Modela??o de clima em estufa climatizada para produ??o e enraizamento de estacas de eucalyptus globullus Labill

Disserta??o de mestrado em Agricultura Biol?gica, apresentada ? Escola Superior Agr?ria do Instituto Polit?cnico de Viana do CasteloO controlo ambiental em culturas protegidas assume uma grande import?ncia e, a par da rega e da nutri??o, ? um dos factores limitantes do crescimento e desenvolvimento das plantas. A efic?cia deste controlo pode ser avaliada pela utiliza??o de modelos matem?ticos. Estes modelos de previs?o das condi??es clim?ticas interiores, ap?s a sua valida??o, permitem a simula??o para diferentes condi??es clim?ticas exteriores e/ou diferentes estrat?gias de funcionamento dos equipamentos. O presente trabalho permitiu encontrar as condi??es ambientais favor?veis para a maximiza??o da produ??o de rebentos nos p?s-m?e e do enraizamento de miniestacas de Eucalyptus globulus Labill. e, ainda, a defini??o de objectivos e de estrat?gias de programa??o ambiental mais eficientes. O trabalho foi desenvolvido numa estufa do tipo ?Venlo? em vidro, equipada para a propaga??o clonal de Eucalyptus globulus Labill. pela t?cnica de miniestacaria, localizada nos Viveiros do Furadouro, Grupo Altri, em ?bidos. O desenvolvimento dos modelos clim?ticos incluiu a realiza??o de balan?os de energia e de massa, que permitem simular a temperatura e a humidade relativa no interior da estufa em fun??o dos dados clim?ticos exteriores, do tipo de estufa, do tipo de cobertura e dos equipamentos existentes. A determina??o das condi??es favor?veis ? produ??o de rebentos e enraizamento de quatro clones, foi realizada atrav?s de uma an?lise multivariada de componentes principais. Efectuou-se ainda uma an?lise de regress?o para as vari?veis mais explicativas. Foram propostos e validados dois modelos, o modelo de aquecimento e o de arrefecimento, obtendo-se diferen?as absolutas entre os valores de temperatura e de humidade relativa medidos e simulados, respectivamente, de 0,98 e 1,31?C e de 6,78 e 7,46%. Concluiu-se que existe uma grande influ?ncia das condi??es ambientais na propaga??o vegetativa de Eucalyptus globulus Labill.. Na estufa de p?s-m?e, no per?odo de quatro semanas que antecederam a colheita, os valores de radia??o solar global de 5,0 e 5,7 MJ m-2 d-1 e de d?fice da press?o de vapor de 0,80 e 0,85 kPa, resultaram numa maior produtividade de rebentos dos clones AC58 e GM258, que variou entre 70,0 e 81,0 rebentos m-2 semana-1. A m?xima percentagem de enraizamento de 74,9% e de 62,1%, respectivamente para os clones AC58 e GM258, foram obtidas para valores de temperatura m?dia do ar de 23,5?C e de 25,2?C, no per?odo das quatro semanas ap?s a prepara??o das miniestacas para enraizamento. Os clones BC422 e YG15 apresentaram uma menor depend?ncia da propaga??o vegetativa com as condi??es ambientais. A interac??o entre as condi??es favor?veis de propaga??o vegetativa e a possibilidade de prever as condi??es clim?ticas no interior das estufas, resulta na possibilidade de testar e simular diferentes estrat?gias de programa??o dos equipamentos, permitindo a m?xima produtividade com o menor consumo de energia.The environmental control in protected crops is the outmost importance and, along with irrigation and nutrition, is one of the factors limiting the growth and development of plants. The effectiveness of this control can be assessed by the use of mathematical models to predict the inside conditions and, after its validation, to simulate its behavior for different outside climatic conditions and/or for different alternatives to achieve the equipment set points. This study aimed to find the optimum environmental conditions to maximize minicuttings production and rooting of minicuttings of Eucalyptus globulus Labill. and also, setting goals and strategies of more efficient environmental control, in a greenhouse controlled with a proportional environmental control system. The study was conducted in a "Venlo" greenhouse covered with glass, equipped for the vegetative propagation of Eucalyptus globulus Labill. through minicuttings, located in Viveiros do Furadouro, Altri Group, in ?bidos, Portugal. The development of climate models for the prediction of temperature and humidity inside the greenhouse was based on energy and mass balances, as a function of the outside climate data, the type of greenhouse, the cover material and the environmental control equipment. To determine the optimum conditions for the vegetative propagation of four clones, a multivariate analysis was performed for the key components. For the more explanatory environmental variables of the process, a regression analysis was carried on. Two models were developed and validated, the model of heating and of cooling, resulting in absolute differences between the values of temperature and relative humidity measured and simulated, respectively, of 0.98 and 1.31?C and of 6.78 and 7.46%. It was concluded that there is a great influence of the environmental conditions in the vegetative propagation of Eucalyptus globulus Labill.. In the greenhouse unit for minicutting production, during the four weeks prior to harvest, solar radiation values of 5.0 and 5.7 MJ m-2 d-1 and the vapour pressure deficit of 0.80 and 0.85 kPa, resulted in a greater productivity of minicuttings for clones AC58 and GM258, which ranged between 70.0 and 81.0 shoots m-2 week-1. The maximum rooting percentages of 74.9% and 62.1% was obtained for values of mean air temperature of 23.5?C and 25.2?C, respectively, for clones AC58 and GM258, during the rooting period of four weeks. The clones BC422 and YG15 had a lower dependence of the environmental conditions on their vegetative propagation. The interaction between the optimum environmental conditions for vegetative propagation and the ability to predict climatic conditions inside the greenhouse, results in the possibility to test and simulate different control strategies of the avaiable equipment, allowing for maximum productivity with lower power consumption