Anatomical and ultrastructural studies in citros: effects of nitrogen-fertilizer forms in fertigated groves

• Grant number: 14/22417-3
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2015
• End date: February 29, 2016
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Dirceu de Mattos Junior
• Grantee: Guilherme Petená
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

The citrus industry is an agricultural activity of economic and social importance in Brazil, accounting for about 48% of the total domestic production of fruit. Productivity gains are possible with the use of varieties more responsive to nutrient application. The nutrient availability affects the development of plant tissues, which can affect both direct and indirect factors of fruit production formation. Concentrations of nitrogen (N) and calcium (Ca) in plants thus induce anatomical and ultrastructural changes related to N use efficiency and quality of leaf and flower and fruit production as well as probable resistance of the plant to biotic stress that commonly affect the citrus industry. Given the above, this project conducted within the graduate master's program at the IAC, assess the effects of applications of nitrogen fertilizer sources: ammonium nitrate (AN) and calcium nitrate (NCA), both fertilizers at 80 and 320 kg ha-1yr-1 in the orchard of sweet orange, used in a long-term study of citrus fertigation (Quaggio et al., 2014). The anatomical and ultrastructural changes in leaves and petals of orange blossoms induced by concentrations of N and Ca will be identified. Values of fresh and dry mass, leaf area, leaf specific weight and total content of nutrients, which are related to results obtained in the analysis of light and electron microscopy will be measured. The project will contribute to the elucidation of basic aspects of strategies for nutritional management of orchards. (AU)