efeitos da interacao genotipos x ambientes. Incluindo a selecao por estabilidade, adaptabilidade e os dois atributos simultaneamente, ocorreu mudanca de clones e de posicao entre os clones no ordenamento de selecao. Com a selecao simultânea por estabilidade e adaptabilidade (MHPRVG), os ganhos aumentaram em comparacao com a selecao pelos valores genotipicos preditos entre os ambientes, principalmente, e houve incremento dos ganhos em relacao a testemunha comercial. Por exemplo, os cinco melhores clones pelo criterio MHPRVG apresentaram-se 56% superiores a testemunha comercial para a caracteristica produtividade em volume.

Adaptabilidade de híbridos multiespécies de Eucalyptus ao Estado do Rio Grande do Sul

RESUMO – Neste trabalho, objetivou-se estudar a adaptabilidade de hibridos multiespecies de Eucalyptus em quatro ambientes do Estado do Rio Grande do Sul. Os ensaios foram realizados nas areas da empresa CMPC Celulose Riograndense, nos Municipios de Minas do Leao (Horto Florestal Cambara), Encruzilhada do Sul (Horto Florestal Capivara), Dom Feliciano (Horto Florestal Fortaleza) e Vila Nova do Sul (Horto Florestal Sao Joao). No ano 2007 foi implantada uma rede de testes clonais com 146 clones de Eucalyptus, pertencentes a 34 diferentes especies e, ou hibridos, em delineamento de blocos ao acaso com 30 repeticoes e uma planta por parcela (Single Tree Plot). Aos 3 anos de idade, foram mensurados o diâmetro a altura do peito (dap) e a altura total (Ht) das arvores dos experimentos. O incremento medio anual (IMA) foi calculado de acordo com o volume individual por clone e o estande de plantas no hectare na idade de avaliacao do teste clonal. Concluiu-se que em um programa de melhoramento do eucalipto a analise simultânea de produtividade, estabilidade e adaptabilidade deve ser preferida em relacao ao simples ordenamento de valores genotipicos. Na selecao simultânea, destacaram-se entre os melhores materiais geneticos do ordenamento, hibridos do tipo “three-way cross”, formados por tres diferentes especies de Eucalyptus. Os hibridos mais promissores para a geracao de clones superiores foram E. urophylla x (E. camaldulensis x E. grandis), E. grandis x (E. urophylla x E. grandis), E. saligna x (E. grandis x E. urophylla) e E. grandis x E. kirtoniana (E. robusta x E. tereticornis) e E. grandis x E. urophylla. Palavras chave: Eucalyptus spp.; Performance relativa; Ganhos preditos; Estabilidade; Clones. ADAPTABILITY FOR EUCALYPTUS MULTI SPECIES HYBRIDS IN THE STATE OF RIO GRANDE DO SUL

The use of mini-tunnels and the effects of seasonality in the clonal propagation of Eucalyptus in a subtropical environment

Summary Environmental seasonality plays a key role in the physiological processes of root formation in vegetative reproduction for commercial cloning. The authors hypothesised that (1) subtropical climatic seasonality causes higher rates of Eucalyptus mini-cutting production and rooting during warmer months and (2) the use of mini-tunnels to cover the stumps (stools) providing cuttings would enhance these processes year round. This study evaluated the effects of seasonality and the use of mini-tunnels using eight clones of Eucalyptus spp. under subtropical environmental conditions over the course of a year. The production systems studied were (1) mini-stumps planted in a clonal hedge (control) under a retractable roof shelter and (2) mini-stumps planted inside mini-tunnels under the same shelter. Five parameters were evaluated: (1) the temperature in the two environments; (2) the production of mini-cuttings by the stumps; (3) foliar area of the cuttings at harvest; (4) the survival of cuttings after 30 days in the greenhouse with micro-sprinklers and (5) rooting of cuttings at 45 days from setting. The use of mini-tunnels increased air temperature, increased mini-cutting production by 53% and promoted a reduction in foliar area of the cuttings at harvest. Rooting was found to be greater in warmer months (summer and spring) with an overall mean rooting rate of 80% versus 68% during the colder months (autumn and winter). The hypothesis that mini-tunnels enhance rooting of the cuttings produced in them was only partially confirmed, as this technique improved rooting (from 76% to 85% for the control versus the mini-tunnel conditions, respectively) only during the warmer months.

INFLUÊNCIA DO SISTEMA DE CORTE BASAL DE MINIESTACAS NA PROPAGAÇÃO CLONAL DE HÍBRIDO DE Eucalyptus urophylla X Eucalyptus globulus subsp. maidenii 1

Mini-cutting technique has allowed establishing large scale clonal forests. However small progress has been observed in nursery management practices for recalcitrant genotypes. The present work aimed to evaluate the influence of different base cut systems in mini-cuttings for seedlings production of a hybrid clone of Eucalyptus urophylla x Eucalyptus globulus subsp. maidenii. Three evaluations were performed: 1) survival in the greenhouse at the 30 th day; 2) number of rooted seedlings in the shade house at the 45 th day; and 3) viable seedlings in the hardening area at the 60 th day. Rooting evaluation was based on survival rate. The experimental design was in randomized blocks with four replications and three treatments: 1) perpendicular cut at the base of mini-cuttings (control); 2) bevel cut at the base of mini-cuttings (diagonal cut); 3) perpendicular cut at the base of mini-cuttings with three longitudinal incisions in the base. Four blocks were assessed, each block was composed by 228 plants. The results of rooting were over 80% in the best treatments, indicating that the clone propagation is feasible using mini-cutting technique, and it does not show a recalcitrant behavior. The basal cut system in bevel and in longitudinal incisions did not favor rooting.