Influência do microclima nas trocas gasosas e na produção de estacas em jardim clonal de eucalyptus spp. e corymbia spp.
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Data
2019-06-12
Autores
Santos, Rafael Lima
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Universidade Estadual Paulista (Unesp)
Resumo
Os avanços no setor florestal foram impulsionados, especialmente, pelos plantios com espécies do gênero Eucalyptus, tornando os viveiros florestais a base deste processo produtivo. Com o aumento da demanda por madeira se faz necessário obter cepas altamente produtivas sem aumentar a área do jardim clonal. O objetivo deste trabalho foi analisar como as estruturas de jardim clonal e as estações do ano afetam as atividades fisiológicas e a produtividade de estacas de cepas de clones de Eucalyptus spp. e de Corymbia citriodora F. V. Muell x Corymbia torelliana Hook. O experimento foi instalado em 2017 no jardim clonal do viveiro do Departamento de Ciência Florestal da FCA/UNESP, em Botucatu, São Paulo, em parcelas subdivididas 4x4x2, sendo quatro estruturas de jardim clonal: Pé direito alto; Minitúnel difusor; Minitúnel azul e Descoberto, quatro clones (três clones de Eucalyptus spp. e um clone de Corymbia citriodora F. V. Muell x Corymbia torelliana Hook) e duas estações do ano (inverno e primavera). As mudas com aproximadamente 25 cm de altura e 3 mm de diâmetro de colo foram plantadas em canaletão de fibrocimento com 4,5 m de comprimento por 0,9 m de largura, em espaçamento de 0,15 x 0,15 m. Após 15 dias do plantio, as mudas foram cortadas, deixando todas com altura de 8 cm, com objetivo de estimular a brotação das gemas laterais. O sistema de irrigação utilizado foi gotejamento com bocais e vazão de 1,6 L h-1. Os manejos hídricos e nutricionais foram adaptados a cada época do ano, dependendo das condições climáticas (lâmina de irrigação média de 4,7 mm no inverno e 5,3 mm na primavera). Foram avaliadas: produtividade mensal (número de estacas/cepa/estrutura, nas duas estações); variáveis climatológicas (temperatura, umidade relativa e radiação solar); Variáveis fisiológicas: trocas gasosas (taxa de assimilação de CO2, condutância estomática, concentração interna de CO2, taxa de transpiração, eficiência do uso da água e eficiência de carboxilação e fluorescência da clorofila a (eficiência quântica potencial do FSII, eficiência quântica das antenas, coeficiente de extinção fotoquímico, coeficiente de extinção não fotoquímico e taxa aparente de transporte de elétrons). Na análise estatística foram ajustados modelos lineares generalizados mistos com distribuição Poisson para a variável produtividade e fisiológicas, todas com função de ligação logarítmica, considerando medidas repetidas no tempo pelo método de Equações de Estimação Generalizadas. Foi utilizado o Programa estatístico SAS e para comparações entre tratamentos foi utilizado o teste Tukey-Kramer. A qualidade dos ajustes foi feita através da análise dos resíduos de Pearson padronizados. Cada ambiente forma um microclima, apresentando características climáticas peculiares e que, dependendo da estação do ano e da estrutura, houve diferença na produtividade das cepas. Os clones plantados sob o minitúnel difusor produzem mais estacas/cepas nas duas estações do ano, quando comparados com as demais estruturas.
