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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estimativa de um índice de estresse hídrico para a cultura da cana-de-açúcar com base na temperatura foliar / Estimating of crop water stress index to sugarcane based on the canopy temperature

Trentin, Roberto 24 February 2010 (has links)
Made available in DSpace on 2015-03-26T13:50:02Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1247950 bytes, checksum: 0840510708636790c84fc24445425dfd (MD5) Previous issue date: 2010-02-24 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this work was to evaluate the behavior of leaf temperature and transpiration of sugarcane under different matric and meteorological conditions to estimate a crop water stress index (IEHC), which can be applied in irrigation management and estimates of productivity. Because of the need to apply water stress to plants, the experiment was conducted in a greenhouse, belonging to the Agricultural Engineering Department at the Federal University of Viçosa, Viçosa, MG, Brazil. Bud chips of sugarcane (cv. RB867515) were planted on May 6, 2009, in plastic pots with a capacity of 10 liters, which were filled with a commercial substrate. In total, 192 plants were grown for 6 months within the greenhouse, but only a portion was used in measurements. To evaluate the effect of water availability on leaf temperature and transpiration, under different meteorological conditions, three classes of water tension (&#936;) were maintained in the substrate: no water stress (&#936; < 0,5 bar), moderate (4,0 < &#936; < 6,0) and severe (&#936; > 11,0 bars) water stress. A meteorological data acquisition system was implemented for measuring global solar radiation (Rg), air velocity (U), air relative humidity (UR), air temperature (tar) and transpiration of three individual plants randomly chosen. In addition, leaf temperature (tc) was obtained by positioning an infrared thermometer at three different points of each plant used in the transpiration measurements. Based on the measurements obtained without water stress, it was found that the leaf temperature followed fluctuations of solar radiation caused by conditions of partly cloudy sky. In general, tc was lower than tar under no water stress conditions, with maximum difference of 6ºC. The effect of water stress on leaf temperature and transpiration was determined from the suspension of irrigation, by performing three measurement campaigns, initiated at 122, 150 and 181 days after planting, with two days intervals, until the water tension in the substrate reached 15 bars. Under severe water stress conditions, tc became 6.8°C higher than t ar. By using regression analysis, relations were established between the differential tc-tar and the variables global solar radiation (Rg) and air water vapor pressure deficit (DPVar), in order to determine the parameters necessary for obtaining the IEHC. / The objective of this work was to evaluate the behavior of leaf temperature and transpiration of sugarcane under different matric and meteorological conditions to estimate a crop water stress index (IEHC), which can be applied in irrigation management and estimates of productivity. Because of the need to apply water stress to plants, the experiment was conducted in a greenhouse, belonging to the Agricultural Engineering Department at the Federal University of Viçosa, Viçosa, MG, Brazil. Bud chips of sugarcane (cv. RB867515) were planted on May 6, 2009, in plastic pots with a capacity of 10 liters, which were filled with a commercial substrate. In total, 192 plants were grown for 6 months within the greenhouse, but only a portion was used in measurements. To evaluate the effect of water availability on leaf temperature and transpiration, under different meteorological conditions, three classes of water tension (&#936;) were maintained in the substrate: no water stress (&#936; < 0,5 bar), moderate (4,0 < &#936; < 6,0) and severe (&#936; > 11,0 bars) water stress. A meteorological data acquisition system was implemented for measuring global solar radiation (Rg), air velocity (U), air relative humidity (UR), air temperature (tar) and transpiration of three individual plants randomly chosen. In addition, leaf temperature (tc) was obtained by positioning an infrared thermometer at three different points of each plant used in the transpiration measurements. Based on the measurements obtained without water stress, it was found that the leaf temperature followed fluctuations of solar radiation caused by conditions of partly cloudy sky. In general, tc was lower than tar under no water stress conditions, with maximum difference of 6ºC. The effect of water stress on leaf temperature and transpiration was determined from the suspension of irrigation, by performing three measurement campaigns, initiated at 122, 150 and 181 days after planting, with two days intervals, until the water tension in the substrate reached 15 bars. Under severe water stress conditions, tc became 6.8°C higher than t ar. By using regression analysis, relations were established between the differential tc-tar and the variables global solar radiation (Rg) and air water vapor pressure deficit (DPVar), in order to determine the parameters necessary for obtaining the IEHC
2

Efeito do manejo hídrico durante a rustificação em mudas de Gallesia integrifolia (Spreng.) Harms e Handroanthus impetiginosus (Mart. ex DC.) Mattos / Effects of hydric management during the rustification in seedlings of Gallesia integrifolia (Spreng.) Harms and Handroanthus impetiginosus (Mart. ex DC.) Mattos

