Influência do ângulo foliar na qualidade de mudas nativas cultivadas sob diferentes manejos hídricos
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Data
2018-12-18
Autores
Delgado, Luiz Gustavo Martinelli [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Devido à necessidade do cumprimento das exigências ambientais às atuais legislações, há um aumento considerável na procura de mudas florestais nativas tanto em quantidade quanto em qualidade. Assim, visando melhorar a produção de mudas em qualidade e com menor dispêndio de recursos, o objetivo do presente estudo foi avaliar como a lâmina de irrigação aplicada e o ângulo foliar das espécies influenciam nas qualidades morfológicas, fisiológicas e nutricionais de mudas florestais nativas e na fração de lixiviação. O experimento foi conduzido no Viveiro do Departamento de Ciência Florestal, Faculdade de Ciências Agronômicas da UNESP, no município de Botucatu/SP. O delineamento experimental adotado foi o inteiramente casualizado, em esquema fatorial 7x3, sendo sete ângulos foliares (espécies) e três lâminas de irrigação (6, 9 e 12 mm), aplicadas parceladamente duas vezes ao dia. Foram avaliadas as seguintes variáveis: altura, diâmetro do colo, massas secas aérea, radicular e total, área de projeção da copa, conformação do sistema radicular, índice de qualidade de Dickson, potencial hídrico foliar, conteúdo relativo de água na folha, transpiração diária, condutância estomática, déficit de pressão de vapor, intensidade de coloração verde na folha, fração de lixiviação, condutividade elétrica da solução escoada do fundo do tubete e teor e acúmulo de nutrientes. Os dados das variáveis morfológicas, fisiológicas e fração de lixiviação foram submetidos à análise multivariada de componentes principais, sendo selecionadas aquelas que explicaram a maior parte da variabilidade dos dados. Para as variáveis selecionadas, foi realizada análise de variância, seguida do teste de Scott-Knott (p<0,05). Os dados da conformação do sistema radicular foram comparados percentualmente e da solução escoada no fundo do tubete ao final do experimento, diariamente, durante seis dias. O grau de associação entre acúmulo de nutrientes e lâminas de irrigação foi obtido por meio da correlação de Pearson. A lâmina de irrigação aplicada e o ângulo foliar das espécies influenciaram nas qualidades morfológicas, fisiológicas e nutricionais das mudas. As mudas das espécies Ficus luschnathiana (166º), Sapindus saponaria (147º) e Acnistus arborecens (144º) apresentaram melhor qualidade quando submetidas à menor lâmina de irrigação diária (6mm). As mudas das espécies Luehea grandiflora (89º) e Alchornea glandulosa (46º) apresentaram melhores qualidades quando cultivadas na maior lâmina de irrigação diária (12mm). A lâmina intermediária de irrigação diária (9mm) produziu mudas com melhores qualidades para as espécies Psidium guajava (156º) e Cecropia pachystachya (26º).
Due to the current environmental laws, there has been an increase in the search for quantity and quality of native tree seedlings. Thus, in order to improve the quality in seedlings production with the lowest costs, the present research aimed to evaluated the influence of applied water depth and the leaf angles of species on the morphological, physiological and nutritional aspects from native tree seedlings and on the leaching fraction. The experiment was carried out in the nursery from Forest Science Department, at School of Agronomy UNESP, in Botucatu/SP. The experimental design was completely randomized in a 7X3 factorial scheme, with seven leaf angles (species) and three irrigation depths (6, 9, 12mm) partially applied twice a day. The following variables were considered: height, stem diameter, shoot, root and total dry mass, crown projection area, conformation root system, Dickson quality index, leaf water potential, water content on leaf, daily perspiration, stomatal conductance, vapor pressure deficit, leaf chlorophyll, leaching fraction, electrical conductivity of the solution leached from plastic tubes and nutritional accumulation. Data from morphological and physiological variables, together with the leaching fraction were submitted to a multivariated analysis of main components. The variables were selected according to a better explanation for data variability. It was carried out a variance analysis followed by the Scott-Knot test to the variables selected. Conformation data from root system were compared in percentage terms, while the solution leached from plastic tubes were daily considered. The degree of association between the nutritional accumulation and the different water depths were calculated by means of Pearson correlation. The applied irrigation depth and the leaf angle had influence on morphological, physiological and nutritional aspects from seedlings. Seedlings of Ficus luschnathiana (166°), Sapindus saponaria (147°) and Acnistus arborecens (144°) presented better quality when submitted to the daily lowest irrigation depth (6mm). The seedlings of Luehea grandiflora (89°) and Alchornea glandulosa presented better quality when submitted to the daily highest irrigation depth (12mm). The daily medium irrigation depth (9mm) produced better seedlings of Psidium guajava (156°) and Cecropia pachystachya (26°).
Due to the current environmental laws, there has been an increase in the search for quantity and quality of native tree seedlings. Thus, in order to improve the quality in seedlings production with the lowest costs, the present research aimed to evaluated the influence of applied water depth and the leaf angles of species on the morphological, physiological and nutritional aspects from native tree seedlings and on the leaching fraction. The experiment was carried out in the nursery from Forest Science Department, at School of Agronomy UNESP, in Botucatu/SP. The experimental design was completely randomized in a 7X3 factorial scheme, with seven leaf angles (species) and three irrigation depths (6, 9, 12mm) partially applied twice a day. The following variables were considered: height, stem diameter, shoot, root and total dry mass, crown projection area, conformation root system, Dickson quality index, leaf water potential, water content on leaf, daily perspiration, stomatal conductance, vapor pressure deficit, leaf chlorophyll, leaching fraction, electrical conductivity of the solution leached from plastic tubes and nutritional accumulation. Data from morphological and physiological variables, together with the leaching fraction were submitted to a multivariated analysis of main components. The variables were selected according to a better explanation for data variability. It was carried out a variance analysis followed by the Scott-Knot test to the variables selected. Conformation data from root system were compared in percentage terms, while the solution leached from plastic tubes were daily considered. The degree of association between the nutritional accumulation and the different water depths were calculated by means of Pearson correlation. The applied irrigation depth and the leaf angle had influence on morphological, physiological and nutritional aspects from seedlings. Seedlings of Ficus luschnathiana (166°), Sapindus saponaria (147°) and Acnistus arborecens (144°) presented better quality when submitted to the daily lowest irrigation depth (6mm). The seedlings of Luehea grandiflora (89°) and Alchornea glandulosa presented better quality when submitted to the daily highest irrigation depth (12mm). The daily medium irrigation depth (9mm) produced better seedlings of Psidium guajava (156°) and Cecropia pachystachya (26°).
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Palavras-chave
Arquitetura de mudas, Irrigação, Viveiro