Advances in the forestry sector were driven especially by plantations with species of the genus Eucalyptus, making nurseries the basis of this productive process. With increasing demand for wood it is necessary to obtain highly productive strains without expanding the area of the clonal garden. The objective of this work was to evaluate how the clonal garden structures and the seasons affect the physiological activities and productivity of cuttings of Eucalyptus spp clones. and Corymbia citriodora F. V. Muell x Corymbia torelliana Hook. The experiment was installed in 2017 in the nursery clonal garden of the Forest Science Department of FCA / UNESP, in Botucatu, São Paulo, in 4x4x2 subdivided parcels, with four different clonal garden structures: high right foot; diffuser mini-tunnel; blue mini-tunnel and uncovered, four clones (three clones of Eucalyptus spp. and one clone of Corymbia citriodora F. V. Muell x Corymbia torelliana Hook) and two seasons of the year (winter and spring). The seedlings with approximately 25cm of height and 3mm of lap diameter were planted in a fiber cement cantilever with 4.5m in length by 0.9m of width, in 0.15 x 0.15m spacing. After 15 days of planting the seedlings were all cut at 8cm height, to stimulate the sprouting of the lateral buds. The irrigation system used was dripping with nozzles with 1.6 L h-1 flow. Water and nutritional management were adapted to each season according to environmental conditions (mean irrigation depth of 4.7mm in winter and 5.3mm in spring). The following were evaluated: monthly productivity (number of cuttings / strain / structure, in the two seasons); climatic variables (temperature, relative humidity and solar radiation); Physiological variables: gas exchange (rate of CO2 assimilation, stomatal conductance, internal CO2 concentration, transpiration rate, water use efficiency and carboxylation efficiency) and fluorescence (potential quantum efficiency of FSII, quantum efficiency of the antennas, photochemical extinction coefficient, non-photochemical extinction coefficient and apparent rate of electron transport). In the statistical analysis, mixed generalized linear models with Poisson distribution for the productivity and physiological variables, all with logarithmic linkage function, considering measures repeated in time by the Generalized Estimation Equation method. The SAS statistical program was used and the Tukey-Kramer test was used for comparisons between treatments. The quality of the adjustments was made through the analysis of standardized Pearson residues. Each environment forms a microclimate, presenting peculiar climatic characteristics and that, depending on the season and the structure, there was a difference in the yield of the strains. The clones planted under the diffuser mini-tunnel produced more stakes / strains in the two seasons compared to the other structures.
Advances in the forestry sector were driven especially by plantations with species of the genus Eucalyptus, making nurseries the basis of this productive process. With increasing demand for wood it is necessary to obtain highly productive strains without expanding the area of the clonal garden. The objective of this work was to evaluate how the clonal garden structures and the seasons affect the physiological activities and productivity of cuttings of Eucalyptus spp clones. and Corymbia citriodora F. V. Muell x Corymbia torelliana Hook. The experiment was installed in 2017 in the nursery clonal garden of the Forest Science Department of FCA / UNESP, in Botucatu, São Paulo, in 4x4x2 subdivided parcels, with four different clonal garden structures: high right foot; diffuser mini-tunnel; blue mini-tunnel and uncovered, four clones (three clones of Eucalyptus spp. and one clone of Corymbia citriodora F. V. Muell x Corymbia torelliana Hook) and two seasons of the year (winter and spring). The seedlings with approximately 25cm of height and 3mm of lap diameter were planted in a fiber cement cantilever with 4.5m in length by 0.9m of width, in 0.15 x 0.15m spacing. After 15 days of planting the seedlings were all cut at 8cm height, to stimulate the sprouting of the lateral buds. The irrigation system used was dripping with nozzles with 1.6 L h-1 flow. Water and nutritional management were adapted to each season according to environmental conditions (mean irrigation depth of 4.7mm in winter and 5.3mm in spring). The following were evaluated: monthly productivity (number of cuttings / strain / structure, in the two seasons); climatic variables (temperature, relative humidity and solar radiation); Physiological variables: gas exchange (rate of CO2 assimilation, stomatal conductance, internal CO2 concentration, transpiration rate, water use efficiency and carboxylation efficiency) and fluorescence (potential quantum efficiency of FSII, quantum efficiency of the antennas, photochemical extinction coefficient, non-photochemical extinction coefficient and apparent rate of electron transport). In the statistical analysis, mixed generalized linear models with Poisson distribution for the productivity and physiological variables, all with logarithmic linkage function, considering measures repeated in time by the Generalized Estimation Equation method. The SAS statistical program was used and the Tukey-Kramer test was used for comparisons between treatments. The quality of the adjustments was made through the analysis of standardized Pearson residues. Each environment forms a microclimate, presenting peculiar climatic characteristics and that, depending on the season and the structure, there was a difference in the yield of the strains. The clones planted under the diffuser mini-tunnel produced more stakes / strains in the two seasons compared to the other structures.
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Palavras-chave
Ecofisiologia, Variáveis Climatológicas, Variáveis Fisiológicas, Ecophysiology, Climatic Variables, Physiological Variables