Desempenho de progênies e clones de Eucalyptus grandis hill ex. Maiden em sistema silvipastoril
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Data
2018-04-27
Autores
Bernardi, Camila Motta Marin
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Universidade Estadual Paulista (Unesp)
Resumo
Neste estudo objetivou-se estimar parâmetros genéticos e estatísticos para caracteres quantitativos nos primeiros seis anos de crescimento de progênies de Eucalyptus grandis em sistema silvipastoril; comparar a produtividade, estabilidade e adaptabilidade das progênies em diferentes idades e mensurar a produção de forragem e as características morfológicas e bromatológicas do capim Urochloa decumbens cv. Basilisk em crescimento livre no sub-bosque das árvores. Foram mensurados a altura (ALT), diâmetro a altura do peito (DAP) e sobrevivência (SOB), aos 2, 3, 4, 5, e 6 anos após o plantio. O delineamento utilizado foi o de blocos casualizados desbalanceados com 150 tratamentos (147 progênies de Eucalyptus grandis e três clones comerciais: C041H, P4295H e H15), 26 repetições e uma planta por parcela, no espaçamento de 2,0 x 2,5 x 4,0 m. Para avaliação do capim foram coletadas amostras da área abaixo e entre as linhas duplas de E. grandis. Na análise individual, os clones comerciais tiveram praticamente 100% de seus indivíduos entre os primeiros 250 classificados, as progênies 25 e 162 apresentaram número significativo de indivíduos nesta classificação. Em relação a classificação dos genitores, ao longo dos anos, os clones C041H e H15 sempre ficaram entre as primeiras posições. Mas as progênies 25 e 162 superaram o clone P4295H nos caracteres ALT, DAP e VOL, com correlação alta e positiva entre os anos para ALT e DAP (>0,74). Houve diferença significativa entre os tratamentos no decorrer dos anos de avaliação para os caracteres mensurados. Na análise conjunta para estabilidade, adaptabilidade e produtividade, as progênies 25, 162, 163 e 6 ficaram muito próximas a materiais comerciais (H15 e C041H) e tiveram maior estabilidade, adaptabilidade e produtividade em relação ao clone testemunha P4295H para o caráter DAP. A correlação entre os valores genéticos aditivos e de dominância para os caracteres ALT e DAP foram altos (>0,77). A produção de massa seca total de (MST) (645 kg ha-1) de capim e de folhas (272 kg ha-1) foram significativamente maiores (p<0,05) nas áreas menos sombreadas, entre as fileiras duplas e, valores nutritivos importantes, como a fração protéica e a digestibilidade, não apresentam grandes variações entre os tratamentos. Os resultados mostram ser possível continuar o programa de melhoramento genético com formação do pomar de sementes por mudas e teste de segunda geração, pois existem materiais com grande potencial de produção no local de estudo para futuros cruzamentos e formação de novos genótipos de E. grandis.
The objective of this study was to estimate genetic and statistical parameters for quantitative traits in the first six years of growth of Eucalyptus grandis progenies in the silvipastoril system; to compare productivity, stability and adaptability of progenies at different ages and to measure forage production and morphological and bromatological characteristics of Urochloa decumbens cv. Basilisk in free growth in the understorey of the trees. Height (ALT), diameter at breast height (DAP) and survival (SOB) were measured at 2, 3, 4, 5, and 6 years after planting. The experimental design was a randomized block with 150 treatments (147 progenies of Eucalyptus grandis and three commercial clones: C041H , P4295H and H15), 26 replicates and one plant per plot, at a spacing of 2.0 x 2.5 x 4 , 0 m. For evaluation of the grass samples were collected from the area below and between the double lines of E. grandis. In the individual analysis, commercial clones had practically 100% of their individuals among the first 250 classified, progenies 25 and 162 presented a significant number of individuals in this classification. Regarding the classification of the parents, over the years, the clones C041H and H15 always were among the first positions. But progenies 25 and 162 outperformed clone P4295H in ALT, DAP and VOL, with high and positive correlation between the years for ALT and DAP (> 0.74). There was a significant difference between the treatments during the evaluation years for the characters measured. In the joint analysis for stability, adaptability and productivity, progenies 25, 162, 163 and 6 were very close to commercial materials (H15 and C041H) and had greater stability, adaptability and productivity in relation to control clone P4295H for the DAP character. The correlation between the additive and dominance genetic values for the ALT and DAP characters was high (> 0.77). The total dry matter yield (MSM) (645 kg ha-1) of grass and leaves (272 kg ha-1) were significantly higher (p <0.05) in the less shaded areas between the double rows and, Important nutritional values, such as protein fraction and digestibility, do not show large variations between treatments. The results show that it is possible to continue the genetic improvement program with the seed orchard formation by seedlings and second generation test because there are materials with great potential of production in the study site for future crosses and formation of new genotypes of E. grandis.
The objective of this study was to estimate genetic and statistical parameters for quantitative traits in the first six years of growth of Eucalyptus grandis progenies in the silvipastoril system; to compare productivity, stability and adaptability of progenies at different ages and to measure forage production and morphological and bromatological characteristics of Urochloa decumbens cv. Basilisk in free growth in the understorey of the trees. Height (ALT), diameter at breast height (DAP) and survival (SOB) were measured at 2, 3, 4, 5, and 6 years after planting. The experimental design was a randomized block with 150 treatments (147 progenies of Eucalyptus grandis and three commercial clones: C041H , P4295H and H15), 26 replicates and one plant per plot, at a spacing of 2.0 x 2.5 x 4 , 0 m. For evaluation of the grass samples were collected from the area below and between the double lines of E. grandis. In the individual analysis, commercial clones had practically 100% of their individuals among the first 250 classified, progenies 25 and 162 presented a significant number of individuals in this classification. Regarding the classification of the parents, over the years, the clones C041H and H15 always were among the first positions. But progenies 25 and 162 outperformed clone P4295H in ALT, DAP and VOL, with high and positive correlation between the years for ALT and DAP (> 0.74). There was a significant difference between the treatments during the evaluation years for the characters measured. In the joint analysis for stability, adaptability and productivity, progenies 25, 162, 163 and 6 were very close to commercial materials (H15 and C041H) and had greater stability, adaptability and productivity in relation to control clone P4295H for the DAP character. The correlation between the additive and dominance genetic values for the ALT and DAP characters was high (> 0.77). The total dry matter yield (MSM) (645 kg ha-1) of grass and leaves (272 kg ha-1) were significantly higher (p <0.05) in the less shaded areas between the double rows and, Important nutritional values, such as protein fraction and digestibility, do not show large variations between treatments. The results show that it is possible to continue the genetic improvement program with the seed orchard formation by seedlings and second generation test because there are materials with great potential of production in the study site for future crosses and formation of new genotypes of E. grandis.
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Integração, Parâmetros genéticos, Pomar de sementes por mudas, Produtividade, Urochloa decumbens, Genetic parameters, Integration, Productivity, Seedlings seed orchard