Lima, Paulo Ricardo 21 February 2014 (has links)
Made available in DSpace on 2017-07-10T17:36:55Z (GMT). No. of bitstreams: 1 2014_Diss_Paulo_Ricardo_Lima.pdf: 1308778 bytes, checksum: fcc1fc80a1ef2f3cfecb3a398ecc76bb (MD5) Previous issue date: 2014-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The knowledge of Morphophysiological mechanisms that allow a plant tolerate water stress conditions constitutes important tool for analyzing the quality of seedlings, so it the work aimed to quantify the effects of water management in the period of rustification in seedlings of Handroanthus impetiginosus (Mart. ex DC.) Mattos and Gallesia integrifolia (Spreng.) Harms by means of foliar thermometry and parameters morphometric of quality and additionally analyze the performance of seedlings after the rustification, in soil sandy and loamy soil. The experiment was conducted in a protected ambient at the State University of West Paraná, campus Marechal Cândido Rondon - PR. The treatments were comprised of four hydric regimes: daily irrigation (control), every two, three and four days in 60 seedlings per treatment for four weeks. The mensurations involved the measurement of the leaf temperature (TF), the increments in height, the stem diameter, in the mass dry of root , in the mass dry of shoot and leaf area. The mensurations of TF occurred at the end of each irrigation management cycle and for the other variables were held measurements at the beginning and end of rustification. After the impositions of hydric managements, the seedlings were taken to pots containing sandy soil and clay soil to check the influence of different hydric management as well as soil type in the seedling survival. The analysis between the control treatment and irrigation every two days resulted in significant differences (P> 0,05) merely for leaf area, whereas in and both species studied presented decreased of leaf area with the increase of hydric restriction. Seedlings of H. impetiginosus with of irrigation cycles every three days, showed a reduction in the rate of growth in diameter of 29%, of 58% to increment the dry mass of shoots and 32% for leaf area compared to the management control. Seedlings of G. integrifolia irrigated every three days showed no significant differences (P> 0,05) compared with irrigated daily. The irrigation management every four days in seedlings of H. impetiginosus enabled higher speed of growth of the root system and reduced aerial growth, resulting in warming the leaf, whereas the irrigation management every four days in seedlings of G. integrifolia presented reduction in the rate of growth of the shoot and not presented difference (P> 0,05) in the root system growth and also resulted in leaf warming. The use of the infrared thermometry allows benchmarking the leaf temperature during rustification of seedlings of H. impetiginosus and G. integrifolia. Was no influence of soils in the seedling survival of H. impetiginosus and G. integrifolia, and symptoms of hydric deficit always if manifested first in clay soil, mainly in seedlings not adapted to hydric stress. In both species, the symptoms of hydric deficit presented by the seedlings of different management hydrics showed that seedlings submitted to the irrigation regimes every three and four days, were attenuating slowly the symptoms of hydric deficit compared with others hydrics management / O conhecimento dos mecanismos morfofisiológicos que permitem a uma planta tolerar as condições de estresse hídrico constitui importante ferramenta para analisar a qualidade de mudas. O trabalho objetivou quantificar os efeitos do manejo hídrico no período de rustificação em mudas de Handroanthus impetiginosus (Mart. ex DC.) Mattos e Gallesia integrifolia (Spreng.) Harms por meio da termometria foliar e por parâmetros morfométricos de qualidade e adicionalmente analisar o desempenho das mudas após a rustificação, em solo arenoso e argiloso. Conduziu-se o experimento em ambiente protegido na Universidade Estadual do Oeste do Paraná, campus de Marechal Cândido Rondon PR. Os tratamentos foram compostos por quatro regimes hídricos: irrigação diária (tratamento controle), a cada dois, três e a cada quatro dias, em 60 mudas por tratamento, durante quatro semanas. As mensurações envolveram a medição da temperatura foliar (TF), os incrementos na altura, no diâmetro de colo, na massa seca radicular, na massa seca da parte aérea e na área foliar. As mensurações da TF ocorreram ao final do ciclo de cada manejo de irrigação e para as demais variáveis realizaram-se as mensurações no início e final da rustificação. Após a imposição dos manejos hídricos, as mudas foram levadas para vasos contendo solo arenoso e argiloso, para verificar se há influencia dos diferentes manejos hídricos, bem como do tipo do solo na sobrevivência da muda. A análise entre os tratamentos controle e irrigação a cada dois dias resultou em diferenças (P> 0,05) apenas para área foliar, sendo que ambas as espécies estudadas apresentaram redução da área foliar com o aumento da restrição hídrica. Mudas de H. impetiginosus com ciclos de irrigação a cada três dias, apresentou redução na taxa de crescimento em diâmetro de 29%, de 58% para incremento da massa seca da parte aérea e de 32% para área foliar em comparação ao manejo controle. Mudas de G. integrifolia irrigadas a cada três dias não apresentaram diferenças significativas (P> 0,05) em relação às irrigadas diariamente. O manejo de irrigação a cada quatro dias em mudas de H. impetiginosus possibilitou maior velocidade de crescimento do sistema radicular e reduziu o crescimento aéreo, resultando no aquecimento foliar, enquanto que o manejo de irrigação a cada quatro dias em mudas de G. integrifolia apresentou redução na velocidade de crescimento da parte aérea e não apresentou diferença (P> 0,05) no crescimento do sistema radicular e também resultou no aquecimento foliar. O uso da termometria infravermelho permite aferir a temperatura foliar na rustificação de mudas de H. impetiginosus e G. integrifolia. Houve influência dos solos na sobrevivência das mudas de H. impetiginosus e G. integrifolia, e os sintomas de déficit hídrico sempre se manifestaram primeiro no solo argiloso, principalmente nas mudas não adaptadas ao estresse hídrico. Em ambas as espécies, as diferenças dos sintomas de déficit hídrico apresentadas pelas mudas dos diferentes manejos hídricos mostraram que mudas submetidas ao regime de irrigação a cada três e quatro dias, foram atenuando lentamente os sintomas de déficit hídrico em comparação aos demais manejos hídricos

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