Crescimento e rela??es h?dricas de gen?tipos de mamoeiro (Carica papaya L.) cultivados sob irriga??o por acionador autom?tico

• Ano de defesa: 2012
• Autor(a) principal: Dias, Gustavo Cardoso de Oliveira
• Orientador(a): Vasconcellos, Marco Antonio da Silva
• Banca de defesa: Campostrini, Eliemar, Carvalho, Daniel Fonseca de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural do Rio de Janeiro
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Fitotecnia
• Departamento: Instituto de Agronomia
• País: Brasil
• Palavras-chave em Português: Carica papaya; produ??o de mudas; automa??o da irriga??o; sensores de umidade; trocas gasosas
• Palavras-chave em Inglês: Carica papaya; seedling production; automation of irrigation; moisture sensors; gas exchange
• Área do conhecimento CNPq: Agronomia
• Link de acesso: https://tede.ufrrj.br/jspui/handle/jspui/3621

The Brazil stands out as a leading producer of papaya in the world, so the concern to improve the techniques of seedling production is of paramount importance, since the initial development of the papaya tree is directly related to its early flowering and fruit production. The study of water relations has received attention in recent years, since the deficiency or excess of water often becomes a limiting factor for productivity. So in order to control the flow of water to crops, ensuring the necessary moisture, was developed a automatic controller for watering systems are made with low cost domestic items with the operation based on the formation of the equilibrium between of the soil solution and the water contained inside automatic controller. The aim of this study was to generate information about the consumption of water and possible changes in growth and development in papaya plants of groups Solo and Formosa. The effects of two different genotypes in response to different levels of activation of the automatic controller at the stages of germination and seedling growth. Experiments were conducted in a greenhouse in Depart. Plant of the IA / UFRRJ, using plants of the varieties of the Solo group (Golden) and the Formosa group (Tainung) in containers, and subjected to different levels of activation of the automatic controller, determined by different heights of the switch relative location the capsule of ceramic inserted into substrate (30, 60 e 90 cm), being monitored the applied water depth in each treatment. The experiment was set in randomized blocks with five replications in a factorial simple design 3 X 2, combining three height of the switch and two varieties. The variables were: percentage of germination, emergence speed index, rate of growth height and stem diameter, leaf area, leaf number, specific leaf area, fresh and dry weight (shoot + root), stomatal conductance, relative water content (RWC), vapor pressure deficit of the air (VPDair) and relative chlorophyll content. Being monitored consumption and losses of water and nutrients by the EC, it estimated at the end the all volume of water used by plants of papaya. No effects were observed for percentage of germination and emergence speed index. The difference of 30cm presented greater drainage and lower values of EC and SPAD readings, indicating a loss of nutrients in the substrate and nutrient deficiency in plants. The drainage effects were more pronounced for 'Tainung 01' with the lowest root system. The seedlings of cultivar 'Sunrise Golden ' had the fastest growing in heights of the switch 60 cm. Cultivation in heights of the switch 90 cm caused mild water deficit a reduction in stomatal conductance and the RWC indicates a lower water status. The data indicate that the technology is feasible, but you must use dripper with less flow to avoid excessive drainage.